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BOSTON SOCIETY OF NATURAL HISTORY;
BEING A NEW SERIES
OF THE
BOSTON JOURNAL OF NATURAL HISTORY.
VOLUME III.
BOSTON: ^ic-tin'
PUBLISHED i;y the society, 1878-1894.
75
s-i
PUBLISHING COMMITTEE.
Al-PHKIS HYATT, | CHARLES S. MINOT,
WILLIAM U. FARLOW, \ THOMAS A. WATSON,
SAMUEL HENSHAW.
CONTENTS OK VOLUME 111.
T. On Di^nun m < i!As.-ii(.()i.i,K Uri>. ; wnii uuikk nutks <in Hi xi.i;v'> i'ijopuski) (■i.as.>i\-icatiiis
111- WORMS. Plate 1. By Cluirles Sedgwick Minot. (Published June 1 1, 1878.) . . 1
11. Tim: KAKI.Y TVI'KS OK IXSELTS; OIS THE OKIGIX AND SEVJIKNUE OF IN.SECT I.IKK IX rAl.AEO/.OIC
TIMES. By Samuel H. Scudder. (Piiblislietl March G, 1879.) ..... 13
III. Palaeozoic cocki!oa<'hes : a complete revision of the species of iiom woiti.Ks, with
AN kssay toward their CLASSIFICATION. I'lutos 2-6. B>/ Siriuuel H. Scudder. (Piih- lisheil Xovember 29, 1879.) -^rj
IV. New ani> interestim; hydroids from Chesapeake Bay. Plates 7-9. By Samuel F. Clarke.
(I'ul.lished .January, 1882.) I;i5
\'. Aucllll'Ml.VroDA, A SVBORDINAL TYPE OF SPINEL) JIYRIAPoDS FRO.M THE CARBONIFKROIS l-OK-
MAiioN. Plates 10-13. By SumuA H. Scudder. (Published May, 1882.) . 143
\'l. Some OBSERVATIONS ON THE EMBRYOLOGY OF THE TELEO.STS. Plates 14-1(!. By J. S.
Kingsley and H. W. Conn. (Published April, 1883.) 183
VII. The CARBONiFER(jrs hexapod INSECTS OF (treat P.khain. Plate 17. By Samuel H.
Scudder. (Published June. 1883.) 213
VIII. On the development of Ofxanthis nivkis and it.-~ parasiie, Teleas. Plates 18-25.
By Howard Ay ers. (Published January, 1884.) . . . . . . . . 2'lh
IX. Two new and diverse types of carboniferofs mykiapods. Plates 21! and 27, figs. 1-4.
By Samuel H. Scudder. (Published March, 1884.) 283
X. The species of Mylackis, a cahboniferois genis of cockroa( hes. Pl;ite 27. figs .^-ll.
By Samuel H. Scudder. (Published March, 1S84.) 299
XI. Notes ON THE peeping FRoi;. Hyla pickki;ini:ii Lf.C'ontk. Plate 28. By Mm-y H. Iluickley.
(Published May, 1884.) 311
XII. Palaeodicitoptera : ou the affinities and classification of palaeozoic Hexapoda.
Plates 29-32. By Samuel H. Scudder. (Published April, 1885.) .... 319
XIII. Winged insects from a paleontological point of vlew, or the (;eoi.O(;ical histokv
of insects. By Samuel H. Scudder. (Published April, 1885.) ..... 353
XIV. The life-history of the Hydromedu.sae : a discission of the origin of the Medisae,
AND of the significance OF METAGENESIS. Platcs 37-44. By W. K. Brooks. (Pub- lished June, 1886.) "... 359
The OLDEST known INSFXT-LARVA, MoRMOLCCOIDES ARTICILATI S, FROM THE CONNECTKTT
River rocks. Plate 45. By Samuel H. Scudder. (Pulilished September, 1886.) . 431 Note on the supposed myriapodan genus Trichiulus. By Samuel H. Scudder. (Pub- lished September, 1886.) Vix
A review of mesozoic cockroaches. Plates 46-48. By Samuel 11. Scudder. (Puli-
lished September, 1886.) 439
A North .A.merican Antih hi s — its structure and development. Plates 49-50. By
Edward A. Burl. (Publi-^lied October, 1894.) 487
Index ................ 507
Errata ................ 509
ME]\ioms
READ BEFORE THE BOSTON SOCIETY OF NATURAL HISTORY.
I. Ox DiSTOMUM CRASSICOLLE RuD. ; WITH BkIEF NoTES ON IIuxLET's PROPOSED
Classification of Worms. By Charles Sedgwick Minot.
Read Feb. 21, 1877.
_L HAVE recently ^ attempted to prove in detail that the Nemertines cannot be retained among the Plathelminths, and that the remaining forms of the claws must be grouped diiferently from the hitherto accepted manner. One of the principal changes was the vmion of the Trematods and Cestods in one division under the name of the A''aginifera3. The following paper has been prepared with a view to justify the proposed change, by a com- parative investigation of a fluke and a tape worm. I have chosen Distomum crassicolle on the one hand, and Caryophylheus on the other, as representative species. I have already prepared sections of the latter, but am obliged for personal reasons to postpone the detailed investigation of them ; and it appears to me desirable, therefore, to pubUsh my observations on Distomum at once.
I prepared in July, 1876, whUe in Leipzig, three series of sections, and mounted two specimens in Canada balsam. All of these preparations were stained with carmine. Each of the three series comprised a whole individual from beginning to end, and without a break ; the sections were made with the aid of a sledge microtome.^ Two of the series were of transverse, one of longitudinal sections; nevertheless there were parts of the animal which could not be well seen in any of the preparations. I must therefore apologize for the incompleteness of the following description, although unavoidable, because I cannot at present obtain any more specimens of this species.
Distomum crassicolle measures about 4 °""- in length, and 1.2 """• in width, and its dorso- ventral diameter is about 1-0.9""°- Its oral sucker is small, fig. 1, J/, although somewhat larger than the ventral one, S, which is placed on the ventral median line, near
1 Minot. On the Classification of some of the lower Arbeiten des Zoot.-zooL Inst. Wurzburg. Bd. in, p. 405.
Worms. Proe. Boston Soc. Nat. Hist., Vol. XIX, p. 17. 1877.
Minot. Zur Anatoraie der Turbellarien, zugleich ein ^A description of this invaluable instrument may be
Beitrag zur Classification der Platthelminthen. Semper's found in the American Naturalist for April, 1877. .»
UEMOIBS BOST. SOC. NAT. HIST. VOI.. lU. 1 A/, /^/
2 C. S. MINOT ON DISTOMUM
the end of the anterior third of the body. The posterior t^YO-thirds are taken up mainly bv the convolutions of the uterus, Ut., which in all the specimens I have examined was filled with an enormous number of eggs. The yolk glands of authors, or the egg-food- stocks, F, as they may be more appropriately named, lie -on each side of the body, forming two masses, which when seen from above have a triangular outline. They are restricted to the first third of the body. The mouth occupies the middle of the front sucker, M. The digestive canal begins with a very short tube, above which- lies the central nervous system, N, and which leads to the muscular pharynx. Ph. The canal continues beyond this, simple and of small diameter, until it gets about half way to the ventral sucker, where it divides, sending a simple sac-like branch, Z>, obliquely backwards and outwards on each side. These branches do not extend beyond the level of the front edge of the ventral sucker and end blindly. The digestive tract is therefore remarkably small and simple in proportion to the size of the animal. The ovary, Ov., is a rounded body lying asyriimetrically upon the right hand of the ventral sucker, in front of which there is a small depression, the sexual antrum, [GescMechtsvorraum), in the right of which the sheath of the penis, Pe., opens, while the uterus, Ut., opens on the left. The penis runs backward over the sucker, and behind the point where it is attached to its sheath, it enlarges to form the penis bulb, which corre- sponds to the Cirrhusheidel of the Cestods.^ The testes, two in number, are of unequal size and as^onmetrically placed. That on the left, Te., is the smaller, and hes the further forward, being quite near the ventral sucker, while the slightly larger right-hand testis, Te.', is placed further back. They are both nearly spherical. The spermiduct, /§;. d., from each is \Qvy fine, and runs towards the penis bulb, into which it undoubtedly opens, though I have not been able to discover the exact communication. The uterus, Ut., extends back- ward from its external opening, and, passing beyond the penis-bulb, then enlarges and forms the unusually complicated convolutions which, as before mentioned, fill up the pos- terior two-thirds of the body, and which I found it impossible to follow. It ends, however, in the shell gland {Schalendruse), which lies just behind the penis, but is not represented in fig. 1. The oviduct and the ducts of the egg-foodstocks also communicate with the shell gland, from which a fine tube also i-uns iipwards to open on the back. The main stem, W.V., of the water vascular system extends from the hind end of the animal straight forward half the length of the body. Its diameter gradually diminishes as it runs forwards. It is hoped that, this brief account of the general topography of the organs will serve to characterize the species, and render the following details intelligible.
In all my sections I find the outside limit of the body to be a membrane, fig. 9, B.3I., of nearly even thickness, but without any distinct structure, unless a faint striation indicat- ing a fibrillar composition be regarded as such. It is armed with a number of very minute spines, which lie close together and are restricted to the anterior part of the back. This membrane is the cuticula of authors. I -cannot accept that designation, because I consider it to represent a basement membrane. I have in my two previous papers already suggested this homology. I have accordingly attempted to find epidermal cells lying exteriorly to the membrane in question, but hitherto without success. I must, however, still maintain
^Leuckart. Die menschlicben Parasiten. Bd. i, p. 178-179.
AND THE CLASSIFICATION OF WORMS. 3
my ophiion for the following reasons: first, because I liml that the supposed (uiticula hends in at the mouth {cf. fig. 10), and continues down the digestive tuhe into the two branches of the same, where it becomes the basement membrane of the epithelial lining of the gut — the ^' cutictda" is therefore the continuation of an undoubted basement membrane; seconill}^ because our membrane corresponds exactly in appearance and position with that which is really a basement membrane in Cestods,' but which had always been called " cuticula "; it overlies a layer of glandular cells and muscles,- as in Caryophylheus, Tiv>nia and Amphi- lina,'' termed by German investigators, the Ilaiitschlcht, and wrongly regarded as the epidermis, as I have elsewhere shown, — simply because the limiting membrane was neces- sarily the cuticula, and the underlying cells consequently are epidermis. In Distomum crassicolle and in other Trematods, there are muscular fibres close to the " cuticula," sepa- rating it from the underlying cells, which quite agrees with the interpretation of it as a basement membrane. If the view here advocated is true, we must account in some manner for there being no epithelium discoverable outside our memljrane. This may be done in two ways : 1, the cells ma}' have been destroyed in preparing the oljjects in the preserving and hardening fluids ; or, 2, it may be a regular phenomenon of the development of Trematods that the epidermis is thrown off. On the whole, I incline to the latter view, because it would explain why no epidermis has ever been noticed upon any of the thousands of living or freshly killed specimens that have been carefully observed by helminthologists. There are, too, many cases known in which the larvae of Distoma are provided with a ciliated external layer of cells, which is thrown off, or shrivels up, as development pro- ceeds ; I may refer to Wagener, Pagenstecher, Leuckart, v. Linstow, Zeller, and many others, as having observed this phenomenon. This justifies the supposition that the same thing may occur in adult forms. If this should turn out to be the case, the difficulties which now prevent any comparison of the epidermis of Trematods with that of the remaining Plathelminths, would be entirely removed. Until further investigations shall have determined this point, the question of the homology of the limiting layers of the body of Distomum, etc., must remain an open one.
The muscular system is not highly developed. There is but one distinct layer, formed by a single row of longitudinal fibres (fig. 9, L) exactly as I have found in Caryophjllceus midahiUs and Tcenia sp. ? from the intestine of a mocassin snake, Cenchris jjisclvoi'us, which had lived some time in Berlin and Wiirzburg. Leuckart* says that the Trematods have three layers of muscles, the external being a circular coat ; but in D. hepaiicum there is also a single row of longitudinal fibres immediately under the so-called cuticula. In our species there are a very few circular muscles (fig. 2, H) within the longitudinal layer. The dorso- ventral, or the sagittal muscles, are quite nmnerous, and form the most conspic- uous part of the muscular system. They run for the most part nearly straight up and down, more rarely quite obliquely, but they show a great reduction in their number and complexity of arrangement, as compared with the non-parasitic Pharyngocoela, approach-
1 Schiefferdecker was the first to describe the true cpidcr- ^W. Salensky. Ueber Amphilina. Zeitchr. Wiss. Zool., mis of Cestods. Jena. Zeitschr. Nat. Wiss. Bd. viii, p. 459. xxiv. (1874.) p. 300.
2 Cf. Schneider. Untersuchungen iiber Platthebninthen ^ Leuckart. Parasiten r, p. 459. p. 5, where he especially mentions this point.
4 C. S. MINOT ON DISTOMUM
ing the Cestods in this respect, though in the Trematods I have examined I foiuid no deep nuiscuhu" coat which so characteristically separates the " Mittelschicht " from the " Rinden- sohioht" [cf. lAHiokart, Parasiten) in segmented tape worms.
From these observations, it will be seen that the muscular system of Distomum resem- bles that of the Cestods more closely than it does that of the Planarians. But the exist- ence of the single row of external longitudinal muscular fibres should be especially noted as bearing upon the homologies of the muscular layers of Plathelminths. This subject has been discussed in my paper (see above) in Semper's Arbeiten. It also overthrows, beyond all question, Schneider's ^ attempt to classify worms according to their muscular systems, because some species of Taenia do, and others do not, have the external longitudi- nal layer, and it is evident that orders and classes cannot be founded upon characters that are not constant within the limits of one genus.^
The parynch3-m in my preparations appears as a meshvvork of granular protoplasm, with a few oval nuclei imbedded in it. The cavities of the meshwork are more or less rounded in outline. This appearance is well known, but has been variously interpreted. Walter ^ believed that there was a series of intercommunicating cavities, formed by a reticvilated connective tissue ; the cells of which consisted of a central area of protoplasm enclosing the nucleus and sending out processes which united with those of the neighboring cells, very much as in the embryonic connective tissue of Vertebrates. Leuckart,* on the other hand, asserts that the whole consists of cells, there being no real cavities ; that appearance being produced by the cells containing a large amount of clear fluid, while the granular protoplasm is collected together with the nucleus against the membrane at one pole of the cell, similarly to the characteristic cells of the Chorda dorsalis of Vertebrates. If Leuck- art's view is correct, good preparations must show a curved outline passing near the nu- cleus, and there must be also as many nuclei as there are distinct rounded cavities, since each of these is a cell. I have been unable to observe such an appearance, but, on the contrary, I have often seen such stellate cells as were described by Walter. In Caiyophyl- ItBus, we find that the meshwork is very fine, the spaces being much more numerous than the nuclei, though of about the same size ; if, therefore, Leuckart's view is correct, it would be necessary to explain this discrepancy between the number of the nuclei and of the spaces he calls cells ; at present I do not see how this is possible. In the segmented Ces- tods the parenchym contains numerous pale, oval cells, without any processes, besides a few stellate cells. I am not certain of there being any corresponding cells of rounded shape in the basal tissue of the flukes. Both kinds are found in the Pharyngocoela, as I have stated in my paper in Semper's Arbeiten, and they will probably be de- tected in the Trematods, when properly searched for, thus adding a new minute homology within the class of the Plathelminths. I may add that Salensky ^ agrees in his description
' Anton Schneider. Untersuchungen iiber Platthelmin- ' Walter. Beitriige zur Anatomie einzelner Trematoden.
then. Giessen. 1873. Archiv f. Naturgesch., 1858. Theil i, p. 287.
' Huxley, in his recently published Manual of the Anat- ■* Leuckart. Menschl. Parasiten. Bd. r, p. 457-458.
omy of Invertebrates (Amer.ed., p. 172), repeats the cur- c gaiensky. Amphilina. Zeitscbr. wiss. Zool., xxiv,
rent statement that the circular coat is external. Of course this statement requires modification to accord with recent observations.
p. 303.
AXD THE CLASSIFICATION OF WORMS. 5
of the parenchyin of Ainphilina with wliut Walter and myself have fmiid in other Treina- tods. Blnmherg' aj^rees with rjouckart, while Sehneider'- gives a siiij^nlar iiiter|)retati*)n to the histological appearance of the parenchyni, which seems to me quite innvaiiantaljle.
The curious cords of fine traheculte, forming a meshwork, and to which the Germans have applied the name of Balkcnstranrje, are known to exist in a variety of Planarians and Cestods, and Salensky describes them in Amphilina, but I cannot discover anything like them in DlMonmm crassicoUe nor D. hepaticiim.
The true water vascular system (fig. 1, W.v.) may, however, be very easily .seen ; in part, at lea.st. There is onl}^ one main stem, which is enormously large. It begins at the hind end of the animal, where it opens externally, and enlarging very quickly (fig. 7) it runs straight forward (fig. 1, W.v.) close underneath the back, its diameter gradually dimini.sh- ing, reaching half the length of the body. I have not seen any branches or canals con- nected with it. One might perhaps easily di.scover them with the help of injections, which I hope to try at some future time. In my scries of longitudinal sections, there are several in which the wall of vascular sac is cut parallel to its surface. In these ca.ses there are a nmnber of pale nuclei \nsible. The}' are themselves of unequal size (fig. 8), but are much larger than any other nuclei in the body of the worm. They are at irregular distances from one another, and though they probably form part of a pavement epithelium, yet I could not trace any indication of intercellular lines, or of cell membranes around them. But the characteristic feature in the lining of the main sac is the presence of innumerable small, highly refractile granules, nearly spherical in shape, and yellowish in color (fig. 8). They are of various sizes, irregularly distributed, but apparently never touching one an- other. I can surmise nothing as to their nature. They appear with equal distinctness in transverse sections, and lie within the membrane upon which the lutima rests. This may be considered a basement membrane ; it has a fibrous structure and is colored by carmine.
I agree with AValter (/. c.) in considering the spaces in the parenchym to be connected with the water vascular system. In Disiomwn hepaticitm I have seen branches pass off from the main stem and connect directly Avith the lacunas of the parenchym, but my attempts to repeat this observation on D. cros><icolle have hitherto been unsuccessful.
Among the d^ermal muscles, and immediately underneath the so-called " cuticula," are pear-shaped cells, with large circular or oval nuclei, which ai-e usually not uniformly stained, aud contain distinct nucleoli. These are probably unicellular glands, at all events they are, as is proven by their position and histological character, the homologues of the layer of gland cells which underlies the basement membrane in Cestods and Pharyngocoela. I have seen them in various Trematods, and they probably exist in all flat worms. But in Trematods and Cestods they are less developed than in the Planarians, showing the close relationship of the two parasitic orders.
The oral sucker may be best described in connection with the digestive apparatus. The ventral sucker (fig. 7, S) is a small ckcular disc, whose vertical diameter is about one-third of the width of the disc (fig. 11, S, longitudinal section). It is composed mainly of ver-
iBlumberg. Ueber den Bau des Amphistoma conicum. ^ Schneider. Untersuchungen Uber Platthelmintben. 1873.
Inaug. Diss. Dorpat, 1871. p. 12-15.
6 C. S. MINOT ON DISTOMUM
tical muscular fibres. The basement membrane of the body passes over its free surface, and there is another basement membrane separating tlie sucker interiorly from the paren- chym (see fig. 11, h.m). The upper and the lower surfaces of the sucker are nearly par- allel with each other, thei-efore the vertical muscular fibres are almost of uniform length. Thev run somewhat irregularly, and seem often to bend around at their ends, as may be observed in the sucker of Mesodiscus,^ Tajuia,^ etc. There are only very few circu- lar fibres, and I have not noticed any radiating ones. The suckers of all Plathelminths that I have examined are characterized by the great predominance of the vertical fibres, difiering in this respect from those of the leeches, which are formed chiefly by circular and radiating fibres.^ Between the fibres in D. crassicolle there are numerous rather large oval nuclei, with a very darkly stained nucleolus, which is highly refringent and excentri- cally placed. To what sort of cells these nuclei belong I cannot make out.. They are mostly congregated in the upper part of the sucker.
The oral sucker (fig. 10, M), as seen in longitudinal section, presents the same histo-, logical appearance as the ventral sucker. The digestive canal passes through it a little below its middle, and descending obliquely forwards it reaches the mouth. The vertical fibres are here placed perpendicularly to the axis of the digestive tube. In life, however, the sucker can be everted, so that what forms the beginning of the intestinal canal when at rest, is spread out so as to form the flat outer surface of the sucker. Under these circum- stances the arrangement of the fibres corresponds precisely to that found in the ventral sucker ; we may therefore conclude that the primitive form is that preserved in the ventral disc, while the oral sucker has undergone a secondary alteration jDroducing its present shape.
Immediately behind the sucker of the mouth there follows a short division of the intes- tine before we reach the pharynx (fig. 10, a). The shape of this part depends upon the position of the pharynx ; when that organ is drawn back the division in question is drawn out to a narrow straight tube ; when the pharynx is pulled forward the tube is shortened, and bulges out, as drawn in fig. 10. This prtepharynx exists probably in all Trematods, its use being to permit the free play of the pharynx backward and forward.
The pharynx (fig. 10, ph.) closely resembles the oral sucker in its minute anatomy, but is very much smaller, and the oval nuclei are most numerous among the posterior fibres. Up to this point the axis of the digestive canal has been straight.
Just behind the pharynx {cf. fig. 10) it bends suddenly upwards, and ascends to the dorsal side of the body, and then curves backward and runs without again changing its direction or character, directly to the point where the fork of the intestine branches {cf. fig. 7). This part may be called the oesophagus. It is provided with an internal cu'cular muscular coat, and an external longitudinal one, as may be easily seen either in longitudi- nal (figs. 10 and 12) or transverse sections. Each coat is composed of a single layer of delicate fibres.
Up to where the intestine branches, I have found it lined by the inflected continuation of the basement membrane of the body, but without any epithelium ; which probably exists,
'Minot. Semper'3 Arbeiten. B.l. in, Taf. xviii, Fig. 36. Zeitschr. f. Wiss. Zool., 1873. Taf. ix, Fig. 2, Z). 'Xitsche, H. Untersuchungen liber den Bau der Taenien 'Lcuckart. Parasiten. Bd. i, p. 646.
iVND THE CLASSIFICATION OF WORMS. 7
though as for as I am aware, there is no special statement pubHshed concerning an epithe- lial lining of the oesophageal and phar3-ngeal regions in Trematods. I have again and again had occasion to observe tlie destruction of the intestinal epithelium in various worms by the action of alcohol and other hardening fluids, and for the present I must therefore assume tliat the same cause explains the absence of the epithelium in the specimens I have examined.
The two coecal branches (figs. 1 and 3, D) are lined Ijy a very distinct and beautiful epithelium (fig. 12, A, transverse section of the wall of the ccecum), consisting of short, broad, cylindrical cells, containing each a proportionately large oval nucleus. The nuclei lie in the middle or basal portion of the cells, never in the upper part, and have sometimes one. more frequently tAvo, highly refractile, eccentric nucleoli. The protopla.sm of the cells is granular, the upper part is more deeply stained by carmine than the lower. In some of my preparations this epithelium is cut parallel to its surface ; fig. 12, B, represents such a spot. The amount of intercellular substance is small, and the cells present polygonal out- lines, and are four, five, or six-sided. The epithehum, as is shown in fig. 12, A, rests upon a basement membrane. The muscular layers outside are reduced to a few fibres running in various directions, but apparently mostly circular. A similar epithelium to the one here described I have found in several other Trematods, so that it may be considered character- istic of the class. It is very different from the intestinal epithelium in Planarians, and as far as I know, from that in any other class of worms.
There are a great many unicellular glands in the anterior part of the body. They are bottle-shaped (fig. 14), their necks running out towards the oval sucker. Their contents appear collected, as seen in the figure, almost exclusively on one side, forming there a very dark stained, finely granulated mass enclosing a relatively small nucleus, which can only be detected by close exammation. The other half of the cells is quite clear and colorless. Is it not probable that this peculiar distribution of the granular matter Ls caused by the alcohol producmg a contraction of the cell-contents ? The body of the cells is very large, and rounded at one end, while it tapers gradually towards the other, till it runs over into a long narrow tube, which may be called the duct. The cell membrane is very dis- tinct. The cells are distributed further back on the ventral, than on the dorsal side. Transverse sections show the nuclei much more distinctly than longitudinal ones do. In a section through the hiud end of the oral sucker (fig. 2), the ducts of the ventrally placed cells may be seen at each side, while the bodies of cells situated dorsally are seen crowded together in the iipper part of the section. These glands are undoubted homologous with the so-called •• Speichel-di-iisen " of German authors, first mentioned by Walter,' and since then observed by various other writers.^ Similar glands are said to exist in various Pha- ryngocoela, but I have not observed them in any of the Planarians I have investigated.
The great development of the uterus, and the large number of eggs contained in it, effectually hide some parts of the sexual apparatus, my description of which will therefore be somewhat incomplete.
1 Walter. Zeikcbr. Wiss. Zool. Bd. viii, p. 198-199; and ^ Leuckart. Parasiten, i, p, 470.
Archiv fiir Naturgesch. 24 Jahrg. Bd. i, (1858) p. 291-292.
8 C. S. MINOT ON DISTOMUM
Tlie testes are of unequal size and asymmetrically placed (fig. 5), as I have already mentioned. They are surrounded by a fibrous membrane just like that which encloses each sexual gland in the Planariaus/ and forming a complete envelope. This membrane is continued on to the eftereut duct (fig. 13, d, e), which is a small tvibe. Neither within this tube nor within the testicular capsule, have I been able to discover any traces of a lining epithelium. The contents of the testicles are cells, and spermatozoa both ripe and in various stages of development, but all irregularly distributed, producing such confusion that the exact development of the spermatozoa cannot be followed. I could only make out that the heads are developed out of the nviclei of the parent cells.
The efterent ducts run towards the penis bulb, into which they of course open, though I have not seen the communication. The penis bulb is really the fixed basal portion of the penis. Its walls, as seen in transverse section, fig. 4, A, are very thick, and marked off both internally and externally by a thin membrane, whose appearance recalls the basement membrane of the body. The rest of the wall between the limiting layers consists mainly of rounded cells each containing a nucleus, but with their remaining histological characters nearly obliterated in all my preparations. The cavity of the bulb contains a mass which I suppose to be the coagulated sperm, but no evidences of an epithelial lining are visible, nor can any distinct muscular fibres in the wall of the bulb be seen, though usually they are highly developed in Plathelminths.
The general shape of the penis and its bulb may be best seen in fig. ]1, wliich repre- sents a longitudinal section. The penis proper is seen to rise almost perpendicularly at first, and then cm'ving around backwards to gradually enlarge, passing over into the bulb without any sharp line of demarcation. I could not make out the distribution of the muscles in the penis on account of the numerous cells, apparently glandular, whose large, dark stained nuclei are very noticeable. The canal is not straight, but undulatory in its course. I am quite sure there is no flagellmn. The penis bulb is the same organ that Moseley^ calls the Prostata in Planarians, and corresponds to the Cirrhusheutel of the Ces- tods. I have in my previous papers already noticed the exact homologies which may be traced m the male organs of Plathelminths, and in D. crassicoUe we find the same parts : 1, testicles, 2, spermiducts, 3, penis bulb, 4, penis, 5, penis sheath, or male antrvuu. The slight development of the penis bulb, with its few muscles, in Trematods, is like what we find in the Cestods,^ but very unlike the enormous muscular sack of Planarians, again tes- tifying to the close relationship existing between the two parasitic orders.
The ovary (fig. 4, Ov.) is asymmetrically placed, and presents in transverse section a nearlj- circular outline, its diameter being about the same as that of the larger testicle, namely, two-thirds of the vertical diameter of the body. Like the testicles, it is sur- rounded by a delicate membranous envelope, closely connected with the parenchjrm. The ovary consists of numerous rounded cells, with a distinct membrane and large oval nuclei ; part of the body of each cell is clear, the remainder is filled with a dark stained, finely
» Minot. Semper's Arbeit. Bd. iii, Hft. iv. « Cf. Leuckart. Parasiten, i, pp. 178, 263; and Sommer
^ Moseley. On Stylochus, etc. Quart. Journ. Micros. Sci. und Landois. Bau der geschlechtsreifen Glieder von Botri-
Jan., 1877. ocephalus latus. Zeitsclir. wiss. Zool., xxii. (1872.) pp.
54, 77.
AND CLASSIFICATION OF WORMS. " 9
granuliited protoplasm. Nearly all the cells are developed to about the same extent, but whether or not they are arranged in the form of a branchnig tubular gland, as in the Ces- tods,^ I have not been able to determine. The oviduct is larger than the elTerent canal of the spermaries, and opens into the shell gland on the undei'side.
Fig. 6 is a diagrammatic combination of several sections, made from camera lucida drawings of each section, which were traced on thin paper, and then superposed. The drawing corresponds, therefore, to several successive planes. The ovary, On., lies furthest forward, and gives off the oviduct Ocd., which is a tube of considerable size ; but the connection of which with the shell gland is not represented in the figure. The shell gland, Sh.fj., is the enlarged end of the uterus ; its upper extremity is constricted, and opens into a large spherical vesicle, the spermatotheca, Sp.th., which I have found filled with spermato- zoa in all my specimens. In the individual whose female organs are represented in fig. 6, the whole of the beginning of the uterus was filled with sexual products, so that the course of the tube was comparativel}^ easy to follow. It descends downward on the left, then bends abruptly upwards for a short distance, then downwards again, making a U-shaped curve to the right. In this portion the eggs are already surrounded by a membrane, which increases in thickness as the eggs pass down the uterus. In the shell gland, Sh.g., sperma- tozoa, food cells {yolk cells auct.) and egg cells proper, are all intermixed. Passing down the uterus we no longer distinguish any spermatozoa, but the food cells gradually become balled together around the egg cells, and the pellets, as we might call them, thus formed, appear at the beginning of the U-shaped bend, above mentioned, surrounded by a thin membrane or shell.
There is also shown in fig. 6, Vg., a delicate tube running from the upper or constricted end of the shell gland upwards to the middle of the back. This is the vagina. Its course is incorrectly represented in the drawing, inasmuch as it is really much more u'regular than I have figured it, so that great pains were necessary to follow it in my sections, but I finally succeeded in tracing it from the back to the shell gland. I paid particular attention to this point, because it was on account of the existence of a vagina in both orders that the union of the Trematods and Cestods was first proposed. The vagina was first discovered by Blumherg^ in Am2yhisto7ni(m conicum, and his observations led Stieda^ to suppose that Laurer's* canal, which was long held to connect the testicles with the shell glands, and had been found in thirteen different species of Trematods {cf. Stieda 1. c), was really a vagina, since Blumberg found it to be so in Amphistoma, and Stieda in Distomum hejxttictim. Zeller^ has since described a vagina in Distomum macrostomum, and found two vaginae in Polystomum integer rhnum!^ Independently, and ignorant of these discoveries, Dr. Fitz, in his excellent paper on the anatomy of Fasciola Jacksoni^ found the vagina in that
1 Sommer u. Landois. Ueber Bothriocephalus. loc. cit. , * Laurer. Disquisitiones anatomicae de Aniphistomo con- XXII, p. 57-58. Sommer. Uber Tajnia, etc., loc. cit., ico. Diss, inaug. Grjphiae. 1830.
XXIV, p. 528 find Taf. XLiii, 7H. ' 2eller. Ueber Leucochloridium paradoxiim. Zcitscbr.
^Blumbt-rg. Ueber Ampbistomum conicum. Inaug. Diss. wiss. Zool., xxiv. p. 569. Dorpat, 1871. ^ Zeller. Weitercr Beitrag zur Kenntniss der Polysto-
2 Stieda. Ueber den angeblichen inneren Zusamraenbang men. Zeitschr. wiss. Zool., xxvii, p. 249.
der miinnlichen und weiblichen Organe bei den Trematoden. ' Fitz. New York Med. Journ. Nov., 1876.
Ai-chiv fur Anat. Pbys. Wiss. Med., 1871, p. 31.
MEMOIKS EOST. SOC. NAT. UI3T. VOL. lU. 2
IQ C. S. MINOT ON DISTOMUM
species also. These observations seem to me sufficient to justify the conclusion that this canal exists in all Trematods, while it is evidently the same as the vagina in Cestods. No corresponding tube has yet been observed in any of the Pharyngocoela.
All the female organs thus far described are Imed by a delicate membrane, which is li'^htly colored bv carmine ; it appears structureless, and I have not noticed any epithelium or muscular coat.s connected with it.
1 have to add that the uterus does not always begin with just such curves as are repre- sented in Fit'. G, Ui. Upon leaving this part of the body it rims backward, enlarges, and after a very long and irregular course it passes forward, diminishes its diameter, and curves downward on the left of the penis, beside which it finally opens. Around its terminal portion there are numerous cells, probably glandular, having large nuclei, very much like those seen m the penis.
The shell gland and the beginning of the uterus are surrounded by numerous pear- shaped cells, containing a nucleus in the rounded end, while the narrow neck, which is sup- posed to act as a duct, is directed towards the uterus. These cells have been found in a great many Trematods and Cestods, and are supposed to secrete the matter that forms the egg shells ; if this be the case, they will probably be found in some form in Planarians, etc. They are so much alike in Trematods and Cestods that they afford an additional argument for the union of the two orders.
The egg food stocks, as may be seen for example in fig. 4, do not fonn two solid glands, but are broken up into a number of more or less spherical divisions (fig. 16), from which run out short ducts ; aU those of one side finally collect together in one common duct, which runs o]jh([uely backward, meeting its fellow from the other side directly over the shell gland. I cannot say in what manner they finally open into the shell gland. They can be seen in fig. 1 as two dark lines, one crossing the ovary, the other passing just in front of the left testicle.
All the cells in the food-stocks appear to be fully developed, and I find none still xmdergoing change into food cells ; this agrees with the large number of eggs in the uterus indicating that all my specimens had been sexually mature for some time. The food-cells, fig. 16, are large and spherical, with a pale nucleus placed centrally, but nearly concealed by the great number of large refi-ingent granules in the protoplasm, giving the yolk cells their brownish coloring. The cells seem to be more or less distinctly sejiarated from one another, each having a special membrane, but with no visible intercellular cement. This structure of the food-cells is common to all Vaginifers, at the time the cells are ready to break loose and pass? to the shell gland.
The eggs in the upper part of the uterus are elongate spheroids in fig. 15, A, and the food-ceUs already reduced in size, can still be distinctly seen. Further down the ute- rus the eggs gradually become concavo-convex, as appears most distinctly in optical sec- tion, fig. 15, B, the shell growing much thicker and more resistant. Freshly laid eggs still present the same appearance.
The central nervous system appears as a transverse fibrous band overlying the hind end of the oral sucker (fig. 2), and enlarged at each side where the gangUonic cells mostly He. They are indistinct in all my preparations. I could not follow any nerves from the baud. In position and appearance it is exactly like the central nervous system in other Trematods.
AND THE CLASSIFICATIOX OF WORMS. 11
In two papers, cited at tlie head of this article, I have ah-eady considered the striking similarity existing between the Oukes and the tape worms in their adult forms. The examination of D'istomum crassicoUe has confirmed my views ; but it is not yet pos- sible to perfectly homologize the water-vascular system in the two orders, nor to explain the absence of the nervous system ami the digestive canal in the Cestods. In all other respects there is an essential agreement ; but the developmental history, accompanied in one order by a different alternation of generations from that occuring in the other, must be explained Ijcfore the union of the two divisions can be settled beyond all possibility of doubt.
Prof Huxley Muis recently proposed some alterations in zoological classification, appar- ently taking Hsckel's gastrasa theory as a starting j3oint. He is thereby led to suggest various changes in the classification of the worms, which result in an arrangement very different from that which seems to me most near the truth.
I cannot but consider it very unfortunate that Prof. Huxley has so entirely accepted the gastrtiea theory, for it has been very severely condemned by various competent naturalists, and it is not, so for as I am aware, generally adopted. Sufficient condemnation of the theory that the primitive germinal layers are really homologous in the ways expounded by Ha3ckel, is found in the fact that the layers arise by processes apparently altogether dif- ferent in different animals ; for it is the estaldished law that those parts are the same which are formed in the same manner. That the germinal layers are homologous, few natural- ists now doubt ; but that the Gastrula is the primitive form has been as urgently denied by some embryologists as affirmed by others. Under these circumstances it seems to me pre- mature to recast the whole of zoological classification in accordance with the demands of the " Ga^trceatheorie."
I am not surprised, therefore, that Prof. Huxley's results are very discordant with those of other naturalists as to the classification of the worms. Huxley, taking into considera- tion that the adult tape worms have no digestive canal, as do their allies, suggests separat- ting them from the other Plathelminths, and joining them with the Acanthocephala under tlie name of Agastrsea. I believe that there is not a single close homology yet demon- strated between the Echinorhyuchi and the Cestods, while, on the other hand, it has long been known that the Cestods were related to Trematoda and Turbellaria, and I have only endeavored to show that the relationship is even much closer than had been supposed. I am not aware that Huxley has brought forward any new arguments which prove the im- possibility of maintainmg the order of the Vaginiferae.
Prof Huxley has further divided the class Annelida, separating the Ollgoclioeta from the Polychfeta, upon what appear to me very insufficient grounds. What especially concerns us here is the approximation of the annelidan leeches and the Trematods ; in favor of this union I am not acquainted with a single argument, and therefore it appears unnecessary to discuss it further, for I hold it for a well established truth that the leeches are annelids and have no immediate connection with the Plathelminths.
1 Huxley. On the Classification of the Animal Kingdom. Jouru. Linn. See, Lend., Vol. Xli, p. 199.
12 C. S. MINOT ON DISTOMUM.
Note. Since this article passed from my hands, three papers on the anatomy of Trem- atods have appeared. The first is by Dr. Cobbold,^ and does not contain anything of spec- ial interest in connection with the views above advocated. Dr. Cobbold is apparently unacquainted with the discovery of the vagina, and makes no mention of any structure corresponding to Laurer's canal, which Huxley however describes,^ in Asji'ulognster conchi- cola. as running from the upper end of the oviduct (i.e., the uterus) back to the testis. He adds in a note that the description is based upon observations made before the publica- tion of Blumberg and Stieda's discoveries, and at that time he had no doubt of the connec- tion of the canal with the testis. The third and most important article is a capital memoir by Dr. Wierzejski,^ who describes in a Calicotyle from Haja Schulzli, a double vagina, so that the female apparatus has three external openings, and resembles very closely that of Polystomum as described by Zeller (Z. c).
Explanation of Plate I.
The drawing on stone was made by Mr. J. H. Emerton, to whose admirable skill I am much indebted.
LETTERS COMMON TO ALL THE FIGURES.
B.m. B.iseraent membrane.
D. Branches of the intestine.
£^. Eggs.
J^. Food stocks.
6^/. SaUvary glands.
i. Longitudinal muscles.
JV Mouth and oral sucker.
If. Central nervous system.
Oe. CEsophagus.
Fig. 1. Gives a general view of the whole animal seen from below.
Figs. 2-6. Transverse sections at various heights, arranged in their natural succession from in front back- ward.
Fig. 2. Through the hind end of the oral sucker, to show the central nervous ganglion.
Fig. 3. Tlyough the two branches of the digestive canal.
Fig. 4. Oblique section passing through the ovary and the blind end of the right digestive cojcum, and the front of the ventral sucker. Cf. Fig. 1.
Fig. 4, A. Transvei-se section of the penis bulb.
Fig. 5. Slightly oblique section through both testes.
Fig. 6. Diagrammatic combination of several sections, to show the origin of the uterus, and its relation to the shell gland and vagina.
Fig. 7. Through the liind end of the fluke, to show the main water-vascular trunk.
Fig. 8. Surface view of the lining of the water vascular system.
Fig. 9. B:isement membrane of the body, with the underlying skin muscles. Dr., subcutaneous glands.
Figs. 10 and 11 represent longitudinal sections.
Fig. 10. Through the mouth, pharynx and oesophagus, a. prepharyngeal region of the digestive tract.
Fig. 11. Through the ventral sucker and the penis.
Fig. 12. Epithelium of the digestive c(eca. A. Transverse section. Ji. Surface view.
Fig. 13. Connection of the sperniiduct and testicle.
Fig. 14. Cells of the so-called salivary gl.inds.
Fig. 15. Eggs. A, from the upper, 7?, from the lower part of the uterus.
Fig. 16. Egg-foodstock.
Fig. 17. Longitudinal section of the walls of the oesophagus.
> Cobbold. Jonm. Linn. Soc., Lond., Vol. xiii, p. 35. « Wierzejski. Zur Kenntniss dcs Baucs von Calicotyle
» Huxley. Anatomy of Invertebrate Animals. Chap. iv. Kroyeri Dies. Zeitschr. f. wiss. Zool., xxix, p. 550.
|
Ov. |
Ovary. |
Sp.(l. |
Sperniiduct. |
|
Ovd. |
Oviduct. |
/Sp.th |
Spermatheca. |
|
I'ar. |
Parenchym. |
>Sz. |
Spermatozoa. |
|
P.b. |
Penis bulb. |
Te. |
Left testicle. |
|
Fe. |
Penis. |
Te'. |
Right testicle. |
|
Fh. |
Pharj'nx. |
m. |
End of uterus. |
|
R. |
Circular muscles. |
m. |
Convolutions of Uterus. |
|
S. |
Ventral sucker. |
Vg. |
Vagina. |
|
Sh.g. |
Shell gland. |
W.vi. |
Water vascular trunk. |
M^.-moir?Pi.'M..n:.Mr K.5t|ir;rV,!JU
PI. F D
4. ;
Ovd Sp.th. ^- Vg
I
.-tp^,
W.y. 7
^■^
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eur l^ ■
/ A
JI7
dSBalfcidi ii'm£&£toi
II. Toe Early Types of Insects; ok the Okigin a.vd Sicqikn-ce ok Insect Like in
Palaeozoic Times.
By Samuel H. Scuddek.
Ucad Nov. 20, 1878.
J.N THE year 1833, Aiulouin e.xhibiterl at a meeting of the Entomological Society of France the wing of an orthopterous insect from Coalbrook Dale in England.' Thi.s was tlie first discovery of insects in the coal-formation. Since then many authors, notahlv (iermar and Goldenberg,- have added to our knowledge of the in.sects of tlie palaeozoic rocks, until now perhaps one hundred species are known. Yet insect remains in the.se strata may still be looked upon as the greatest rarities. By far the larger part of these hundred species are known to us by single specimens, and very fragmentary ones at that — a wing or even a mere piece of a wing being usually all that we know of a given form. It has been claimed by some writers that we should anticipate the earliest types of insects to be winged and not apterous, and the remains that have been found would seem at first glance to sustain such a hypothesis. But as the wings retain after inhumation more characteristic features than other parts of the body, it is not surprising that naturalists have made most use of them in describing the fossil forms ; and we should scarcely be warranted in deducing therefrom the absence of other fragments of the body ; moreover a characteristically apterous form of
' Ann. Soc. Ent. France, Vol. u. Bull., p. 7-8. It is also stated that the same specimen was exhibited by Audouin on Feb. 25, 1833, before the Academic de? Sciences; but no re- port of the meeting was published, unless in Le Temps newspaper, which I have not seen. The insect was consid- ered by Audouin as neuropterous, but has recently been shown by Swinton to be orthopterous.
^ For Germar's writings on palaeozoic insects, see the following : — 1. Beschreibung einiger neuen fossilen Insecten. < Munst., Beitr. z. Petref, v: 79-94, pi. 9, 13. 4". Bay- reuth,1842. — 2. Die Vcrsteinerungen des Steinkohlengebirges von Wettin und Ldbejtin in Saalkreise. f. Halle, 1844-53.
For those of Goldenberg, see the following : — 1. Prodrora einer Naturgeschichte der fossilen Insecten der Kohlenforma- tion von Saarbriicken. <C Sitzungsb. raath.-nat. 01. K. Akad. Wiss. Wien, ix: 38-39. 8°. Wien, 1852. (In this his name is given as Goldberger). — 2. Brief an Herrn v. Carnall. < Zeitschr. Deutsch. Geol. Gesselsch., iv: 246-48. 8°. Berlin, 1852. — 3. Ueber versteinerte Insectenrestc in Steinkohlengebirge von Saarbriicken. < Amtl. Ber. Vers. Gesellsch. deutsch. Katurf, XXIX: 123-26. 4°. Wiesbaden, 1852. — 4. Die fossilen Insecten der Kohlenformation von
Saarbriicken. •< Palaeontogr., tv: 17-40, pi. 3-6. 4°. Ca.ssel, 1854. — 5. Beitrage zur vorweltlichcn Fauna des Steinkoh- lengebirges zu Saarbriicken (Ucbersicht der Thierreste der Kohlenformation von Saarbriicken). < Jahresb. K. Gymn. u. Vorsch. Saarbr., 1867, 1-26. 4°. Saarbriicken, 1867. — 6. Zur Kenntniss der fossilen Insecten in der Stein- kohlenformation. <; Neues .Tahrb. f. Mineral., 1869: 158-68, pi. 3. 8^. Stuttgart, 1869. — 7. Zwei neuc Ostracoden und cine Blattina aus der Steinkohlenformation von Saarbriicken. < Neues Jahrb. f. Mineral., 1870: 286-89 with figures in te.xt. 8°. Stuttgart, 1870. — 8. Fauna Saraepontana fossilis. Die fossilen Thiere aus der Steinkohlenformation von Saar- brucken. Heft 1-2. 4°. Saarbrueken, 1873-77. (Heft 1 is the same as No. 5, above, with the addition of plates; a supplementary part is promised by Goldenberg.)
For other papers descriptive of the palaeozoic insects of Europe, see the ivritings of Andree, van Beneden and Coemans, Preudhommcde Borre, Brodie, Charles Brono-niart, Buckland, Corda, Curtis, Dohrn, Fric, Geinitz, Giebel, Hagen, Heer, Jordan and Meyer, Kirkby, Mahr, Murchison , Roemer, Rost, Salter, Sternberg, Swinton, and Woodward ; and for those of America, papers by Dana, Dawson, Harger, Lesquereux, Meek and Worthen, Scudder, and Smith.
14 S. H. SCITDDER ON THE EARLY TYPES OF INSECTS.
cockroach' has been described tVoin the rocks of Saarbriicken, which are as old as any of the insect-bearing beds of Europe. The insects of the middle Devonian of New Brunswick,^ on the other hand, are known only by their wings and the most diligent examination of thousands of fragments of shale has failed to reveal anything else. Further discussion of this point may be dismissed with the remark that geological data are not likely to throw much light upon it.
It is of course of prime importance that we should understand the relative subordination of groups in insects, before investigating their order of succession in time. Many attempts have been made to harmonize the current views of their relative rank and geological suc- cession ; but hitherto with indifferent success, mainly from the prevalence of the opinion tliat Coleoptera were to be ranked highest among insects, while this suborder has been kno^^^l. from the first, to occur in Carboniferous strata, and some other suborders only much later. Another obstacle which has stood in the way of a clear comprehension of the facts has been the ver^' common division of hexapod insects into two series^ upon Avhich the Engli.^h entomologists have perhaps specially insisted, called Mandibulata and Haustellata, a division based upon inadequate physiological grounds. Or if it be maintained that the function expressed in these names has a structural basis, it would be easy to point out that in either of the two divisions the diversity of structure of the mouth parts is so great as to admit of no common expression in other than physiological terms. If it were not so, the claim made by Agassiz,'' on embrj-ological grounds, of a higher rank for the haustellata insects would hold good, and we should be at a loss to account for the simultaneous appear- ance of Coleoptera and Hemiptera.
An apparently more rational division of the true insects into two series is that which separates tho.se with complete from those with incomplete metamorphosis ; the yoimg in the former ca.se unlike, in the latter resembling, the parent. This however, taken abso- lutely, separates closely allied groups, such as the caddice flies and dragon flies, and one form of metamorphosis shades into the other ; moreover it allies the Coleoptera with the H\-menoptera rather than with the Hemiptera or Orthoptera, and disaccords to so great a degree with the general relations of structure among insects as to show that it cannot be considered as of so fundamental an importance as we should suppose it would prove. Yet it is an important factor in the life history of insects, and cannot be disregarded totally, as is done in divisions based upon the mouth parts, but must be considered in any attempted dis- tribution of the suborders. So too must the nature of the wings, for the possession of wings is the preeminent characteristic of hexapods as a whole, and we should naturally anticipate fundamental features in the differences of their structure.
My own view of the primary relations of the suborders of hexapods was first exjiressed by Packard in 1863,* when he said that Coleoptera, Hemiptera, Orthoptera, and Neuro- ptera " .seem bound together by affinities such as those that unite by themselves the bees, moths and flies." To the latter or higher series he has since applied ^ the term Metabola
* {PiAt/zorterita granosuf.) Goldcnb., Faun. Sar. foss., i: ' L. Agassiz. Classif. ins. embryol. data. pp. 4-8.
18, pi. 1, fig. 17. 4 Packard. On synthetic types in insects. Bost. Journ.
' These DeTonian insects, which were first briefly noticed N-'*-- Hist., vii : 591-92.
by me in Bailey's Observations on the Geology of Southern ' Packard. Guide to the study of Insects. Introduction.
New Brunswick (8^. Fredericton, 1865) will form the subject 8° Salem, 1869. In later editions these names are also in-
of a ipecial paper now nearly completed. troduced in the text, on p. 104, with varying spelling.
S. H. SCUDDER ON THE EAKLY TYPES OK INSECTS. 15
(in a more restricted sense than (irst used \>y Leiich), and U) tne former, Heterome- TABOLA. The Metal)ohi are lUKHR'stionably more homo^'eneous than tlie other group. One of their primary feature.s i.s foinid in the more clearly marked regional division.s of the body ; this is a consideration of great significance, since in the progress of structure, from the worms, through the crustaceans to the insects ; or within the clas.s of insects, from the myriapods, through the arachnids to the hexapods ; or ui the developmental history of the MeUiboIa themselves, from the larva, through the ])npa to the imago, we discover a con- stantly increasing concentration of the segments of which the body is composed into distinct regions, culminating in the Ilymenoptera, where head, thorax and abilomen are most sharply defined. This feature was first insisted upon by Aga.ssiz in his renuirkable essay on the classification of insects (I.e., pp. 20-28), but its application to the division of the hexapods has not before been pointed out ; yet a very little consideration will show how much more clearly these regions are marked in the Metabola than in the Heterometabola, especially if the separation of the thorax and abdomen is examined. This is indeed what we might, not unreasonably, look for in the highest members of a group characterized, as are the hex- apods, by the possession of organs of tlight : the greater development of these organs would necessitate a more compact and distinctive organization of the region devoted almost ex- clusively to them ; and accordingly in the Metabola we have, on the one hand, a more highly organized thorax, more definitely separated from head and abdomen, than in the Iletero- metabola ; and on the other hand, greater power of continuous flight, of poise, of rapid movement, of sudden and repeated change of direction, and a far greater grace of move- ment in the former than in the latter.' "This specialization of the thorax led me at one time to think of proposing the term Sternoptena for the Metabola; and, in allusion to the general preponderance of the abdomen in the groups composing it, Gastroptena for the Heterometabola. For the latter series the term Gastroptena would be more distinctive, but the names suggested by Dr. Packard seem to me better adapted to general use, besides having the advantage of prior application, and I accordingly adopt them.
In addition to the primary features mentioned (which were not stated by Packard), the Metabola are characterized by a usually cylindrical body with a very small prothorax ; mouth parts formed in whole or in part for sucking, the points of the mandibles seldom opposed to each other ; front wings membranous and much larger than the hind wings, which latter are sometimes aborted ; the larva cylindrical and very unlike the adiUt, and the pupa always in- active. The Heterometabola on the other hand usually have a flattened body, with a very large prothorax ; mouth parts usually adapted for biting, the points of the mandibles then opposed to each other ; front wings usually more or less coriaceous or with ver}- numerous and thickened veins, and usually smaller than the hind wings, which latter are only excep- tiouably aborted, and never throughout large groups ; the larva is usually flattened, often resembling the adult, and the pupa either active or inactive.
^ This we affirm only as a general rule, taking eath sub- change of flight is very striking ;- but these do not affect
order as a whole. There are, it is true, apterous or sub- the characters of suborders as wholes; and in the exceptions
apterous Hymenoptera, bungling and inert lUers among the which might be noticed, the specialization of flight is
Lepidoptera, and Diptera which have a heavy and direct nearly always accompanied to a certain degree by a corres-
flight ; and on the other hand, groups like the Odonata ponding development and distinctiveness of the thorax. among Xeuroptera, whose rapidity and power of suddeu
16 S. II. SCUDDEH ON THE EARLY TYPES OF INSECTS.
The except ioiit! in the former group are only in the Hymenoptera, which usually have mandibles well developed for opposing each other. In the latter, more heterogeneous giHiuiK the exceptions are more abundant. In the Coleoptera the metamorphosis is com- plete.' In the llemiptera. the mandibles are developed as needles and with the other ]iarts of the mouth form a sucking tube ; in many of them also the front ^vings are almost wholly membranous. The Neuroptera, using the term in the Linnaean sense, are the leiist amenable to law ; their fore wings are usually membranous, though the veins are gen- erally thick and approximated ; a few (Ephemerina) have small hind wings; many of them show the regional divisions of the body almost as sti'ikingly as the Metabola, although the abdomen is generally developed to an excessive extent, and in such insects the prothorax is not greath- developed ; while, as before stated, part of them have an incomplete metamor- phosis, and so have been classed with the Orthoptera by the later German writers, and others have an incomplete metitmorphosis. The structural affinities, however, of the Neuroptera proper and the so-called Pseudoneuroptera are so close that they cannot be disconnected, notwithstanding the striking differences in general features between them ; and although, thus composed, the Heteromctabola exhibit anomalous features in nearly every suborder contained in it, we must accord to this division of hexapods into Metabola and Hetero- metabola a closer connection with all the facts than any that has yet been proposed.
How clo.sely this division accords with the geological succession of insects will appear from the fact that all the suborders of Heteromctabola, and none of Metabola are repre- sented in the palaeozoic rocks.^ This is the more striking from the fact that, if we omit mention of the single discovery of insect wings in the Devonian, the three orders of in- sects,— hexapods. arachnids and myriapods, appear simultaneously in Carboniferous strata.'
' It would appear, at first sight, as if Dr. LeConte, in his count, should therefore be looked upon as a sign of rela-
Classification of the Coleoptera of North America (8°. tively low rank. I am pleased to be able to state, from a
Washington, 1861), Introduction, p. 8, held that Coleoptera recent conversation on this point with Dr. LeConte, that he
were to be ranked as the highest suborder among hexapods. aUl not intend to extend the argument drawn from the pro-
His table wolild seem to indicate this ; but he speaks witli thorax over the whole hexapod series, but only over those
hesitation, as if proposing only a provisional arrangment, most nearly related to Coleoptera, and purposely expressed
reniarking : " We can merely state in general terms that himself in guarded lan^ua^e.
those [l.exapods] having a perfect metamorphosis are the -, jj„ generalization s^ broad as this and at the same time
highest ; and those having the thoracic segments agglutin- ^^^^^^^ ,^^^ ^.^^ ^^^^ ^^^^ j^^^.^^^ ^^^^^^ i^^,^^^^ ^^^ „^^.
atcd, or the prothorax separate, are to be considered above „uit! i--i- iui i-i* • uri-
' ' ' ablv Bronn, dividing the hexapods into two series, — Mandi-
those in which the larval character of similarity among the i,,,,;^^ ^„j g^^^^^i^ ^^^ equivalent terms) - claim that the
thoracic segments is preserved." To the first proposition carboniferous hexapods were all biting insects, and that the
no one will take exception ; the latter ought to be restricted .^^^ing insects first appeared in the Jura. The latest state-
in Its apphcation to those groups only to which the Cole- ^,„t „f ^y^^^ ,„,j ^^^^ ^^^^ ^^ H^^^,^^, (g^„ j^j^^p^
optera are most nearly relate.l, viz.: to the other Hetero- Qrgan., n, p. xcix, 18G6), but Dohrn's Eugereon was
metalKda : so far as they are concerned this would seem to p„,,iished in the same year, and by the light of this strange
be an indication of special and therefore comparatively i^.^.t ^^^^ palaeozoic insects now appear, as I shall en-
high structure; but otherwise, as a mark of inferior organ- jeavorto show below, under an entirely new aspect, and
ization since It u« opposed to the progress of structure seen render it probable that there were manv, as there certainly
throughout the articulates, marked bv a condensation so to i- • ^ • i •' »•
, . . -^o, •••ai-^'.K, IV <» cwimtuoavioii, so Lu were some, sucking insects in palaeozoic times.
speak, of the thoracic segments. Many Neuroptera and , r. , .^ , • , , , , •, , , rw..v„,.„„ _,.»v.i t, r /-,!,• , T^ ,. ■ Carboniferous arachnids have been described by Orthoptera, notably such forms as Corydahs and Forficula r. i t--' ti T>f i . ,,r i. -c c I /.i,^ 1,..,, ,1— „i u 1 •, -.t /^ 1 N , Corda, iric, Ilarger, Meek and Worthen, Koemer, ocud- (the latter classed by early writers with Coleoptera), show , , T.r , , , •> • , ^ , :r, (V^:. ..»>i. 1 ui . /-, 1 , ' der.anu Woodward: while myriapods from the same form- in Uieir prothorax a close resemblance to Coleoptera ; and ,. , , , ., , , Vv t. > , -nr , .».« >,—. .:-„ . I • . e .-,■ . ^, . ation have been described by Dawson, Meek and Worthen, the Ten- size and importance of this segment in Cole- c 1 1 , -ht- i i u • , ^. r , , »»•<.,-. — 1..« .1.. _i. I 1 1 • • . . bcuduer, and Woodward : besides others from other palaeo- optera, when the whole hexapod series is taken into ac- • l , , t^ , , ,, . .
ZOIC beds bv Dohrn and Ueinitz.
S. H. SCUDDKR OX THK KAKI.V TYI'KS <»l" INSKCTS. 17
Tlie earliest known Diptera ocrur in tin- F/iassii- rocks at Chelti;nliain, l)uinl)|fton ami Forthainpton in Knji:lan(l ; the Lepiiloptera ' in tlie middle Oolite (Solenliolen ) ; and the Ilyinenoptera in the same ibnnation.'- The Metal)oIa are then later in time and more per- fect in development than the Heterometahola.
When we analyze the insect fauna of the earliest times more closely, we n<jtiee (hat the higher suborders of Ileterometabola, the Colcoptera and Hemiptera, are represented in the palaeozoic rocks by very few types, as compared with the Orthoptera and Neuro])tera-, the two former groups having but tin-ee or four each,^ while Goldenl)erg enumerates fifteen or sixteen of each of the others from Saarbriicken alone, and doultle that number must l)e known. No Coleoptera nor Hemiptera have yet been found in the palaeozoic formations of America, while I am acquainted with about forty Orthoptera and Neuroptera from these rocks. The almost entire absence of Coleoptera from palaeozoic rocks is the more remarkable, becau.se their crust is much thicker than that of other insects, and their shards as hard as the shell of the body. This is peculiarly the case in the lowest an<l presum- ably oldest type, the weevils or Curculionidae. Their remains have been jjreserveil with the greatest readiness in more modern strata ; in fact, in all the newer rocks, Coleoptera are best repi'esented of all insects ; yet in the oldest, very few have been found in com- parison with the remains of the lower suborders. This is a striking and indisputable fact, and notwithstanding the paucity of the material whereon to ba.se a general statement, is scarcely to be explained on any other hypothesis than that of the later appearance of Coleoptera.
In the Orthoptera again, nearly all the families represented belong to the lower series ; only four or five membei's of the saltatorial families have been found, the cockroaches of the Carboniferous period outnumbering all the other Orthoptera many times. In the la.st catalogue of fossil cockroaches (by Goldenberg), thi'rty-five species are recorded from the Carboniferous rocks and only seven from the Tertiary formation. Indeed about one-half the known species of palaeozoic insects are cockroaches.
Or, if we look at the Neuroptera, we find that the Neuroptera proper, or those with com- plete metamorphosis, scarcely occur at all in the palaeozoic rocks ; whereas the lower Pseudoneuroptera, with incomplete metamorphosis, are comparatively abundant. Many of the reticulate-winged insects of early periods, however, combine the characters either of the Neuroptera and Orthoptera, or of the Neuroptera proper and Pseudoneuroptera. So striking, indeed, is the comprehensive nature of these early types that Dohrn, and after him
' The carboniferous Breycria of de Borre (Comptes the carboniferous limestones of Aiitun. Geinitz also de-
rond. Soc. Ent. Belg., [2.] xiii : 7-11) is univers^ally con- scribes Iiorings of a larger beetle in fossil woo<l from the
ceded to be a neuropterous insect. See the remarks in the Saxon coal measures to which Fric gives the name of
same journal by Hagen, Heer, McLachlan, de Selys, Xi/lorycles planus; and Sternberg others from Bohemia of
Scudder, Van Volxem and otliers. a doubtful character, which Fric calls Xijl. seplarius. Cure.
„ . . , , , „ „ ., , , ,T xi Presloicii Buckl. has been shown to be an Arachnid.
^ A single species, doubtfully referred by Ueer to the -r., , it . /. .i. i . i. m ;„„_«
, , , , , , n , • , r - i- The only Hemiptera from these lowest rocks are /• uigora
latter suborder, has, however, been lounu in the Lias ol _,, . ^', , n , . ,^,- • /-. i i u c
Ebersi Dohrn and Fulgonna Ktieven Ooldenl)., from
Saarbriicken, and Macrophlebium Holtebeni Goldenb., from
' The only Coleoptera known to me are Curculioiiles Mancbach ; besides Fulgorina lebachensis Goldenb., from
Ansticii Buckl., from Coalbrook Dale, Troxites German the Permian. £ur/»;reon jBoeci-in^J Dohrn, cannot be classed
Goldenb., from Altenwald, and the borings of a ffi/lesinits here, as will appear further on.
described by Brongniart as occurring in petrified wood from
MEMOIRS BOST. SOC. NAT. HIST. VOL. III. 2
18 S. II. St UDDER ON THE EARLY TYPES OF INSECTS.
Goldoiiberjr. pro]H)se.s to jrroup them under a new siibordinal division, to which Goldenberg hasappliod the name PalaoodictAoptera.'
This vie\r I am incHned to think a correct one, but no definition of the group has yet been attempted ; and while, on the one haml, Goldenberg appears to have gone too far in referring to it the Carboniferous insects from Illi^iois descril)ed by Dana, and the Devonian insects of New Brunswick, it would seem probable that Woodward's Archimantis^ should be classed therein, as well as the genera Eugereon, Dictyoneura, Paolia and Haplophlebium ; and it is by no means improbable that they all possessed mouth parts structurally com- parable to the remarkable Eugereon of Dohrn, which certainly can be referred to no exist- ing group of insects. When more of their structure is known, they will probably be found to agree in the possession of a remarkably depressed, cockroach-like body, with ample thoracic segments, the prothorax well sejjarated from the other joints, broadly expanded or extended, reticulated wings, lancet-shaped mandibles and maxillae, long labial palpi which have no direct part in the haustellate structure of the mouth, and multiarticulate antennae. Tliis is a combination quite at variance with that of any group of recent or of newer geo- logical times, and indeed is known to us only in the palaeozoic rocks. It forms a synthetic ty])e in the largest sense, and may be said to combine features of all the Heterometabola.
But it was not the only such type then existing; for, as has already been noted, there are many other palaeozoic insects which combine in their structure features now characteristic of diverse groups. Such are nearly all the Devonian insects. It is also not a little re- markable to find that recent types existed in the earliest periods side by side with these- Some of the Devonian insects, for example, are to be referred with very little question, not only to the Neuroptera, but even to a particular family of Neuroptera now existing, the May flies. Indeed, the presence, at the apparition of a given group, of modern types, side by side with those which elude our classification of existing forms, is one of the. peculiar problems of palaeontology.
Perhaps no more striking instance of this can be found than the recent discovery by M. Charles Brongniart, in the upper Carboniferous rocks of Commentry, of one of the most specialized forms of insects which exist ; of a type mdeed so modern, that, so far as I may judge from a rough sketch sent me by Brongniart, one would not have been surprised to meet with its exact counterpart in every detail, living in the tropics of the old woi'ld. It is a species of large, spinous, thick-bodied Phasma or walking-stick, with abbreviated teg- mina, long wings and body, rather long and slender legs and antennae, and in all its parts
" Cf. Dohrn, Palaeontogr., XIII : 338-39; XI v: 134. Gold- the neuration of the wings. The projection in front of the
enberg, Faun. Sar. foss., ii : 8. Dohrn first proposed the head, therefore, would seem to be, not a prolongation of the
term Dictyoptera, but afterwards withdrew it, as preoc- head itself, comparable, as supposed by Woodward, to that
copied. of the head of some living Mantida;; but a rostrum, like that
» Woodward. On a remarkable orthopterous insect from °^ Eugereon, though much shorter than it, and by its state of
the coal-measures of .Scotland. < Quart. Journ. Geol. Soc. preservation apparently amalgamated with it into a single
Lond., 1876 : CO-61, pi. 9. Woo<lward, it seems to me, has ""^'^ ' °'"' '' '"''y ^^ ^'^'^ '=''"■"'" *'°"'' "^'^^ ""^ °*'='" P*""'^
in all probability mistaken the affinities of this insect. If removed, for it would then probably appear as an integral
hij figure is placed beside Dohrn 'e first illustration of P^"^ °^ '^^ ^''^'^- '^^^^ <='°'^ relationship of the wing-
Eugercon, the similarity of the two will be apparent. The structure in Archimantis, Eugereon and the other genera
form and relations of the head, prothorax and broadly specified above render it not improbable that they were all
expanded wings (nearly all that is preserved in Archi- sucking insects. Protophasma however, similarly related,
mantis) are the same in each, as well as, in a general sense, certainly was not.
S. H. SCUDDER ON THE EARLY TYPES OF INSECTS. 19
perfectly reproducing the customiirv niid yet unique features of the Phnsmida of to-day.' The family had not previously hci'u known earlier than the Tertiaries.
We may gloan still another fact from the .scanty data the rocks aflord us concerning the early types of in.sects. All the Ilcmiptcra of tlie palaeozf)ic rocks helong to the Iloin- opterous division of the suborder ; indicating, what is generally conceded, that this divi.sion is lower than the Hcteroptera, which first appeared in the Jura.^ Now one conspicuous difference between these two divisions is found in the structure of the ba.«e of the front wings, which is coriaceous in the Heteroptera ami membranous in the Homoptera ; show- ing that differentiation of the front and hind wings is. jus we .sjiould suppose it might be, a later development, the homogeneous condition preceding it. Among (Jrtiioptera, none of the families, unless it be the walking-sticks, have more densely coriaceous fore-wings than the earwigs and the cockroaches. The earwigs first appeared in the Oolite ; and wliile cockroaches were abundant from the earliest times, it is not, with one exception, until we reach the Lias that we find .species with close approximation and multiplication of the veins of the front wings, giving them a coriaceous appearance. This exception, Ledrophora Girardi? in which the veins are nearly obsolete, occurs in the Trias ; and it is the earliest indication of a.ny differentiation of the front and hind wings in cockroaches ; for all the palaeozoic species had tegmina which were as distinctly veined as the wings, and could not, in any sense, be called coriaceous.* The same distinctness of the veins is apparent in all the other palaeozoic Orthoptera ; so that, excepting the two species of Carboniferous Coleo- ptera and Protophasma (which do not appear to differ' in this respect from living types), we may say that the wings of palaeozoic insects were homogeneous.
Inasmuch as we know the earliest insects principally from the remains of their wings, it is interesting to note in them a further striking fact. If we should formulate the charac-
• Since the above was written, I have received from M. ^ Perhaps a similar statement may be made even of the
Bron<niiart his final memoir on Protophasma (Note sur un few Coleoptora known. For, if we accept LcConte's prim-
nouveau genre d' Orthoptere fossile de la famille Jcs Phas- ary divbion of Coleoptera into normal and rhyncoph-
miens — Ann. Sci. Nat., [6] vii, Art. 4), by which it ap- orous, the former the higher, and look upon the Troxitcs
pears that the wings must be excepted from the statement of Goldenberg, as I strongly incline to do, as a curculionid,
given above; for they differ remark.ibly from the wings of — the only indic.ition of the higher normal Coleoptera in the
livinc Phasmida, and resemble e.\traordinarily the wings of palaeozoic rocks will be the borings brought to notice by
Pal.ieodictyoptera, and especially those of Dictyoneura. Geinitz, which were evidently made by a longicorn, a
They could not have been folded longitudinally to the de- family of normal Coleoptera ranking rather low in the
gree that the wings of Phasmida are now plaite<l, for the series.
anal area embraces less than one-third of the wings, and . „ „ , ,. , ., „ , , , ^ -.r- _. i
, . . .1. • <- .1. . c \ ■ ' Heer. Ueber die fossilen Kakcrlaken. < Viertel-
the interspaces between the veins of that part of the wing r o n i rr • l ««, i c t qo
. , • v. J, 1 jahrschr. naturf. Gesellsch. Zurich, ix : 297, pi., fig. 5. 8°.
Zurich, 1864.
which lies above the anal area, are not straight but curved; in the number and arrangement of the veins in this upper part of the wing we have an almost exact counterpart of the ■• Exception should perhaps be made to the very remark-
win^s of Dictvoneura; the same, to a less extent, may be able cockroach described by Goldenberg (Faun. Sar. foss.,
said of the wings of the Fulgorina described by Golden- i : 17, pi. 2, fig. 14, 14a), under the nameof iJ/a/dna inWjnw;
berg. This type of wing structure was therefore a very this insect has a slender, perhaps cylindrical, abdomen with
common one among palaeozoic insects, and accounts for tegmina and wings which appear to be equally leathery and
Brongniart's suggestion, hardly to be received, that these in which nearly all trace of veins are lost. Here, however,
Fulgorina should be considered Neuropterous ; indeed the all the wings appear to be alike in form, consistency and
neuration of the wings of the numerous carboniferous structure; and Goldenberg has given us only a meagre ac-
Blattariae does not lack a somewhat close adherence to the count of it, which is the more unfortunate, since it is second
same type, and we may yet succeed in establishing an un- in interest only to Eugereon and Protophasma. usual degree of homogeneity in the wing structure of all or nearly all palaeozoic insects.
20 S. II. SCUDDER ON THK EARLY TYPES OF INSECTS.
toristiesi of the wing structure of living insects (wliicli show, indeed, a variety of type truly marvellous, and ranging from exceeding simplicity to a complexity which nearly baffles all attempts at homology), we should not need to modify our statement in the least particular to include the wing-structure of the insects of earliest times. The plan of neuration upon which the wings of insects were then constructed is the plan we find in all existing types. At the same time, as stated above in a note, there was an unusual degree of homogeneity in the wings of palaeozoic insects.
This review clearlv indicates that the laws of succession of the insect tribes are quite similar to those which have long been known to hold in other groups of the animal king- j dom : and that the facts are, in the main, such as the theory of descent demands. The ex- ' ceptions to theory, however, and indeed the general facts, are such as to indicate that pro- found voids exist in our knowledge of the earliest history of insects. The appearance of hexapods in the middle Devonian long previous to any traces either of myriapods or of arachnids ; the apparent advent of generalized groups of a comparatively narrow range, before those which are wider in scope and embrace the former ; the apjiarition of Cole- oi)tera. which present no indication of any divergence from the subordinal type, in Carbon- iferous beds first yielding an abundance of insect remains, — that is, as early as any insects ' whatever, excepting the homogeneous-winged Heterometabola of the Devonian ; and the occa.sional discovery of highly specialized types at very early periods : — all point to the far earlier existence of widely comprehensive types, from which all these comparatively specialized but still more or less synthetic forms must have originated. The additions to our knowledge of palaeozoic insects within the past twenty years, and the increasing indi- cations of dry land at earlier and earlier epochs,^ must leave little doubt in the reflecting mind, not only that insects existed in no scanty numbers in Devonian and even in Silurian times, but that persistent research over wider fields will probably enable us, at no distant da}', to replace hypotheses with facts.
In conclusion, we may recapitulate, as follows : —
1. With the exception of the few wings of hexapods known from the Devonian, the three orders of in-sects — hexapods, arachnids and myriapods — appeared simultaneously in Carboniferous strata.
2. Hexapod insects may be divided into a higher group (Metabola), including Hymen- optera, Lepidoptera and Diptera; and a lower group (Heterometabola), including Coleo- ptera. Hemiptera. Orthoptera and Neuroptera.
3. All Devonian and Carboniferous insects are Heterometabola, the Metabola making their first appearance in the Jurassic period.
4. Many .synthetic or comprehensive types existed in palaeozoic times, combining the characters either of all the Heterometabola; of Orthoptera and Neuroptera; or of Neur- optera proper and Rseudoneuroptera. s
5. The Devonian insects either belong to comprehensive types related to the two lower ■ suborders only, or are low P.seudoneuroptcra ; and were undoubtedly aquatic in early life.
G. The lower suborders of Heterometabola, — Orthoptera and Neuroptera, were much more abundant in palaeozoic times than the higher, — Coleoptera and Hemiptera.
Cf. IvfcVjuereux. Land p)ant.<i, recently discovered in the first page of this paper will bo found a resume of our
the jilurian rocks of the United States. < Proc. Araer. knowledge of this subject.
Philofc Soc., xvii: 163-73, pi. 4. 8'. Philadelphia, 1877. On
s. II. sci'i)i)i:i: «»N iiiK i;ai:i.v tvi'Ks oi- inskcis. 21
7. XfarK' all tlic palacDZoii' OitlittptL-ni bfluiij^ tn llie lowi-i' iiiiii-.<altati)iial laiiiilies, and are almost e\<lusivi'ly coi-kroacln-s.
S. Tilt' Nt'iiroptera propt'i" wi-ri- at tliat time imicli larvr tliaii llic luwer I'M-iuloiH-nir- ojitiTa.
U. All the oarlitT t\ pL's wcio tlu'rt-Hjro dI" iiit'fi-ior i)i-;iani/.atii)ii.
10. The general type of wing .■struct iire in insect-; lias remained mialteied I'rom llie earliest times.
11. With the e.\i'i'[itiiiu of two s|)e(ics of Coleoplera and one of ( )rlho|)tera. the front and hind wings of palaeozoic insects were similar and memliranons. heterogeneity making its appearance in nie.sozoic times. At the same time, the neuration of the wings (if palae- ozoic insects in otherwise widely diverse types was much more similar than now.
12. The series of facts presented to us hy the progress of geological research leads to the conviction of the prohahle existence and po.ssihle di.scovery. in the Devonian and even in the Silurian formations, of winged insects, still more generalized in structure than any yet detected in the palaeozoic rocks.
It may also he added that nearly all the earlier in.sects were large, many of them gigantic in size, anih further, that there is a .striking similarity hetween the carhoniferous insect-fauna of Europe and North America.
XoTE. The preceiliiii; pages were printed before I cliaiiceil upon the following p:is.sage from Lacurduire (Introd. al'entoni. I, p. 326), wliich may bo taken as a note to the last jiaragra])!! of tliinl page of tliis paper: —
" Toutes les difierences que Ton observe d.ms le tliora.ic des Inseetes piuvieniK-nt ilu plus ou nioins ile devel- oppemenl qu'a pris chaque anncau tlioraciciue, du nombre de pieces que cliacun d'eu.v presente, et de lu grandeur relative de eliaeune de ees pieces en |)articulier. Si le prothora.x a acquis un developpefnent extra- ordinaire, et s'est en (pielque sorte separe du mesothora.Y et du nietatliora.x, on aura le tliora.ic d'un Coleoi>tere, d'un Dermapti^re, d'un Ortlioptere et d'un Ilemiptere. Si au contraire le prothorax est reduit a des dimensions tres-e.\igues, et que le mesotliora.v intiniement uni au metathorax ait pris lui accrnisseiiicnt ('norme, on aura celui d'un Hynienopt^re. d'un Lepidoptfere et d'un Di])t6re."
111. P.vLAKozoir CocKitOACiiKS : A roMri.KTE Rkvisiox ok tiik Si'Kciks ok Born
WoKLD-S, WITH AX EsSAY TOWAUD TIIKIK Cl.ASSIKICATIOX. Bv SaMIKI. II. SciDDi;!:.
X HE f;tii(ly of fossil insocts has hitherto rumishuil very littk: material fuwanl a knowledge of the general laws whieh have governed the progress of animal life. The rea.sun of this is not far to seek. The delicate nature of their I'ramework is such that they are never found preserved in any abundance, and seldom in such condition a.s to preclude doubts as to their affinities ; the number of extinct known forms bears, indeed, a very small propor- tif.n (n fli:it of (itlicr fossils. >Ti)n'()ver. the most iuujortant ueriod in the history of any
Erratuin f.r V„l. HI, Part \, No. IIF. .,f the Moiiioiis of the Boston Society of Xatiinil History.
By an iitifortunate acciiltnt, tlnee of tlic species .lesciibe.l in this memoir have been ascril)o<l to tlie wrong .liscoverer an.l to an incorrect horizon and locality. Mojmi/lacris lieros (]>. 54, j)!. 5, f5.'. 9), Archimylacris jxtniHelum (p. 8.i, |.i. 6, tig. 6), and the species described \vithout a name (p. V2S, ]>\. 0, fi-'.' 13) were ail discovered by Mr. K D. Lacoe, and not by Mr. Mansliel.I, in the neighborhood of Pittston Penn. JVeci/mi/ktcris heros, like the single other species of tiie same genus, was found in a lieavy black shale in the lowest productive coal measures, or the roof shales of vein C. Archhiujlacris jMraUdum and the other species came from Campbell's ledge, near tiie bottom of the intercon-lomerate (Roger-s No. XII). It is due to these gentlemen to state tliat the mistake is entirely mine.
n ^ -1 T^ .. ,.-. SAMUEL II. .SCUDDER.
Vambridge, Dec. 20, 1879.
one most likeh' to be fruitful m results.
Their remains were first made known by Gormar in 1842, in Count Miinster's Beitnige zur Petrafacteukunde, where four species from Wcttin were described and figured. Soon afterwards, in his general work on the fossils of Wettin and Lobejiin, Germar redescribed these with as many more ; and additional forms have been published from time to time by Goldenberg. lleer, E. Geinitz and others, until the number of European .species at present recognized in the palaeozoic rocks is about forty. To find the original descriptions of these foity species one must look for no less than sixteen difl'erent papers by seven different writers ; rarely, too, have any of them received any further study after their original description ; it necessarily follows that our knowledge of them is very fragmentary, and a worse showing could be made were we to include the American species, of which descrip- tions of seven have appeared on six separate occasions.
' Compare this with the r.itio of fossil to living maiiim.ils, - One species had been previou.^ly described, but as a fern
as seen in the list given in Murray's Geographical Distribu- leaf, tion of Mamuiab, pp. 320-64. 4°. London, 1866.
III. Palaeozoic Cookuoaciies : A (omplkte REVtsioN ok the SrEciEs ok Both Worlds, with ax Essay xowAiin tiikiic Classikicatiox. Bv Samuel II. Scuduek.
X HE study of f().-<sil insects lias hlthortt) niriiisliod very little material toward a knowledge of the general laws which have governed tiie progress of animal life. The reason of this is not far to seek. The delicate nature of their Iramework is such that they are never found preserved in any abinidance, and seldom in such condition as to preclude doubts as to their allinities ; the number of extinct known forms bears, indeed, a very small propor- tion to that of other fossils. Moreover, the most important period in the history of any group of animals is its earliest; and while the later appearance of maunnals, creatures possessing a bulky framework less liable to destruction, enables the naturalist to recon- struct what must be a very significant part of the primitive mammalian faunas, the very early appearance of insects, with their fragile framework, is a serious obstacle to obtaining any light whatever concerning their origin. Fragment by fragment have the few fact-s been patiently gleaned ; yet to-day we po.ssess for the entire palaeozoic period not more than one species of insect to every thousand existing forms.' A few scattered generaliza- tions concerning these earlier insects have been attempted, and in the preceding paper I endeavored to collect all that was known upon the subject, and to show that some general statements might be made, not likely to be gainsaid by further facts. The present paper discusses with greater fulness the cockroaches of the palaeozoic period, a group which contains fulh' one half the species of insects known from the ancient rocks, and tberelbre one most likely to be fruitful in results.
Their remains wei'e first made known by Germar^ in 1842, in Count Minister's Beitrjige zur Petrafactenkunde, where four species from Wettin were described and figured. Soon afterwards, in his general work on the fossils of Wettin and Lobejiin, Germar redescribed these with as man}' more ; and additional forms have been published from time to time by Goldenberg. Heer, E. Geinitz and others, until the number of European species at present recognized in the palaeozoic rocks is about forty. To find the original descriptions of these forty species one must look for no less than sixteen different papers by seven different writers ; rarel}', too, have any of them received any further study after their original description ; it necessarily follows that our knowledge of them is very fragmentary, and a worse showing could be made were we to include the American species, of which descrip- tions of seven have appeared on six separate occasions.
' Compare this with the ratio of fossil to living mainm.'ils, - One species had been jirevioiisly described, but as a fern
as seen in the list given in Mun-ay's Geographical Distribu- leaf, tion of Mammals, pp. 320-64. •1'^. London, 18G6.
24 S. 11. SCLDDKK (»N rALAKOZOlC t'Ot'KUOAt'l IKS.
It is tnio thai .■<uiiio .<Ii_ulit siij::i;-osli()ns have licen luaile toward the chissificatioii ul' these insoct.s. hut. a.s will he .>ihowii further on, without much success. With rare exceptions all have heen tlescrihed inuler the <i-eueric term Blattina ; the species, however, have occasion- allv heen confoundeil. and their relationslii]) to one another and to the cockroaches of later tiino.s lia,s never heen seriously examined. This examination seems the more desirahle for two reasons. First ; as a general rule, it is the upper wing of these creatures wliicih has been preserved, allowing the best comparison not only with their living representatives, but with one another ; for, owing to the transparency of the front as well as hind wings of palae- ozoic insects, the venation is remarkably distinct, and from the nature of the part preserved is rareh- displaced in fossilization. Second ; our opportunities for any generalizations con- cerning palaeozoic insects are exceedingly limited ; and this group, as the most abundant of all the ancient types, oflers the most inviting field of research. It would appear, too, that the known species are in reality only the fragment of a vast host which existed at that time, but have left no further traces, a host so great as to render it suitable to charac- terize the carboniferous epoch, so far as insects are concerned, as the age of cockroaches.
This conclusion is drawn from two facts. Every new discovery of palaeozoic cockroaches, with scarcely an exception, reveals new species, so that upwards of sixty different kinds are enumerated in this paper, showing great diyersity of structure, and seldom represented by moi-e than a single specimen ; this indicates that their petrifaction is a rare event, and that the few relics we have really represent a vast horde. Tiie second fact is the decreasing representation of these insects in the rocks as we ajiproach the present time, coupled with a very generous allowance of cockroaches living at the present day. If we divide the time which has elapsed since cockroaches appeared into three great divisions, corresponding to the palaeozoic, mesozoic and caenozoic epochs, embracing the present period in the last- named, we shall have, say, sixty species in the palaeozoic, thirty-five in the mesozoic and only sixteen fossil species in the caenozoic (even including those occurring in that most prolific insect-trap, the Prussian amber), Avith upwards of five hundred living species.^ If we then con.sider the present as a part of the pliocene, and take only five hundred species as the number actually living in each of the three divisions of caenozoic time, making fifteen hundred in all, and sixteen as the numl)er now reported as existing in tertiary times ; and, finally, assume the .same ratio between the uidvuown and the known to have held in the palaeozoic as in the caenozoic epoch, we shall have five thousand, six hundred and twenty-five species as the number of palaeozoic cockroaches. Even if enormously exag- gerated, this estimate will at least indicate the prodigious quantity of cockroaches which then existed and give an additional reason for the pi'csent revision."
Giebel, who puljlished the first list of palaeozoic cockroaches, then supposed to Ijc only eight in number,'' brought them all inider the generic term Blattina, and placed witli them also .some of the me.sozoic species. In a foot-note (p. 315) he promises to give a "careful revLsion" of all the Wettin cockroaches, but this he has never done.
Heer, in his catalogue of fos.sil cockroaches,* was the first to attempt an}- division of the palaeozoic forms ; his classification was as follows : —
' This is certainly a low cstimaU-. of existing types. Brun- co.snio|iolitan distribution and vexations feonndity — tlic doni-
ner in 1875 enumerated nearly four hundred species, and ination in short — of certain existing species of cockroach. fincc that lime c-nonnons ad<lilions to this family have been ' Giebel. Die Insectcn und Sl)inhen dor Vorwelt, 8°.
maile. particularly liy de Saussiire. Leii)/.ig, I85C. pp. 313-lG.
= Perhaps we may fairly add that the early appear.ince and < Ilcer. Viertcljahr.sclir. naturf. GesdlNrli, Ziu IlIi. Jain.;.
prevalence of cfKkro.i.hei' also explains in a nicasirre (In- ix, pp. 287 e/ .w/. (18«4.)
S. 11. SCl'DDKW ON rALAK()/<»I( ( < XKIK >A(IIKS. 25
Div. ;i. lJcti('iiI;itioii tetriiiroiiiil ; main veins (Vec. ( 9 spocics. )
Div. I). Main veins eonneeted at the liase. (1 sjiecies.)
Div. c. Ueticulation polygonal ; main veins free. (2 species.)
Div. il. Hind wings. (2 .species; one wrongly placed here.)
Tile only other cla.ssification which has been attempted is that rocontly made \>y (Joldcn- lnTg,' which is merely an e.\tensi(jn of lleer's. He (irst .»;eparates those of the true carhon- iferous series from tho.se occurring in tlie dyas, and I'or tiie former oilers the liiliowing .scheme :
I with simple (piadraiigular cells arranged
( fore-wings niemt)ranous j ])riiicipal -, in rows; (Iroup 1. (11 sj).)
W (r^l • ' with distinct venation ; -' veins free; ( with j)olygonal cells; Group II. (18 sp.) ° 'j I princijial veins connected at the Itase ; (iroup III. ( 1 .sp.)
[fore wing.s coriaceous, with indistinct venation ; (Ii-oupl\'. (Isp.)
Wingles.s ; (Jroup V. (1 .sp.)
The few species from the dyas are divideil into that from Weissig (1 sp.), and those from Lcl)ach (2 sp.), and the latter are placed severally in groups corre.sptmding exactly to Groups II. and HI. of the carboniferou.s .scries.
Nearly all the species represented by fore-wings, whether in the classification of llccr or of Goldenberg are grouped, then, according to whether the minute cross-venation or reticu- lation of the wings is composed of polygonal cells or simply of cross veins running directly from one nervule to another. There are three serious ol)jections to the naturalness of such a classification. First, it assigns a high importance to a necessarily insignificant feature in the structure of the wing. Second, the reticulation is frequently invisible either from its actual absence or the imperfect preservation of the fossil. And third, the same wing exhibits, certainly in some American species (e. g., Etohl. vemista, E. Lesqiiereuxil), a tran.s- verse reticulation in one part of the wing, and a honeycomljcd reticulation in another. We may therefore fairly .set aside these cla.s.sifications as insufficient and unsatisfactory.
More than ten years ago, in studying the first fossil cockroaches that came under my ob.servation, and noticing the diversity of structure in the wings of palaeozoic species, I described two types under new generic names ; but on the discovery and separate descrip- tion of additional forms, it seemed best to revert to the common custom of referring all to Blattina until the present revision or some other was attempted.- A considerable number of new and interesting forms having recently accumulated, it seeme<l a favoral)le oppor- tunity to pass the entire series under review; accordingly the illustrations of the ilescribed European species were copied and brought, "as given in the plates, to the same scale (X 2 diam.), and, when necessary, so reversed as to place the costal margin on the left, the base of the wing being uppermost. This renders comparison more direct and simple, and. in such as have been reversed it is merely the same as if one looked at the wing from tlie opposite surface.
A compari.sou of these with American types at once showed that, among the latter at least, a remarkable degree of diversity obtained, necessitating the division of the palaeozoic cockroaches into two tribes, according to the structure of the uppermost vein of the front wing : this vein, in one tribe, exclusively American, being composed of a series of hjng
'Goldenberg. Fauna sar.iepontana fossilis. Heft 2, pp. - Can.id. Naturalist (2) vii, 271.
18-20. 4°. Sa.arbrucken, 1877.
20 S. II. SCUDDER ON PALAEOZOIC COCICROACHES.
and unoqual rays spreading from a common base, much like the rods of a fan ; while in the other, found on both continents, the shorter and equal rays originate at regular inter- A-als. as branches from the side of a main vein. No such important distinction exists in the coi'kroaohes of the old world coal-measures, even in the most aberrant types ; but within each of these two tribes, other distinctions appear, in the relative extent or position of the dillorent areas, in the mode of branching of the main veins, or in the point of origin of the branches, aflbrding valual)le data for genei'ic distinctions, and a tolerably safe clue, it is believed, to the true relationship of the species.
The cla.ssification proposed in this paper, based upon the structnre of the framework of the wing, and generally neglecting its mere form or surface sculpture, may be expressed briefly by the scheme on the opposite page, which will be more fully developed in the body of the memoir.
A word may be said concerning the nomenclature emjDloyed in this scheme. It will be noticed that the generic term Blattina, first employed for palaeozoic cockroaches by Germar and since imiversally adopted in the same sense, has been dropped. It is not a little curious that the first four species described by Germar (and, I may add, the first American palaeozoic cockroach, described by Lesquereux) all belong to a single genus as here defined, namely Etoblattina, a genus at the same time the richest in species ; so that there ' can be no doubt whatever as to which of these genera should bear the old name, if any of them can do so. It were indeed to be wished that it might be retained by Etoblattina, and to preserve the old name as far as possible I have retained it as a part of all the compound terms I have employed to designate the genera represented in the Evu'opean carboniferous fauna, as well as in the tribal name which embraces them. But before Germar made this use of the term Blattina, earlier indeed by about thirty j^ears,^ he applied it to a cockroach from amber, which must be employed as the typical species, and which is utterly distinct from any of the palaeozoic forms. We are therefore imwilliugly compelled to reject the name for palaeozoic cockroaches, and, unless indeed it be a synonym of some earlier name, to employ it for the tertiary Blattarian only.^
The use of the term Palaeoblattariae for all the palaeozoic cockroaches to distinguish them from more modern types requires also an explanation. In commencing this investigation it wa.s anticipated that the mode of distribution of the principal veins of the wing and the relative area occupied by each would furnish some ground for discussing the affinities and natural classification of these animals and of separating them into genei-a and species. But the degree of divergence from living types which the palaeozoic forms exhibit, and their own division into two large groups was entirely unexpected. To appreciate the former distinctions, it will be best first to examine the wings of living Blattariae.
The structure of the organs of flight in cockroaches has received an unusual share of attention, principally from Messrs. Brunner and de Saussure, who have devoted a great
'Germar. Mag. d. Entom. Jahrg. i, 16 (1813). it ho placed Elobl. primacva, IlemmloU. labachensU and
' In his first use of the term Blattina, Geruiar employed it Pelnthl. (jraciUs. Goldenberg {loc. cit.) further credits
without any explanation whatever. In his work on Wettin Berendt with the first use of the term, but I cannot discover
fossils (p. 81), he says: " Blattinac nomine utimur, quo that Berendt used it either in 1830 or in 183G, the two oc-
omnes species complcctimur, quae antehae ad Blattae genus casioiis when he referred specially to fossil cockroaches;
sunt relatae." Goldenherg (Palaeontogr. iv, 5) was the first while Germar certainly emjiloyed it in 1813. Nor did Ber-
to define the genus, as follows: " Vcnis omnibus areae endt use it in 1845 in the essay prefixed to his Organischc
analis hemelytri in marginem internum excurrentibus." In Reste im Bernstein.
S. 11. SCUDDKR ON TALAKOZOIC COCKROACHES.
I'Al.AKOlILATTAIil.VK.
Trilic I. Afi/liu-ril'ie. Bninchus of the mudiaittin.il vein iirrangwl fii a radiaUj ninnncr, montly tprinfriiif; from .-i I'oiniiiuii point at the biiso of tlio wiii;^; nieiliaslin.il aiva siilitriaii;^iil:ir, uniforiiily Uipcriii'; apically. (3 ■jciiiTa. Aiiirricaii.)
!Wiii|;8 lirn:iil. Mt;ili:Lstinal anil scapnlar areas to^i'tluToccnpyin;; less tlian half tin; win;?. Ex- ternonieilian area toleral.ly lap^'.., ..Npainlin^' iv„'.ilarly bi-yoml tin- flr-l hianeli. Mylacris. (r, .p.,!. .). Wings slender. Mediastinal and scapular areas lo^'etlier or(ii|ivin^' inure tlian lialf tlie wiiif;. Externomcdian area small and compressed, scarcely expandiii'^ apicallv. liithomylacris. (3 sperieo.) Some of the apical branches of the mediastinal vein arising; beyond tin; base of the wine; ami scarei'ly partnltinj; in the radiate arrangement of the others. Necymylacris. (2 f|>e<i(«.)
Tribe II. nialtinnriae. Branches of the mediastinal vein arising at re;;nlar intervals from a prini'i|>al Klein; medinnlinal area generally band-shaped. (8 genera. Botli worlds.)
Internomcdian vein termin- ating beyond, rarely at, the middle of the onter half of the wing. Scapu- lar and extcrnomedian areas tugether. covering le.«s than one half of the wing.
/Mediastinal area comp.ir- atively short, rarely ex- ceeding, seldom e(pialling two-thirds the length of the wing.
Me<liastinal area long, usu- ally at lea.st three-fourths the length of the wing, sometimes nearly reach- ing the tip.
Scapular area not reaching the tip of the wing, the extrem- ity of the main vein curving upward, Externonieilian area eomparalivcly Large.
Etoblattina. (20 species. Both worlds.)
Scapular area extending beyond and embracing the tip of the wing, by the backward sweep of the main vein. Kx- ternoniedian area comparatively small. •
Archimylacris. (2 species. American.)
Kxternomcdian branches inferior, so that the nervnles divaricate on either side of the seapiiKar-externo- median inlersp.ace. Anthraco- blattina. (7 species. European.)
Br.inchcs of scapular vein superior.
Extcrnomedian branches superior, so that the nervnles divaricate on either side of the externomedian- internomedian interspace.
Gerablat- tina. (12 si>ecies. Both worlds.) Branches of scapular vein inferior.
Hermatoblattina. (2 sjiccics. European.)
Internomedian vein termin- ating before the middle of the outer half of the wing. Scapular and externo- median areas together covering more than half the wing.
Externomedian vein di- rected toward and ter- minating near the apex
of the wing
inferior.
its branches
Principal veins closely crowded in the b.x=al half of the
wing. Branches uniformly distributed all over the wing.
Scapular area terminating .above the apex of the wing.
Progonoblattina. (2 species. European.)
Principal veins widely separated in the basal half of the wing. Branches much more closely crowded in some p.arts of the wing than in others. Scapular area termin- ating below the .ipcx fif the wing.
Oryctoblattina. (l species. European.)
Externomedian vein directed toward and terminating near the middle of the inner border y Of the wing, its branches superior. Petrablattina. (2 species. Both worlds.)
23 S. II. SCUDDKll ON PALAEOZOIC COCKROACHES.
tloal of study to this ftimily,' and having used the teginina, and wings for systt'inatic purpo.^os. have examined an innnense series of specimens. These authors distinguish in the tegmina four, in the wings five, principal veins, the distribution of which is prettv constant in their general features, variable in the details; and this permits excellent characters to lie drawn for the separation of the genera, etc. The four veins of the tegmina are the mediastinal, the scapidar, the internomedian and the anal.^ The nuMHastinal vein runs from the root of the wing in a nearly straight course to about the middle of the costal border, throwing off branches to that border. The scapular vein extends to the tip of the wing in a nearly straight course and throws off toward the costal border a number of branches, which maybe simple or forked and disposed with greater or less regularity ; in some instances, especially toward the tip of the wing, it also tlu'ows out branches on the opposite side. The anal furrow is an impressed curved line, characteristic of cocki-oachcs, running to the inner margin before the middle of the wing ; within the area thus marked off at the base of the wing are a number of simple or forked anal nervules, often curved, but alwaj'S straighter than the anal furrow ; these, although they impinge upon the latter, are to be considered branches of the anal vein, for they correspond to the radiate nervules of the longitudinally plicate portion of the hind wings. Between the scapular and anal veins runs the internomedian vein, an irregular nervui'e, the l^ranches of which may be inferior or superior, longitudinal or oblique, simple or forked, and it is here there- fore .that the greatest variation in the manner of distribution occurs, although the relative extent of all the fields may greatly vary.
The hind wings have two features which are different from what we find in the tegmina ; the first is the great expansion of the anal area, the innermost nervule of which is not developed as a furrow ; the second is the presence of a new and distinct vein, the externo- median, lying between the scapular and the internomedian. There is no doubt that in the tegmina this vein should be regarded as amalgamated with the scapular vein, and the branches occa.sionally found near the apex of the tegmina, parting from the so-called .scapular vein and terminating on the inner or apical margin (e. g., Chorisoneura), as tlie branches of the externomedian vein; the more so since in some genera (Ectobia, etc.) the internomedian vein is also amalgamated with the scapular, so that the so-called scapular vein appears to throw branches indifferently to one side or the other of the wing.
This curtailment or disappearance of the externomedian vein is due according to Sau.s.sure to the contraction of the tegmina. In comparing the tegmina with the wings, he remarks :' " La portion de I'organe [i. e. the tegmina] situ^e en arriere de la nervure humerale [.scapular vein] s'est tellement contractee que le champ anal a penotre dans le champ di.sco'i'dal [internomedian area] et se trouve un peu enveloppe par celui-ci. En y penetrant, il I'a etrangle a la base, en refoulant la veine discoidale [internomedian vein] cfjntre la nervure humerale [scapular vein], en sorte que ces deux nervures se confondent a la base ; et il s'est rctreci lui-meme. Dans cette contraction, I'aire yitree [externomedian area] a dlsparu." We should be careful however not to give Saussure's words a meaning they were not intended to convey ; the broadly expanded plicated area of the hind wings
' Brunner. Nouveau Systeme dcs Blattaircs. 8°. Vienne, 28. — /&., Miss. Suient. au Mcxiqiic, Ins. Ortli. 1°. Paris,
1 865, pp. 4-12. — Sau.4sure. Etmlcs sur I'aile des Orthopttres ] 870, pp. 4-8.
•< Ann. .Sc. Nat. [5] Zrxil., x, pp. 161, sef.; — lb., Orlhop- '' This is Hcer's terminology, not Brunncr'snor Saussure's.
teres de I'AiD^riqae moyennc. 4^. Geneve, 18C4. pp. 16- ' Ann. Sc. Nat. [5] Zool., x, p. 196.
s. II. scri)i)i:i; «>\ r.\i.Ai:<>/<tic ( ixkijoaciiks. 29
is with little ili)ubt ;i comparatively lato (k-velopiiient, and we may not look upon the tegmina as a contraeted I'oiin of the wings; hiit rather, at the disappearance ol'the externo- median vein in the tegmina as one stage in the increasing heterogeneity of the organs ol" llight, as we pass from ancient times to the present; imleed the hind wings of insects in general contain far more inilieations of the earlier strnctnre and ornamentation of the wings than tlie Iront pair.' As one example of this we find that the exteriiomcdian vein was perfectly developed in the front wings of all the palaeozoic cockroaches, and althongh probably some of the UiHerent nervures were sometimes blended at the base {c.y^., EtohlaU . nissoma. Pctrahl. fjrarilis), apically each vein was always develojied fpiite separate from the others.
This is a distinction of ]>rime importance, and .so far as we can di.scover, there is not a single cxcej)tion in ancient or modern types. In all the i)alae()/oic species, the externo- mcdian exists as an independent vein ; in all modern species the vein itself is blended with the scapnlar, and can only be occasionally recognized near the extremity by its branches.
Besides this difference there is another which, although of le.ss importance, is perhaps as constant and certainly is significant. In palat^jzoic cockroaches the anal veins of the fore wing, as first noted by Goldeiiberg, impinge upon the border, just as they do in the few liiml wings which are preserved. In living cockroaches, the branchns of the anal vein in thi" hind wing, preserving here again the ancient characteristics, impinge upon the margin of the wing; while the specialization of the anal area of the fore wing — a distinctively r>lattarian feature — has gone .so far as to affect the direction of the veins, which do not impinge upon the border, but run parallel to it and strike the anal furrow.
For these rea.sons, as being of •finidaniental importance in the structure of the tegmina, and indicative of the profound changes the entire group of cockroaches has undergone since its origination, it appears necessary to sepai-ate the palaeozoic cockroaches from those existing at the present day as a distinct subfamily type.
In reviewing the existing species, in order to obtain .some clue among them to the nearest allies of the palaeozoic cockroaches, it W'Oiild appear that very little resend)lance exists between the fore wings of the ancient species and those of the Blalldrine splnoHac, as compared with those of the Blattariae muticae. Further than this it wouhl perhaps hardly be po.ssible to go, unless indeed we were to compare some of the Blaberidae of the present day, comprising the giants of the time, with some of the ancient types, which, while generally larger than recent forms, also often boast of their very great size. Unfor- tunately we know almost nothing of the strticture of the legs in the ancient cockroaches; they have been preserved, so far as appears, in only one or two instances. In one, Blat- t'lna 7'lschhehii, Goldenberg .speaks of a fragment of a hind leg, consisting of the femur and tibia with traces of spines {Spuren von Dornen); but as neither his illustration nor his description show whether the spines occur on the femora or on the tibiae, we have no proof as to whether the former should be considered spinosae or muticae. In the illustration of the other [Anthracohl. soj^ita) no spines appear; and the dcscriber of this species. Dr. E. Geiuitz, gives no further account of the legs than their size; perhaps their preservation allows of no further statement. Ijut this point shoidd be studied.
' This point, which I hope to exp.ind ami illustrate on reflect liow commonly the liiml wings of insects arc con- aiiother occasion, is \%'hat might well be expected when we cealcil by the front pair, when the insect is at rest.
30 S. II. SCUDDEU t)N PALAEOZOIC COCKROACHES.
Li-t us now oxjuuiuo tlu' lU'iiration of the wings of cockroaches with special reference to its (k'vel()|)nient. in order to determine wiiich of the two tribes into which we have divided the Pahieolilattariae is to be considered the more primitive type. At the outset we may remark that were we to btvse our ideas of the relative rank of the existing suborders of insect.s upon the degree of complication of the neuration of their wings alone we should luidoubtedly fall into error. Yet, although in studying the most ancient insects this portion of their structure is nearly all we have to guide us, we may confidently assume that it is here sufficient to determine their relationship with accuracy. The variation in the structure of the wings of existing insects is the result of a multitude of forces exerted through aeons, and exhibits every imaginable form from extreme simplicity to excessive complexity : in some insects the wings, like the rest of the body, have retained an ancient simplicit}^ of structure, as in the May-flies; in others they appear to have lapsed into simplicity, or to have retained a simple distribution of the veins, when the other parts of the bod}- have become liighh' organized, such as the Lepidoptei\i generally; in still others, by the diversity of use to which the wings have been put, they have become in diflerent ways extremely complicated, so that the plan t)f neuration is greatly disturbed or nearly lost; as in the hind wings .of earwigs, and of many cockroaches and beetles, and in both wings of dragon flies, — nearly all of which insects are otherwise lowly organized.
This differenti'ation of the neuration, we may jvidge by many proofs,^ had made slight progress in palaeozoic times. The wings of the then existing insects were comparatively simple and imiform. Nevertheless, the variation of structure was already sufficient in the carboniferous epoch to prove that we must look far back of it for the origin of winged insects. We have already shown that differences existed among cockroaches warranting their division into two great groups; and as a whole this family group was distinctly ••separated, even at that early time, from all other insects, even as they are to-day, unless we except their nearest allies the Mantidae, in the burial- of the innermost anal vein at the bottom of a deep sulcation, dividing the anal area from the rest of the wing. They were also peculiar — although a few ancient types partially shared with them this character- istic— in that the large nundjcr of mediastinal branches, as well as the main mediastinal vein, terminate on the costal margin only, and do not leave it simply supported by the main vein lying in close proximity. This peculiarity necessitated a somewhat central origin for the veins at the ba.se of the wing, and apparently led to the diversity noticed in the two types of ancient cockroaches.
If we were to express in simplest terms the structure of a symmetrically developed wing (like that of the palaeozoic cockroaches with its five principal branching veins), we should figure.the middle vein as running straight to the apex, forking as it went and occupying the apical margin with its branches; while the similarly forking branches of the upper two veins would curve toward and terminate upon the costal margin, and those of the lower veins upon the inner margin. A wing has already been found ^ quite as simple in idea as this, but belonging to the other group of palaeozoic insects, in which the wing is not symmetrical, but where all the veins and their branches impinge upon the inner and apical margin of the wing. In such a wing, differentiation of the veins may scarcely be said to
' .See the preceding paper: Tlie early types of insects. ' Sciulder. An insect winj; of extreme simplicity from the
coal fonMati(jn. < I'roe. IJost. Soc. Nat., Hist, xix, 248-49.
S. II. SCrODKK ON PALAEOZOIC (OfKUOACHES. 31
exist; the second repents the first, and the lourth tiie liftii, a irltk- further renuived iVoin the base, wliile the third vein, fillinj; the spare l)etween the secoml and lointh, dilRMs from them only hy its straightness and apieal termination; the j;eneral resemldaiu-e of ea<'h t<» the otiiers is very close. Yet one has .scarcely more to do tiian to deepen the inner anal vein, and perhaps remove the main veins a little nearer the costal horder, ;^ivinj; a very slight a.synnnetry to the wing, to impress npon such an ideal wing distinct hiattarian features; for in all tlie palaeozoic cockroaches, partially excepting Oryctohlattina. tlie (hstri- bution of the scapular branches more or less resembles that of the mediastinal, and that of the internomedian the anal, while the externomedian branches occn])y the miildle ground and the ajjcx of the wing, .seldom swerving to either siile.
It is, however, highly prol)al)le that such an ancient wing was broad at the base, for this was the case with nearly all the palaeozoic insects, and certaiidy, which is more to our pur- pose, with all the carboniferous cockroaches ; it is furtheruKjre a characteristic of the cock- roaches of the present da}', and therefore all the more probably of high anticjuity. In this case the mediastinal and anal areas must have been more broadly triangular in sii:i|M' than the neighboring areas, and their veins consequently arranged in a more radiate fashion, the difl'erent branches arising close together from a connuon ba.se ; while in the neighboring areas they would naturally arise at intervals from a main stem. This condition is precisely that of the Mylacridad and would natnrally precede that in which the mediastinal vein, to strengthen the part of the wing most liable to strain, follows the basal curve of the costal margin and throws its branches off at intervals toward the border, heightening at the same time the resemblance between the distribution of the branches in the scapular and medias- tinal areas ; a tendency to this appears in Necymylacris and it ii? fully developed in the Blattinariae. That the anal vein has not followed the same rule is doidjtless due, partly to the small need of special support for the lower base of the wing, and partly to the deep impression of the inner anal vein, which has forced, as it were, the other branches to ally themselves with it.
This view of the relative primitiveness of the two types of ancient cockroaches is strengthened by noticing the further differentiation of the tegmina in modern limes, where the only remaining relic of repetition of characters in adjoining areas is the resendilance of the disposition of the scapular and mediastinal branches ; and even this resemblance recalls tlie features of the Blattinariae, rather than of the Mylacridae. In all the Palaeoblatti- nariae, so far as we know them, (excepting perhaps in Oryctoblattina,) the internomedian veins have the same general tendency to repeat the downward and outward curve of the anal veins as we find in the corresponding veins of the costal region. But in recent cock- roaches, not only do the anal veins run parallel to the inner margin and impinge upon the anal furrow, but the internomedian veins may branch in any direction, so varied has the ]ilan of distribution grown ; in general however the internomedian vein may be said to liave assumed in modern types the rSle played by the externomedian vein in the Palaeo- blattariae ; and in not a few instances in the ancient types there is a marked tendency ot both the scapular and internomedian veins, especially toward the apex of the wing, to as- sume a mode of distribution more closely resembling that of the externomedian than of the mediastinal and anal branches respectively. Indeed the similiarity of the distriliution of the veins in the scapular and externomedian areas has induced me to j)lace Hermatoblattina
32" S. II. SCUDDER ON TALAEOZOIC COCKROACHES.
and Progonoblattinix near (,)ryotol)latlina high in the series. Petrablattina, has also been placed very high, on aeoonnt of the apparent amalgamation of all the i)rincipal veins next the ha.se. as they generally appear in modern types.
On zoological grounds, then, we should look upon the Mylacridae as the older type, but when we come to examine the geological record, we discover very little special corre- .spondence between the.se features of structure and the relative age of the insects in ques- tion. Our oldest American species are Gerahlattlna fascigera and PdrahkiWna sepidta, and probably Blatthia vemista, all of which are Blattinariae, not Mylacridae ; the other American members of the group of Blattinariae are found in all the rocks up to the permo- C4n-boniferous, while the Mylacridae are confined to the true coal-measures, imless Necym. hcros and Archim. parallclum fall below them. On the other hand, it is Avorthy of remark that of the nine species placed highest in the entire series below, before their stratigraphi- cal position was at all considered, and belonging to five distinct genera, Petrablattina ffracilis, Hermatohlatt'ma lehachensis and perhaps Gerahlattlna halteata belong to the permian or dj-assic formation, and comprise nearly one half of the species certainly known from that horizon. And it will be seen further on that much the largest percentage of the European cockroaches (Blattinariae only) come from the upper carboniferous beds; of the American (Mylacridae and Blattinariae) from below them. It must not be overlooked however that the great mass of palaeozoic cockroaches as a Avhole come from the highest carboniferous rocks, and that the stragglers that have been found below these uppermost beds are fiir too few for us to base any safe generalizations upon them.
As to the geological range of the species, it would appear as if it were always extremely limited, did we not reflect that very few of the species are known by more than one example. It has been claimed by Dr. E. Geinitz that five of the species first described from the carboniferous series, viz. : Etphl. anthracophila, Etobl. carbonaria and Etohl. didtjma of Wettin, Anthracobl. spectabilis of Lobejun,and Gerabl. 3fahri o{ Manehach, all from the uppermost carboniferous rocks, were also found in the lower dyas of Weissig. He supports his statement by figures or descriptions in three instances, and in each of these ca.ses I shall show that the reference was incorrect : Etobl. didyma being referred below to a distinct species, Anthracobl. sopita; Etobl. anthracojjhila to Etobl. flabellata; and Gerabl. Mahri to a second distinct species, Etobl. elonyata. This result throws some doubt upon the unsupported references in the "two other cases, and while these remain in doubt,' Eloblattina flabellata is the only species unquestionably found in both the carbon- iferous and dya.ssic series of the old world. The only other European species said to have been found at two distinct localities is Etobl. didyma, which Germar descinbed from Wettin and Mahr says has been repeatedly found at Ilmenau ; but these places are at the same horizon.
In the new world the only instance of the discovery of a second specimen of any species i.s in the presumed case of Gerablattina balteuta, where one was found in what are termed permo-carboniferous rocks, on account of some question as to their true horizon, and the other in undoubted uppermost carboniferous rocks. The so-called permo-carboniferous rocks, however, are deemed by some geologists as certainly upper carboniferous.
' Geinitz himself refers to Anihrac. specluliUU with a (jiiery.
S. II. SCUDDKIl ()\ TALAKOZOIC roCKKOAt'IIES.
33
Few of the genera appear to be conlineil to very narrow geological liinitw excepting tluwe which are poor in species. Mylacris (o sp.) however is only fouml in the lower or niiiKlle carl)oniferous series, as is also Necyinylacris (2 sp.) and Archyniylacris (2 sp.). (leral)lat- tina (12 .sp.), Progonohlattina (2 sp.) ami Oryctohlattina (1 sp.) are the only European genera not occurring in the dyas and the first of these occurs in the pernio-carboniferous of Auierioa; but Anthracoblattina (7 sp.), though occurring throughout the range of cock- roaches in the European palaeozoic rocks, luus its largest development (G-0 sp.) either in the dyas or in the very highest of the upper carboniferous beds.
The following table represents the cockroach founa of the diflferent localities in the palaeozoic beds of Europe, the two doubtful species of \Vei.ssig being placed in brackets.
DYAS.
Weissig, S.ixony.
Etoblattin.t fl.ibellata. [Anthracoblattina spcctabilis.]
" -wcissigensis. " Ropita.
[ " carbonaria.] " liinTccla.
Lehachy near Sa.irbrilcken, Rlicnish provinces of Prusssia. Ilennatoblattina lebachensis.
Petrablattina qraciii-s.
Stockhcim, Bavaria.
Antliiacoblattina Riickoiti
CARBONIFEROUS. Saarhrilcken (immediate vicinity), Rhcnisli provinces of Prussia.
Etoblattina primaova. Antliracoblattina wiiileriana.
" labachcnsis. Gerablattina intermedia.
" insignis. " scaberata.
Hermatoblattina wemmetsweileriensis.
Saarhrilcken (basin).
Anthracoblattina Remigii (Cusel, Rhenish Bavaria) .
Ger.abhattina weissiana (Brflcken, Waldinohr, Rhenish Bavaria).
Manebach, near Ilmenau, Saxc Weimar. Etoblattina didyma.
" manebachensis.
Ger.ablattina Goldeubergi.
Gerablattina clathrata.
« Maln-i.
Proffonoblattina Fritscliii.
Wettin-LdhcjUn^ Prussian Saxony. Etoblattina euglyptica. " affinis.
" flabellata.
" anthraeophila.
" Dohrnii.
" annglyptica.
" carbonaria.
" didyma.
MEMOIRS BOST. SOC. NAT. HIST. VOL. III.
Etoblattina nissoma.
" leptophlebica.
" parvula.
Anthracoblattina spectabilis. Gerablattina Geinitzi.
" Jliinsteri.
" jiroducta.
" German.
Oryctobl.ittina reticulata.
34
S. II. SCUDDEH ON PALAEOZOIC COCIvROACHES.
Kleiii-Opitz^ noar Dresilen, Saxony. Erliiifiwn., S\vitzorl:inil. Durham, England.
Anthr:U'ol>l:ittina drcsdensis. Progoiioblatlina helvetica. Etoblaltiiia inaiitiilioules.
TIio following lalilo. mainly based on the '' Chronologische Uebersicht des Stemkohlen- AlilaLrorungon in Europa". given by Dr. H. B. Geinitz in Geinitz, Fleck ii. Hartig: Die Steinkohlen Deut.schland.x. 4", Miinchen, 18G5, may serve to indicate the i:)robable relative age of the Eui-opean sjiecies. The carboniferons beds are divided by him into five zones, as follows, commencing at the base : I. Ilanptzoue der Lycopodiaceen ; II. der Sigillarien ; III. der Calamiten ; IV. der Annularien ; V. der Farren. The two dyassic species enclosed in brackets are those credited by Dr. E. Geinitz to this formation. Perhaps all the carbon- iferous species should be classed together as upper carboniferous, excepting the thi-ee placed under zone ii-iii; and these to the middle carboniferous.
Etoblattina flabcUata. (Weissig.) " \veissigensis.( " )
[ " cai'bonaria.] ( " )
" elongata. ( " )
LOWER DTAS.
Antlii'acoblattina sopita. (Weissig.) " jioiTecta. ( " )
" Rilckei-ti. (Stockheim.)
Hermatoblattina lebacheusis. (Lebach.)
[Anthracoblattina spectabilis.] (Weissig.)
Petrablattina rrracilis.
(
)
CARBONIFEROUS ZOXE V.
Etoblattina didyma. (Manebach.)
" manebachensis. ( " )
Anthracoblattina dresdcn.sis.(Ivlein-Oipitz.) " Rcmigii. (Cusel.)
Gerablattina Goldenbergi. (Manebach.)
" clathrata. ( " )
Mahri. ( " )
" weissiana. (Briicken.)
Progonoblattina Fritschii. (Manebach.)
EtobI:
ittina primaeva. labachensi.s. englyjitica. afliiiis. flabellata.
CARBONIFEROUS (Auerswald.) (Labach.) (Wettin.) (LobejHti.) (Wettin.)
anthracopliila. (
)
Dohmii.
anaglyjitica.
cailjonaria.
diilynia.
russoma.
( " ) ( " ) ( " ) (Wettin.) (LObejiJn.)
ZONE IV-V.
Etoblattina lejitoplilebica. (Lobejiin.) " parvula. ( " )
Anthracoblattina spcctaljilis. ( " ) Gerablattina intermedia. (Werametsweiler.) " Geinitzi. (Lobojaii.)
" Munsteri. (Wettin.)
" producta. ( " )
" . . Germari. ( " )
Hermatoblattina wcrametsweileriensis.
(Wemmetsweiler.) Oryctoblattina reticulata. (Wettin.)
CARBONIFEROUS ZONE II-V. Etoblattina mantidioides. (Durham.) Progonoblattina helvetica. (Erbignon.)
•f^: r CARBONIFEROUS ZONE II-III.
=< ' Etfjbl.-ittina insignis. (SaarbrUcken.) Anthracoblattina wiiitcriana. (Dudweiler.)
"^ '. Geniblattiua scaberata. (Altenwald.)
S. H. SCUDDElf OX r.\I.AEOZOIC CO('Ki;(>A( IIKS 35
Tlio American sjR'cies come from llio roll()\vin<; localities, the Mylacriilac liein;.' placecl in tlie left hand, the IJlattinariac in fin- li'/lit IkhhI roluinn.
ACADIAN ( OAI.-riKMi. Sifdneij, ("a])0 Hrctoii.
Myhicris brettiiicnso. I'<-tr;il)l:iltiii,i sc|iiilt:i.
Heuri.
J'irtou, Nova Scolia.
ArcliynivliuTis acMiHcmii.
ArrAi.AciiiAX roAi.-KiEi.n. Cannelton, Beaver Co., Penii.
Mylacris jiennsylvaniouin. Archyinylafris |iarallcliiiii.
Mansticl.li. Ni-eyinylacris heros.
J'iHslon, Luzerne Co., Penn.*
Lithomylacris angustuiii. Etnlilattina Les<|uereii\ii.
" pittstoniammi. Gerablattina fascigcra.
Neeymylacris lacoaiuiin.
Cassville, W. Virginia.
Geiablattina balteata.
BeUaire, Ohio.
Gorablattina balteata.
EASTERN INTERIOR COAL-FIELD. Danville, III.
Lithomylacris simplex.
Colchester, 111.
Jlylacris antliracophiluni.
WESTERN INTERIOR COAL-FIELD. Froff Bayou, Arkansas.
Etoblattina venusta.
The correlation of the beds in the Eastern border and Interior basins of N. America is not yet satisfiictorily accomplished. The period of the deposition of the millstone grit in the interior basin may even possibly be synchronous, I am infomied by Professor N. S.
1 Concerning the localities in the vicinity of Pittston, Mr. impregnated with carbon. The specimens came from Port
R. D. Lacoe, to whom I am indebted for all the specimens Griffith at the outcrop of the shales at one of the prin-
described from there, writes me that the shale containing cipal anticlinals th.it cross the otherwise quite level coal
Etoblattina Lesquereuxii was picked up in the vicinity of field, and once apparently formed long narrow islands in the
Pittston, in a pile of culm or impurities from a mine; the carboniferous lake, against the southeastern side of which
exact locality w.ts unknown to him, but from the character many small objects drifted and lefl their impress. Gera-
of tlie slate he had no doubt of its being from the roof shales blattina fascigera was found by Mr. Lacoe in the anticlinal
of the D seam, of anthracite coal. Lithomylacris angustum next north of the one first mentioned and also on the south-
and L. pitlslonianuin arc from the roof shales of the E seam eastern side. Necymylacis lacoanum comes from the lowest
of coal, which when unaffected by weathering much re- productive coal measures near Pittston. semble the shales of the D seam, but is very rarely so hio-hlv
30
S. II. SCUDDER ON PALAEOZOIC COCKROACHES.
Shaler. with some of the hiter coal deposits of the eastern border region; but assuming the millstone grit of the cast and west to be of the same age, we may express tolerably well the geuertil stratigraphical relations of the species by the following table :
|
1 5 •< s |
AppiiUclilan coal- |
Bom of Millstone gril. |
Top of Millstone grit. |
Lower or Middle Coal Measures. |
Upper Coal Measures. |
Penno-carbon ifcrous . |
|
Nccymylrtcris heros. |
Mylftcris penusylvani- cuni. Mylacris Mansfleldil. Necymylacris lacoa- iiuni. |
Lithomylacris pittstou- Lithomyliicris angus- tum. |
||||
|
Acadian co«U- flcld. |
Mylacris Heeri. Mylacris bretonense. |
|||||
|
Eastern interior coal-fiold. |
Mylacris anthracophi- lum. Lithomylacris simplex. |
|||||
|
i s t \ |
AppatflchiaD coal- laeld. |
Archimylacris paral- lelum. Gerablattina fascigera. |
Etoblattina Lesquer- euxii. Gerablattina baltea- ta. |
Gerablattina baltear ta. |
||
|
Acadian coal- field. |
Petniblattina sepulta. |
Archimylacris acad- |
||||
|
Western interior coal-field. |
Etoblattina vennsta. |
If we assnme the separation between the upper and middle carboniferous to be correct, we shall have the following percentage of the species from the different formations in either country :
In Europe : Above the upper carboniferous 26 per cent. ; in it 74 per cent. ; below it 7 per cent.
In America: Above the upper carboniferous 6 per cent.; in it 24 per cent.; below it 76 per cent.
Certain species appearing in the lists twice over make the totals of percentage in each case above 100. It would appear from this summary that the American cockroaches are the older, and a certain light is thus thrown upon the occurrence of Mylacridae in the New World only.
I have already given some reasons for believing, not only that cockroaches formed the majority of insects in palaeozoic times, but that the actual number of species was very great. That they were also abundant in individuals is probable, judging from the present fecundity of their descendants and from a few other facts. Goldenberg, for instance, re- marks (Faun. Saraep. foss. l, 17) that where one finds any remains of cockroaches in £he palaeozoic rocks, one nearly always discovers more than a single fragment ; at least this was the case with Etohlattina primaeva, E. labachensis and Blattina Tischheini ; and he judges from this, that, as at the present time, these creatures collected in numbers in a single spot ; but it seems rather to indicate merely the great numbers of individuals which then existed. Goldenberg elsewhere remarks (Faun. Saraep. foss. ii, 21) that cockroaches formed nearly one-half the insects of the coal period, reaching then their greatest develop- ment. He finds reasons for this, first, in the warmth and obscurity of the forest vegetation of that time, which only suited such animals as these ; and second, in the intimate corre-
S. H. SCUDDKR oX PAI.AKOZOIC COCKROACIIKS. 37
latioii l)i't\V('(Mi the insect ^V()^I(] iuid llie plant worlil. Iiv wliii'li the rninicr linils its piiii- cipal noiirisl'iiu'iit in the hitter. Such a looil-piaiit lor tlie |)alae(i/<»ic corkiDach he woulil discover in tiie tree-like Ntjegijeralhia, or tiie Coniaites of the perioil ; just as llieally of the Ibnner, the sago ])ahn, furnishes food to the corkroaclies of to-day. I leer alscj relates, in his es.say on fo.ssil cockroaches, that the hotunica! )xarden at Zurich accidentally imported from Culm cockroaches in all stajres of development in stems of Cycads, and thereupon suji;jrests that Noeggerathia might very prohahly have heen the food of palaeozoic cock- roaches. 1 have also described a species of Platyzosteria (J'. HdhttUunns) which lives in the tops of the cabbage palmetto, S<ih(il pdhaclto. We thus arrive at some indications of tli«' manner of life of these ancient creatures.
Ileer believes the .scantiness of our knowledge of fossil cockroaches to be due to the slight attention that has been paid to them, and that in the miuss of plant.s which have been e.xhumed from the coal beds, many more will be found when the.se Lave been carefully ex- amined with this in view. At the time he wrote not a single species of cockroach had been founil in more than one spot (and at Wettin and Manebach they formed almost or ipiite the only insects found there) while many species of plants were connuon to the diilerent beds from which cockroaches had been exhumed. Notwithstanding the considerable in- crease of our knowledge since that time, this is almost as true now as then.
In this paper we have discus.sed almost exclusively the front wings of the palaeozoic cockroaches. In an appendix, however, those species which have been described Irom other fragments are reviewed and the descriptions put into an English dress. These species are Bhdttna Ti.schbeini, Bl. laiinervis and Bl. venosa, described from hind wings or very im- perfect remnants of fore wings ; and Poli/zosterUes grnnosus, a wingless species. Acridites carbonaria, first described by Germar as the wing of a saltatorial orthopteron and sub.se- quently considered by him as the hind wing of a cockroach, possibly o[ JEiohl. dldyma, and so catalogued up to the present time, appears rather to be a neuropterous wing and there- fore is not discussed here. Besides these a couple of obscure fragments from the American I'ocks are In'iefly noticed but without name. It onl}- remains to give an alphabetical list of the former and present names of palaeozoic cockroaches, and the bibliography of the sub- ject, before taking up the species iu detail.
SV.NOXYMICAL TaBLE OK HITHERTO DESCRIBED PALAEOZOIC CoCKI!OACIIE.S.
Arcliimyliicris acadicum Scudd. =: Arcliimylacris acadicum. Blattina euglyptica Gold. fi<;. 9. = Gcrablattlna prodiicta.
Blattidiiim mantidioides (jold. == Etoblattina mantidioidcs. Blattina euglyptica var. wvisi-iana Gold. = Gerablattiiia Blattina alfinis Gold. = Etoblattina allinis. weissiana. .
Blattina anaglyptica Germ. =r Etoblattina anaglyptica. Blattina fascigera Scudd. :^ Gcr.tblattina fascifrcra.
Blattina anaglyptica var. labacliensis Gold. ;= Etoblattina Blattina tiabcllata Germ. (Miin.st). := Etoblattina llabellnta.
labacbensis. Blattina flabellata Germ. (Wettin). =: Gerablattina Miin- Blattina antln-acophila Germ. = Etoblattina antbracophila. steri.
Blattina anthraeophila Gcin. = Etoblattina flabellata. Blattina Fritschii Hccr. = Progonoblattina Fritscbii.
Blattina bretonensis Scudd. =: Jlylacris bretonensc. Blattina Geinitzi Gold. = Gerablattina Geinitzi.
Blattina carbonaria Germ. = Etobl.-tttina carbonaria. Blattina Germari (Gielx;!) Ilecr. = Gerablattina German.
Blattina clatbrata Hcer. = Gerablattina clatbrata. Blattina Goldenbcrgi Mahr. = Gerablattina Goldenbergi.
Blattina didyma Germ. = Etoblattina didynia. Blattina graeili-s Gold. = Petr.iblattina gracilis.
Blattina didyma Gein. = Antbracoblattina sopita. Blattina Ileeri Scudd. = Mylacris Heeri.
Blattina dresdensis Gein.-Deiebm. =: Antliracoblattina dres- Blattina lielvetica Heer. = Progonoblattina helvetica.
densis. Blattina insignis Gold. = Etoblattina insignis.
Blattina euglyptica Germ. = Etoblattina euglyptica. Blattina intermedia Gold. = Gerablattina intermedia.
IMattina euglyptica Gold. fig. 8. =: Etoblattina Dobrnii. Blattina laliachensis Gold. = Etoblattina labacbensis.
38 S. II. SCUDDER ON PALAKOZOIC COCKROACHES.
Blattiii.i latinorvis llcor. = UliUtina latinorvis (liiiul win;,'). IMalliiKX po]niUa Scmlil. := ritrablatliiia scpiiUa.
Blatlinn U'liaclu'iisi-i Gold. = llorinatolilaltina lehaclionsis. Blattina spuctabilis Gold. 3= AnUiracoblattiiia spectabills.
Blnttinn loplophU-bioa Gold. =: Etoblattiiia loptoplik'bica. Hlattina Tist'hbciiii Gold. = Blattina Tisdibeini (fi-aginent).
Bl.tdina Maliri Gold. = Gi'ralilaltina Mahri. Hlattina vonosa Gold. = Blattina veiiosa (fragraent).
Blattina Maliri Gi-in. = Ktoblatlina clonj;ata. Blattina vonnsta Lc^q. = Etoblattina venusta.
Blattina manidiaolionfis Ciold. ::= Etoblattina maneb.aclicnsis. Blattina weissiana Gold. = Gerablattina wcissiana.
Blattina parvnla Gold. := Etoblattina parvnia. Blattina weissigonsis Gein. = Etoblattina weissigensis.
Blattina ]>orrocl,i Goin. = Antliracoblattina porrecta. Blattina wennuetswcileriensis Gold. = Herniatoblattina weni-
Blattina priniaeva Gold. = Etoblattina priniiu'va. mctsvveileEiensis.
Blattina Kemigii Dohrn. := .Vntliracoblattina Rcmigii. Blattina winteriana Gold. =: Antliracoblattina wiiiteriana.
Blattina rt'ticulata Gorm. = Orvotoblattina reticulata. RIylacris aiitliracopliiluni ■ Sciidd. =t Rlylat-ris aiitbrac-o-
Blatlina Kiickerti Gold. = Anthraooblattina Riickcrti. iiliilnm.
Blattina riissoma Gold. = Etoblattina russoma. rulyzostoiitos graiiosus (Gold.) .lord. = Poljzostcrites gra-
Blattina scaburata Gold. = Gerablattina .'caberata. nosus (bod)).
BIBLIOGUAPnY.
The papers are arrangerl clirouologicall}^ under etich author, and the order of the authors Is by a chronological arrangement of their first papers. Papers on the European insects precede those on the American species.
EUROPEAN.
RosT (W.) De filicuin ectypis obviis in lithanthracuni Wcltiucnsium LoLejuneiisium fosdinis. Halae.
8°. No date. pp. 31. (Not seen.) Germar (E. F.) Beschreibimg einiger neuen fossilen insecten. 11. In Scliiefertlion des Steinkolilen-Gebirges
von Wettin. <Munst., Beitr. zur Petrefactenk. Heft 5 : 90-94 taf. 13. . 4°. Bayreuth, 1842.
Die Vei-steinerungen des Steinkolilengebivge.s von Wettin und Lobejiiii ini Saalkreise ; also entitled ;
Petrifacta stratorum lithanthracuni Wettini et Lobcjuni in circulo Salae reperta f°. Halle, 1844-53. Ueberreste von Insekten ; also entitled : Insectorum vestigia. Heft 7 : 81-88, taf. 31, 1851 ; — Heft 8, tab. 39, fig. 15, 1853.
GoLDEXBERG (F.) Prodroni einer natiirgeschichte der fossilen Insecten der Kohlcnfonnation von Saar- l>rncken. < Sitzungsb. math. nat. CI. k. Akad. Wiss. Wicn, Bd. ix: 38-39. 8°. Wieii, 1852. The name is wrongly given in this paper as Goldberger.
Ueber vei-steinerte Insecteiu-cste im Steinki)lilc'ng(!biigc von Saarbriickiii. < Amtl. Ber. Vers.
Gesellsch. deutscli. Naturf., xxix: 123-2G. 4°. Wiesbaden, 1853.
Die fossilen Insecten des Kolilenformation von Saarbriicken. < Palaeontogr., Bd. iv : 17-40, tab. 3-6.
4°. Cassel, 1854. Also separately, pp. 24, tab 1-4. 4°. Cassel, 1854.
Beitrage ztn- vorweltlichen Fauna des Steinkohlengebirges zu Saarbriicken ; also entitled, within :
Uebersicht der Thierreste der Kolilenformation von Saarliriickcn. <Jabresb. k. Gymn. u. Vorsch. Saarbr. pp. 1-26. 4°. Saarbrticken, 1867. The same paper, with the addition of two plates, referred to in the text of this, but not published witli it, ajijicared umkr the title: Fauna Saraepontana fossilis Heft 1. 4°. Saarbrucken, 1873.
Zur Kenntniss der fossilen Insecten in der Stcinkohlcn-formation. < Neues Jahrb. f. Miner., Jahrg.
1809: 158-68, taf. 3. 8°. Stuttgart, 1869. An abstract (?) which I have not seen, appeared in the report of the 42<1 Versamml. deutscb. Naturforscher in Dresden in 1868.
Zwei neue Ostracoden und eine Blattina aus der Steinl^ohlenformation von Saarbriicken. < Neues
Jahrb. f Mineral., Jahrg. 1870: 286-89 (figs.) 8°. Stuttgart, 1870.
Fauna Saraepontana fossilis. Die fossilen Thiere aus der Steinkdhkiifornialioii von Saarbrucken.
les Heft, mit zwei Tafeln Abbildungen. 4°. Saarbrucken, 1873, p]). 26, jil 1-2. 2es Heft, mit zwei Tafeln Abbildungen. 4°. Saarbrticken, 1877, pp. 4, 54, pi. 1-2. GiEiiEL (C. G.) Die Insecten und Spinnen der Vorwelt mit steter Beriicksichtigung der lebenden Insecten und Spinnen numographisch daigestellt ; also entitled: Fauna der Vorwelt mit steter Beriicksicht- igung der IcVjenden Tliiere. II. Band : Gliederthiere. Erste Abtheilung: Insecten und Spinnen. 8°. Leipzig, 1856.
S. II. SCl'DDKi: ON I'M. AKD/.OIC ( (X KUo.VCHPIS. 30
Ui.r.n. (O). Ueber .lie r.>s>iUn K:ikirl:ikcii. < Vii'rlilj:iliiMlir. ii:il. Gt-scllsfh. ZOricli, J:ilir^'. ix : •^7a-302,
1>1. 8°. Zdricli, 1,S(J4. Die Urwoll (IcT Scliwciz. Mil sii-Ucn l:iii'lscliaflliclu-ii HIIiKtii, i-lf Tafflii, finer neoloj^isclien I'c-Ikt-
siclifskiirte iler Srliuciz iini] z.iIilriiclicMi in iliii Text einifedriKkun Abl)il<liingen. H°. ZOricli, IKO;"). Lc inomle ]iriniitive tie hi SuissO. Tnnluit <le l':illeiii:in<lu |t;ir Isaac Dcinole. 8^. (ieiu>ve el
Bale, 1872.
The i)riiiiitive worhl of Switzeilanil. Kililcil by James Ileywoocl. 2 v. 8". Ixtmlon, IXTG.
DoiiRX (A). Zur Keiintniss del' Insecteii ill «ler rriinitrrortiiatioiieii. < I*:ihieoiit«!.;r. Hil. .\vi: I2!(-34, laf.
8. 4°. Oa.ssel, 18(>7. KiKKBY (J. W.) On the rem:iins of inserts from the eoal ini asuies of Diiririin. < Geol. Ma;,'., vol. iv : :J88-
ao, pi. 17, fi^'s. 6-8. 8". LoiKbm, 1807. M.MIK ( — .) Beitrag zur Kenntuiss fossiler Iiiseeteii iler Steiiiko)ilonforniation TiiUringens. < Neiics Jalii-b.
f 3Iinerah, Jahrur. 1870: 282-80 (tigs.) 8°. Stuttgart, 1870. Geixitz (E.) Versteinerungcn aus ileni Brandsehiefer deruiiteren Dvas von Weissit,' bci I'ilhiit/. in Sachsen
<Neues Jalirb. f. Mineral., etc., Jahru'. 1873: G'Jl-704, taf. 3. 8^. Slutlgart, 1S73. Also separate, |i|..
14, pi.
Ueber neue AufscIilUsse iiu Brandsehiefer dcr uiitercn Dyas von Weissig bei I'illnitz in Saehseii.
<XeiiesJahrb. f. Mineral., Jahrg. 1875: 1-lJ pi. 1. 8^ Stuttgart, 1875. Also sep uate, pp. 14, pi.
Gkixitz (II. B.) Berieht fiber die . . . auf ileiii Reviere des Carlsehaehtes der Lugaii-Xiederwilrtseliiiitzer Steinkohknwerke gcsaninielten Steinkohlenplanzen. <Sitzungsb. naturxv. GeselKscli. Isi8,187'J: 7-13, t.if. 1. 8'. Dresden, 187!t.
AMEIilCAX.
Lesquerecx (L.) Botanieal and pahieontological report of the geological state survey of Arkansas. <; Owen (D. D.) Second report of a geological recoiiiioisance of the middle and soiithciTi counties of Arkansas, made during the years 1859 and 1860. 8°. Philadelphia, 18C0. p]^ 295-399, ],]. 1-6.
ScuDDER (8. H.) [Description of Archimylicris acadicum in] Dawson (J. W.) Acadi;in Geology. 2d ed. 8^ London, 18t>8, p. 388, fig. 153.
Descriptions of fossil insects found on Mazon Creek ami near Morris, Grundy Co., III. < Wortheii
(A. H.) Geological Survey of Illinois, vol. iii. Supplement to description of articulates, pp. 560-72, figs. 1-10. 8°. [Springfield,] 1868.
Two new fossil cockroaches from the carboniferous of Cajie Breton. < Canad. Xatur., n. s., vol. vii :
271-72, figs. 1-2. 8°. Montreal, 1874.
Xew and interesting insects from the carboniferous of Cape Breton. <Proc. Amer. Assoc. Adv. Sc.
vol. XXIV H, 110-11, figs. 1-2. 8°. Salem, 1876. < Cana.l. Natur., n. s., vol. viii: 88-90, figs. 1-2. 8°. Montreal, 1876. Also separate, [pp. 2]. 8°. Montreal, 1876.
Fossil palaeozoic insects, with a list of described American insects from the carboniferous forinatirm.
< Geol. -Mag., n. s., Dec. 2, vol. in : 519-20. 8°. London, 1876.
Xote on the wing of a cockroach fr'om the carboniferous formation of Pittston, Peiin. < Proc.
Bost. Soe. Nat. Hist., vol. XIX : 238-39. 8°. Boston, 1878. <Scudd., Entom. Notes vi: 35-36. 8°. Boston, 1878.
40 S. H. SCl'DnKU OX PAI.AKO/.OIC COCKKOACIIKS.
PALAEOBLATTARIAE.
Palaeozoic cock roaclu's ; in which the fore wings -arc diaphanous, generally reticulated and nearlv s\ ininetrical on either side of a longitudinal middle line ; the externomedian vein is conijiletely developed and divides in the outer half of the wing, its branches gener- allv occupving the a]>ical margin. The internomedian area is broad at its base (beyond the anal area), rajjidly tapers apically and is filled with oblique, mostly parallel veins, having nearlv the same direction as the anal veins, which, like them, strike the inner margin.
Their bodies apjiear to have been Hat, but slenderer than iisual in cockroaches of the present dav, the pronotal shield depressed, more or less elliptical, but sometimes longer than broad, the head partly concealed b}- it as in living types. They were of large size ; but wliile the average was considerably above that of existing cockroaches^ none were much larger than some S. American species of Blabera. Germar was the first to note the diaphaneity of the fore wings,- and Coldenberg the presence of the externomedian vein,^ and the cour.se of the anal branches.*
Mylacridae.
In this group the mediastinal vein of the tegmina with its branches consists of a number of veins, simj^le or forked close to their origin, spreading in a fan shape and appearing to arise from a single point or near a single point close to the base of the wing ; or in other words, the branches originate from the main vein close to its base and to each other, the outermost being much longer than the innermost, often double as long as it, and either straight or uniformly arcuate ; the area of the vein is thus triangular and more or less than half as long as the wing. The character of the vein therefore much more nearly resembles that of the anal vein than of the others. The group is confined, geographically, to America, and the wings are a little stouter on the average than those of the Blattinariae, the breadth being usually contained in the length less than two and one half times.
MylaCriS (,"V/.«z«;;r).
Mylarris Scudd., in Worth, Geol. Surv. 111. iii„ 568-69 (1868).
The mediastinal vein of the upper wing consists of about five principal stems, two or three of which fork before the middle, all of them straight -or ver}' gently curved, the outermost extending half way or even more to the tip of the wiiTg ; the point from which the principal stems originate is either in the middle of the wing or nearer its inner than its costal margin. The scapular vein is always arched strongly at the base before branching, which it commences to do as soon as allowed by the branches of the mediastinal vein ; it then runs subparallel to the costal margin always to the extreme tip of the wing ; during the larger part at least of its course it runs very nearly along the middle line of the wing.
' The average length of the front wing appears to have . . . woilinvh das Jlittelf'eld in einc ausseres uml u\n innc>n>
been alK.ut 20 mm. MittelfelJ getheilt wird. Goi.dk.nberg, Palacoiitogr. iv,
' Der tieulliche Aderverlauf, den wir . . . wahrnelinien, 20-2J.
zeijrt uns daher, da.ss diese vorweltlichen Arten perganient- * Bc-i den Blatten dcr Jetzwelt niiinden die Adirn dieses
ani'.'e Obcrflijgel besassen. Gekmah, Verst. Steink. Wet- Ilinterfiddes [anal field] tlieilweisc in die Begrenzimssader
lin, 82. [anal fiMTow] dissellien, wiihrend liei den Lias- iind Kolilen-
• Beijenen [lebenden Blatten] liisst sieli in diesem Felde blatten s-aninitlidie Adern dieses Feldes in den Nnhtrand
nar eine "ieh stark vcrastelnde Mittelider w;ihrnehmen, [inner margin] anslaufen. Goldenberg, Palaeontogr. iv, 20. wahr«nd die Kohlcnblatten hier zwei Mittcladern zeigen
S. H. SClDDKi; (»\ I'AI.AKo/.oK ( ( »( KIK )A(IIKS. 41
so that llu' ari'.-i ol' tliis win jrciicrally dcriiiiics liall' llic liirailtli nl' tlic \^illL^ ami tn;.r,.(||,.|- with the brimches ol" the iiieiliasliiial vein, half of the whole area of the winj;; it emits four or five branches, some of which fork, occasionally twice, ami all of which rini parallel or very nearly ])arallel to the outer brancii o(' the metliastinal vein; to j,'ain the apex and to keep this parallelism the terminal part of the scaimlar vein curves i^ently upward. The exteruomedian vein seldom forks before the middle of the wiiifr and rarely occupies much space, generally branching })ut three times at the most. althoii<rh one or m<»re of these branches may have secondary forks ; <!;enerally these branches are so straight that it is difficult to say whether they are superior or inferior to the main vein, but they appear to be in<hfierently one or the other. The intcrnomediau and anal veins divide between them very equally the inner margin nf the wing, the anal furrow being distinct, gencralh curviMJ considerably' and, from the great breadth of the wing, luiving its general course very oblique; the internomedian vein generally has but three or four branches, but several of these usually fork close to the base, the branches redividing. so that rarely less than nine or ten branches of this vein strike the margin, the first oflshoot of the penultimate branch often having several inferior veinlets; the vein begins to branch at nearly the same point as the scapular vein, and occupies a subtriaiigular area with its spreading branches. The branches of the anal vein are in general more longitudinal than these of the internome- dian vein, are nearly parallel, often forked and rather regular ami abumlant. I)ut in one species are irregular and connected by cross branches.
The wings are peculiar for their iniusual breadth at base and. .so far as known, their tapering apex, produced mostly by the co.stal curve; the greatest breadth lies before the middle of the wing, and their length is hardly more than double their width, in which particular they differ greatly from Lithomylacris. They have a form common in iccent Blattariae, such as Nyctibora, strongly tapering posteriorly, with convex anterior and posterior margins.
This genus dilVers principally from Lithomylacris Ijy tiie form ol' tlie wing and by the obli([uity of the anal furrow of the same; and from Necymylacris by the much greater breadth and longitudinal extent of the areas covered by tlie mediastinal and .scapular veins, accompanied by a corresponding diminution of the extent of the externomediau area. The species are all of a rather small or moderate size and are found only in the new world.
The only fragment apart from front wings which has been discovered is a pronotal shield, presumably belonging to one of these sjiecies. It is shaped much as in the mo<lern Periplaneta.
Mylacris bretonense. PI. •'). fig. 1.
Bhdtlna bretonensis Scudd., Can. Nat., vii, 271-72, fig. 1. Figured also in Dawson's Acadian Geolog}', Suppl. to 2d ed., p. 5-j, fig. 5.
The front wing has a pretty regularly tapering ovate outline, with a slightly produced but rounded tip ; the costal margin is apparently regularly and considerably convex, especially near the base, and at least the middle third of the inner margin is straight, while the apical third of the wing tapers about equally from both sides. The veins appear to originate from a point scarcely above the middle line of the wing, and together to be directed considerably upward at base, following the strongly arcuate basal curve of the
MEMOIRS BOST. SOC. NAT. HIST. VOL. III. 6
4^ S. II. SCUDDER ON PALAEOZOIC COCKROACHES.
costal luaririn nearly across the l);is;il lilth of tlie wing. The nu'diastinal area i.s execption- allv small lor this genus, even if \vi' consider, as is probable, a marginal half to be (lestroveil ; the veins in the fragment of it are somewhat obscnre, consisthig of only two or three parallel to each other, the lower or inner forking twice near the base and terminating a little before the middle of the wing. The scapular vein suddenly bends at the end of the ba.siil fifth of the wing and runs closely j^arallel to the costal margin for a distance equal to about half the length of the wing, and then curves somewhat rapidly to a longitudinal direction, running down the middle line of the wing and terminating at its tip; its first vein, which like most of the others is deeply and simply forked, continues the direction of the basal part of the stem ; the last is a shoot wdiicli parts from the main stem at about the middle of its longitudinal course; the intermediate ones, to the number of five, part at equal distances from one another in the ol)li(iue portion of the main stem, and are straight and parallel to the direction of the basal branch. The cxternomjedian vein parts abruptly from the .scapular vein shortly before the end of its basal course and runs subparallel to it, diverging gently from it in the apical half of the wing and emitting, at regular and distant intervals, three or four superior, gently arcuate, simple or forked longitudinal branches, commencing at a little belbre the middle of the wing, the finst branch ajjproaching the scapular vein and then continuing beside it; the area occupies only a narrow space at the extremity of the inner margin. The internomedian vein parts from the scapular just before the externbmedian and in a nearly similar way; it runs nearly parallel to the latter, but with a very straight course, to about the middle of the apical half of the wing; nor- mally it 'probably emits foiu- or five simple or forked branches not quite so closely crowded as those of the two preceding areas; but in the specimen examined several of them spring from an offshoot of the second branch which runs parallel to the main stem, the latter forking once at its tip ; there is also a strongly arcuate vein, close and parallel to the anal furrow, which seems to be a basal branch of this vein parting from it while still amal- gamated with the preceding veins. The anal furrow is deejjly impressed, strongly arcuate, roundly bent near the base, its apical half nearly straight, and strikes the inner margin a little before the end of the basal third of the wing; owing to the basal curve the anal area is nearly as broad as long, and is filled with six or seven neai'ly straight veins of varying obliquity, some of them branched and the branches uniting irregularly with the neighbormg branches in a very peculiar manner, somewhat, apparently, as in Bl. mantidi- oides.
The fore wing only is preserved and is of a rather small size, being only 1G.35 mm. long and 7.2 mm. broad, or the breadth to the length as 1 : 2.3 ; all the veins and their branches (excepting of course the anal furrow) are very delicate and the branches generally rather clo.sely crowded ; the surface appears to have been smooth as the interspaces are wholly unbroken by any cross nervules. The wing is nearly complete, but the margin is rather ragged and a considerable portion of the edge of the costal border appears to be gone.
From the comparatively small extent of the mediastinal area and the nearly parallel veins therein this species cannot be confounded with any other form of Mylacris.
The .specimen occurred on dark grey .shale, associated with ferns and leaves of Spheno- phijlhim Schlotheirnii, and was found with the following species in the productive coal- nieuisures (or middle coal-formation) of Sydney, Cape Breton, by Mr. Richard Brown, F. G. S., and communicated to me by Principal Dawson, to whose kindness I owe many similar favors.
S. H. SCUDDEH ()\ PALAEOZOIC (.()( KKOACHES. r.\
Mylacris Heeri. PI. 5, fl<;. ll.
lilattlna Heeri Scudil., Can. Nat., vii, 272, fij^. 2. Fij^'ured also in Dawson's Acadian Geology, Suppl. to 2d cd., p. .5"), fig. (p.
Fore wing. Tlie tip of the only specimen known is broken .m) tluit the e.xaet form cannot be stated, but the wing was probably a little more than twice as long as broad ; the cestui margin is regularly and moderately conve.v. perhaps a little flattened in the middle ; the base of the inner margin is nearly straight. The veins originate from a jmint a very little below the middle of the wing, and having scarcely the least upward cin-ve at ba.se are nearly straight. The mediastinal area is very large, regularly triangidar, with only a few distant straight very gently diverging veins; in the .specimen before me there are four veins, of which the lowest is forked almo.st at the base and the .second in the middle; almost the entire costal edge preserveil is covered by this area and it probably covered two thirds of the wing along this border, and occupied fully half the breadth of the wing at base. The scapular vein is very gently sinuous, being curve<l slightly downward close to the ba.se and upward toward the tip. the intervening portion being straight and pa.<sing exactly down the middle line of the wing; the branches, four in number, are straight, equidistant, parallel to the nearer mediastinal veins, only the basal one (which originates very near the base) being forked and that close to the tip ; the vein itself judging from its apical direction, terminates just before the tip, leaving at the margin a very narrow field fur this area. The externomedian vein is straight and forks prol)ably at the middle of the wing; how many times it forks is uncertain, two branches only being present in the fragment; the area must occupy the whole of the apex of the wing. ITie internomedian vein is also remarkably straight, having only the slightest curve at the extreme base and probably terminating just as far before the tip as the scapular vein ; it emits, in the fragment preserved, three rather closely approximated branches, the outer more longitudinal than the others and forked; from the course of the U25per branch of this fork (not represented as sufliciently longitudinal in the plate) and from the absence of other primary branches from the apical portion of the main stem which is preserved, it is probable that this secondary branch runs parallel to the main stem and that the outer branches are emitted from it, as in the preceding species. In keeping with the straightncss of the other veins, the anal furrow is exceptionally straight; it is deeply impressed only over its basal half and is ver}- gently and equally curved throughout, terminating probably at about the middle of the posterior border; the anal veins are five or six in number, most of them forked near the middle, the innermost compoimd, and the outer more closely approximated than the others; all of them are straight beyond a frequentl}' curved ba.se.
The species is a tolerably large one, the fragment of the wing being 21 nnn. long (its probable entire length about 2;>-2t) mm.) and its breadth 11.8 nnn., or the breadth to the length as 1 : 2.1. The veins and their branches are rather distinctly impressed, somewhat distant and regular; the interspaces are transversely and very faintly wrinkled, rather than provided with cross-nervules; the surface is nevertheless pretty smooth; the costal margin is very delicately marginate. The tip of the wing is broken off, so that from a fourth to a fifth is gone, but the fracture extends much further down the inner margin, extendiuaj even onto the anal area.
44 S. II. SCUDDEK ON PALAEOZOIC COCKKOACIIES.
Tlie coui"so of tho anal furrow separates this species from all others of the genus. Ill the .struofiire of tlio intornonieilian vein, but in hardly any other special feature, it is allied to ^f^|L hrctoiiciisc. In the general distribution of nearly all the veins it is very nearly related to ^fl/I. jiennsi/lvan'tcion. a sliglitlj' larger or at any rate a broader species; indeed these two species are more closely related than any other two American forms; but the slight curvature and consequently groat length of the anal furrow of this species forbid their being considered the same, and lliis dillers also from tlie other in the less crowded neuration of all parts of the wing, in the less sinuous course of the scapular vein, and in many other minor points.
The single specimen occurred on dark grey shale, associated with ferns and leaves of SpJienojiht/Ilxm Schlofhciviil, and was found, with the preceding species, in the produc- tive coal measures (or middle coal formation) of Sydney, Cape Breton, by Mr. Richard Brown. F. G. S., and connuvuiicated to me by Principal Dawson.
Mylacris pennsylvanicum iiov. sp. PI. 5, figs. 13, 14. Fore wing. Only the basal half of the wing is preserved, with none of the inner margin, so that it is 'impossible to determine the form of the wing; the course of the veins however would seem to indicate a shorter and stouter, as it certainly is a broader wing than in Mt/l. Ilecri. The outline as given in fig. 14 probably makes the wing a little too long. The costal margin is regularly and considerably convex, more so than in 3Iyl. Heeri. The veins originate from the middle of the wing or slightly below it, and curve a little at the base. The mediastinal area has a basal width of half the wing and, separated from the scapular by a scarcely curved line, strikes the costal margin close to the limit of the frag- ment, and probably somewhat, perhaps considerably, past the middle of the wing; the extreme base is covered in the specimen by a foreign object, but four veins aj^pear beyond it,' the two middle ones simple, the others deeply forked, all tolerably close, scarcely divergent, oblique and very gently arcuate ; toward the humeral angle there are no veins and the edge of the wing at this point is very narrowly and delicately marginate. The scapular vein is gently and broadly sinuous throughout and probably terminates before the ape.x of the wing, to judge from its apical curve; it runs very closely parallel to the costal margin through most of its course, and down very nearly the middle line of the wing, perhaps nearer the costal than the inner margin ; it commences to divide very ne.ar the base and emits five branches, all but the first of which are simple and all are siibparallel to the course of the outer mediastinal veins ; the basal branch is doubly forked and renders this portion of the area a little more crowded. The externomedian vein is arcuate until it divides, before the middle of the wing certainly, and some distance before the extremity of the fragment; it forks only once however in the part preserved, two parallel veins running longitudinally to the edge, equidistant from each other and the veins on cither side. The internomedian vein runs in a broadly sinuous course parallel to the preceding vein, and although much ob.scured upon the specimen, at least one and perhaps two branches can be seen to be emitted before the division of the externomedian vein. The anal furrow is strongly impressed upon its basal half, less so but still distinctly upon the apical half, appears to be composed of a pair of fine grooves closely approximated, and is regularly and not very strongly arcuate, terminating on the inner border at some distance before the
' In both the figures on our plate the vein nearest tlie humeral angle should be erased; it does not exist.
S. II. SCrDDKU ON I'AI.AKOZOIC COCKHOArllKS. I;-;
end of the mediastinal area, and alxint opposite the origin of the la.st scapuhir l»ran<li ; the anal veins are nmnerons an<I crowded, the lirst deeply forked and hasally distant fnnii the furrow, the others sinii)le and all sliirhlly arcuate and sulipiiraiicl to tin- hasal half of the furrow.
Tiie sinj^le known fra>rnient re|)rescnfs a toleralily large species, the hreailth of tin- wing being 13.0 nun., while its length may lie estimated as anywhere from li4 to ."10 mm., the actual length of the fragment heing ll> nmi. and the hreadth to the li-ngth altont as 1 : li. It is the under sinface of a left wing which is exposed, in whicii all the veins and hranches of the costal half (namely those of the mediastinal and .scapular areas) are prominent, while all the others arc very obscure, and a.s the ob.seurity afl'ects to some degree the anal I'urniw, it is probably entirely due to the preservation ; by favorable light and on careful examina- tion, slight iuflications of tran.sverse wrinklings may be seen in the scapular area, but there could have been no regular nor delinite reticulation.
The species, which is peculiar for its breadth and the .-flight tendency of its branches to subdivide, appears at first glance to have consideralde resemldance to Mijl. Jlvcri ; but it i.s certainly distinct from that by the .stronger curvature of the anal furrow and con.secjueiit abbrevifvtion of the anal area ; it also didcrs by the sinuosity of the .scapidar vein, the more arcuate line of .separation between the mediastinal and .scapular areas and the more crowded branches of at least these areas. From ^f'/f- anthrdcujihihttn it may be distin- guished by the lack of the strong deflection of the base of the principal veins, by its less crowdeil venation, simpler branches and 1)V the direction of the branching portion of the scapular vein, which is iiarallel to the border in this species, but converges toward it in Mi/l. anihracophilum.
A single .specimen, marked No. 284 I)}' the discoverer. Mr. 1. F. Mansfield, was found at Cannelton. Beaver Co., Penn., in dark sandy shale immediately under a vein of cannel coal known as the Acin C of Professor Lesley. It is partly covered by a leaflet of Sphoiophijl- linn Schlotheimii. Lower coal measures of Penn.
Mylacris anthracophilum. I'l. o, figs. 6-8.
Mylacris anthracojihila Scudd., in Worth. Geol. Surv. 111., iii. oGS-TO.. fig.s. o, Ck
Fore wing. The wing is very broad at the base and tapers almost from the base by the slope of the costal margin, which is strongly and regularly arcuate, while the inner margin is nearly straight, bringing the rounded but rather produced apex in the lower longitudinal half of the wing; the extreme apex is broken. The veins originate below the middle of the base and curve strongly upward before assuming a more longitudinal direction, when all are subparallel to the costal margin. The limitation between the mediastinal and scapular areas is strongly arcuate basally, straight apically, and the mediastinal vein termi- nates at the end of the apical three-fifths of the wing; the mediastinal branches, three or four in number, most of them forked, are straight or very gently arcuate, and radiate from a common point near the middle of the base of the wing, some of them plainly emitted from the principal vein just beyond the base, and one from the same at a considerable distance from the base. The scapular vein is strongly arcuate at the base, but, next the last branching of the mediastinal vein, takes a nearly straight longitudinal direction, sub- parallel to but slightly converging toward the costal margin, and terminates near or at
46 S. n. SCUDDKR OX PALAEOZOIC COCKROACHES.
the tip of tho winir l>ut Ik'Iow tlio iniddlo lino of tlic s;iiiu>; it emits five equidistant almost equal longitudinal branehes. each of which forks at or somewhat beyond its middle and at similar distances from the costal margin ; the mediastinal and scapular branches accordingly change their direction in the most gradual way from nearly transverse to longitudinal, and the mediastinal and scapular areas together occupy nearly one-half the width of the wing. The externomedian vein, strongly arcuate, like the preceding, at the base, begins to divide a.-* soon a.s that, and beyond this is straight, terminating at a short distance before the tip of the wing; its first branch passes down the middle of the wing and dies out a little beyond the midille ; its three other branches, which like the first are superior, are emitted further out in the apical half of the wing and are each simply forked before their middle ; the upper fork of the first of these approximates very closely to the scapular vein, leaving no pas.sage for the basal branch. Beyond the base the internomedian vein is also straight and emits four equidistant branches, the first (at near the origin of the basal branches of the preceding veins) being doubly, the others, excepting the apical, simply forked. The anal furrow is deeply impressed, very regularly and rather gently arcuate, terminating a little before the middle of the wing ;. the anal veins are numerous, gently sinuous and mostly simple, the upper ones deeply forked and more distant.
The species is a little above the medium size, the length of the fragment preserved 28.5 mm., being .scarcely shorter than the real length of the wing; its greatest breadth, at the end of the basal fifth, 13. 5 mm, or the breadth to the length as 1 : 2.1. The specimen is very nearly perfect, and represents the upper surface of a right wing ; the anal area is swollen ; the veins of the wing are prominent, and the interspaces are rather regularly divided by inconspicuous straight cross-lines.
The species is reinarkable in this genus for the form of the wing, which has its tip noticeably within the middle line of the wing and somewhat produced. In this it diflfers .decidedly both from 3Iyl. hretonense and Myl. Mansfieldi. It agrees better in this 2)oint with Myl. Heeri, but the crowded neuration of Myl. anthracopMlum, wdth the strong deflection of the base of the veins distinguish it at once from that species. There is only left Myl. pennsylvaniciim with which to compare it ; and although the apex of that species is .so far lost as to render it very imperfect, we may be sure from the sinuosity and apical curve of the scapular vein that the apex of the wing is not within the middle line ; it is further distinguished from 3fyl. j^eiinsylvanicum by its tapering form and the very strong basal deflection of the veins ; so that this species is abundantly distinct from all the others. Besides the front wing a pronotal shield has been found. At least it probably belongs to this species, as the size agrees and both came from the same locality and were col- lected at the .same time. It is of nearly the same form as in Pei'ijflaneta americana (Linn.), broadest in the middle of the posterior half where it is roundly angulate, and in advance of which it tapers very rapidly to a convex front, hardly angulate laterally; posterior border broadly and strongly convex ; its immediate edge narrowly and very slightly raised ; the whole pronotum is a little convex, and the surface is nearly smooth, with a few minute, transverse and longitudinal lines; its greatest breadth is 16 mm.; its anterior breadth 9.5 mm. ; length 12 mm.
The .specimens above described were found by Mr. A. H. Worthen, at Colchester,
S. IT. SCUDDKU ()\ I'AI.AKOZOIC COCKROACIIKS. 47
McDonoiigh Co., Illinois, in tin- lool" shales of coal No. 1* of tlif Illiiioi.s Survey, ami \>y him coiiiinuiiii'iited to nic. Lowit coal nicasuiTs of Illinois.
Mylacris Mansfieldii ik^v. s|>. I'I. Ti, t\>r. 15.
Fore winji;. The l)a<e of llie wing is liroken, hut tlie part preservetl shows an oval outline, with similaily arcuate c()stal and inner inarj^ius and a somewhat iiointed lip. tlie e.\tremity of which is roumled ; the tapering of the wing includes all the apical half. The mediastinal area is very large, occupying fully one-half the breadth of the wing at the Inuse and covering about two-thirds of the costal margin; the veins of its outer half (the ba.se is broken in the specimen) are very long, very slightly arcuate, slightly radiate but sub- parallel, simple or deeply forked and clo.sely crowded, and the limitation of the area next the scapular vein is straight. The scapular vein runs nearly parallel to the costal margin, at least in the middle of its course, but in the apical third becomes longitudinal, pa.ssing down the wing scarcely' above its middle line ; it commences to divide near tlu- ba.se of the fraguTent. and prol)ably a little before the end of the basal third of the wing, and emit.s live branches at unequal distances apart, one or two of which are singly or doubly forked, and all lun ])arallel to the outer mediastinal branches ; the vein terminates at the tip of the wing and so the area occupies on the margin the apical third of the costal border. The externomedian vein has a slightly arcuate course, which, contrary to what is customary, runs subparallel to the inner margin and, commencing to divide a little before the middle of the wing, emits, near together, three inferior branches which are long, simple or forked and longitudinal, the basal ones more or less arcuate in the same sense as the main vein ; as these branches are inferior, the interspace between the scapular and externomedian veins (running almost exactly down the middle of the wing) is marked by the divergence of the opposing nervules. The internomedian vein is broadly arcuate and terminates on the inner border considerably nearer the tip than the mediastinal vein ; it emits three branches, the apical one compound, the others more or less deeply forked, so that this area is as crowded with veins as the others. The anal furrow is lightly impressed, scarcely arcuate in its apical half, and terminates at the edge of the fragment, probably at about the end of the basal half of the wing.
The species is a tolerably large one, the largest of the genus, the fragment of the wing measuring 24 mm. in length and 13 mm. in breadth ; proljably the entire length was about 30 mm. and the breadth to the length as 1 : 2.3. The wing is a left one and the upper surface is exposed ; the veins are lightly impressed throughout and uniformly and rather closely crowded ; the surface is nearly smooth, but wnth care a delicate wrinkling of ob- scure transverse lines can be made out.
The wing is peculiar for its tapering oval foruT and the inferior origin of the externo- median branches, which distinguishes it at once from every other species of this genus.
The single specimen found was sent to me by Mr. I. F. Mansfield and by him obtained at Cauuelton, Beaver Co., Penn., in dark sandy shale immediately under the veiil of canuel coal known as vein C of Professor Lesley. Lower coal measures of Pennsylvania.
48 i^ H. SCUDDER OX PALAEOZOIC COCKROACHES.
liitlKnylacziB dot. gen. {ix*«s:, ^aUxfec).
TTie niedia5tinil vein of the upper wings consist? of about five principal shoots, only two or three of which foik and these generaDy close to the base, all of them straight or genii V corred. and the ontCTmost extending to Taiiable distances along the- costal margin, bat generaDv bercMid the middle of the wing: the point toward which these branches converge b considerablv nearer the inner than the costal margin of the wings : this with the great length vf the outermost dioot gives the mediastinal area an unusual extent for Myla- cridae. The scapular vein is considerablv curved before branching, but beyond its first brandi is almost exactly straight, even the outer portion scarcely curving, and nms down the middle line of the wing to the tip. so that the mediastinal and scapular areas together occupv fullv half of the wing ; it emits fotir or five branches, more or less closely approxi- mated, according as one or two of them fork or not. and all run subparallel to. but rather leae obliqnelv than, the outer branches of the mediastinal vein. The extemomedian area is verv narrow and of small extent, ooctipying the lower half of the narrow tip of the wing, the vein fii?t branching at or beyond the tip of the wing, and then but once or twice, either guperioriy or inferioriy. the first branch sometimes forking- The intemo- median- and anal veins together divide nearly equally between them the inner margin of die wing, the anal farrow being rather conspicuous and gently arched, and. firom the narrowness of the wing and the inferior position of the common point of origin for all the principal veins, tmusually longitudinal, most of the species differing in this respect some- what conspicuously fiiom those of Mylacris; ihe intemomedian vein has only two or three branches, which are very longitudinal and very long, and yet fork comparatively little, rarely doubly ; the vein may emit its first branch some\diat before, opposite to. or oooaderably beyond the origin of the first branch of the scapular vein. The branches of the anal vein are known only in one species, where they are parallel, rarely fork, and are slightly more longitudinal than the branches of the intemomedian vein.
The wings are remarkable for their elongate form and nearly parallel sides ; the greatest breadth is at about the middle and they are generally three times as long as broad, being exceptionally -rlender for Mylacridae.
Upj>er wing* are all the remains known of this genus, which differs from Mylacris in the more attenuated and equal shape, the slight obliquity and gentle curve of the anal furrow. the slight importance of the extemomedian area, and also by the unusual sulcation of the interspaces between aD the veins ; from Necymylacris it is readily separated by the very wide extent of the combined mediastinal and scapular areas. The species are all of rather small sire and are foimd only in America.
Lithomylacris aagnstum nov. =p. PI. -5, figs. 2, 3.
The fore wing is long and very slender, the inner margin straight, the costal margin ver\- :_' regularly convex: the wing narrows from the middle, at first very slightly,
in the .. more rapidly ; the tip is broken in part, but was evidently well rounded
and, from a less rapid narrowing of the wing, probably' not so slender as in the preceding species. The veins take their rise fit)m a point considerably below the middle of the wing, the lower ones scarcely curving upward in passing outward, the upper ones curving very gently and broadly next the base. The mediastinal area is fully half the width of the
S. n. SCTDDER OX PALAEOZOIC COCKROACHES. 49
wing at the base, ami occupies very nearly two-thirds of the costal margin, it« limitation next the scapular area being almost straight, a slight sinuosity being scarcely perceptible ; the gently radiating veins of this area are six or seven in number, those next the shoulder simple and distant, the two outer somewhat sinuous, simply or doubly forked and clo<4.-r. The scapular vein curves gently upward at the base until it has nearly reached the middle of the -wing, next pa^es down the middle or slightly below it, subparallel to the costal margin, and then curves gently upward again, its entire course being ven* broadlv and gently sinuous, terminating at the apex ; it begins to divide at the end of the basal fifth of the wing, almost before it has lost its upward curve, and emits half a dozen oblique branches, the first pair near together, the rest at subequidistant intervals ; the second and third are forked near the middle (one of the branches of the former again at the tip), but the others are simple ; they become increasingly longitudinal toward the tip but only to a very slight degree, continuing the decreasing radiation of the mediastinal veins ; together these two areas occup}" more than half of the wing. The extemomedian vein runs in a straight coiu^e nearly to the middle of the wing, scarcely turned downward from a longi- tudinal direction; here it forks, the upper branch again forking near the tip, the lower at less than half way to the border, each of the latter forks again dividing, the upper before, the lower beyond its middle ; all follow a longitudinal direction and occupv upon the margin only the lower half of the narrow apex of the wing. The intemomedian vein is remarkably straight throughout and is indeed the only palaeozoic cockroach known in which it is straight ; it terminates just before the tip of the wing, commences to divide almost as soon as the scapidar vein, and emits, long before the middle of the wing and at regular and short intervals, three straight veins, the first simple, the others forked in the middle, all having a constantly lessening obUquity, so that the outermost fork is parallel to the main vein; besides these the main vein emits another sUght longitudinal branch close to the apex, and the whole area occupies about one-half of the inner border of the wing. The anal furrow is very deeply and sharply impressed and scarcely at all ai-cuate, running in nearly a straight line to a httle before the middle of the wing ; the anal veins, four in number, one of the middle ones forked, are straight, equi- distant and parallel to the furrow.
The wing is a little above the mediiun size, 29.5 mm. long, and yet only 9.-5 mm. broad, or the breadth to the length as 1 to a little more than 3. It is nearly perfect, being only a Uttle fragmentary about the base and the lower portion of the tip. It is a left wing, of which the imder surface is exposed, showing the veins and anal furrow as ridges ; the anal furrow is remarkably prominent, and most of the veins are also very prominent ; this is especially true in the veins of the scapular and extemomedian areas ; the Intemomedian vein itself, as far as its apical fork, is also almost equally prominent, but all its branches are mere lines upon a flat field : whUe in the areas covered by the prominent veins the inter- spaces are roundly sulcate. giving additional prominence to the veins ; in the mediastinal area, however, where the veins are somewhat prominent, the interspaces are not sulcate, and the anal area, which must as a whole be broadly vaultetl or tiunid as seen firom the upper surface, partakes of the nature of the intemomedian area ; the surlace itself of the whole wing is smooth, no trace of cross venation being discernible. From its deflection in the reversed specimen, it would seem that the whole costal edge was slightly margined.
StE^IOIBS BOST. SOC. XAT. HIaT. VOL- HI. ■
50 S. H. SCUDDER ON PALAEOZOIC COCKROACHES.
This speoios. like the next, is ])i'oiiliar lor the division of the internomedian vein, which, excepting for a small apical fork, emits all its branches near the base ; in shape it doselv resembles that species, even to the flatness of the internomedian area ; but it (lilTei-s from it in its greater length, the greater frequency of the branches, and their much more abundant forking, especially in the externomedian vein, which also divides much nearer the base in this species than in Lith. jjittstoiiiannm. The shape of the wing and the closer venation at once separates this species from Lith. siilcatnm.
The single specimen was found with the following species by Mr. R. D. Lacoe, at Port Grilhth switch-back, near Pittston, Penn., in the roof shales of the E seam of coal of the Second Penn.sylvania Survey, and by him forwarded to nie for examination. Upper coal measures of Pennsylvania.
Lithomylacris pittstonianum nov. sp. PI. 5, figs. 4, 10.
Fore wing. The single specimen known is very imperfect, the base, anal area, and a large part of the tip being lost, and the remainder badly fractured ; it is evident, however, that the wing is very long and slender, with a gently and regularly arcuate costal margin ; probably the w-ing is nearly equal, tapering very gently on the apical half The veins must originate below the middle of the wing, and are nearly straight. The mediastinal area, which is more than half the width of the wing at the base, terminates at the middle of the costal margin, and is separated from the scapular area- by a straight border, the veins, six or seven in number, being straight, gently divergent, and simple or rarely con- nected close to the base. The scapular vein runs parallel to the costal margin in the basal half of the wing, gradually approaches it in the apical half, and terminates probably a little before the tip ; it emits five simple, straight branches, which divaricate very slightly in continuation of the divergence of the mediastinal veins, which they entirely resemble ; the mediastinal and scapular areas together occupy just about one half of the wing. The externomedian runs parallel to the scapular vein, divides a little beyond the middle of the wing, and emits about four inferior, .slightly arcuate branches, which are simple (unless the first be apically forked), and together probably occupy the entire apical margin of the wing. The internomedian vein is very gently arcuate, and must terminate just before the tip of the wing ; it emits, wholly in the basal third of the wing, three simple or simply forked branches which are very longitudinal. The anal furrow is distinctly but not heavily impressed, very gently arcuate, and must terminate at about the end of the basal third of the wdng ; but such is the slenderness of the wing and the low origin of the principal veins, that the anal area must be several times longer than broad.
The wing is of moderate size, the fragment measuring 22.5 mm. in length and 8.5 mm. in breadth ; probably the entire length of the wing is 26 mm., or the breadth to the length as 1 : .3 ; it is a left wing with the upper surface exposed ; the veins are all verj- distinctly impreased, excepting those of the internomedian area, which are obscure ; the interspaces between the veins are vaulted also, so as to add to the impression of the veins themselves ; but otherwise it is smooth excepting in the flatter internomedian area, where a delicate and crowded cross-veining is faintly marked ; the basal third of the costal edge is gently margined.
With the preceding species, this insect is peculiar for the basal attachment of the internomedian branches. In its shape it resembles only Lith. sulcatum in this genus ; fiom
S. H. SCUDDEU ON I'Al.AKOZOIC COCKROACHES. 51
tliis it (liflors in the simplicity of tin- l)r;iiiclR>s, which arc very nirdv furcate ; conse- quently tlie venation is miicli more open, anil in this respect it approaches /yi7/<. «/»»y>/fr, with which, from its shape, it coulil nr)t ])ossil»ly he oonfonnded.
The single specimen foiiml was obtained l)y Mr. U. 1). Lacoe with the preceding at Port Grifhth switch-ljack, near I'ittston, I'enn.. in the roof shales of the E seam of coal (of I'rof Lesley's table). Upper coal measures of IVnnsylvania.
Lithomylacris simplex ii<>v. sp. PI. 5, fig. 5.
Fore wing. The wing is long oval, tapering beyond the basal third, but very gradually, the costal nuirgin much arched next the ba.se, the humeral hjbe being large and well rounded ; but along the most of its course the co.stal margin is very gently convex, almost straight in the middle ; inner margin gently convex, the tip tapering but well rounded ; the wing is much broader than in the other species of the genus. The veins originate .some- wiiat below the middle of the wing, and curve upward very slowly with a broad arcuation. Mediastinal area occupying more than half the l)asc of the wing, and on the costal margin almost the entire extent of the wing, terminating only a little before the tip ; it is sep- arated from the scapular area by a very gently and broadly arcuate limitation, and is fdled with very few veins (only three in the specimen seen), each of which forks once near or at its base ; all are divergent and gently and broadly arcuate, the outer the least so, and all fail to reach the margin. The scapular vein is very broadly arcuate, running down the middle of the Aving parallel to the costal margin, and, finally longitudinal, terminates ju.st beyond [i.e., below) the extreme tip of the wing ; it commences to divide while still arcu- cuate, just beyond the basal fourth of the wing, and emits at subequal distances apart four simple, gently arcuate branches, having a similar direction to the outer mediastinal veins, but if anything less longitudinal. The externomedian vein, arcuate as far as the division of the scapular, is straight beyond this, parallel to and rather distant from the same, fork- ing simply at the end of the middle third of the wing, and occupying onl}- an inconsider- able space on the border just below tlie tip of the wing. The internomedian vein is similar to the pi-eceding at the base, but becomes straight a little sooner and continues straight to the tip, terminating about as far from the ape.x as the mediastinal vein ; it emits a very short branch close to the tip, another a little beyond the middle of the wing, and two others, which must have their origin much nearer the base, as in the other members of the genus ; ouh- the apical portion of the outer of them, however, can be traced on the specimen. The anal furrow is distinct but not deeply impressed, is very regularly and rather gently arcuate, and terminates just beyond the middle of the wing, affording a very large anal area.
The wing is of medium size, measuring probably 24 mm. in length (the fragment is 22.0 mm. long) and 10 mm. in breadth at the middle, which is probably not quite so broad as the middle of the basal half of the wing ; or the breadth is to the length as 1 : 2.4. It is neai'ly perfect, a small portion of the tip only being lost, together with the whole anal area ; it represents a left wing seen from the vmder surface, the veins behig in rehef ; the veins are prominent, but not remarkably so, and the anal fm-row no more prominent than they, if it is as prominent ; as in the preceding species, the branches of the internomedian vein are not elevated ; indeed they cannot all be traced in the somewhat worn specimen, and the vein itself, as well as the externomedian, partakes in part of the obscurity ; this
52 S. n. SCUDDER ON PALAEOZOIC COCKROACHES.
resrion al^JO is flat, while the interspaces of the scapular and mediastinal areas, especiallj' of the former, are broadly silicate {i. e., arched on upper surface) but much less so than in the other species of the ireniis : the surfiice seems to be completely smooth, is of a carbonaceous black in the specimen, distinguishing it strikingly from the clay-colored matrix. The ex- treme edge of the entire humeral lobe is marginate as for as the mediastinal veins.
The win<'- is peculiar for the veiy large propoi'tion which the mediastinal and anal areas occupy to the rest of the wing, and for the extreme simplicity of the neuration, in which there is not a single forked branch outside the mediastinal area ; tlie veins are very distant and the species is at once distinguished from the others of the genus by the much stouter shape of the wing, which is much less, while they are much more than three times as long a.s broad.
The single specimen discovered was obtained by Mr. Wm. Gurley, from the coal meas- ures of Illinois, about six miles from Danville, and sent me by him for study. Lower coal measures of Illinois.
Necymylacris nov. gen. (v^xu?, .uo/uz/vtV.)
Tlie mediastinal vein of the upper wing differs from the same vein in the "other members of this group, to judge at least from the most perfect specimen, in emitting from the outer- most vein several branches at infrequent intervals, even to a long distance from the base ; these branches may themselves be compound, so that a cei-tain resemblance or approxima- tion to Blattinariae may be seen ; but, in addition to these, there are the usual radiating veins next the humeral lobe ; in the t}q)ical species, the only perfect specimen of the genus known, the last vein terminates in the middle of the apical half of the wing, but in the other it appears to be much shorter. The gcapular vein, curved or bent before branching (which it does near the end of the basal third of the wing) thereafter runs in a straight or sinuous course to a little before the tip of the wing, emitting three or four veins which may be multiple-branched or perfectly simple. The externomedian vein is forked a little before the middle of the Aving, and emits a number of forking branches, which, while they ai'c longi- tudinal in direction, are superior, so that the equal interspace between the externomedian and internomedian veins is marked by oppositely diverging branches ; the externomedian area occupies the entire or almost the entire apical border of the wing, so that it is of a narrow wedge-shaped form. The internomedian area is apparently more extensive than the anal, the anal furrow terminating on the Jnner margin nearly opposite the tei'mination of the mediastinal area and having a rather oblique curving course ; the internomedian vein emits five to ten branches, generally simple, occasionally forked at the base, and in one of the .species itself forks longitudinally not far beyond the middle, the upper fork dividing near the tip and the lower emitting the apical branches ; these all run in a slightly curved course more oblique than the anal furrow. The branches of the anal vein are numerous, run more longitudinally, are more closely crowded toward the anal angle and fork feebly, excepting the upper one which, though considerably curved, is well sej^arated from the anal furrow and emits several inferior branches.
Besides upper wings, the slight fragment of a part of one of the lower wings has in one instance been found, in which the veins of the apical j^ortion arc thickly crowded, straight and parallel, and fork feebly toward their tip.
S. H. SCUDDKU ON I'AI.AKO/.OIC (■()tKIi( lAc IIKS. 53
Tlie jrc'ims diflers from tlie two preciMliiiir by tiio .smaller extent, Imili in Incaillli ami loiititli, of tlie combiiietl nu'diastiiial and scapular ureas ; from both also, Iml parlirularly from Litliomylacris, in the j^reat extent of the externomedian area. The specie.s are of large .size, including the largest American forms, and arc uid<no\vn to Kurojie.
Necymylacris lacoanum imv. sp. I'l. .'>, lii;. IJ.
Fore wing. The form is indeterminaide from the oidy fragment known, altiiongh it is probably proportionally shorter than in iYcc. heron; the veins are all strongly curved at the ba.se. The mediastinal area is less extensive than in the other .species of the genus, and resembles the other genera of Mylacridae to a greater extent in a more radiate disposition of the veins, at least four in number, of which the last ha.s at lea.st three rather distant and apparently simple branches, the outermost originating at some distance beyond the (irst division of the scapular and internomedian veins; probably the area does not extend beyond the middle of the Aving. The scapular vein has a ratlier strongly sinuous curve and at least three straight and simple branches, of which the first, probaltly arising in the middle of the basal half of the wing, is in direct continuation of the basal portion of the vein, and thus separates the scapular from the mediastinal area by a straight line; the branches are parallel to the outer of the -mediastinal veins, and the area, which is certainly broad, probably more than a third of the breadth of the wing, extends no doubt nearly to the tip of the wing. The externomedian vein beyond its basal curve is straight, and first divides beyond the last (preserved) branch of the scapular vein, or, probal)ly, shortly before the middle of the wing; it emits at least two superior branches, the simple bases only of which are preserved in the specimen, but, from the divergence of these, the area probably occupies the entire apex of the wing. The internomedian vein is regularly and very strongly arcuate, probably terminating at some distance before the tip, and emits four ecjuidistaut. well-separated branches, one of which is deeply forked, the others simi)le, all straight or gently arcuate and very long, the area occupying apparently more than half of the wing. The anal furrow is scarcely more distinct than one of the veins, and is nearly as straight as thev, appearing to originate from the internomedian vein near the base of the ■wing, and terminating probably a little before the middle of the wing ; the anal veins are numerous, especially toward the basal angle, gently arcuate, simple or forked, the outer one very much curved,' distant from the "others, and compound.
The wing is of medium size, the largest fragment measuring about 1.3 mm. long, and the breadth of the two fragments when miited nearly 12 mm.; probabl}' the entire length of the wing was about 25 mm., and the breadth to the length as 1:2. It is a left wing, of which the upper surface is exposed, but is very fragmentary and shattered, no part of the border, unless in the unimportant anal area, being preserved ; probably nearly half of the apex is gone, as well as a slight part of the base; the veins are delicately impressed, but distinct, excepting toward the costal border, and the surface flat, and, at least in the internomedian and anal areas, rather distinctly marked Avith very frequent transverse wrinkles.
Hind wing.. Protruding from beneath the front wing is a small fragment of a hind wing, apparently the apical lower portion of that of the opposite side of the body ; all that can be made out are about a dozen straight equidistant parallel veins, about half of them (mostly those nearer the apex of the wing) forking simply; their direction, as they lie on
54 S. H. SCFDDER ON TALAEOZOIC COCKROACHES.
the stone, is parallel to that of the seapular veins of the front wing. In distinction from the veins of the front wing, these are slightly elevated, and the basal half of the fragment ha.s a glistening surface, while that of the apical half is dead and shows exceedingly faint traces of transverse wrinkling like the cross neuration of the front wing. If, as the direc- tion of the veins leads ns to snppose, the wing is that of the opposite side of the body, and has its natural position as closed, the hind wing of this insect must have been very broad, broader iinleed than the i-emains of any other palaeozoic cockroaches would lead us to presume in them.
Notwithstanding the fragmentary nature of the fossil, it is plainly distinct from any other known form. The structure of the mediastinal vein, although approximating to a certain degree that of the Blattinariae, plainly shows it to belong to the Mylacridae, and is indeed not very different from the same vein in Liihorn. angusium, while the very arcuate form of the internomedian vein, combined with the great breadth of this area, separate it at once from all the species of Mylacridae mentioned here. Its generic affinities with Necymylacris are doubtful, and the material is insufficient for accurate determination of all the points which should be settled before reference to a distinct genus can be made, but it agrees with that genus to a certain extent in several points in which it differs from other Mylacridae, and especiall}^ in the mediastinal vein (although it is here very much simpler than in y^ecipn. heros — as indeed is the Avhole neuration) and in the anal area, whose extent and the distribution of whose branches, and particularly the character of the compound branch next the anal furrow," is very similar.
The single specimen known (numbered 2009) was found by Mr. R. D. Lacoe in the lowest productive coal measui'es near Pittston, Penn., and by him sent me for examination.
Necymylacris heros ikjv. sp. PL .5, fig. 9.
Fore wing. The wing is long and slender, very long obovate, nearly equal ; the costal margin is very gently convex, nearl}^ straight along the middle, the inner margin even less convex, and the gently tapering apex rounded; the veins originate from near the middle of the base of the wing, and most of them curve upward a little for a short distance. The mediastinal vein is at first directed toward the middle of the basal half of the costal margin, but close to the base bends abruptly, and runs in nearly a direct line to the middle of the outer half of the costal margin, .separated therefore by a straight line from the scapular area; next the humeral lobe, which is smooth, are two or three weak radiating veins which spring from the base of the principal vein; -but most of the slowly narrowing mediastinal area is filled with scarcely radiating branches which spring miequivocally from the main vein beyond the ba.se ; there are three such principal branches, all originating in the ba.«al third of the wing and compound, besides a simple apical branch near the tip ; each of the.se compound branches, which are as nearly longitudinal as their position allows, emits, generally at some distance from its base, two or three outer simjsle oi- forked branches, so that the costal margin is filled with crowded veins. The scapular vein. gently arcuate until it divides, near the middle of the basal half of the wing, is thereafter straight, running down near the middle line of the wing and parallel to the costal margin ; a little beyond the middle of the wing, however, it is deflected very slightly upwaid, the change being .scarcely perceptible, and terminates on the apical margin just before the
S. II. SCTDDKIi ()\ PAI.AKOZOIC COCKKt ).\( HKS. 55
extreme apex; it omits four luandics at imei|ii;il distances apart, all >A' tli<-iii nearly lonj^i- tudinal, tlio first heinir conipoimd ami diviflinj; only at the middle of the wing.' the second doiiMy forked, and the third simply forke<l. hoth at a long distance from the (trigin. while the last, arising opposite the fork of the third, is simple. The exlernomeilian vein is very broadly sinuous, being rather strongly arcuate at the ba.se, then runs in a nearly straight line a little divergent from the ccstid margin, and, finaU^'. in the apical third of the wing, becomes more longitudinal, and terminates just before the apical margin; it first divides opposite the second branch of the seapular vein, or at the end of the basal two-filths of the ^ving, and emits at subetpial intervals, the last a little beyond the middle third of the wing, four superior longitudinal branches, the fir.st of which runs down the middle line of the mng, forks at a little before the end of the middle third of the wing, it.s upper fork again dividing; the second forks in the middle of its course, and the others are simple; all are closely crowded together, and occupy upon the border the lower part of the apical margin. The internomedian vein follows nearly the direction of the preceding, being strongly arcuate at the base, straight and considurably oblique in the second quarter of the wing, beyond this subparallel to the costal margin ; at its change of direction, almost exactly in the middle of the wing, it emits a branch, which runs clo.se to the main stem, and, except- ing for an apical shoot, emits all the regular branches beyond its origin ; including these secondary branches there are about ten simple slightly arcuate oblique veins, whose direc- tion, especially that of the basal ones, is rather at variance, from their regular obliipiity, with that of the branches of all the other veins; the basal branches are more closely approximated than the ajjical. The anal area being broadly tumid, the anal furrow is very deeply impressed, and is very strongly arcuate on the basal half, nearly straight on the apical half, and terminates a little before the middle of the wing; the anal vein next the furrow is straight and nearly longitudinal at base, curved gently downward be^'ond, and emits three or four arcuate distant branches; the other veins are very numerous and crowded, generally simple, nearly straight or arcuate, in an ojiposite sense to the first, and about as longitudinal as the mediastinal branches.
The wing is of extreme size, the lai'gest of the American species, and only exceeded by Anthracohl. spectabilis of Europe; it is 48 mm. long and 18 mm. broad, or the breadth is to the length as 1 : 2.7; the specimen is almost absolutely perfect, and represents the under surface of a right wing; the princi2)al veins and the main branches of the mediastinal ^ scapular, and extcrnomcdian areas before the}' fork are all distinctly pronounced ; the forks of the same are delicately elevated, while the branches of the internomedian and anal areas are very delicately impressed, — all as seen on the under surface; the surface is flat, except- ing where the principal veins are most pronounced, and here the interspaces are a little and broadly sulcate; all the interspaces, even in the anal area, but especially those which are sulcate, exhibit a minute tracery of nearly straight, very closely approximated, exces- sivel}^ delicate, scarcely impressed cross lines; those of the anal area are not sufiiciently distinct in the plate.
This insect, from its extreme size alone, cannot possibly be confounded with any other American species, nor from the peculiar distribution of the mediastinal branches, in longi- tudinal bunches depending from the main vein, with any palaeozoic species. This peculi-
1 The plate represents the first offshoot of this first branch ion; it forks near the tip or directly opposite the extremity as simple, but this is inaccurate, and was overlooked in revis- of the first branch itself.
56 S. II. SCUDDER ON PALAEOZOIC COCKROACHES.
aritv of the moiliastinnl vein is of special interest as showing a certain affinity to the lihittinariao. next which it is here phiced; yet the distribution of the branches is never- theless radiate, and the form of the area triangular and not baud-shaped, according in this respect wholh- with the Mylacridae. It should be taken as the type of Necymylacris, for the imperfection of the i)receding species renders its alliance with this somewhat doubtfid.
Tlie single specimen, which I ov.e to the kindness of Mr. I. F. Mansfield, was obtained bv him at Cannelton, Beaver Co., Pcun., in a dark sandy shale immediately under the vein of cannel coal known as vein C of Professor Lesley. Lower coal measures of Pennsylvaiaia.
Blattinakiae.
Li the second group into which the palaeozoic cockroaches may be divided, the medi- astinal vein is not constructed like the anal vein, but like the other veins of the wing, being composed of a main vein which extends at least half way to, usually some way beyond, and sometimes quite to, the tip of the wing, emitting toward the costal border several branches which are usually subequal, equidistant and parallel, often forking once in some part of their course, the apical branches occasionally many-branched. The area covered by this vein and its branches is thus band-shaped, and terminates beyond the middle of the wing. The group occurs both in Europe and America, all of the European and somewhat less than half of the American species falling therein. The wings as a general rule are slenderer than those of most of the Mylacridae, the breadth being contained in the length on an average more than two and a half times.
Etoblattina (^Vo?, Blattinn) nov. gen.
Blatt'ma Auct (pars).
The mediastinal vein of the fore wings W'ith its l)ranches covers a rather narrow and not very extended area, being seldom more, seldom much less than one-fourth of the Avidth of the wing, and generally terminathig apically from a little more than one-half to a little less than two-thirds the distance toward the tip of the wing ; in one or two instances, as particularly in E. leptojihleblca, it extends a little more than two-thiixls the distance; the area is usually of uniform width nearly to the tip, but it sometimes tapers throughout the entii'e apical half, and in U. jjrbnaeva, where the whole wing is very broad, it tapers with unusual rapidity and throughout the greater part of the wing; the principal vein emits from five to ten simple or forked, equidistant, oblique branches. The scapular vein gen- erally terminates just before the tip of the wing, rarely at the tip itself, and occasionally is decidedly removed from the tip, though not to a great distance ; it genei'ally begins to fork a little before the middle of the wing, occasionally at it, and rather more frequently only one-third the distance from the base; and the branches usually take on the mode of distri- bution of those of the mediastinal vein, although the similarity is sometimes lost from the greater breadth of the area and the consequently greater length of the veins ; in other instances, and particularly in those in which the early branching of this vein is correlated with more than an average length in the mediastinal area (as particularly in E. venusta), all similarity is lost, the division assuming more or less of an arborescent form, generally accompanied by frequent ramifications ; as a general rule, however, more or less similarity exists between the two areas, and in some (as in E. affinis, E. Dohrnii) the resemblance is
S. n. SCUDDKR 0\ TALAKOZOIC COCKKOACIIF.S. 57
very great; the general course of tlie scapular vein is usually parallel to the costal margin, but without partaking of its generally slight convexity; heyond the inuncdiato base of the wing therefore its course is nearly straight, sometimes with a gentle sinuosity; occa.sionalIy it is conspicuously sinuous, as in IJ.Ifthacheusis,>io that the greatest hreailth of the scapular area is double that of the mediastinal; yet even here the general rosemldance and trend of the branches of the two veins may be perfectly kept. The externomedian vein is of moderate importance, occupying always a portion, generally the whole, of the apex of the wing, generalh- commencing to branch not far from the first divarication of the scapular vein, but in this respect showing great variation ; its branches are not numerous, occasion- ally reduced to two or three, and while longitudinal are yet always superior, so that the equal sinuously curving space between the externomedian and inteniomedian veins is always marked by divergent branches, very frequently arising exactly one opjiosite an- other. The internomedian vein originates near the middle of the wing in aliout half of the species (the first half of the .species described below), somewhat above the middle in the other half; usually it is pretty straight be^-ond the arched base, and does not terminate so near the apex of the wing as does the scapular vein ; but not infrequently it reaches jis fur as the scapidar, or at any rate extends further than it otherwise would by curving outward near the tip, and thus reaching to a greater distance ; there is therefore much diflerence in the rapidity with which this area narrows, being very rapid in some (as in £". nissoma), very gradual in others (as in E. Lesquereuxn); its numerous veins are nearly straight; usuall}- some of them are simple, and they have an obliquity about equal to those of the mediastinal vein, although of course in an opposite sense. The anal furrow is rather more lightly impressed than usual, arcuate and very oblique, generally terminating on the inner margin at about two-fifths the distance from the base ; the veins of the anal area are usually simple or forked near the base, very frequent, subparallel and subequi- distant, generally less arcuate than the anal furrow ; in one species, M. mantidioidea, they are very irregular.
Usually the upper wings are moderately slender, from a little less than two and a half to about two and three-quarter times as long as broad ; but a few of the species have wings more than three times as long as broad, and the first two species differ from the others, not only iu their unusual breadth, being only a little more than twice as long as broad, but also in other features, such as an unusual breadth (and in E. lahachensis an imusual length) of the mediastinal area, the narrowness of the extei-nomedian area, and the extreme longitudinality of its branches; as, however, the form of the wing often appears to differ very considerably in species of the same genus in this group, there is not sufficient ground for the separation of these species from the others even as a section, and the more so as there are several other species, placed in the middle and at the other extremity of the genus, which have quite as broad wings. The general average is scarcely less than two and three-quarter times longer than broad, which is a trifle slenderer than the average of the whole tribe ; and it is not a little curious that this is exactly the same proportion as holds in the geuus next to this most prolific in species, Gerablattina.
Besides the front wings, which constitute most of the fragments of this genus preserved, there are two which show the hind wings also; one of the.se also has the thorax and abdomen, and a thuxl the thorax. The hind wings appear to resemble the front wings closely, and not to be much larger, at least in oue of the species; the thorax ui both
MEMOIRS BOST. SOC. NAT. HIST. VOL. HI. 8
5S S. H. SCUDDER OX PALAEOZOIC COCKROACHES.
is similar, being suljtriangular. tapering anteriorly, but with I'oundeel sides and a rounded front. The abdomen in the single species where it occurs is extraordinarily slender, but apparently not cylindrical, as would at first appear from Goldenberg's illustration.
This genus differs from Archimylacris in the greater conformity of the mediastinal and scapular areas, the superior position of the branches of the externomedian vein, and the usually smaller extent of the scapular area; from Anthracoblattina, Gerablattina, and Ilormatoblattina by the greater brevity of the mediastinal area and the correlated greater importance of the scapular area, as well as from the former by the superior position of the veins of the externomedian vein, and from the latter by the superior position of the branches of the scapular vein ; from Progonoblattina it is readily separable by the unim- portance of the externomedian area; Oryctoblattina differs from it in its excessive and peculiar development of the mediastinal area with its inferior branches, and by the exces- sive narrowness and length of the mediastinal area, as well indeed as by nearly every other feature in the wing ; while Petraljlattina, with the extraordinary development of its externomedian area, formed of longitudinally directed but yet superior branches, can be confounded with no other.
This genus is by for the most numerous in species of all the carboniferous types, a third of the species belonging to it ; it is, however, almost exclusively European, for only two American species fall into it, one of these the first described from America ; this is not a little curious, for the first knoAATi fossil cockroaches of the European coal measures also fall into this genus.
Etoblattina primaeva. PL 3, fig. 7.
Bkitima jyrimaeva Gold., Sitzungsb. math-nat. CI. k. akad. Wiss. Wieu, ix, 38 ; — lb., Pa- laeontogr., iv, 22, taf. 3, fig. 4 ; — lb., Foss. Ins. Saarbr., G, taf. 1, fig. 4 ; — lb., Jahresb. Gymn. Saarbr., 16 ; — lb.. Faun, saraep. foss., i, 16, taf. 2, fig. 13 ; — lb., Faun, saraep. foss., ii, 19, 51 ; — Gieb., Ins. Vorw., 316 ; — Bronn, Leth. Geogn., 3 aufl., i, ii, 683, tab. 9', tig. 15*; — Heer, Viertelj. naturf. Gesellsch. Zurich, ix, 288 ; — Roem., Leth. geogn., tab. 47, fig. 18 ; — Gein., Geol. Steink. Deutschl., 149.
The front wing has a very regular ovate form, and is broader iy proportion to its length than any other species of Blattina, being only twice as long as broad ; be3'ond the expand- ing base, the front margin is very gently convex, and the hind border, at first nearly straight, tapers considerably in the apical half; the apex is very broadly rounded. The veins originate in the middle of the whig, but all curve at first upward, and where the middle ones assume a general longitudinal direction, the externomedian is considerably above the middle. The mediastinal vein passes with a very slightly sinuate course to a short distance beyond the middle of the front margin, emitting five or more sunple or simply forked oblique branches. Beyond the basal curve, the main stems of the scapular, extemo- and internomedian veins are longitudinal, nearly straight, and parallel ; the first terminates in the upper and the last in the lower part of the tip, leaving only the central part of the apical margin in the possession of the externomedian vein. The scapular vein branches from its base and emits about five branches which are generally simply forked, and the last of which runs parallel to the extremity of the main stem. The externomedian is forked before the middle of the wing, its branches approximate and simjily or doubly
S. II. SCUDDKR OX I'AI.AKOZOIC COCKUOACIIES. 59
forked. The internomedian is scarcely arcuate, so that the area it covers narrows princi- pally by the curvature of the inarj,'in ; the vein emits four or five simply or doubly forked branches. The anal furrow is strongly arcuate on the ba-sd, straigiit on tiie apical hidl", and terniinates at the niidille of the inner margin; the anid veins, eight or nine in nunilnr. are simple, parallel, and gently arcuate.
The single specimen of the wing known is blackish brown, perfect, excepting the extreme tip, the costal Ijorder distinctly marginate ; the veins are distinctly pronounced, ijnd the interspaces filled with delicate transverse veins, running from the veins and not meeting tho.se of the opposite vein directly, but fonning by tiieir mode. of union pentag- onal, .'sometimes tetragonal, cells, which can be seen by the naked eye ; those toward the apex of the wing being larger than the others. Length o'J nun., I)readth Id nnn., or tiie breadth to the length as 1 : 2.4.
Goldenberg compared this species, which is of large size and one of the largest of the genus, Avith Etohl. carhonaria, but like the following species it is distinguished from other Blattinariae by the unusual breadth of the wing as compared with the lengtii ; and in this respect this species is the more remarkaljle, being only twice as long as broad ; it is al.>*o readily distinguished from the following by the rapid narrowing of the mediastinal area, and by the brevity also of the same area.
Several specimens have been found in the Auerswald coal-seam in Gersweiler near Saarbriicken, Germany. Upper carboniferous.
Etoblattina labachensis. PI. 3, fig. 5.
Blattina anaglyptica var. labachensis Gold., Vorw. Fauna Saai-b., IG ; — lb., Faun. .';araep.
foss., i, 16, taf 2, fig. 15 ; — lb.. Faun, saracj). fo.ss., ii, 19. Blattina labachensis Gold., Faun, saraep. foss., ii, 51.
The front wing has a regular obovatc form, a very little more than twice as long as broad, the sides nearly parallel. Beyond the base, the costal bonier is broailly convex, the inner border very nearly straight, the aj^ex very regularly and Iiroailly rounded. Tiie veins originate near the middle of the wing and have scarcely any basal curve. The mediastinal vein is very long and scarcely sinuate, teraiinating beyond the middle of the apical half of the costal border, which is unusual in this genus ; it emits a large number of generally simple or forked oblique branches, and is it.self so far from the border as to make the area very broad, about one-third the breadth of the wing in the middle. The limit between the scapular and externomedian areas cannot be certainly determined, cither from Goldenberg's illustration or description ; but is probably, almost certainly, as marked in our plate, where the latter is exceedingly narrow, as in the preceding species, occupying the extreme tip ; both the principal stems are longitudinal and straight, and both probably fork near the middle of the wing, to judge from the incomplete course of those given in Goldenberg's illustration, and the branches sometimes fork singly, all the forks having a longitudinal direction, parallel and close to each other. The internomedian bends a little from the longitudinal course of the other veins toward the inner border, while passing over the anal ai-ea, but beyond that is nearly longitudinal, scarcely arcuate, terminating only a little below the tip of the wing, making the internomedian area, like the mediastinal, of luiusnal length for a snccies of this genus, by which it seems to have some affinity to Gera-
60 S. II. SCITDDEE OX PALAEOZOIC COCKROACHES.
blattina; tho area is also of unusual 0(iuality, occupying like the mediastinal about one-third the breadth of the wing ; the main vein emits four or five branches, which may be simple or forked, but all have a nearly similar oblique direction. Tlie anal furrow is, apparently, not especially distinct nor marked as an arcuate vein, but is nearly straight, terminating at the middle of the inner margin, and, like the other anal veins, following the direction of the internomodian veins ; as no mention is made of the innermost region of the wing by Dr. Coldenljcrg. perhaps his illustration is foulty at this point, as indeed it would be rather anomalous ; more proljably the species would not be found to differ greatly in this respect, from the preceding.
This species has a brownish colour, and a delicate reticulation, formed on the same gen- eral plan as that of the preceding species. It is of comparatively small size, being 20 mm. long and 9 mm. broad, or the breadth to the length as 1 : 2.2.
It was at first considered a variety of Etohl. onaglyj^dca by Goldenberg, but aftenvards separated by him. He noticed at the outset the smaller size and broader shape, but it also differs decidedly in general shape, in the far smaller extent of both the scapular and inter- nomedian areas, the length of the mediastinal area, and the widely different distribution of the veins in the internomedian area. The breadth of the wing separates the species at once from all the other species of Etoblattina excepting the preceding, and it is also pecu- liar, as remarked, for the great length of the mediastinal and internomedian areas, although in the last point other species of Etoblattina equal it. It differs from the preceding species by its much smaller size, its broader tip, and the small extent of the scapular area.
Several specimens have been found in the coal shales of the Labach coal seam near Saar- louis, Germany. Upper carboniferous.
Etoblattina euglyptica. PI. 2, fig. 16; pi. 4, fig. 7.
Blattina euglyptica Germ., Verst. Steink. Wcttin, vii, 80-87, tab. 31, figs. T'', T'', 8 ; — Gieb., Ins. Vorw., 315; — Heer, Viertelj. naturf. Gesellsch. Zurich, ix, 287; — Gold., Fauna saraep. foss., ii, 19.
Compare also the synonomy of Etohl. Dohrnli, Gerahl. i^roduda, and G. weissiana.
The front wing is long and slender, having a very regular and rather strongly arcuate costal margin and a straight inner margin ; the tip in the specimens known is broken, but there is no reason to suppose it to have been other than regularly rounded. The veins originate in the middle of the base, but immediately curve upward, so that the mediastinal area is narrow and equal, occupying about one quarter of the width of the basal half of the narrow wing, the main vein reaching somewhat beyond the middle of the wing, and emitting about nine oblique, simple branches. The scapular vein, curving somewhat strongly near the base, is beyond it nearly straight, rather distant from the mediastinal, and terminates at some distance short of the tip, commencing to divide at some distance before the middle of the wing, and emitting three or four long branches, which fork midway in their course, and are somewhat more longitudinal than the mediastinal branches. The extemomedian vein is very similar to the preceding, and approximates it rather than the internomedian vein, while its coui'se assumes the curve of the latter ; it begins to divide at the middle of the wing, and emits three or four strongly divergent but nearly longitudinal branches, which fork again and occupy with these forks the entire apex of the wing, en-
S. IT. SCUDDER OX I'ALAKOZOIC COCKllOACIIES. 61
croacliing a little upon the costal and especially upon the inner margin. The internomedinn vein is somewhat arcuate at .the base, curving upward to above the middle of the wing, but afterwards extends to the inner margin in a nearly straight, arcuate course, ternjinatiiig probably at .«ome distance beyond the middle of tlie apical half of tiie wing, and emitting six or .seven simple, oblique, straight, parallel and rather distant l>ranclies. The anal fur- row is distinct, sharply arcuate, and terminates near the middle of the basal third of the wing, the four or more rather distant simple anal veins being subparallel to it but le.s.s curved.
Two specimens were descril)ed by Germar, l)oth plainly belonging to the .same species,' which is a large one, the wings measuring 10. -O mm. in I)readth, and the longest fragment 31 mm. in length ; the entire length was probably 3.3 mm., and the breadth to the length as 1 : 3.1-4. The specimens subsequently referred to this species by Goldenberg not only do not belong to it, but are referable to several distinct species (cf. Etohl. Dohrnli, Gerobl. producta, and Gerahl. iceissiana).
Hind wing. One of the specimens figured by Germar has. besides the larger part of the left fore wing, broken fragments of the two hind wings, one of which, the left, we have reproduced on pi. 4, fig. 7. These show that the neuration of the hind wing was very sim- ilar indeed to that of the front wing. The mediastinal vein extended further toward the tip, but was somewhat similarly formed. Tlie scapidar vein had the same general arrange- ment and proportional extent. The same is true of the externomedian vein, excepting that the branches appear to be inferior instead of superior ;' but of the rest of the wing nothing can be d termined ; the interspaces throughout are of the same width. From the distribu- tion of the veins it would appear as if the anal field were plicated, and this Germar asserts, but the fractm'ed condition of the fossil does not allow of certainty, .so far as the illustra- tions show.
It would appear from Germar's figure that there is some difierence in the venation of the two wings ; the mediastinal area appears much longer, for instance, in the right than in the left wing. On the right wing an additional principal vein, the marginal, extends down, next the costal margin, as far as the middle of the wing, but this portion is broken from the left wing.
This species is one of the largest of the slender forms of Etoblattina, the front wing having at the same time a more equal width than usual. In this particular it differs from the preceding species conspicuously ; from Etohl. affinis, to which it appears to be most nearly allied, it diflers in its very much greater size and in the more distant neuration. From Etohl. Dohrnii, which was referred to the same species by Goldenberg, it differs in the course of the mediastinal vein, which is parallel to the costal margin ; probably also by the smaller extent of the internomedian area apically ; and by the form of the wing, Avhich has a more strongl}' convex costal margin, and especially an arcuate base which bends the roots of all the vems downward, instead of leaving them straight as in the latter species ; . it is also a little larger.
The two specimens come from Wettin, Germany. Upper carboniferous.
iGiebel says tliat the two fore ivings figured by Germar stood when perfect wings are discovered"; but the differ- "show some differences, whose meaning will only be under- enccs are so very slight that they cannot have specific value.
02 S. II. SCUDDER OX PALAEOZOIC COCIvROACHES.
Etoblattina aSinis. TI. 2, fig. 2.
Blatt'tna affilms Gold., Nouos Jalirb. f. mhienil.,, 1SG9, 15t>, taf. 3, fig. 3 ; — lb., Faun. saraep. fos.'?., ii. 10.
The front wing is long and slender, straight and a little tapering beyond the base ; both costal and inner margin arc nearly straight almost to the tip, which is well rounded. The veins originate a little above the middle of the wing, and curve a little upward in passing from the base. The mediastinal vein is arcuate, subparallel to the costal margin and rather close to it ; the area occupies one-fourth the breadth of the wing, and terminates at some distance be3-ond the middle of the wing, emitting a 'large number of oblique, generally simple, approximate branches. The scapular vein is also arcuate but much more gently, rather distant from the mediastinal before branching, and terminates just before the ex- treme tip of the wing ; it commences to divide near the middle of the wing, and emits about five long, straight, simple or simply forked branches, closely approximate, and pre- serving very nearly the direction of those of the mediastinal area. The externomedian vein has a course very similar to that of the preceding vein, commencing to divide at nearly the same point, and emitting three or more compound or irregularly forking, closely approximate, longitudinal veins, occupying at their extremity a narrow area at the apex and the extremity of the inner margin of the wing. The internomedian vein is gently arcuate, having a nearly straight course from scarcely above the middle of the base of the wing nearly to the end of the innei» margin, emitting a large number of slightly sinuate, subparallel, simple or simply forked branches, oblique toward the base of the wing, and gradually more longitudinal toward the apex. Anal area unknown.
The single specimen known is perfectly preserved, with the exception of the minor veins near the base of the wings and the anal furrow ; it is a small sj^ecies, being only 17 mm. long, and 5 mm. broad, and the breadth to the length as 1 : 3.4.
This .species is one of the slenderest of the smaller species of Etoblattina, and is peculiar for the straightness and gently tapering form of the front wing ; in its form it most resem- bles Etohl. leptophlehica, from which it differs a good deal in neuration, and especially in the les.ser breadth of the scapular area and the less crowded disposition of the veins. Goldenberg considered it as coming between this species and Etohl. anarjhjptica, but its much c\oi^(iV a^Yiiiy to Etohl. Jlahellata must be conceded; from this species it diffei's par- ticularly in its straight costal edge and its longer mediastinal area ; it is also a slenderer species. From the species which precedes it it is sufficiently separated by its very much smaller size, as also by the straight costal margin.
One specimen. Lubejiin, German3^ Upper carboniferous.
Etoblattina flabellata. PI. 2, fig. 4.
Blattlaa flabellata Germ., Miinst. Beitr. z. Petref., v, 92, tab. 13, fig. 4% 4*^; — Gieb., Deutschl. Petref., 637;— Heer, Viertelj. Naturf. Gesellsch. Zurich, ix, 287; — Gold., Faun, saraep. fo.ss., ii, 19. (Not Bl.flahellata Germ., Verst. Steink. Wettin.)
Blattina anthracophila E. Gein., Neues Jahrb. f. Mineral., 1873, 094, taf 3, fig. 2 ; — lb., Yerst. unt. Dyas Weiss., 4, taf., fig. 2. (Not Bl anthracojMla Germ.)
Compare also synonymy imder Gerahl. Munsteri.
S. 11. SCUDDER 0\ I'ALAKOZOIC COCKROACHES. 03
Tlie front wing is \o\v/ ami slcii'lor. of only slij^litly xmoqual broa<ltli, the costal ImnkT beinjr gently convex and the inner bonier nearly straight nntil near the tip, wliile the tip itself is well rouniled. The veins originate consideralily above the niiildle of the bjuse, and curve somewhat so as to be subparallel at fii-st to the costal margin. The mediastinal vein is pjirallel to and not distant from the costal border, the area being less than one lourth the width of the wing, and terminates at or a little beyond the middle of the wing, emit- ting a considerable number of oblique, usually simple branches. The scapular vein is .some- what distant from the preceding and also runs very nearly parallel to the costal margin, along the base of the anterior third of the wing, terminating just before the tip of the wing; it commences to branch just as the mediastinal connnences to bend towanl the costal margin, and has four or five, generally simply forked, occa.sionally simple, branches, which have a direction very similar to that of the mediastinal branches, although much longer than they. The externomedian vein is rather strongly sinuate, commences to branch directly opposite the first dividing of the scapular vein, and emits at rather large angles four or five branches, which are usually forked once, but, in two of the s[)eeimens known, one of the forks of the second branch again divi<les ; the branches occupy on the margin the entire apex of the wing, the main vein following very closely the course of the succeeding vein. The internomedian vein is also strongly arcuate, and beyond the middle of the wing assumes a more longitudinal course than before, extending the area very nearly to the ex- tremity of the inner margin ; toward the base this area, with the anal, occupies more than half the breadth of the wing. Init it narrows rapidly beyond, and the vein emits a number of branches, the ba.sal half of which are simple, straight, oblique, and comparativel}- distant, •while the apical half of the same are simple or simply forked and considerably more longi- tudinal. The anal furrow is distinct, very strongly and regularly arcuate, and terminates at the end of the basal third of the wing ; the anal veins are few, simple, similarly arcuate and parallel.
The species is a comparatively small one, the front wing measuring lj-17 Tiim. in length and G-6.0 mm. in breailth. the breadth to the length being as 1 :2.-3G. Geinitz describes his specimens as supplied with delicate cross-veins.
Germar described two species under this name, which I have of course retained for that bearing the earliest date, described in Miinster's Beitrage. The other, described b}' Germar in his Carboniferous fossils of Wettin, is redescribed further on under the name of Gerahl. Mi'msteri, where also the points of departure will be noted. Dr. E. Geinitz, in his fossils of Weissig, has figured the present species with brief remarks, comparing it to Gennar's Bl. anthracophila, and giving it that name in the explanation of the plate where it is figured ; the points of resemblance pointed out by Dr. Geinitz are the simple character of the basal branches of the internomedian vein, the sudden assumption of a longitudinal direction of the same vein beyond the middle of the wing, and the simple character of the anal veins. With Etohl.jlabellata he says it does not agree on account of the structure of the medias- tinal area ; but it is evident from this remark that he has compared it, not with the true Etohl.flabeUata, but with Gerahl. M'dnster'i, and that his comparison i.s, therefore, in great measure justifiable. In all the points of his comparison with Elohl. anthracophila, how- veer, it agrees even better with the true Etohl.flaheUata, with which it also agrees in the distribution of the externomedian branches and in size, points in which it is at variance with Etohl. anthracophila. Had Dr. Geinitz compared his specimen with the illustrations
C4 S. n. SCUDDER ON PALAEOZOIC COCKROACHES.
of Gonnar's species as given in Miinstcr's Beitrilge, lie would certainly Lave come to a dif- feRMit conclusion.
As indicated above, the species is very closely allied to Etohl. anthracopMla, from which it dilVers in the points mentioned, as well as in the greater narrowness of the mediastinal area, and in the less arborescent branching of the extremity of the internomedian area. From Etohl. afflnis, with which it agrees in size, it differs in its rather shorter mediastinal area, the wider interspaces of the externomedian area, and in the shape of the wing, the costal margin of which is more convex and the whole wing not so slender.
Germar's single specimen came from Wettin, Germany. Upper carboniferous. The two specimens described b}' Geinitz, from the lower dyas of Weissig.
Etoblattina anthracophila. I'l. 2, fig. 1.
Blatt'ina antliracophila Germ., Miinst. Beitr. z. Petref., v, 92-93, tab. 13, fig. 3 ; — lb., Verst. Steink. Wettin, 8-1 (" ? = Bl. cmaglyj^tka ") ; — Gieb., Deutschl. Petref., 637 ; — Heer, Viertelj. naturf. Gesellsch. Zurich, ix, 287 (" = Bl. anacjlyptka ").
Compare the synonymy of Etohl. flahellata.
The front wing is of medium size, rather slender and regularly tapering, both costal and inner margin very gently convex, the tip broken in the only specimen known, but probably rather contracted and well rounded. The base of the veins is not preserved. The medias- tinal vein terminates a very little beyond the middle of the wing, and the branches, the apical ones at least, are tolerably distant, simple, and a little curved ; the area is rather broad, occupying in the middle more than a quarter of the breadth of the wing, and nar- rowing throughout nearly the whole of the ajiical half; the basal half or more unknown. The scapular vein is very closely approximated to the mediastinal, begins to divide before the middle of the wing, or opposite the last branch of the mediastinal, and has an arcuate course beyond this, the convexity downward, and terminates a little before the apex of the wing ; the branches are about six in number, having a direction parallel to those of the mediastinal vein, simple or forked (in the specimen cited, the first two are forked, the oth- ers simple), and the branched portion of the area occupies about one-third of the breadth of the wing. The externomedian vein is broadly sinuous, its curve in the fragment pre- served, and the location of the other veins, indicating that it curved rather strongly at base ; it commences to branch with the scapvilar vein and emits two or more very long branches, the first of which is compound and the second simple in the specimen ; the vein occupies a long and very narrow area in the middle of the wing, and on the margin the entire tip and a portion of the extremity of the inner border. The internomedian vein is also sinuous, being at first probably arcuate, then straight and very gradually approaching the inner margin, until a short distance beyond the middle of the wing, when it assumes a longitudinal direction, and finally curves downward to the border in the middle of the api- cal fourth of the wing ; it throws off a considerable number of veins, those emitted before it a.«sumes a longitudinal direction being straight, oblique, simple and rather distant, those beyond being simple and compound, and rather closely approximated. The anal fuiTOw is rather strongly and regularly arcuate, terminating at about the end of the basal third of the wing ; the anal vein.s, about six in number, ai-e simple and subparallel to the furrow.
S. II. SCUDDKU ON PALAEOZOIC COCKHOACIIES. Co
The species Is of mediiun size, tlie fraj,'ineiit of the sin<rle front \viii<^ which is preserved measuring 24 ram. ; the length of the wing is prohably about 2o or 2(j mm. ; the breadth is 9.5 mm. in the middle, making the length to the breadth as 1 : 2.7, but the breiulth is probably a little greater toward the hiisi^.
After describing this insect in Miinster's Ik-itriige, Gcrmar concluded that it was pn)l)ably the same as his Bl. anaijli/pfirrt, described in the same place, and subsequent authors have accepted this assumption, apparently without any .special e.\amination of the matter, with the exception of Dr. E. Geinitz, who has referred to this species a wing described by him from Weissig. Eiohl. anthracophila, however, differs from Etohl. anntjhjptiva in several important points : the mediastinal area is a little shorter; the branching of the scapular vein more closely resembles tli;rt of the mediastinal, originates fartiier towards the middle, and is less arborescent, and the distribution of the externomedian bran(;hes is less regular ; besides this the shape of the wing, and especially the curve of tiie costal border, is very different. The wing referred by Geinitz to Etobl. anthracophila is, however, to be consid- ered as belonging to Etohl. flahellata and not to this species, for the reasons mentioned in the remarks here appended to the description of Etohl. flnhcUuta. Our present species is indeed closely allied to the last named, but may be .separated from it by the greater breadth of the mediastinal area, the approximation of the scapular to the internomedian vein, the greater narrowness of the .scapular area, the greater marginal extension of the externome- dian area, and the more arborescent branching of the internomedian veins in the outer half of the wing ; it is also considerably longer. It is also somewhat larger than Etohl. loels- sir/ensis, which stands very close to it, and differs also by the tapering form of the wing, the larger marginal area of the externomedian area, and in the branching of the veins of the same area ; tliis is both less regular and commences much farther toward the b;tse of the wing; at the same time the vein itself is much less sinuous than in Etohl. weissif/ensls.
The single specimen known comes from Wettin, Germany. Upper carboniferoas.
Etoblattina Tveissigensis. PI. G, fig. 5. Blattina weissigensis E. Gein., Xeues Jahrb. f. Mineral., 1873, G92-94, taf 3, fig. 1 ; — lb., Verstein. unt. Dyas AVeiss., 2-4, taf, fig. 1 ; — lb., Xeues Jahrb. f. Mineral., Mil'), G ; — lb., Neue Aufschl. Dyas v. Weiss., G.
The front wing is long, slender and equal, the costal margin rather gently and ver^- reg- ularly convex, the inner margin straight with a very slight and very broad median excision, the apex weU rounded, and almost produced. The veins originate from the middle line of the Avmg, and curve rather gently upward before assuming a nearly longitudinal direction. The mediastinal is parallel to the costal margin, curving rapidly to meet it a little beyond the middle of the wing ; the area occupies nearly a third of the breadth of the wing, and possesses comparative!}' few and very distant oblique branches, most of them rather deeply forked. The mediastinal vein is in close contiguity to the mediastinal, is also parallel or subparallel to the costal margin, and jjeginning to branch where the mediastinal begins to curve toward the margin, emits a considerable number (about seven) of rather crowded branches, most of which are simple, gently arcuate or sinuous, and whUe less oblique than those of the mediastinal area, are similar in distribution ; in the single specimen known the first of the branches is compound, the rest simple ; the vein terminates just before the tip. Beyond the basal curve the externomedian vein is straight untU it branches, a little beyond
MEMOIBS BUST. SOC. NAT. HIST. VOL. m. 9
66 S. IT. SCrDDEll OX PALAEOZOIC COCKROACHES.
the miilillo of tho wing- ; hoyoiul this it emits two or three sometimes forking branches, whii'li are lon<ritiulinal anil nearly approximated, so that the marginal extent of the area is very slight, ocoviining only the very tip of the wing. The hiternomedian vein, running con- tiguous with the preeetling in the basal curve, parts rather rapidly from it, being directed at fii-st toward the middle of the outer half of the inner border in a nearly straight course, until opposite the branching of the e.xternomedian vein, when it assumes a slightly arcuate, longitudinal direction, and terminates just behind the tip of the wing; in the middle of the wing it is therefore very distant from the externomedian vein, which it afterwards rapidly approaches ; in the basal portion, the distribution of the veins is very similar to that of the scajndar area, but they are distant ; beyond they are more frequent and arborescent, the branch originating at the point of change in the main vein, emitting a compound branch- let, which repeats the distribution of the branches of the main vein beyond it. The anal furrow is distinct, strongly arcuate, somewhat bent in the middle, rather distant from the internomedian vein and its first branch, and terminates at the end of the basal third of the wing ; the anal veins are frequent, simple, arcuate and parallel to the furrow.
The wing is of rather small size, being 19 mm. long, and 6 mm. broad, or the breadth to the length as 1 : 3.17 ; the veins of the middle of the wing are very sharply defined, and the surface is delicately granulate.
Dr. Geiuitz compares this species with Etohl. anaglyptica and Etohl. leptophlebica, and in a secondary' way with Bl. affinis. It is indeed related somewhat closely to these species, and especially to the first named, and in form resembles best, though not very well, the two last named ; but in essential features it has closer affinities with Etohl. anthracophila, which is somewhat larger than it, and is otherwise distinct from it by its general form and by the distribution of the branches of the externomedian vein, which divides much nearer the base, and occupies a larger marginal area than in Etohl. anthracopthila ; the branches of the basal portion of the internomedian vein are also much closer together in the same species.
The single specimen described by Geinitz came from Weissig, Saxony. Lower Dyas.
Etoblattina Dohrnu. V\. 2, fig. .5.
Blattina euglyjit'ica pars Gold., Neues Jahrb. f. Mineral., 1869, 162-G3, taf. 3, fig. 8 (nee 9).
Not Bl. emjlyptica Germ. Compare also sjnionomy of Gerahl. p)i'oducta.
The front wing is of a very regular shape, tlio tip being well rounded, and the upper and lower halves almost exactly alike in form, the costal and inner borders gently convex; the wing is largest in the middle, scarcely tapers toward the base, but more rapidly toward the tip, and especially near the apex. The veins originate together considerably above the middle of the wing, and have scarcely any, if any, basal curve. The mediastinal vein is straight, and terminates a little short of the extremity of the middle third of the wing, and emits, mostly from near its origin, half a dozen very long and unusually longitudinal simple veins ; next the base the area occupies nearly one-third the breadth of the wing, and it tapers very gradually on its apical half. The scapular vein is also nearly straight, cur^X'd upward toward the costal margin only near the tip, and terminates just before the apex of the wing ; it runs parallel to the costal margin along the middle of the anterior
S. II. SCUDDEU ON rAl.AKo/.oIC COriaiOACHES. 07
two-thirds of the wing, coinineuces to <Hvi<lL' he-fure tlie miildk' of the winjr, ami fiuils only two or thri'O simple or forked branches, having the course of the apical branclii-s of the preceding vein. The externoniedian vein takes a .straight course nearly down tiie middle line of the wing, doe.s not divide until pa.st the centre, and then emits two or three com- pound or forking branches, which spread at a consi<lerable angle and occupy the entire apex of the wing. The internomedian vein, scarcely arcuate throughout most of it« course, and slightly more longituilinal toward the extreme tip, terminates on the inner margin just I)efore the apex, opposite the extremity <jf the scapular vein, ami emits oidy a few rather distant .straight or occasionally forke<l luanches.' The anal furrow is not very strongly arcuate, and terminates at about the end of the ba.sal two-hfthsof the wing; the anal veins, about five in number, are rather distant, similarly or less arcuate, mostly simple, or when forked, but slightly so.
The wing is of medium size, inea.suring about 20 nun. in length, and KL-'j mm. in breadth ; or the breadth to the length is as 1 : 2.5.
The wing is peculiar for its s3Mnmetry of f(jrin, and the straightness and longilndinality of the veins, and particularly for the very longitudinal direction and b;usal attachment of the veins of the mediastinal area. It is not very closely allied to any species ; from the true Etohl. eutjhjptica, which Dr. Goklenberg considered it to be, it differs in form and size, and in the branches of the media.stinal area ; from Gerahl. producta, which Goldenberg placed in the same species, it differs in the brevity of the mediastinal area and the nature of the branches in the same, in the origin of the division of the externomedian vein, and in the gradual narrowing of the internomedian area. It is perhaps most nearly allied to Etohl. weissigensis and Etohl. anthracophila ; from the former it is sufficiently distingui.shed by its form, as well as by the distribution of the apical branches of the internomedian area, and the great length of the branches of the mediastinal vein ; from the latter by the nearly uniform breadth of the wing and the same peculiarities of neuration. I have placed the American Etohl. Lesquereuxii beside it, but it is not very nearly related, the branches of the mediastinal and also of the anal area being very diiferent, while the whole wing in Etohl. Lesquereuxii is larger and much less bilaterally symmetrical.
A single specimen is known, and was found at Wettin, Germany. Upper carboniferous.
Etoblattina Lesquereuxii nov. sp. PI. G, figs. 3, 4. (See also figure in te.vt below.)
Front wiug. This is long and .slender, the costal margin very uniformly and consider- ably convex, the inner margin straight or scarcely convex, the whole wing nearly erjual, the apical fifth tapering, the tip well rounded. The veins originate at about the middle line of the wing, the mediastinal and the united anal and internomedian in rather prominent ridges, the scapular and externomedian in a furrow between them ; all together curve upward at first before assuming a more longitudinal direction, so that at the parting of the anal and internomedian veins, the anal area has more than half the width of the wing. The mediastinal vein runs subparallel to the costal margin, but continually and very grad- ually approaches it, much as in Etohl. Dohrnii, striking it at an unusually slight angle at a pomt a little beyond the middle of the whig ; it emits about nine equidistant, and rather
1 In my plate the anal furrow is incorrectly represented as one is the anal furrow, so that there is one less vein in the being a forked vein ; in reality the vein following the forked internomedian area than is represented.
6S S. II. SCFDDER ON PALAEOZOIC COCKROACHES.
distant, simple, curving branches (the basal ones not represented on the plate), of which the ba.-^al ones are obliqne while tliose beyond grow more and more longitudinal. The scapvilar vein runs very nearl^• parallel to the costal margin, most nearly approaching it whore it fu*st divides, a little beyond the end of the basal third of the wing, and then, pa.«sing in an arcuate cour.se oppo.sed to the curve of the costal niargin, reaches the latter just before the ape.x of the wing ; it emits about four branches, the terminal one sim- ple, the others forked and the second even trebly, tlie general direction of all being less longitudinal than the apical branches of the mediastinal vein ; at the widest the scapular area is two-fifths the breadth of the wing. Beyond the basal curve the externomedian vein is straight until it divides, at some distance beyond the middle of the wing, and up to this point it is unusually distant from the scapular vein on the one side and the inter- nomodian on the other ; at its division, that is, at the origin of its first branch, it turns abruptly but slightly downward, and runs subparallel to the apical portion of the costal border ; its first branch is doubly forked, the ofishoots inferior and thrown off at nearly equal distances from the origin to the tip of the branch ; the two other branches of this vein are simple, longitudinal and nearly straight, the last arising before the end of the middle third of the wing, and the middle one mid- way between the first and third ; all together occup}' the entire tij) of the wing ; the origin of the middle branch being incorrectly given in our plate, a cor- rected figure of the apical half of the internomedian vein is here inserted. The internomedian vein is straight from a little beyond its separation from the anal to its last branch, and is thence feebly arcuate in a slightly more longitudinal course, terminating a little farther from the tiji than the scapular vein ; it emits four simjile or forked, very distant, slightly arcuate branches ; Efobiafiina in the Specimen upon which the description is based, the two middle branches are simple, the others forked. The anal furrow is very distinct, especially on the basal half, rather strongly and pretty uniformly arcuate, terminating at the basal two-fifths of the wing ; the anal veins are numerous, being six or seven in number, and generally forked, often very deepl}^, and excepting the extreme short ones, are gently arcuate in the same sense as the furrow.
Tlie wing is of medium size, being 25 mm. long, and 9 mm. broad, or the length to the breadth as 1 : 2.78.
It appears to present the under surface of a left wing, as the anal fm:row is in relief. The principal veins and branches are also in delicate relief and distinct, excepting the anal veins. The surface of the wing is glistening and, excepting on the apical third, flat ; toward the apex, and especially on the apical fifth, the interspaces are broadly furrowed, leaving the veins in sharp relief In this part of the wing also, and indeed over nearly the whole surface, but less distinctly than here, the interspaces are broken by a delicate tracery of minute, irregular, pentagonal or rhomboidal cells, changing toward the base to a series of closely approximate, obscure, transverse lines, at right angles to the neigh- boring veins, and often forking feebly.
In the extent and distribution of the branches of the scapular and externomedian veins, as well as .somewhat in the form of the wing, this species reaemhles Ulobl. iceissigensis, but it differs very much from it in the nature of the mediastinal vein, besides being a much larger insect. It agrees best with Utobl. Dohrnii hi size and in the general limitation of the
S. II. SCUDDKR OX PALAEOZOIC COCKUOAC IIKS. 09
various areas, Ijut the sha])i' of the wiiij^ dilVeis <'oiisiileral)ly, ami the lii'anches ol' tlie ine«li- nstiiial vein arise at e(Hial distances all along the [jrineipal vein ; the anal area too is larger anil more crowded with veins. From Elohl. uimijlijptk-n, to which it is closely allied, it nniy be distinguished by the brevity, .slenderne.s.s, and diminishing extent of the media-stinal area, 08 well as in the later division and more longitudinal direction of the externomedian vein. In the characteristics of the mediastinal and scapular areas and their relations to eac-h other it reseml)les both E(ohl. (ijfini.t and J'Jfohl. jlabclUdit, but it dillers from both in the more apical division and diflerent distril)ution of the externomedian branches. Finally it is read- ily di.stiuguishable from the other American species of this genus, J'Jlohl. viniisht, in the nature of the mediastinal area, and the less arborescent distributi(jn of the branches of the scapular vein.
Tlie single specimen kmnvn was obtiiineil by Mr. K. I). Lacoe ; it is pre.served on a piece of carbonaceous shale picked up near Pittston, Peun., in a pile of culm, and is con- sidered by him as doubtless coming from the roof shales of the D seam of unthracitu (of Prof. Lesley's classification). Middle carljoniferoas.
Etoblattina anaglyptica. PI. 2, fig. 1.").
Blattinn annghjptica Germ., Miinst. Beitr. z. Petref., v. 92, taf. 13, fig. 2; — lb., Verst. Steink. Wettin. vii, 84, tab. 31, fig. 4; — Gieb., Deut.schl. Petref., Go7; — lb., Ins. Vorw., 314-15; — Ileer, Viertelj. naturf. Ge.sellsch. Ziirich, ix, 287; — Gold., Faun, saracp. foss., ii, 10.
Compare al.<o the synoiiyniy o'i Etohl. anfJtracojjhila and E. luhnchensls.
The front wing is long and tolerably .slender, the costal border strongly arched, while the inner border is straight; the tip is broken, but is probably well rounded. The veins originate at some distance above the base, and probably curve upward a little^ at first. The mediastinal area is very narrow, occupying not more than one-quarter the breadth of the ■^^^ng, the vein running subparallel to the margin and terminating beyond the ba.sal three-fifths of the wing; it emits a large number of rather clo.sely approximated oblique branches, mostly simple, occasionally forked. The scapular vein is somewhat distant from the mediastinal, and has a broadly sinuate course, terminating shortly before the ajjcx of the wing; in the middle of the wing the area occupies considerably more than one-third of its entire breadth, and, commencmg to branch as far back as the end of the ba.sal third of the wing, it emits three or four, mostly forked, sometimes doubly forked branches, having a direction very closely parallel to the branches of the mediastinal vein. Tlie externomedian vein, beyond its basal curve, is very nearly straight, and terminates at the extremity of the inner margin, so that just the whole apex of the wing is occupied by the externo- median area ; it commences to branch at some distance beyond the preceding vein, but still much before the middle of the wing, and emits three longitudinal branches, each of which forks nearly opposite the origin of the terminal branch of the scapular vein, and most of the forks again divide halfway to the tip, the whole being very regularly di.sposed. The internomedian vein follows the straight course of the externomedian to a short dis- tance beyond the middle of the wing, the area thus rapidly narrowing, and then takes a
1 This does not appear so well in our plate as in the representation by Germar in his Wettin fossils.
70 S. II. SCUDDEIl OX PALAEOZOIC COCKROACHES.
lonjritiulinal course, roaclung the margin only far toward the apex; before this turn in its direction, the vein emits three or four straight branches, most of which are simple, but the la.>*t one emit.s on the outer side a oouijiound branch somewhat similar to the arborescent divisit)n of the main stem at its bend, which (ills the apical half or more of the area with dichotomizing veins. The anal furrow is distinct, strongly and regularly arcuate, tei-mi- nating near the end of the basal third of the wing ; on account of the anterior origin of the main veins at the base of the -wings, the anal area is nearly as broad as it is long, and the anal veins, which arc numerous and approximate, are arcuate, parallel, and mostly simple.
The wing is of medium size, being probably 26 mm. long (the fragment preserved has a length of 2o mm.), and is 10 mm. broad ; or the breadth is to the length as 1 : 2.5. The representation on my plate gives it a very little too small, and especially too short.
Germar subsequeutlj'^ placed his Bl. anthracophila with this species, but wrongly, as I have endeavored to show in my remarks under that species. Goldenberg at one time consid- ered Uennatohl. labachensis as a variet}' of this, but aftei'wards more correctly removed it from that category ; for the princi2:)al distinction in this case also, see the remarks under that species. We have placed it between the two American species of this genus, not because it seemed most closely allied to them, but because their place in the series appeared to lie here. Etohl. anaglypfica, however, seems to be very closely related to Etohl. venusta in most of its featiu-es, but is smaller than it, has a proportionally smaller scapular field and a considerably larger externomedian field ; the distribution of the apical branches of the in- tcrnomedian vein is also more complex in this species than in Etohl. venusta ; fi'om Etohl. Lesqnerenxii it is at once separable by the form of the wing and the greater breadth and extent of the mediastinal area. Among European sj)ecies it is perhaps most nearly allied to Etohl. mcmtidioicles and Etohl. carhonaria, but differs from both of them in much the same particulars as from Etohl. venusta ; it is also larger than they, and especially than Etohl. mantidioides.
The single specimen comes from Wettin, Germany. Upper carboniferous.
Etoblattina venusta. PI. 6, fig. 12.
Blattina venusta Lesq., Owen, 2d Rep. Geol. Ark., 314, pi. 5, fig. 11 ; — Heer, Viertelj. naturf Gesellsch. ZUrich, ix, 287; — Scudd., Geol. Mag., v, 170-77; — Gold., Faun, saraep. foss., ii, 19.
Front wing. The wing has an oblong subovate form, apparently resembling that of Etohl. carhonaria, so far as can be judged from the rather imperfect fragment which repre- sents the American species ; the costal margin, however, is nearly perfect, and is very regidarly and considerably convex — more convex, perhaps, than in any other species of Etoblattina. Althongh the base of the single known specimen is broken, the veins by their curve appear to have arisen near the middle line of the wing, and to have been well arched in running from the base. The mediastinal vein runs subparallel to the costal margin, gradually approaching it in its apical half, and at last rather suddenly impinging on it, at about the end of the middle fifth of the wing ; it emits an excessive number (sixteen or more) of mostly arcuate, simple or forked veins, closely crowded and subparallel, at base nearly transverse, at tip very oblique ; in its middle the area is nearly one-fourth the width
S. H. SCTDDKi: OX l'AI.M.o/( m < ( RKIJOAlUKS. 71
of tlie winj^. The snipular vein runs siil>|i,iriill(.'l to the co-^tal border iiii'l ratlii-r ilistaut IVom it. liiit ilocs not have a re^uhir curve, for it tlivides not far from the eml of the l)a.<al thinl of the winir. and turns from the orij^inal eoiu'so a.-* nmeh a.s does the hran<-li ; it appears, tlierefore, to be foniied of two stems, and each of these emits in a similar manner three branches, the first two forked, tlie hist simple; the distribution of the branches of this vein is therefore arborescent, the veiidets beinj; niaiidy lon;ritudinal. and toj^ether occupvinj^ all the space beyond the meiliastinal vein almost, if not «|uife. to tin- tip. The externomedian vein has a Ijroadly arcuate course, tlw apical portion of which is nearly straijfht; it begins to divide near the middle of the wing, opposite the secondary forking of the scapular vein, and emits four straight longitudinal branches, which, if they fork at all, only do .so next the apical margin ; they occupy a very slender field on the apical margin, apparently more below than above the very a|)ex. The internomedian fol- lows closely the course of the externomedian vein. l)eing nearly straight in its apical half, and terminates shortly Ijcfore the tip of the wing, emitting eight or nine long, arcuate, gen- erally simple, occasionally forked branches, the apical ones more longitudinally dis|)osed than the others, and all tolerably close. The anal furrow is strongly arcuate, and strikes the inner margin certainly before the middle of the wing, perhaps considerably before it ; the few anal veins that can be seen appear to show that they are not verv innnerous and are arcuate next the anal furrow.
The wing is of a tolerably large size, the length of the fragment l)eing 'J4.i"> mm., the probable length of the wing from 28-30 mm., and the breadth of the fragment doubtless that of the whole wing, 12.75 mm. ; the breadth to the length l)eing about as 1 : 2.27. The upper surface of the wing is exposed, and is flat and admirably preserved ; the veins at the base of the wing with their branches, as far as the forking of the scapular, are slightly raised ; beyond this point, the principal veins, although elevated, are sulcate, and the branches of the mediastinal, scapular, and externomedian are feebly impressed, while those of the internomedian vein are slightly elevated ; the anal furrow, in the part l^'ing parallel to the first internomedian vein (the only part preserved), is impres.sed in its ba.sal hali", elevated in its apical half, and then indistinguishable in character from the first inter- nomedian branch, excepting in being a little less sharply elevated and slightly broader ; the cross veins are equalW distinct or nearh' so throughout the wing, and are slightly ele- vated, making a delicate tracery over the wings just indistinguishable by the naked eye ; in the apical half of the wing they are nearly all straight and regularly transverse, but in the basal half, and e.specially in the central' region of the wing, they are more sinuous and interlacing ; this is especially true in the mediastino-scapular interspace, between the first and second branches of the scapular vein, and on either side of the externomedian vein where it first divides.
Although figured by Lesquereux nearly twenty years ago, this first known of American fossil cockroaches has never before lieen described, the remarks in the Arkansas report being only of a general nature. In the strongly curved outline of the costal margin, this species resembles Etohl. anaglyptica, with which it agrees also in the general distribution of the areas ; it is undoubtedly more nearly related to this .species than to any other, but differs from it in many minor points : the veins of the media.stinal area are much more frequent and crowded in Etohl. vemista ; the branches of the scapular vein have a much more arborescent distribution, and its first branch has as many sub-branches as the main stem,
72 S. H. SCUDDER ON PALAEOZOIC COCKROACHES.
while in fJiohl. ana(jh/j)t'u-a it is only simply forked ; the division of the externoniediiin vein couunonces fartiior from the base in Etobl. venus(a,and the apical portion of the inter- nomodian vein does not have a subarborescent distribution as in Etohl. anarjiyptica. In the form of the wings and the distribution of the scapular branches, it shows a certain likeness to Etobl. 7yiantidioides, but its much greater size and more extensive mediastinal area read- ily separate it from that species. The points in which it differs from the only other Amer- ican sjK'cies of the genus will be found mentioned under Etohl. Lesquereuxii.
A single specimen only has been found, which lacks the base and tip, and has a ragged inner margin. It is doubtful whether the dotted line in PI. 6, iig. 12, by Avhich I have in- dicated the supposed outline of the base, is correct, for the curves of all the veins would seem to indicate that too much is represented, as lost ; but as this would represent an anal area of unusual brevity, I have only indicated in the measurements given above the possi- bility of an error in my delineation.
It comes from Frog Bayou, Arkansas, and was obtained by Prof. Leo Lesquereux in black carbonaceous shale, with broken fragments of plants, overlying the thin seam of coal be- tween the millstone grit and the subcarboniferous limestones ; and if the period of deposi- tion of the millstone grit was the same in the eastern and western coal deposits (see the mtroduction). is the oldest, as it was the first discovered of the American fossil cockroaches.
Etoblattina mantidioides. PI. 3, fig. 8. (See also tlie figure on the opposite page.)
Blaita sp. Kirkby, Geol. Mag., iv, 389, pi. IT, fig. 6, 7. Blattidium mantidioides Gold., Faun, saraep. foss., ii, 20.
Tlie single known specimen of this species is composed of only the basal half or more of a front whig, .so that it is impossible to give its shape with any certainty, or to be sure of the . limit between the scapular and externomedian areas. The costal margin is regular and rather gently arcuate, and the inner margin, beyond the basal curve, is straight. This is inaccurately given in our plate as curved like the costal margin, and the terminal portion has therefore been incorrectly restored ; it is for more probable that the shape of the wing was much as in Etobl. carbonaria, and a corrected figure is therefore given on the opposite page. The veins originate above the middle of the base of the wing, and have a gentle basal curve. The mediastinal vein is very short, almost reaching the end of the frag- ment, which certainly does not represent more than one-half of the costal border ; it runs parallel to and not distant from this border, the area occupying less than a fourth of the breadth of the wing; it emits five or six simple or forked, parallel, oblique branches. Between the mediastinal and intemiomedian areas, near to the base of the wing, are three veins; whether the middle of these belongs to the upper or lower — i. e., the scapular or externomedian — cannot be told from the broken specimen ; it appears, however, to branch from the scapular, and this I deem to be the most probable relation of this vein, although it is otherwise indicated on the plate by the mark at the border ; for on first study its approximation, toward the end of the fragment, to the iuternomedian vein seemed to render this its probable relation, and to make me then conclude that its basal union with the .scapular was only apparent ; subsequent study, especially in comjiarison with the species to which it appears most nearly allied, has since made the opposite appear the truth ; and while one cannot be certain of one's ground with so imperfect a fragment, the comparison of this fragment with the more perfect relics of the species near which I have now placed it will convince any one, I think, that its true affinities are here, and that the middle main
s. II. scTDDKi; ()\ PALAFozorr cocFvnoAciir.s. 73
branch probably belongs aoconliiiLrl.v to the scjipular vein. Siipposinj^ thi.s to be ko, the scapular area is very extensive, terininatinji pmbably at or searcely above the tip of tlie wing, and occupying in the middle of the wing ni-arly half its width ; the vein branches very near the ba.se, and each branch divides dichott)niousIy several times, sending forth longitudinal shoots, which in the upper branch at least show, by a certain obliquity, signs of a similarity to the veins of the mediastinal area. The externomedian vein branches dichotomously like the lower branch of the .scapular vein, commencing a little before the middle of the wing; the branches approximate, at least at first, but afterwards probal)ly spread in more or less of a fan shape. The iuternoniedian vein is gently oblique and very slightly sinuous, and, to judge by its a.ssuming toward the end of the fragment a more longitudinal direction, probably terminates far out on the inner margin toward the tip of the wing, the area occupying nearly half the breadth of the wing at the middle; it emit.s a mmiber of parallel, ol)li(|ue, forked, rather distant branches. The anal furrow is strongly and regularly arcuate, terminating at not far from the end of the basal third of the wing; the anal veins are rather numerous, subparallel. nearly straight and usually forked, the forks sometimes terminating on the neighboring veins or on the anal furrow, and so pre- senting a confused appearance.
In addition the wing is described as having the front margin produced and flattened. The fragment is nearly 11 mm. long, representing a wing of com- paratively small size, probably about 18 mm. long; the breadth is about 8 mm. ; the restored portion in the plate is represented as much too short, the breadth to the length being about as 1 : 2.25. The annexed cut is more nearly correct in this particular. Besides the single specimen de.scribed, another fragment, showing one or two veins only, occurred with it, and probably belongs here, for both are similarly marked by a fine and irregular reticulation.
If we have correctly interpreted the parts of this wing, the species is somewhat closely alUed to Etohl. carbonaria, although certainly distinct from it by the brevity of the medi- astinal area and the different distribution of the branches of the scapular vein. In the brevity, although not in the width of the mediastinal area it approaches Etohl. leptophlehica, but the wing does not appear to be so slender, and the distribution of the branches of the scapular vein is again different; from Etohl. russoma, with which it agrees in general features, it differs in its smaller size and the brevit}' of the mediastinal area ; while from Etohl. flahellata, with which it agrees very well in the extent of the mediastinal area, it differs by the very different distribution of the branches of the externomedian vein.
The single specimen came from " the north bank of the Wear, opposite to Claxheugh, about two miles from Sunderland," Durham, England ; from " very near to the top of the coal-measui'es, as developed in Durham." Upper carboniferous, according to the recent classification of Hull.
Etoblattina carbonaria. PI. 2, fig. 3.
Blaftina carhonaria Germ., Verst. Steink. Wettin, vii, 85-86, tab. 31, figs. 6% 6''; — Gieb., Ins. Vorw., 315; — Heer, Viertelj. naturf. Gesellsch. Zurich, ix, 287, No. 3 (not 288, No. 15); — E. Gein., Neues Jahrb. f. Miner., 1875,5; — lb., Neue Aufschl. Dyas v Weiss., 5; — Gold., Faun, saraep. foss., ii, 19, No. 3 (not 20, No. 34).
The front wing has a somewhat obovate form, the costal border being very regularly and rather strongly convex; the tip is broken in the single specimen known, and the inner
MEMOIRS BOST. SOC. KAT. HIST. VOL. IH. 10
74 S. n. RCFDDETJ O^T PALAEOZOIC COCKROACFIES.
border is not continuous, so that its contour cannot bo certainly determined, but it appears to be irentlv convex. The veins start from some distance above the middle of the wing, and curve upward considerably before assuming a longitudinal course. The mediastinal vein continues subparallel to the front border, and terminates scarcely before the middle of the apical half of the wing, emitting seven or eight very oblique, usually forked branches; the area is narrow, scarcely occujiving one-fourth the breadth of the wing. The scapular vein has a sinuous course, diverging slightly from the costal margin and from the medi- astinal vein in the basal half of its course, afterwards converging and terminating barely before the tip of the wing;^ it commences to divide far before the middle of the wing, and anterior to several branches of the mediastinal vein ; its branches are numerous (seven or more"), and simple or forked, having in this respect as in direction, although not at all in length, a resemblance to the mediastinal branches; the mediastinal area occupies two-fifths the breadth of the wing. The externomedian vein beyond its basal curve is nearly straight, and terminates at some distance before the end of the inner border, so that the area occupies rather broailly the lower outer angle of the wing; the vein commences to branch a little beyond the middle of the wing, and emits three or four simple or com- pound branches, which, like those of the preceding areas, are pretty closely crowded. The internomcdian vein follows closely the course of the externomedian, so that the area narrows regularly and rather rapidly ; the vein emits six or seven simple or simpl}^ forked branches, which are pretty straight, oblique, and more distant than those of the other ' areas. The anal furrow is avoU impressed, strongly arcuate, and terminates near the end of the basal third of the wing, while the anal veins are subj^arallel to it, simple, and rather closely crowded.
This gracefully formed wing might well stand as the type of this group of fossil cock- roaches ; it is of medium size, the length of the fragment being 20 nun. ; the probable length of the wing is 22.5 mm., and its breadth is 8.75 mm.; or the breadth to the length as 1 : 2.57.
The pronotal shield attached to the w'ings has a parabolic outline, the hind border, however, strongly convex ; the broadest part is scarcely in front of the middle of the posterior half, where the breadth equals the length; in front of this it tapers rapidly. Length, 9.5 mm.
The wing has much the same shape as Etohl. mcmtidioides, from which it differs in its larger size, the greater length of the mediastinal area, and the distribution of the branches of the scapular and externomedian veins. It also approaches the American Etohl. vemista, which is larger than it, but agrees better in the mediastinal area, and to a large extent in the branches of the scapular vein ; in Etohl. venusta, however, this first divides still further toward the l)ase of the wing; and the branches of the externomedian vein are also simple in the American species and compound in the European. From Etohl. dldyma it differs by its \evy much smaller size, the narrowness of the mediastinal area, and the distri- bution of the externomedian branches.
Germar described the species from seven individuals from Wettin, Grermany. Upper carboniferous. Geinitz mentions a specimen from Weissig, Saxony. Lower Dyas. (But as no description or figure is given, this may be looked upon as dubious.)
Acridiies carbonaria, referred by some authors to Blattiua, appears to be a Neuropteron.
> The area of this vein is represented on our plate as proljably too contracted, tin-owing the extremity of tlie vein broader than it should be, and the restored outline is also at the extreme tip of the wing.
S. H. SCTDDKK <)N I'AI.AKc )Z()IC COCKKOACUKS. 76
Etoblattina didyma. l'\.'2, (!;,'. \:i.
" D!rti/f)j)irri)i rliili/ma Host. Dissert, (lor. Wcttin, "Jl."
Blattinn didyma (term., Miin.>^t. Boitr. z. Pc-trof., v, !I2. t.-ib. 13. fig. IM''; — II).. ViM-«t. Steink. Wettin, vii, 8.], tiib. ;]1, ligs. 2, ;5 ; — Qiienst.. Il.indl). Pi'tref.. tal». liJ. fi-,'. IC ; — Giob., Deut.schl. Petref., 037 ; — lb.. Ins. Vorw., .Ill ; — Pict.. Traite Pal., 2" <^(I., ii, 302, pi. 40, fig. 2 ; — Ileor, Vi.ilclj. ii.itmf. Ccsclls.li. Xiiridi, ix, 2S7 ; — 11... Kaiiii. saracp. fo.s.x.. ii, ]9.
Not Bhiidna'! dldiitiut (Iciin., Vcnst. Steink. Wettin, vii, ST. pi. 31, fig. 10 ; nor ///. didyma Gein., Neties Jalirb. f. Mineral.; nor lUatla f/(V/ymrMIerin. - Ber., Org. Kestc Ik'rn.st., II, 34-30.
Compare the synonomy of Antliravohl. sopila.
The front wing is long and nearly equal, the c(<stal margin regularly and ronsiderably conve.x, the inner margin almost straight until near the tip, the ape.x broadly an<l regularly roundeil. Tlie veins appear to originate .somewhat above the middle of the l)ase, Itut about the midille line of the wing. Tiie mediastinal vein runs parallel to the costal margin at about the middle of the anterior half of the wing, and terminates by a somewhat rapid curve upward at about the middle of the apical half of the wing ; it emits a large num- ber of not very closely crowded simple or forked oblique branches. The scapular vein, beyond its basal curve, has a nearly longitudinal course, but apically bends upward .some- what abruptly,' and terminates just before the tip of the wing; it first divides at about the end of the basal third of the wing; its first branch is compound, but the others, two or three in number,- are simple; the vein is very distant from the mediastinal, .so that the area, at its widest, occupies nearly one-half the breadth of the wing. The e.\ternomedian vein also divides early, before the middle of the wing, and occupies with its branches the entire broad apex of the wing, and encroaches slightly on the inner margin ; it emits first a compound arborescent branch, and then several simple branches, the latter terminating below the extreme apex. The internomedian vein, beyond its basal curve, is nearly straight, and terminates a little before the apex of the wing, emitting eight or nine simple or occasionally forked, somewhat sinuous, oblique branches, besides, in the only example known, a single superior branch parallel to the main vein.' The anal furrow i.s well im- pressed, strongly oblique, and terminates at the end of the ba.sal third of the wing; the numerous anal veins which follow it are similarly but more gently curved and simple or forked.
The wing figured by Germar is a little broken at the base, but otherwise nearly perfect, for although the apical margin is represented as doubtful by Germar, its agreement with the tips of the veins renders it almost certainly correct; the wing thus preserved is 40 mm.
' This is the vcay it is roiircscnted in Gcrmar's larger and main internomedian vein beyond the origin of this superior
presumably more correct figure in bis Wettin fo.ssils; in bis branch is very regubir, while in all those species in which
smaller figure it has no such abrupt bend. the internomedian vein changes from an oblique to a longi-
- Different in the several figures by Germar. tudinal course and is accompanied by an arbore.«<:ent disposi-
' It is impossible, from Germar's figures, to be quite sure tion of the apical branches, this portion of the area is either
that the lowest two or three branches of the externomedian itself filled with siuiilar arborescent branches, or is at least
vein do not belong to this superior branch of the interno- irregular. In his description Germar also assigns these
median vein, which latter would then have the peculiar dis- doubtful branches to the externomedian and not to the in-
po,«ition common to Elnbl. aiiar/fi/ptica and other allied ternomedian vein, and we may therefore reasonably follow
forms ; but the mode of distribution of the branches of the the same course.
76 S. II. SCrDDER OX PALAEOZOIC COCKROACHES.
long and 1"» mm. broiul.' and is thorofore the largest, or one of the largest, of the species of this goniis; the breadth is to the length as 1 : 2.67; with a lens the entire surface is seen to bo covered with a dolioato network of cross veins, connecting the veins by exact trans- verse lines.
The two species to which this insect is the most nearly allied are those between which it is hero placed. From both it is at once distingui.shable by its far greater size; from Etohl. carbonaria it differs in the less extent of the scapular area, the fewer number of veins in the same area, and its earlier division. From FAobl. russoma it is separated l\y its nar- rower and longer uiediastinal area, and the less profuse branching of the scapular and externomedian veins.
Germar described t)ie species from a single specimen and its reverse, found at Wettin, Germany. According to Mahr, the species has been repeatedly found at Manebacli, near rimenau. Germany. Upper carboniferous.
Acr'ulites carbonaria, considered by some authors as the hind wing of tliis insect, is rather to be looked upon as neuropterous. Blatta didyma Germ.-Ber., is an amber insect, which does not belong to the Palaeobluttariae.
Etoblattina russoma. PI. 2, fig. 6.
Blattina russoma Gold., Neues Jahrb. f. Mineral., 1869, 159, taf. 3, figs. 2% 2% 2";— lb.,
Faun, saraep. foss., ii, 20.
The front wing is tolerably broad, the costal margin very regularly and rather strongly convex, the inner margin nearly straight to the tapering, well-rounded tip. The veins originate far above the middle of the wing, and have a slight upward curve for a short distance. The mediastinal vein runs subparallel to the costal border, which it approaches apically in a very gradual manner, and terminates shortly before the end of the middle third of the wing; the area is less than one-fourth the breadth of the wing, and is tilled with seven or eight simple or forked, straight, oblique branches. The scapular vein has a broadly but rather strongly sinuous course, running parallel to the costal margin in the basal two- thirds of the wing, and beyond that curving toward the margin, terminating just before the tip ; it begins to divide in the middle of the basal half of the wing, and emits about five branches, which become less and less compound apically, but terminate on the margin in about a dozen closely crowded branches ; this area occupies more than one-third the breadth of the middle of the wing. The externomedian vein is broadly and rather strongly arcuate next the base, afterwards nearly straight, terminating at some distance before the end of the inner border; it commences to divide at some distance before the middle of the wing, but further out than the scapular vein, and bears a couple of com- pound branches, which subdivide irregularly many times, and fill with numerous veins an area larger than usual in this genus, occupying upon the margin not only the whole of the apical border, but an equal extent of the extremity of the inner border. The interno- median vein is parallel and close to the externomedian vein throughout its course bej'ond the basal curve, and emits about half a dozen long, generally simple and nearly straight branches, parallel to and rather distant from one another; so rapid is the narrowing of the
1 Germar gives the measurement as 30 mm. long and latter are also inaccurate, as the wing is not three times as
10 mm. broad; but evidently by mlst.-ike, as it disagrees both long as broad. The figures we have taken are from measure-
with the dimensions of his nnenlarged figure and his Ger- nients of the smaller figure in the Wettin fossils. man measurements (18 linei long by 6 lines broad); these
S. II. SCl'DDKU ON TALAKOZOIC (OCKUOACIIKS. 77
area, tliiit its leiif^tli ahm'^ the inner niiir^'in is (inly a little lon;.'er than it.s loii;;c'st Imsal braneli. The anal fiinow is strongly inipresseil and its hasal two-tliinls very stron<;ly arcuate, while the apical thinl is straij.'ht. tenninatinj; stmu' ilistance iM-fore the nii<l<lle ol" the wing; the anal field, notwithstanding its unusual length, is almost as hroail. and is liljed with about eight arcuate, moderately distant veins, most of which are simple, those nearest the furrow subparallel to it, the others curved in an opposite direction.
The wing is peculiar for the ])rominence of the lower ba.sal angle, which in nearly right- angled, and for the corres])onding extent of the anal area; it is of medium size, meitsuring 25 mm. in length and 10.5 umi. in breiidth, the breadth being to the length as 1 : 2.'5S. Only a single .specimen is mentioned as having been found, which is perfect but Ibr the obliteration of parts of one or two veins at the tip of the internomedian area.
Goldenberg compares this species to Elohl. curhondriu, remarking that it agrees best with it in size and shape, but must be con.sidered specifically distinct <in account of the peculiar venation of all the areas, and especially of the coinbine(| .scapular and externo- median areas (Mittelfeld), which has nearly double as many l)ranches as in Elohl. car- bonaria; he al,so mentions the peculiar branching of the externomcflian vein by which the vein, beyond its last fork, runs free to the margin, parallel to an offshoot from tiie last branch of the same vein ; and also the shoulder at the base of the wing, which is wrinklefl and jirojects as a sharp angle. Although certainly very closely .allied to the .species mentioned, Elohl. rt(.sso7na differs further from it in the less frequent forking of the mediastinal veins, in the earlier division of the scapular and externomedian veins, the doubly forking ba.sal branch of the former, the greater irregularity in tiie branching of the latter, and in the much more rapid narrowing of the internomedian field. It also differs a little in its greater size, but it is not true that the combined scapular and externomedian areas have nearly double as many branches as m Elohl. carhonurlu; the broken tip of the latter will not allow us to determine just how many there are, but there is room for additional branches in the broken portion, and those actually visible are eighteen, against twenty-live at the very margin of Elohl. russoma; or if we take each vein separately, we find in the nearly perfect scapular vein of Etohl. carhonaria eleven branches, against twelve in Elohl. rus- soma ; in the externomedian vein of the former, which is certainly' very imperfect, seven veins, against thirteen in the latter — a difference which is nearly double, but which is unquestionably due, in part at least, to the imperfect state of the only known fragment of Elohl. carhonaria. From Elohl. dlchjma, Elohl. russoma differs in nearly all the points by which it may be distinguished fi-om Etohl. carhonaria, and, besides, differs consider- ably from it by its smaller size and less symmetrical shape, and the more frequent division of the scapular and lower externomedian branches. From Elohl. leplophlebica it differs in its broader and rounder form, and the much smaller extent of tjie scapular and interno- median areas, as well as in the fuller expansion of the externomedian area.
A single specimen was found at Liibcjiin, Germany. Upper carboniferous.
Etoblattina leptophlebica. PI. 3, fig. 9.
Bluliina leptophlehica Gold., Neues Jahrb. f. Mineral., 1809, 158-59, taf. 3, figs. 1% 1*; —
lb., Faun, saraep. foss., ii, 19.
The front wing is long and slender, tapering, and straight ; the costal margin is very gently convex, the inner margin straight, but the tip of the only specimen is broken.
7S 8. H. SCITDDKH OX PALAEOZOIC COCKROACHES.
The veins oriirinate consi(lor;il)ly al)o\o tlu' midtlle of the wing, and curve slightly upward fwni the hase hefore l)ee()ining longitudinal. The mediastinal vein is gently arcuate, runs for a short distance parallel to the border, then curves gently toward it, and terminates at about the middle of the wing; the area occupies nearly one-third the width of the wing, and is filled with half a dozen forking, occasionally simple, oblique branches. The scapular vein, beyond the connnon clustering of the veins at the base, parts rapidly from the medi- astinal, and pursues a broiidly arcuate course, at first divaricating slightly from the costal margin and allerwards gradually ajipi-oaching it, and terminates probably just before the tip of tiie wing; in the a])ical half of the wing it runs as flir as the middle line of the wing, making the area of unusual width; it emits about eight singly or doubly forked branches (with occasionally a simple one), which are therefore long and closely crowded, and assume a direction parallel to the mediastinal veins and very similar; the branching com- mences in the middle of the basal half of the wing, as far back as the first division of the internomedian vein. The externoniediau vein is nearly straight, but very gently and broadly sinuous beyond the basal curve, and terminates probably not far before the apex, leaving for the area a small marginal extent over the probably narrow apex and lower outer angle of the wing ; notwithstanding the slenderness of the area, the vein commences to branch before the middle of the wing, and emits three or four simple or forked branches (most of them probably forked near the tip, which is broken), which have a longitudinal course. The internomedian vein runs side by side with the preceding, and emits first a series of comparativelj' distant nearly straight and simple veins, about four in number, whicli occupy about one-half of the rather gradually narrowing area; these are followed by a forked and then by a compound branch, whose forks fill the narrowing apex. The anal furrow is strongly impressed, stout, strongly and very regularly arcuate, and terminates at the end of the basal two-fifths of the wing; the anal veins are mostly simple, occasionally feebly forked, very numerous, and very crowded, especially away from the furrow; next the furrow they are rather gently arcuate, gradually becoming nearly straight or sinuous.
The wing is peculiar among its immediate congeners for its straight and tapering slender form, recalling exactly that of Etohl. affinis ; it is also peculiar for the extreme breadth of the scapular area, due to the deep sinuosity of the scapular vein. It is a comparatively small species, the wing being probably only 19.5 mm. long (the fragment preserved meas- ures 16.0 mm.), and is 7 mm. broad in the middle ; or the breadth is to the length nearly as 1 : 2.8. To judge from Goldenberg's figures (he makes no mention of the fiict), the ba.se of the mediastinal area is obscurely striate longitudinallj^ and the rest of the wing, or at least around the anal furrow, very minutely and very obscurely reticulate, with three or four rows of polygonal cells in each interspace.
ThLs species cannot be confounded with any other, for it is widely separated from all with which from its size and form it might be compared, by the broad scapular area, whose long branches .simulate the distribution of those in the unusually short mediastinal area; it is most nearly allied to Etohl. russoma, where the general distribution of the In-anches in the much smaller .scapular area is similar, as is also the early branching of this vein and the exteruomedian ; but the form of the wing, the short mediastinal area, and the much narrower and more gently tapering internomedian area of Etohl. lejitophlehica at once distingui.shes it from Etohl. russoma. It was compared by Goldenberg to Etohl. anagli/jjtica, on account of the form of the wing, but besides diflferiug considerably in the
S. II. SCrUDKi: ON I'AI.AKit/olc ( OCKROACIIES. 79
points of neiiratioii iiiontionod hy (JuIiIouIjit;^, ami by others, liius u much luss convex costal margin aiitl a more re<j:iilaiiy ami jfe-ntly tapering lorni.
The single specimen comes from L'tl)ejun. Germany. Upper carboljiferous.
Etoblattina manebachensis. IM. '1, lig. It.
lUatlina manebacheiisi'S (.iuld.. Neiies .lahrl). f. Mineral., iStJll, iCd, lal. .1, lig. I ; — lb..
Faun, .siraep. foss., ii, I'J.
Tlic front wing is long ohovate, both margins being somewhat similarly curveil, although the inner is more strongly an 1 more regularly convex than the costal margin, the latter being straight in its middle half; the tip is neither broadly njunded nor producecl ; ijie veins originate slightly above the middle of the wing, and curve n])ward gently before becoming straight ; beyond this they are all unusually straight. The me<li,<Lstinal vein rmw parallel to, and tolerably distant from, the costal margin in the bitsal half of its cour.se, the area here occupying a little less than a third of the breadth of the wing ; beyoml, the vein gradually ap[)roaclies the margin, meeting it only a little beyond the middle ol" the wing ; it emits half a dozen or more simple or simply forked oI)rK(ne branches. The scap- nlar vein is very straight, scarcely curved at the extremity as it approaches the border, just before the apical margin of the wing ; it runs subparallel to the costjil margin, commences to divide at the end of the basal third of the wing, and has about five branches ; the bitsal one cempound, the next forked, and the others simple, all taking the course of the medi- astinal branches, and together occupying an area from one-fourth to one-third the width of the wing. The externomedian vein commences to divide scarcely earlier than the scap- ular vein, and emits about as many branches, which are simple, straight and longitudinal for a long distance, commencing to divide only opposite the origin of the last branch, when they fork almost simultaneously, the first again dividing ; the area occupied by them is very regularl}- wedge-shaped, and at the margin occupies the entire apex of the wing. The inter- nomedian vein runs very close and parallel to the preceding vein, being arcuate at the ba.se and beyond straight, meeting the lower border opposite the tiji of the scapular vein ; it emits seven or eight, generallj' simple, occasionally forked, nearly straight, parallel, oblique, and rather distant veins. The anal furrow is well impressed, strongly arcuate, but straight- ened apically, striking the margin a little beyond the basal third of the wang ; the area covers about two-fifths of the width of the base of the wing, and is occupied by eight or nine simple or deeply forked veins, arcuate next tlie anal furrow, straight and crowded toward the inner angle.
The wing, by the similarity of its margins, differs from most Etoljlattinae, E. Dohrnii alone resembling it closely ; it is also peculiar for the extreme straightne.ss of its principal veins. It is of medium size, the single specimen known being a perfect fore wing, 25.5 mm. long, and 10 mm. broad ; or the breadth is to the length as 1 : 2.55. From Etohl. Dohrnii, wliicli it so closely resembles in general form, and in the straightness of the veins, it is readily distinguished by the crowding of the branches, the brevity of the mediastinal vein, and the early division and numerous branches of the externomedian vein. It is larger than, and not so tapering as, Etohl. lepiojjhlebica, besides being immediately distinguished by the straightness of the scapular vein. From Elohl. elomjala it is abundantly distinct by its broader form, and by the straightness of the apex of the scapular vein. The straightness
^0 S. n. SCFDDEU ON PALAEOZOIC COCKROACHES.
of the veins will also distinguish it from Etohl. anthrncoj^hUn. Avith -which it agrees in many iioints. Goldonborir compares it to EtoJ)l. prhnaeva, with which it has certain resemblances indeed bv the straightness of the veins, and the earl}^ division of the exteniomedian vein, but from which it diflers in nearly every other point of its structure, and fiom which it may be distinguished at a glance (to mention no other points), by having scarcely one-half the breadth of the larger species.
A single specimen from Manebach, near Ilmenau, Germany. Upper carboniferous.
Etoblattina elongata. PI. 2, fig. 10.
BMtina sp. (''cf. Mah-r') E. Gein., Neues Jahrb. f Mineral., 1875, 5, taf. 1, fig. 2; — lb., Neue Aufschl. Dyas v. Weiss., 5, taf 1, fig. 2.
The front wing is so imperfect in the only specimen known, that it is difficult to describe its form ; yet to judge of the apical half, which only is preserved, it is the very slenderest of the species of Etoblattina, although nearly as long as the largest ; the two margins approach each other gradually and equally in this apical half, making the tiji exceptionally narrow, although it is well rounded. Only the tip and a portion of two bratiches of the mediastinal vein can be seen, by which we should judge that the vein was rather long, terminating only a little before the apical third of the wing, and had a number of rather distant, straight, oblique and simple branches. The scapular vein runs parallel to the costal margin until close to the tip, when it curves toward the margin, which it strikes scarcely before the extreme apex of the wing; it begins to divide near the middle of the wing, emits half a dozen straight, oblique, simple, rather distant branches, quite jiarallel to those of the medi- a,stinal area, and occupies near the middle two-fifths, next the apex one-half, the width of the wing. The externomedian vein divides opposite the division of the scapular vein, the forks parting but slightly and again dividing (doubly) only shortly before the tip, so that this vein is unusually distant from the veins on either side of it, and occupies on the mar- gin a narrow area, including most of the tip and the apical portion of the inner border. The internomedian vein probably changes its early course ( after being directed, in the un- known basal half, more obliquely toward the inner margin), for the portion in the apical half is nearly longitudinal and nearly straight, curved downward toward, the border very .«lightly ; it tenninates at a little distance before the tip, and emits two or three extremely distant simple branches.
Geinitz describes the surface of the wing as delicately granulate, and apparently of a somewhat rigid, parchment-like consistency. The fragment is 18.5 mm. long, and 11 mm. broad ; the whole wing was probably 35 mm. long and scarcely more than 11 mm. broad, the breadth to the length being as 1 : 3.2; it is, therefore, the largest of the slender, or the slenderest of the larger species, and is peculiar for its tapering ajiex. In the straightness of itij veins it resembles the preceding species as well as Etohl. Dohrnii, but is abundantly distinct from either by its slenderer form. The only other species which has such a taper- ing tip is Etohl. parvula, a much smaller and less slender form. Geinitz considered it as probably the apex of the wing of Gerahl. 3fahri ; the infrequency of the branches indeed make it resemble that species m a general way, but it is difficult to compare it with that from the fact that the only specimen of Gerahl. 31ahri known has lost almost the Avhole of the tip ; but there Is a smgle point which is indisputable, and that is the excessive length
S. ri. SCTDDKU ON I'ALAF.OZOK' COCICHOACIIKS. K]
of the moiliiistinal vein in frcrahl. M't/iri, whU-h roaches the apex wlit'ie that nf the seapiihir vein inipin^^es on the holder in Elobl. tjomjnln ; it is, therefore, plainly inipossihie ihiit they .slionld Ije properly eonsidereil the siiine.
A single specimen is nientioncil In' (leinitz from Weissig, Saxnnw r,<i\\iT l)\as.
Etoblattina parwda. I'l. 2, fig. 9.
lihtUiim pnrvuhi Gold., Xeues .lalul). f. Mineral., 1800, KH, taf. .'1, fig. 0 ; — Hi., Fann.
saraep. fo.>is., ii, H>.
In form the front wing of this species agrees pretty well with that of the last, hnt it i.H not .so .slenih-r ; hoth costal and inner margins have a similar and" pretty .strong convexity, ami the wing tapers rapidly and pretty regularly to a somewhat pointed tip. the very apex of which Is rounded. The vein.s spring from a common point, ahovo the middle of the hiuse of the wing, and have scarcely any basal curve. The ba.se of the mcdiuHtinal area i.s. there- fore, about one-third as wide as the wing at that point, ami the meiliastinal vein, verv grad- ually approaching the cosUd margin, strikes it nearly at the end of the middle tiiird of the wing ; it emits half a dozen or more sim[)le. obli([ue, slightly arcuate luanches. The .««-ap- ular vein is nearly straight, curving only near the tip, and, running snbparallel to the co.stul margin, occupies with its branches a variable width of tlie wing, reaching the middle line in the apical half; it commences to divide at .some distance before the middle of the wing, and emits about half a dozen simple, straight branches, the first one of which is forked near the tip, and all have a direction similar to, but a little more longitudinal than, the mediastinal branches; the vein terminates exactly at the apex of the wing. The externo- mechan vein, emitting near the middle of the basal half of the wing a straight, apically forked branch, which runs clo.se and parallel to the scapular vein, itself bends downward, and then turns out again, and continuing nearly parallel to its first branch, ends .some distance beyond the middle of the apical half of the inner border, emitting a couple of etpiidistant, straight and simple branches on the way ; on the border, then, this area occupies the apical fifth of the inner margin. The interuomedian vein runs in clo.se pro.ximity to the bust vein, and has, therefore, a rather deeply sinuous course, and emits three or four, biusally curved, apically forked branches. The anal furrow is very deeply impressed, strongly arcuate, ter- minating near the end of the basal third of the inner border, and leaving the area nearly as broad as long ; the anal veins of the upper half of the area are ob.scured ; in the lower half they are thickly crowded, nearly straight, unusually longitudinal and deeply forked.
This is one of the very smallest .species, the front wing measuring only 9 mm. in length, and 3.75 mm. in breadth, the breadth being to the length a.s 1 : 2.4. In its minute size it differs from all but the succeeding species, which agrees well, as Goldenberg remarks, with that of the living Edohia Inppoulca (Linn.) ; but it is peculiar, among palaeozoic cockroaches, for the shape of the wing and the distribution of the branches of the lower veins of the wing. It is most nearly related to Etohl. elongata, which is many times its size and is a .slenderer species. It agrees in size w ith Etohl. insif/iiis, but the course of the internome- dian vein is very different, and all the veins and their branches are distinct instead of being nearly obliterated, as in that remarkable species.
A single specimen from Lubejun, Germany. Upper carboniferous.
MEM0IB9 BOST. SOC. SAT. HIST. TOL. in.
t;o S. TT. SCFDDER ON PALAEOZOIC COCKROACHES.
Etoblattina (?) insignis. PI. '2, fig. 7 ; pi. 4, fig. 0.
lilufCma iunitjitls (lold.. Vorw. Faim. Saarbr., 17 ; — Ej., Faun, saraep. foss., i, 17, taf. 2, fi,T. 14; — lb.. Faun, savaop. loss., ii, 20, 51; — Scudd., Mem. Bost. soc. nat. hist., in. 10.
The front wing of this insect seems to have very nearly the same form as that of the preceding species, but has perhaps a little fuller anal area, and a less pointed tip. It is not at all clear from what point the vehis originate, and it is doubtful whether they have a connnon origin. The veins are all exceedingly obscure, and even the limits of the areas are doubt lul. The mediastinal area appears to have a width of one-third that of the wing at the ba.-<e. and the vein seems to terminate at about the end of the middle third of the Aving. The .<ca])ular vein is apparently nearly straight, running down the middle of the wing, and terminating at the tip. The externomedian probably occupies a narrow area ; it can hardly divide before the middle of the wing, and on the margin covers the apical third of the inner border. The internomedian vein probably terminates at the end of the middle third of the wing, perhaps farther out, and is supplied with closely crowded forking veins. The anal furrow i.'^ deeply impressed, arcuate, and rather bent in the middle, and terminates at the end of the basal third of the wing. No branches of veins can be made out, to judge from Goldenberg's drawing, excepting in the internomedian area.
The two front wings are present in" the only specimen yet discovered, one broken at the tip. the other along the inner margin ; between these two the form of the wing can be accurately determined, but the tip is represented inaccurately in PI. 2, fig. 7, as fully rounded, whereas its form should be much as in Etobl. j^nrvula. With that species, it is the .smallest known, the front wing measuring but 9 mm. in length, and 4.25 mm. in breadth, the breadth being to the length as 1 : 2.12.
Goldenberg remarks, that from the slight traces of the veins, the texture of the front wings of this insect was probably similar to that of those of Corydia and Phoraspis.
Hind wing. The hind wing of this species closely resembles the front wing in form and size, and could .scarcely have possessed a plicated anal area; the neiu-ation, too, is nearly as obscure as in the front wing, throwing some doubt upon the presumed thickened consistency of the front wing, .since, in living insects, the hind wing is ahvays membranous. In the original drawings of this insect, which formed the basis of Goldenberg's plates, and which Dr. Goldenberg has been kind enough to send me for study, the two hind wings are not quite alike, the left wing, which I have reproduced in outline in PI. 4, fig. 9, being con- siderably more pointed and narrower than the right wing ; the two wings show, also, a somewhat different arrangement of veins, although these are very obscure in both ; next the front wing, which hides a portion of the costal area, there are in the left wing several longitudinal parallel veins, which cannot be made out in the right ; and the rest of the wing, or fully two-thirds of it, is made up of a single longitudinal vein (the anal), with numerous obliquely longitudinal, simple branches ; on the right wing, however, it would appear as if these branches, holding much the same position, were about equally divided between an anal and an internomedian set, in both of which they appear to be Ibrked as often a.s simple ; the arrangement faintly indicated on the right wing, corresponds better, although not closely, to that of the front wing. Goldenberg considei's all the veins as
S. 11. SrUDDF.R ON PAI.AKOZOIC COCKnOAfllFS. R3
beloiifrin^f to the anal lu'ltl. which he descrihes ns havinj,' " many dehcate, nuliatiiij;, linij^i- tudiiial veins, connected liy scarcely percept ihle dehcate cross veins." Ix-nj^th, 11 mm.; hrea(hh. 4 mm.
This insect is, perhaps, the most complete of any of the palaeozoic species of cockroach, the abdomen being almost completely preserved, bnt the legs nnfortunately wanting. The prouotal shield is shaped somewhat as in Etohl. cnrhoiifiria, being longitndinally oval, broadest near the posterior margin, tapering toward the rounded front, the hind margin apjiarently broadly rounded ; it is somewhat gibbous, and shows in the middle and laterally weak longitudinal furiows ; it is 7 mm. long, and (i.'J') mm. broad. The mesothora.v is very short and inconspicuous ; the metathorax quadilateral, nearly as long as broad, broadest in front, and narrowing rapidly behind ; the front and hind borders are slightly arcuate, the curve opening posteriorly, the lateral angles rounded, the surface marked by weak me<Iian, longitudinal and transverse furrows; length, 2.7-') nun., breadth l»eiiiud, 2 nun. The ab<lo- men is extraordinarily .slender, as it is in no modern types, giving the insect a remarkalily strange aspect; seven segments are preserved, and these grow gradually larger and broader posteriorly; they are sharply separated from each other, and the lateral margins .somewhat upturned; the whole abdomen is 8.5 mm. long; its breadth at b;i.se is 1.0 mm.; at the end of the seventh segment 2.2 mm.
(loldenberg remarks of this insect, that it is Ijy far the most complete and best preserved •of all that have yet been foimd in the carboniferous formation [Aulliraiohl. sajilld wan not then known) ; and that it presents so many anomalies in not unimportant jiarts of its structure, separating it from all hitherto known cockroaches, whether living or fossil, jus to render it highl}- probable that it should be considered a peculiar extinct genus, either belonging to the family of cockroaches, or falling very near it.
.^o little, however, is yet known of parts other than the wings in this genus, and a.s the wings ajjj^ear by their neuration to fall within this genus, it ha,s seemed the hest way to place it here, at least until new examination shall give us a better clue to its true allini- ties. Should the nein-atiou prove clearly distinct from the other members of this genus, there can be no doubt that it should stand by itself.
The single specimen found was discovered, in a bluish shale, in the Skalley-shafl of the Hirschbach coal-pit at Saarbriicken. Gennany. Middle carboniferous.
Archimylacris {''f/r;, ;j.u).axfii^)
Archimylacris Scudd., Daws. Acad. Geol., 2d ed., 388 (1868).
The mediastinal vein of the front wing runs parallel to and not distant from the costal margin to a little beyond the middle of the wing, occupying less than one-fourth the breadth of the wing, and emitting a considerable number of mostly forked, very oblique, but still short branches. The scapular vein is considerably and pretty regularly curved, in the same sense as the costal margin, but rather more strongly than it, lies rather distant from the mediastinal vein, and, beginning to branch at some distance before the middle of the ^ving, occupies with its branches, in the apical half of the wing, an average of nearly or quite one-half the breadth of the wing ; its trend, however, is so far downward that, trav- ersmg the apex of the wing obliquely, it terminates below the tip ; it emits a large number of branches, the general direction of which is similar to those of the mediastinal vein; they fork repeatedh, so that the area is closely ciowded with veins. The externomedian
S4 S. n. SCFDDER ON PALAEOZOIC COCKROACHES.
area is insi<rnilicant ; the vein runs parallel to the preceding, forks a little way beyond it, the hrani'hes again hifureating once or twice, all in a longitudinal way and closely approx- imated, so that at the extremity of the inner margin the area only covers a very limited space. The anal and internomedian areas together cover almost the entire inner margin, are very broad opposite the middle of the former, where they occupy considerably more than half the breadth of the wing, and rapidly and regularly diminish in width ; the anal furrow is very strongl}'^ arcuate, rather distinctly impressed, and terminates at or a little bevond the end of the first third of the inner margin ; there are six or seven simple or forked branches of the internomedian vein, nearl}^ all of which curve a little outward as they approach the margin, and are more longitudinal toward the apex than toward the base. The veins of the anal area are five or six in number, more frequent toward the anal angle, nearly straight and oblique, and simple ; excepting that next the anal furrow, which is arcuate, and emits two or three inferior branches, nearly parallel to the other veins.
The wings are peculiar for the backward sweep of the scapular vein, so that the entire apex is included in the area of this vein ; the two species differ very much in the proportion of the length to the breadth, one being remarkably stout, the other a little more than usually slender.
Besides front wings, one of the species referred to this genus, preserves a fragment of the hind wing, and a pronotal shield ; the former consists of the extremity of the costal margin, and simply shows a collection of closely crowded, forked veins, having a somewhat obli(i[ue direction, so nearly resembling those of the corresponding portion of the upper wing, by the broken tip of which they lie, as to appear at first sight as a continuation of them ; the pronotal shield is attached to the wing, and is very regularly rounded, scarcely exhibiting the least angulation, somewhat broader than long, with a central circular de- pression.
This gejius differs from Etoblattina in the character of the scapular vein and area, and in the narrow limits of the externomedian area; from Anthracoblattina,'Gerablattina, Ilermatoblattina, in the brevity of the mediastinal area, and the much greater development of the scajiular area ; from Progonoblattina in the very different distribution of the branches of the scapular vein, and the far greater extent of the internomedian area ; from Orj-ctoblattina: in the character or position of every area in the wing ; and from Petroblat- tina in the distribution of the veins of the internomedian area and its slight importance.
The genus is confined to America, and is the only one of this gx'oup which has no Em'O- pean representatives.
Archimylacris acadicum. PI. C, figs. 8, 14.
Archimulacris acadicus Scudd., Daws. Acad. Geol., 2d ed., 388, fig. 153 ; — lb., Amer. Nat., I, 630, pi. 16, fig. 2 ; — lb., Geol. Mag., v, 177.
Fore wing. Tlie .shape of the wing cannot be definitely determined from its jmperfec- tion ; the costal margin, however, is very regularly and strongly convex, and all the veins are arcuate, arising apparently from about the middle of the wing. The mediastinal vein h subparallel to the costal margin, but a little less arcuate than it, probably occupies about one-fourth its width, and terminates at about the end of the middle fifth of the wing ; it
S. H. SCUDDER ON I'AI.AKOZOIC COCKROACHES. 86
emits a larfjo minibcr of ol)lifiiio, jriiH-nilly lorkcd. Ntniijrlit, find nearly jtnrallol l)ran<'hog. The seajiiilar vein is very stronj:ly ar<'iiate. |iarallel ainio.'-t tliroiijrlionl to tlieeo.stal niar^^in, terminating beyond the ajjex ; it is rather distant IVonj the mediu>tinal and externoniedian veins until it begins to divide, at aljout the middle of the wing; here, and u little further on, it sends forth a couple of compound branches, besides a short, apical, simple shoot ; the earlier forks of the compound branches have a direction similar H) the me<liastiMal veins, while the later are longitutlinal. The e.xternomedian vein follows clo.>iely parallel to the scapular vein, and emits only two Inanches, superior, simple, and nearly straiglit, near together, and only a little way beyond the branching of the scapular vein; con.secjuently this area occu- pies onl v a narrow space at the extremity of the inner border ; somewhat bel'ore the middle of the wing this vein is connected with those on either side of it by a pair of short, oblifjue, cross veins, having the same direction as the internomedian branches. The internomeiiiau vein is even more strongly arcuate than the preceding, and very regularly curved ; in the part which is preserved, and beyond the ba.sd foiu'th, it emits four etjuidislant, nearly straight, parallel and oblique, simple branches (they are represented as too sinuous in the plate), and there are probably several others in the apical portion. The anal furrow is not deeply impressed, is very strongly and regularly arcuate, ami probably terminates a little before the middle of the wing ; there are half a do'/xMi anal branches, mostly simple and oblique, and straight oj- arcuate, those next the furrow about as wiilely separated as the internomedian branches, the others more closely crowded.
The insect is of medium size, the Aving being 23 mm. long, and the breadth of the I'rag- mcnt 10 mm. ; probal)ly the entire width of the middle of the wing, where it was presuma- bly the widest, was 11.5 mm. and the breadth to the length a.s 1 : 2. The specimen is not very perfect, being partially overlaid by the frond of a fern, by which the lower apical half is ob.scured, excepting most of the longitudinal branches of the scapular and externomeilian veins ; the extreme base is also broken ; if the upper surface is that exposed, it is a right wing ; aU the interspaces of the wing, excepting in the mediastinal area, are traversed by delicate cross veins closely approximated. The shape of the wing at once separates this species from Arch, parallelum.
The single specimen knowo was found by Mr. James Barnes, at the East River of Pictou, Nova Scotia, in shale overlying the roof of the main seam of Pictou coal. I owe an opportunity of examining it to Principal Dawson. Middle coal furnuition.
Archimylacris parallelum nov. sp. I'l. G, fig. G.
The fore wing is very equal, the larger part of both costal and inner margins being straight and very nearly parallel, the wing tapermg only in a very slight degree until near the tip ; the anal angle is broadly rounded, and very similar in this respect to the humeral lobe ; the extremity of the wing is broken, so that the form of the wing cannot be stated ; the veins originate a little above the middle of the base, and curve upward as they pass outward. The mediastinal vein runs subparallel to the costal margin, but gradually approaches it throughout (hardly so represented on the plate), until about the middle of the wing, when it.curves rather rapidly to the border, terminating at some distance beyond the middle ; it occupies less than a fourth the breadth of the wing, and emits, mostly in its outer half, five or six oblique, forked, or simple branches. The scapular vein, beyond its
S(5 S. II. SCUDDER ON PALAEOZOIC COCKROACHES.
strouiT ba.-^al ourvo, is straight, subparallel to, but a little divergent from, the costal margin, juul tonninatos beyond the apex of the wing ; it commences to divide a little beyond the basal quarter of the whig, and emits about seven longitudinal branches at subequidistant intervals ; the fnvst is compound, beginning to branch next the apical curve of the medias- tinal vein ; the others are simple or forked, or rarely doubly forked, and fill the apex and ai)ioal third of the costal margin with straight, crowded veins. The externomedian vein, bevond its basal curve, runs parallel to the preceding throughout, but before it forks, in the centre of the wing, is rather distant from both the scapular and internomedian veins ; it emits three inferior branches, distant at their bases, the first two doubly forked, the last simple, the branches all closely crowded, as in the preceding area, and occupying rather less than the apical fiflh of the inner margin. The internomedian vein, beyond its basal curve, is straighi. only curving downward a little at the extremity, which reaches the bor- der only just before the apical sixth of the wing; it commences to branch before the end of the basal fourth, and emits about seven branches, siiliple or forked, the basal ones trans- verse, oblique, and sinuous, the apical longitudinal, oblique, and nearly straight. The anal furrow is very deeply impressed and strongly arcuate, terminating before the basal third of the wing ; the first of the anal veins is nearly as arcuate as the furrow, more distant from it basally than apicall}^ and has a couple of branches ; the others are generally simple, oblique, ncarlj- straight, and crowded.
The insect is of medium size, the wing measuring, as preserved, 23 mm. in length, and 9.5 mm. in breadth ; the entire length was probably 26 mm., and the breadth to the length as 1 : 2.74 ; only the tij) of the wing is wanting, with the apical third of the costal margin. It is the upper surface of a right wing. The anal area, especially next to the furrow, is rather tumid, rendering the depth of the furrow much more apparent ; on the contrary, there is a depression in the central parts of the humeral lobe ; excepting the anal furrow, the mediastinal vein is more distinctly impressed than any ; the branches of this vein, and those of the two following veins, as well as the veins themselves, are rather obscurely impi'essed, while the veins and branches of the internomedian and anal areas are delicately raised like tracery ; the surface is very flat, and the whole is covered with an obscure net- work of polygonal cells of raised lines, which become more distinct in the anal and medi- astinal areas, where they are mostly changed to transverse lines, frequently forking in pass- ing from one vein to another, or uniting with the neighboring cross vein.
Hind wing. A fracture of the front wing, beyond the middle of the costal margin, with the removal of the parts beyond it, leaves exposed a fragment of the coi-responding portion of the underlying right hind wing. Indeed, as I have proved by experiment, the upper wing may be peeled off from the lower ; the piece broken off, carbonaceous in appearance throughout, represents not only the upper wing, but the film of detritus which lay between the two wings after deposition ; for it shows upon the one side (the under) sharply raised, delicate lines, corresponding exactly in reverse to the sharply impressed veins of the imder wing ; while upon the upper surface are faintly impressed lines which are not opposite those on the other surface of the lamina, but represent the veins of the upper wing. The frag- ment of the hind wing thus exposed is very small, and covers the outer half or third of the costal border. The veins have the closest resemblance to those of the front wing, beyond which they lie, and almost appear as their continuation ; the veins represented on Plate G, fig. 6, above the mark separating, for the front wing, the mediastinal and scapidar
S. II. SCUDDKIf (>\ PAI.AKOZOIC- nKKROACIIKS, 87
areas, together with the vein next helow it, me deHeately niist-d, and proljaldy represent the apical branelies of tlie mediastinal vein of the lowi-r winj;. while all tin* others are distinctly impressed, and prolial)ly belonj^ to the scapular vein. The former vein can he traced (but is not represented on the plate) for a short ilistance, through the thickness of the upper wing, running in a straight line toward the middle of that portion of the bitse of the wing which is covered by the prothorax.
Attached to the front wing is the pronotal shield, this being the only American fossil cockroach in which this part is certainly known. It is of a very broadly and transversely ellip- tical form, but, as preserved, does not have a perfectly regular outline, the curve of the left side being uniform, while that of the right side would place the broadest part of the shield a little behind the middle; with this exception it is extremely regular, either lateral or antero-posterior half being like it.s opposite. The surface is nearly Hat and shows a cen- trally disposed circular or elliptical furrow, irregularly subparallel to the margin, enclosing a slightly convex central area, whose diameter is a little more than a third the breadth of the pronotum; the furrow is coarse and rather deeply impre.s.sed. but irregular from the irregularities of the stone ; the posterior third of the shield is markeil w ith faint, very closely crowded, minute, straight, transverse wrinkles, crossing the whole pronijtum. Length, 7.5 mm. ; breadth, 10 mm.
The parallel-sided front wing can by no possibility be confounded with that of A re him. acadiciim, with its strongly convex costal margin; in this species the strongest part of the curve of the veins is close to the base, as in most palaeozoic cockroaches; but in Arc/dm. acadicioii it is at the middle of the wing, in conformity with its strong costal curve.
The single specimen was obtained by Mr. 1. F. Mansfield, at Cannelton, Beaver county, Penn., in dark, sandy shale, immediately under the vein of Cannel coal referred to vein C of Professor Lesley. Lower coal-measm-es of Penns3lvania.
Anthracoblattina nov. gen. («>^/<a|, Blattina).
Blatlina Auct (pars).
The mediastinal vein of the front wing runs parallel to and generally rather distant from the costal margin, terminating generally beyond, occasionally at the middle of the apical half of the wing, and emits a large number of oljlique, parallel, seldom forking branches ; the area generally occupies nearly one-third of the breadth of the wing. The scapular vein, sometimes curved near the base, is beyond that nearly straight, and tenni- nates shortly before or at the apex of the wing, — in a single instance {A. winteriana) beyond it ; it never branches more than once, usually not at all, before the middle of the wing, and the branches are usually longitudinal in appearance, although in all instances actually superior, and seldom assume the appearance of similarity to those of the mediastinal vein, as in Etoblattina; the branciies are not numerous (more numerous in A. spectabilis than in the others), and seldom fork more than once; owing to the length of the medias- tinal area, the space occupied by this vein and its branches is very restricted, although not more so than that occupied by the next vein. For the extemomedian vein, which is sepa- rated from the preceding by an equal interspace, on either side of which the branches of the two areas diverge at equal angles, is usually a close counterpart in a reverse sense of the scapular vein, excepting that the first offshoot is usually more important than the others, often equalling, with its forks, the rest of the vein. The combined iuternomedian and anal areas occupy fully half the breadth of the wing near the base, and, excepting in
^8 S. II. SCUDDER ON PALAEOZOIC COCIvROACHES.
.4. drcsdeiisis. diminish in breadth more gradually than usual, the inteniomedian vein passiu!? in a verv irontle curve or a nearly straight line to a point on the inner margin usually beyond that to which the mediastinal vein reaches on the opposite border; it emits a larire number (in A. dre.'^densis a small number) of either simple or forked, nearly stmiixht veins, of about the same obliquity as those of the mediastinal area. The anal furrow appears to be tolerably well impressed, is rather strongly curved, and usually ter- minates a little more than one-third down the inner margin of the wing; the anal veins, about half a dozen in number, have a somewhat similar though slighter curve, are nearly parallel, some or all of them simple.
The Avings are stouter than usual, only one of them coming up to the average of the whole group of Blattinariae, the average proportion of the breadth to the length in the genus being as 1 to 2.4.
Only one of the species of this genus shows anything besides the front wing ; this single species is unusually perfect, showing the whole body and the legs as well as both pairs of wings. The body is very slender, but almost equally so, the abdomen being as wide as the rest, but much .slenderer than is usual in modern types. The thoracic shield is longitudi- nally oval, and the legs are similar to those of modern types ; whether or not they are spinous does not appear.
This genus is most nearly allied to Etoblattina, from which it differs principally in the greater size and much greater length of the medastinal area, and the lesser extent of the scapular area; from Archim3'lacris it is similarly separated, although in one species {A. wln- teriana) the termination of the scapular area is somewhat similar, owing to the peculiar conformity of the tip ; from Gerablattina it differs in having the branches of the externo- median vein inferior instead of superior; and from Hermatoblattina in having those of the scapular vein superior and not inferior ; from Progonoblattina it differs in the much more restricted extent of both the scapular and externomedian areas ; from Oryctoblattina in the far less importance and very different nature of the scapular vein, and by the very different character of nearly all the other veins ; and from Petroblattina in the nature and distribu- tion of the veins in the externomedian area.
The species of this genus are altogether confined to Europe, so far as yet known.
Anthracoblattina spectabilis. PI. 2, fig. 8.
BJattina spectabilis Gold., Neues Jahrb. f. Mineral., 1869, 161-62, taf. 3, figs. 7, 7", 7"; — lb.. Faun, saraep. foss., ii, 19; — ? E. Gein., Neues Jahrb. f. Mmeral., 1875, 6; — ?Ib., Neue Aufschl. Dyas v. Weiss., 6.
Fore wing. Although the only described specimen of this species is very imperfect, its form is to a great extent known, excepting toward the base ; the costal margin is regularly and strongly arcuate, while the inner margin is straight; and as the wing tapers rather rapidly in its outer half, the middle of the well-rounded tip is thrown considerably to one side of the middle line of the wing. The mediastinal vein runs parallel to the costal margin nearly as far as the middle of the wing, when it curves somewhat rapidly toward the margin and terminates at about the end of its middle third ; the width of the area is about one-fourth that of the wing, and it is filled with numerous, rather crowded, simple or forked, oblique, straight branches. The scapular vein also runs parallel to the costal margin, and terminates on the apical margin just above the tip, and, being very straight in the apical
S. II. SCUDDKR ON PALAEOZOIC COCKIJOACIIES. 80
half of the Avin<?, approaches tlie costal inarjfiii very grailimlly; it commencos to divide l)efore the middle of the wing, and emits at (M|iii<listniit intervals half ii dozen, simple or forked, straij,'ht and nearly lonj,'itudinal branches. The externomedian follow.s the course of the scapular vein, and begins to branch at the .same point, emittin}^ at unequal intcrvalH four branches, which, with their oflshoots, occupy the apex and very extrennty of the iinier margin of the wing; the first and last of the.se branches in the specimen described are coM)pound, the others simple. The internomedian vein is gently ami regularly arcuate, anil emit.s, in the mi<l<lle third of the wing, half a dozen branches, the ba.sjd ones of which are compound, the apical simple, and all nearly straight or slightly arcuate. Tiie anal furrow is roundly bent where it parts from the other veins, and beyond that Htraight, prob- alily terminating a little before the middle of the wing.
This insect is the largest of the palaeozoic cockroaches, the fragment mea.suring l.'J nun. in length and 22 nun. in breadth ; the probable length of the whole wing was almut 54 mm., or the breadth to the length as 1 : 2.45. Goldenberg de.scril)es the surface an covered with a network of reticulations visible to the naked eye, which near the apex of the wing are formed of transverse, clo.sely approximated, parallel cro.s.s-veins, broken into square cells by other fine lines ; while at the base and in the middle of the wing they form an irregular tetragonal or pentagonal network.
This fme species has no rival in the genus excepting the next to be described, than which it is only a little larger. It diflers from this, however, in the shape of the wing, which is much slenderer and has a less convex costal margin ; it also has a proportionately shorter mediastinal area ; from its size, it can by no possibility be confounded with any other species of the genus. Goldenberg compares it with Elohl. didi/ma, from which, as we have seen, it is generically distinct by the inferior origin of the externomedian veins; but, as he rightly .«avs, it diO'ers from that species in the distribution of the branches of each of the principal veins. Besides being peculiar for its great size, this .species is marked by the crowded venation and by the comparatively conspicuous reticulation.
The specimen described came from Lobejiin, Germany. Upper carboniferous. Geinitz reports the discovery of a specimen at Weissig, Saxony. Lower Dyas ; but as he appends to it a query, it may be considered dubious until direct proof is given.
Anthracoblattina sopita. PI. 4, fig. 8.
Blattina didi/ma E. Gein.. >tcues Jahrb. f. Mineral, 1875, 4-5, taf. 1, fig. 1 ; — lb., Neue Aufschl. Dyas v. Weiss., 4-5, taf. 1, fig. 1. Not BI. didyma Germ., for which see Etobl. didyma.
The fore wing is rather elongated, obovate, the costal border very strongly and regularly arched, the basal two-thirds of the inner margin almost straight, the tip well rounded ; it is broadest in the middle, and narrows almost equally toward both extremities ; the humeral lobe is greatly produced at the extreme base, by its sudden deflection to the root of the wing, forming a rounded subacute angle ; the veins originate rather below the middle line of the wing, and curve strongly upward, following very closely the basal curve of the cos- tal margin. The mediastinal vein runs parallel to the margin over nearly two-thirds of the wing, and then curving toward it, terminates rather beyond the middle of the outer half of the wing ; it emits a large number, a dozen or more, of simple or forked, oblique, and considerably arcuate branches, tolerably distant from one another ; the area occupies nearly
XEMOIRS BOBT. SOC. SAT. HIST. VOL. HI. 12
90 S. IT. SCFDDER ON PALAEOZOIC COCKROACHES.
one-quarter tho breadth of the -whig in the middle. The scapular vein is differently repre- seute<l in the two wings (of the same individual) figured by Geinitz; so differently indeed that Ixith can hardly be correct, and for our description we have chosen the one which accords with the structure of the species evidently allied to this ; in this it runs at first parallel to the costal border, as far as a little beyond the middle of the basal half of the "wing, where it forks ; its first branch is simple and continues in close proximity and parallel to the mediastinal vein, while it itself runs in a nearly straight, longitudinal course, termi- nating just before the extreme tip of the wing; it emits three other simple branches, the last one forking at the extreme tip, just beside an additional short apical branch of the main stem. The externomedian vein, more strongly arcuate next the base, divides a very little beyond the division of the preceding, and then runs parallel to that, emitting in all four branches, the first forking in the middle, the others simple; and all longitudinal, closely crowded, and together occupying an extremely narrow area on the margin at the extreme apex of the wing. The internomedian vein runs parallel to the preceding vein and its basal branch ; but somewhat beyond the middle of the wing, emits a supplemental superior branch running nearly parallel to the main stem, and extending the area so much further out, that it terminates as near the apex as the scapular area, and narrows very gradually ; commencing befoi-e the middle of the basal half of the wing it emits about eight nearly straight, slightly sinuous, oblique branches, the basal ones simply or doubly forked, the others simple, four or five of them emitted before the supplemental vein, the others beyond. Geinitz states, what his illustration bears out, that the second l)ranch on this wing is forked only at the end ; w^hile in the opposite wing it is not only distinctly forked near the base ("nahe der Wurzel," but really at the end of its basal third), but one of the forks again divides at the tip. The anal furrow is rather deeply impressed on the arcuate basal half, lightly on the straighter apical portion, and terminates at about the end of the second fifth of the wing ; the anal veins are arcuate, those next the furi'ow compound, the others simple, and all considerably and equally crowded.
Here again Dr. Geinitz's illustration is at fault, the two wings differing considerably, the anal area being undoubtedly too extended in the wing which we have not copied. Care seems to have been taken only with the wing which does not overlie the body ; this is altogether unfortunate in illustrating an insect which is undoubtedly the most perfect exam- ple of a palaeozoic cockroach Avliich has yet been found ; and the chance to observe the differences between the two wings, as a basis for a distinction between individual and specific differences, is lo.st, excepting in the points actually specified by Geinitz ; and as he particu- larly remarks upon the value of the differences observed hy him, it is the more probable that the other differences, apparent on his plate, do not actually exist, for if they do they are of much greater importance than those he specifies.
The wing figured is a very large one, measuring 45 mm. in length, as stated by Geinitz (in his plate it is 46.5 mm. long), and 20.5 mm. broad ; this he says is shorter than it should be. the wing being contracted by a transverse wrinkling of the specimen, represented in his plate by some wavy, transverse, narrow bands ; the other wing is 50 mm. long and 20 mm. broad, and represents, he thinks, the proper size ; it is not impossible, however, that the wings may have actually varied a little in length, and the breadth to the length may be put down as between 1 : 2.2 and 1 : 2.5. Both wings are nearly perfect, the apical edge of each being lost for a little way, and a few of the veins being obscured. The wing we have
S. n. SCUDDER OX PALAEOZOIC rorKROAflTES. 91
chosen for illustration and prim-ipal iK-scription. as probahh" delineated with greater acr\i- rac'V, is a left wing exhihitinj:; llio upper surface.
Hind wing. Portions of both iiind wings are preserved in connection with the fore wiugs, but show no outline of their fnrnj, but only some branching veins; which from their clo.se resemblance to the scapular and externomedian veins of the front wing, as to the mode and position of their forks, proliably belong to the.se veins ; their branching appears to be a little further from the ba.«e than in the front wing.
The single specimen known, is, with the po.ssilde exception of Klohl. intfifjiiis, the mo.st perfectly preserved of ail palaeozoic cockroaches; for, besides the wings, we have the head, thorax, a part of the body and the legs. It is, therefore, to be hoped that Dr. Geinitz will give a fuller account of it at an early period. The abdomen is probably ill preserved, as it is not represented on the plate, but is said by Geinitz to be 40 mm. long, and about 10 mm. broad, the narrowness of which he remarks. Of the head he makes no special mention ; it projects a little beyond the thorax as a transver.scly oval body, 2 nnn. long, and 'i mm. broad. The pronotal shield is longitudinally oval, broadest apparently in front of the middle, its front border well rounded, the sides convex, and the hind border apparently rather straighter than the front, its length 15 mm., and its breadth Id mm. The two hinder pair of legs are well preserved, apparently .shaped much as in modern types; no mention is made of spines ; the legs are .short, particularly the hind pair, where the whole leg is about 35 nnn. long, the femora and tarsi of about equal length, while the tibiae are a little longer; measuring his figure, we have the length of the former, 12 mm. ; its breadth, 3 mm. ; length of tibia, 14 mm. ; its breadth, 2 mm. ; length of tarsi, 10.5 ram. ; their breadth, 1.25 mm.
The wing is larger than in any other European species, excepting Anthr. speciabilis, from which it is readily distinguished by the more arched costal margin, the longer medias- tinal area, and the earlier division of the scapular vein. It is related to Anlhr. porrecta by the extent of the mediastinal area, but the distribution of the branches and the extent of the other areas differ considerably. Geinitz considers it identical with Elohlntt. rlidi/jnn with which he says it closely agrees, specifying, indeed, the illustration of Germar copied in our PI. 2, fig. 13. He mentions, however, certain differences, such as the greater simplicity and number of the anal veins. But there are much more important differences than these, and such as leave no doubt whatever of the specific, not to say generic, dis- tinction, although there is unquestionably a general resemblance between the two. The shape of the wing is very different from that of Eiobl. didyma, principally on account of the greater convexity of the costal margin in Anth. sopita and the greater median breadth of the wing, as compared with the extremities; in A. sopita again the mediastinal area is considera])ly longer, the scapular area very much narrower, as compared to the breadth of the wing, and its branches longitudinal, instead of oblique, and similar to those of the mediastinal area; the distribution of the veins of the externomedian area is totally differ- ent, the branches being mostly simple and inferior in Anthr. sojnta, while the branches are superior and the uppermost unusually compound in Etohl. didyma, and all together cover an extensive area at the apex of the wing, instead of a very narrow one as in Anthr. sopita. No differences of importance exist in the internomcdian and anal areas.
The single specimen comes from Weissig, Saxony. Lower Dyas.
92 S. II. SCITDDER ON PALAEOZOIC COCKROACHES.
Antliracoblattina diesdensis. (See figure in text.)
Blatt'ma drcsdcims Gein.-ncii'lim., Sitzuiigsh. naturw. Gcsellsch. Isis, 1879, 12-13, figs.
The fore wing is elliptical and very regularly formed, broadest in the middle ; the costal niarsin is prettv strongly convex, especially on the basal half; the inner margin much straighter, and the tip well rounded. The veins originate a little above the middle of the mng. and curve genth' upward before assuming a longitudinal course. The mediastinal vein, beyond the basal fifth of the wing, is nearly straight, scarcely curving upward with a broad sweep apically, and terminating only a little before the apex of the wing ; it emits eight or nine rather closely crowded, nearly straight, oblique branches, about half of which are simple, the others simply or doubly forked at or beyond the middle ; the area is broadest a little before the middle of the wing, Avliere it is one-third the width of the wing. The scapular vein runs parallel and close to the mediastinal until it forks, a little beyond the end of the basal third of the wing, and then turns downward in a nearly straight course subparallel to the costal margin, to just below the tip of the wing; it emits three equidistant longitudinal branches, the first two of which fork near the origin of the simple third, and embrace between- them the upper tip of the wing. The externomedian vein, beyond its curved base, runs in an almost perfectly straight line to just below the ex- treme tip of the wing, and, commencing to branch just before the middle of the wing, or scarcely beyond the division of the scapular vein, it emits four simple, inequidistant, arcuate branches, which (especially the basal pair) are at first oblique and then longitudinal. The internomedian vein is broadly sinuous in its course, being at first convex in the same sense as the co.stal margins, afterwards, on parting from the anal furrow, in the oppo- , , ,, . site sense, and terminates scarcely before the middle of the outer half of
Anihracohlatltna . ,. . . , . ,, . . , . • i i ^
dresdensis. the Wing; the area then dimmishes rapidly in size, and is occupied by only
three or four straight, oblique, distant branches, none of which are long,
and which become continually shorter apically. The anal area is lost, as well as most of
the anal furrow, which apparently terminates not far from the end of the basal third of
the wing.
The length of the wing is 28 mm. ; its breadth 11 mm., and its breadth to its length as 1 : 2.5. It was therefore somewhat smaller than the average of the genus. The frag- ment probably represents the upper surface of the left wing, and is nearly perfect, the tip being broken in two places, and the entire anal area absent; the interspaces are filled with a well-preserved reticulation of polyhedral cells. Geinitz compares this species with Elohl. eurjlyptica, and, although he mentions Anthracohl. porrecta, fails to see how much more closely it resembles the latter species. Besides the diflferences he points out in his comparison with the former, the stouter form of the wing and the inferior origin of the externomedian branches should be mentioned. Of the species of Anthracoblattina, it most nearly resembles A. porrecta, but differs from it in being less parallel-sided, in the unequal width of the mediastinal area, the frequent forking of the mediastinal branches, and especially in the more simple and regular branching of the scapular and externo- median veins; besides these points, the scapular-externomedian interspace strikes the margin below and not at the apex, and the internomedian branches are more distant. It
S. II. SCUDDER ON PALAEOZOIC COCKUOACIIES. 93
is also somewhat closely allied to the much larger Anthracohl. isopita, from which it diflerH principally in the unequal width of the mediastinal area, and the form and infreijuent brandies of the internomedian area. In the form of the latter area, indeed, it differs from all other species of tlie genus, the course of the internc^mechan vein in all t|^t' others being broadly and .somewhat uniformly arched, while in this it is rather strongly sinuous or sigmoid, and ha.s an unusually small nundjer of branches.
The single specimen known was found in the rubbish at the mouth of the Kaiserschacht, near Klein-Opitz, in Sa.vony, and, according to Geinitz, is the oldest insect known from the rock.s of Saxony. Upper carboniferous.
[The publication of this species w;us known to me, by the kind communication of Dr. Geinitz. only after the plates were engraved and the printing of the te.xt well advanced. I have, however, been able to place the species in its proper po.sition in the text, to add a wood-cut, and even to alter all references to the genus where neces.sary.]
Anthracoblattma porrecta. PI. J, (!<,'. '>.
BlaU'ma jjor recta E. Gein., Xeues Jahrb. f. Mineral, 1875, 0, taf 1, fig. 4 ; — lb., Xeue Aufschl. Dyas v. Weiss., 6, taf. 1, fig. 4 ; — Gold., Faun, saraep. foss., ii, 20.
Fore wing. The wing is long and narrow, subequal, the costal border strongly arcuate at the base, but beyond very gently convex to the rather broad, well-rounded tip ; the inner margin is broken, but probably nearly straight; the veins originate at about the middle of the base, and curve gently upward before becoming longitudinal. The mediastinal vein follows very closely the costal margin, but at considerable distance, approaching it very gradually in the apical half of the wing, and terminating onl}' just before the apical .si.\th of the wing ; it emits nine or ten oblique, straight, generally simple veins, and occupies about one-third the breadth of the wing. The scapular vein has a regular, gently and and broadly sinuous curve, runs subparallel to the costal margin, and terminates at the tip of the same ; it breaks into two shoots just before the middle of the wing, the lower of which emits two apical, superior, simple branches ; the upper, at subequidistant intervals, three straight, superior bi-anches, the basal forked, the others simple, similar in direction and appearance to the apical branches of the mediastinal area. The externomedian vein runs closely parallel to the preceding, and emits two inferior branches, one at the point where the scapular vein divides, which is doubly forked, and the other nearly half way to the margin, which is probably singly forked. The internomedian vein is regularly and rather gently arcuate, and terminates on the inner margin a little before the extremity of the media-stinal vein, and emits four long and very gently arcuate, simple branches at regular intervals from the middle of the basal half of the wing. The anal furrow is distinct, very regularly and broadly arcuate, terminating scarcely before the middle of the wing; the anal veins are simple, arcuate, and apparently distant.
The wing is a large one, measuring 34 mm. in length, and 12.5 mm. in breadth, the breath being to the length as 1 : 2.7. The only example known is nearly perfect, and if the upper surface is exposed, represents a left wing, whose inner margin is nowhere well defined, the anal field obscured, and an unimportant fragment of the tip missing. As Geinitz says, it is clearly distinct from any other species, and is peculiar for the reversed similarity of the scapular and externomedian veins, which occupy equal spaces on either
94 S. 11. SCITDDER ON PALAEOZOIC COCIOIOACHES.
side of the extreme apex. It is much smaller than the jii'ecerling species, from which it also differs in form, in the width of the mediastinal area, and the very different distribution of the scapular and externomedian branches. It probably agrees better in size with Anihr. Hiickerli. from which it is abundantly distinct by the much earlier division of the scapular and externomedian veins. From the succeeding species, Anthr. winterlana, it differs strikinglv in the greater width of the mediastinal area, and in the distribution of the branches of the extei-nomedian veins.
The single specimen was found in the coal shales of Weissig, near Pillnitz, Saxony. Lower Dyas.
Anthracoblattina vnnteriana. PL 4, fig. 12.
Blaithui icinteriana Gold., Neues Jahrb. f. Mineral, 1870, 288-89, figs. 1-4;— lb.. Faun, saraep. foss., ii, 19, 25-26, 51, taf. 1, fig. 11.
Fore wing. The basal third or thereabouts of the wing being broken, its shape cannot be fully described, but in the parts which are preserved are some unique peculiarities; the costal margin, straight in the middle of the wing, is afterwards strongly curved, and meets the almost equally curved inner margin at nearly a right angle, the tip being bluntly angu- lated, an extremely rare occurrence in palaeozoic cockroaches. The mediastinal vein is nearh' straight, in near proximity to the costal margin, and when the latter begins to curve toward the apex, this curves in an opposite direction, giving the mediastinal area an elon- gated lancet-shaped form ; the vein terminates at some distance before the apex, probably scarcely before the apical sixth of the wing, and emits a considerable number of rather distant, straight, simple or forked, oblique branches, becoming more longitudinal toward the tip ; the area is probably not more than a sixth of the width of the wing, at the middle. The scapular vein is rather widely separated from the mediastinal, and forks probably not far from the middle of the wing, and continues then in a nearly straight line, subparallel to the costal border, and terminates below the tip of the wing, being near the apex double the greatest width of the mediastinal area ; it emits, at subequidistant intervals, four straight longitudinal branches, the first compound, the second forked beyond the middle, the others .simple, the ultimate branches much more closely crowded than the mediastinal branches. The externomedian vein divides close to the base of the wing, in exactly what manner cannot be said ; for in the only specimen known, three very straight veins, which most probably belong to this area, appear at the basal edge of the fragment, the outer ones forking once beyond the middle of the wing, all parallel to the scapular vein, and occupying a small area near the extremity of the inner margin, shorter than that occupied at the margin by the scapular area, and, by the nearly uniform width of the area throughout the wing, forming a striking contrast to the fan-shaped disposition of the scapular branches. The internomedian vein is also parallel to the same veins, showing only a slight tendency to an arcuate course, and terminating at the same distance from the apex as the mediastinal vein ; it emits four or more, rather distant, simple or forked, straight and oblique branches.
The length of the fragment is stated by Goldenberg to be about 22 mm., its breadth 13 mm.; the entire length can only be roughly conjectured; it may have been 30 mm. long, or above the medium size ; its breadth was to its length probably as 1 : 2.3. Golden- berg's illustration of the natural size would, however, make the fragment only 18.5 mm. long, or his magnified drawing only 21 mm.; the enlargement on our plate chances to
S. 11. SCUDDER ON I'AF.AF.OZOIf COCKKOACIIKS. 95
have been based for si/e upon the siimllest uf these li;;iiies. ami is lluTclure doubtleKs tot) small; in len<j;th it siiould have olost-ly resi-inliled Anthr. liiirktrll. The IVajriin-nt repre- sents the npper snrl'aoe of a left winji;, in which the Im.s4il thinl. the whole anal field, and part of the internomedian is destroyed. The veins are all deeply impressed, und the inter- spaces are correspondingly vaulted, but the mediastinal vein, pnjbably by the mode of preservation, is sharply elevated into a ridge. (Joldenberg <lesonbes the cross venation iw nearly effaced, but where traces of it are found, as consisting of a network of delicate quadrangular meshes, visible only by consideral)le eidargement.
This wing is very peculiar, not only for its pointed apex, but for its elevated mediastinal vein, perhaps due, as remarked, to accident ; and also for the nearly equal breadth of it.s long externomedian area, which is the more striking becau.se unaccompanied bv corre- sponding diflerences in other jjarts. These peculiarities forbid any reference of this fcjrm to any other species, and render unnecessary any special comparison with allied types. It i.s placed in its present position, however, because it reseud)les the preceding species in the di.s- tribution of the scapular and mediastinal branches, and the following in the narrowness of the mediastinal area, more than it does the other species; but the resemblance i.s not very great, nor does it extend to other important parts of the wing. Goldenberg compares it to Blattina russoma, but only as regards the size.
The single specimen was foimd in the Dudweiler coal-pit, near Saarbriicken, Germany. Middle carboniferous.
Anthracoblattina Remigii. PI. 4, fig. 2.
Blatl'ma Bemigii Dohrn. Palaeont.. xvi, 13o-o4, taf. 8, flg. 3 ; — Gold., Faun, saraep. loss.,
ii, 20, 26-27, 51, taf. 1, Hg. 13.
Fore wing. Nearly the whole of the inner margin is wanting, so that the form of the wing cannot be definitely stated ; it ■would appear, however, to have been nearly equal or slightly tapering, for the principal veins are straight for most of their course, and the costal border is very gently and regularly convex, with the appearance of a fully-rouniled apex. The veins originate from above the middle of the wing, and have only a very broad and gentle upward curve near the ba.se. The mediastinal vein runs subparallel to the costal margin, very gradually approaching it, a little more rapidly as the apical third of the wing is entered, termmating scarcely before the apical sixth of the wing ; the area is about one- fifth the breadth of the wing, and is filled with a large number (eight to ten) of arcuate, simple branches, longitudinally oblitiue even at tlie start, and becoming nearly longitudinal toward the apex. The externomedian vein is much more distant from the mediastinal than from the internomedian vein, has a very gently arcuate, longitudinal course, parallel to the costal margin in the basal two-thirds of the wing, and terminates at the very tip of the wing ; it divides, a little before the middle of the wing, into two branches, each of which fork near the tip of the wing only. The externomedian vein runs in close proximity to the pre- ceding, is straight beyond the basal fifth of the wing, is represented by Dohrn as first dividing in the apical third of the wing, and emitting two simple inferior branches ; the space, however, in the apical half of the wing between the externomedian and interno- median veins is so great, that there must certainly be at least another, and that probably a forking vein, originating a little beyond the middle of the wing and occupying this space.
9G S . n. SCFDDER ON PALAEOZOIC COCIOlOACnES.
The intornomodian vein is rathor strongly and regularly arcuate throughout, and termi- nates probably about as far troni the tip of the wing as the mediastinal vein; it emits only three similarly arcuate, long, and very distant branches. The anal furrow is not very deeply impressed, rather strongly and regularly arcuate, terminating at a little before the middle of the wing ; as the veins originate above the middle of the base, even including the anal furrow, the anal area is very large ; the anal veins, to the number of six or seven, are rather distant and simple, at first arcuate, afterwards nearly straight.
The wing is one of the smaller ones, the fragment measuring 14 mm. in length and 6.2 mm. in breadth, the whole wing being probably about 15.5 mm. in length, and the breadth to the length as 1 : 2.5. A large part of the lower outer portion of the wing is broken, but the course of the veins is pretty clear throughout; the upper surface of the wing, which is a left one, is exposed, on which the veins are slightly elevated ; but the anal furrow is rather indistinct and depressed, the anal area being vaulted to a considerable degree, while the middle of the wing is rather concave ; no cross venation can be seen.
The distant venation of the lower part of the wing, i. e., in the anal and internomedian areas, is in unusual contrast to the crowded distribution of the other branches, and marks this wing as very distinct from others; so, too, the narrowness and equality of the space between the mediastinal and internomedian veins in the basal half of the wing is rather peculiar, and allies the species to the following; from which, however, it is remarkably dis- tinct in the narrowness of the mediastinal area ; in this particular, one is reminded only of the pi'eceding species, but the distribution of all the other veins is very different. Dohrn and Goldenberg compare it to Hermatohl. lebachensis, with which, indeed, the general resemblance is greater than with perhaps any other palaeozoic cockroach; but besides its lesser size and the comparative narrowness and equality of the mediastinal area, we find the scapular branches superior, instead of being inferior, as in Hermatohl. lebachensis.
The single specimen was found in an argillaceous schist in a coal-pit on the Eemigius- berge, near Cusel, in Rheinpflalz. Upper carboniferous.
Anthracoblattina Riickerti. PL 4, fig. 1.
Blattina Riickerti Gold., Neues Jahrb. f. Mineral., 1869, 163-64, taf. 3, fig. 11.
Fore wing. The apex of the wing only being preserved, and that not perfect, it is im- possible to describe the form of the wing; the apical half of the costal border, however, is preserved, .showing a curve very similar to that of the species last described. The medias- tinal vein, if I have rightly interpreted it, is remarkably distant from the costal margin, so that the area must occupy more than a third of the width of the wing, terminating just before the apical sixth of the wing, and possessing distant, simple, nearly straight, and oblique branches. The scapular vein is straight or scarcely arcuate in an opposite sense to the costal margin, in the outer half of the wing, and terminates scarcely before the tip, dividing only in the apical third of the wing, and emitting at rather wide angles three simple or forked branches. The externomedian runs down the middle line of the wing exactly parallel and close to the preceding, begins to divide at the same point, and has two equally divergent, simply or doubly forked branches, occupying an exactly equivalent area to those of the .scapular vein. The internomedian vein is gently arcuate in the distal half
S. H. SCUDDEIt OX PALAKOZOIC COCKKOAfllKS. <>7
ot" its course, terininatiuj^ a littlo lu'vonil tlw iiu'iliitslinul vfiii, aii<l lias a lur;;*- miiuKcr of straij^Iit, ol)Ii(|iie, crowdeil Ijraiicla's, simple or deeply forkeil.
The lenj:;th of the fVa^inent is 1(1.') nun.; it.s hreaWth, I.').') nun.; prohahly the len^rth of the wing was about .JO nun., or a little ahove the medium 8i/.e, and the breadth to the length a-s 1 : 2.2. The restored parts in our plate, however, no d«)ubt represent the wing a.s too broad, the projecting part of the internomeilian area being inaccurately diawn. Goldenberg describes the interspaces as filled with parallel and Htraight cross lines. If the upper .surface is exjjosed, the wing is a lefl one.
It is peculiar for the great width of the mediastinal area, even if we have carried it a single vein too far inward ; and the regularly opposed and straight distribution of the branches on opposite sides of the scapular-e.xternouiedian interspace, which follows nearly the middle line of the wing, gives it a peculiar aspect. Goldenberg compures it to Her- nuttobl. lehnchensis, but the different position of the scapular branches, superior instead of inferior, at once distinguishes it from that, not to mention the points referred to by him. It is more nearly allied to AntJir. liemlr/ii, from which, however, it may be distinguislicd at a glance by the far less arcuate form and the much greater frecpuMicy of the iuterno- median branches.
Goldenberg neglects to record this species (of his own description) in his Catalogue of fossil cockroaches (Faun, saraep. foss., ii, 19-21.)
A single specimen, from the Ma.x coal-pit of Stockheiin, Oberfranken. Dyius.
Gerablattina nov. gen. {/■i,/"t^, Blattiiia).
Blattbia Auct (pars).
The mediastinal vein of the front wing runs parallel or subparallel to the costal margin, and generally rather distant from it, frequently more distant in the middle of its course than elsewhere, and terminates generally beyond the middle of the apical half of the wing, frequently far toward the very apex ; it sends a large, sometimes a very large, number of oblique, straight or curving, usually simple branches to the costal margin. As the division between the scapular and externomedian areas is at or before the tip of the wing (in a single species, G. Mahri, perhaps .slightly beyond it), the scapular area is nece.s.sarily much restricted ; generally speaking, it is limited to only a few apical branches, which scarcely originate before the middle of the apical half of the wing ; and in one or two, such as G. Geinitzi and G. Miinsteri, there is only a single apical fork ; but in G. Germari and G. weissiana there are .several branches, which originate near the middle of the wing: the American species, however, seem to form a distinct section ; for notwithstanding that the great length of the mediastinal vein is still retained, the scapular vein begins to 'branch before the middle of the wing, and emits three or four branches, some of which l)ranch again, and that more than once ; the branches of this vein are always superior, whether the extent of the branching be con.siderable or slight. The externomedian vein is very similar to the scapular, although in some, but not all, of the species in which the scapular area is greatly reduced, it does not suffer to a corresponding extent ; in the species placed at the head of the series, as well as in G. Geinitzi and G. Miinsteri, it is considerably more extensive than the scapular area, but in the others, including the American species, it is very simi- larly developed ; all the branches are likewise superior, so that the reverse obliquity of the
KEMOIKS B08T. SOC. SAT. HIST. VOL. m.
flS S. IT. SCITDDER ON PALAEOZOIC COCKROACHES.
branches of iioiixlilHiring veins appears in this genus in the interspace between the externo- niedian and intornoinethan veins. The coml)ined internomedian and anal areas occupy, in the species at the head of the series, somewliat more than half of the width of the wing at the base, about one-half or slightly more than that in the others; and it generally dimin- ishes graduallv and regularly in width, and terminates, with rare exceptions, nearer the tip than does the long mediastinal vein ; in some species the internomedian vein is nearly straight; in others, however, while there is at first a rapid diminution in the breadth oi the area, the vein afterwards runs parallel to the inner border, and extends the area far toward the tip of the wing; the vein has a large number of subparallel, straight or gently curvimr branches, which are indifferently simple or branched, and the obliquity of which] corresponds m most cases very closely, although in a reverse sense, to the branches of the mediastinal vein. The atial furrow is generally pronounced, and straight or gently curved ; in one or two, however, it is very arcuate, and, while somewhat irregular in ter- mination, its tip seems never to be for removed from the end of the basal thii'd of the win"-; the anal veins, where known, are frequent, parallel, arcuate, and generally simple inj the European species and in one of the American species ; but in the other American spe- cies, G. fascigera, they are very different, being nearly straight, multiple-forked, running! in a direction somewhat divergent from that of the anal furrow, and approaching the latter! only near its termination.
The wings in this genus are slightly above the average in slenderness, being 2>reciselyj the same, as a whole, as in Etoblattina, the breadth being contained in the length scarcely] less than two and three-quarter times.
This genus appears to be most nearly allied to Hermatoblattina, from which it differsj sufficiently in the superior position of the branches of the scapular vein ; from Etoblattinal and Archimylacris it may be separated at once by the great length of the mediastinal area J from Anthracoblattina it differs in having the branches of the externomedian vein superior and not inferior ; Progonoblattina, with the wide extent and importance of its scapula and externomedian areas, is readily distinguished from it ; Oryctoblattina for similar rea-j sons, as well as for many others, cannot be confounded with it ; while the strong backward curve of the externomedian vein in Petroblattina, with the extensive area covered by its| longitudinal branches, separates it from that genus at a glance.
Most of the species of the genus, which next to Etoblattina is the richest in kno\ forms, come from the old world ; but two American species must be placed here, althougl the extensive development of the scapular vein would perhaps, as suggested above, warrant separating them as a peculiar section.
Gerablattina Goldenbergi. PI. 3, fig. 13.
Blattina Goldenbergi Mahr, Neues Jahrl). f. Mineral., 1870, 282-84, fig. 1 ; — Gold., Faun^
saraep. foss., ii, 19.
Fore wing. The apical third of the wing being lo.st, its precise form cannot be describee but it was evidently- long and narrow ; the costal margin is regularly and rather strongly arcuate, with a very prominent humeral lobe, the inner margin straight, with its basa angle rather broadly rounded. The veins originate much below the middle of the has and curve strongly upward over a considerable distance, so as soon to occupy the middle of
S. H. SCUDDEK OX rALAEOZOlC COfKHOACUKS. 99
the upper two-thirds of the wiii'f. Tlie tno(lin.stintil urea in nearly one-third the width of tlje wing, tlie main vein running paraHel with the costal margin for a long dixtanee, prohahly over the basal two-thirds of the wing, hoginniiig to turn toward the border only at the very extremity of the fragment, and proliably reaching the border at no gn-at distanee before the tip of the wing; it emits nearly a dozen distant, nearly straight, simple and (»bliijue branches. The scapular vein runs closely parallel to the preceding throughout the frag- ment, suppcsing the two vein.s which appear to originate from it.s under surface to reprcBent the externomedian vein ; whether this interpretation is correct, neither the description nor the illustration of Mahr enable us to state positively; but the resemblance of this wing to others of the genus in which we place it renders it i)robable that here, as is usually the i:ii»e in the genus, the scapular is of less imporUmce than the externomedian vein, and in such a case only one of the three veins which lie between the mediastinal ami internomedian veins in the middle of the wing can belong to the scapular vein ; although this vein is simple in the fragment, the turn of the mediastinal vein toward the costal border renders it nearly cer- tain that it forks at least once or twice in the apical third of the wing. The externomedian vein, on the same a.ssumption, divides into two l)ranches before the middle of the wing, each of which again forks beyond the middle of the wing, and undoubtetlly branches again beyond that, probably occupying upon the margin all the space from a little above the tip to the extremity of the internomedian area ; the general course of the vein is at first strongly arcuate, afterwards longitudinal. The internomedian vein is strongly arched in the basal half of the wing, then becomes straight or bent a little toward a longitutlinal direction, and probably terminates about as far from the tip as the mediastinal vein; it emits only three branches, the first forked, the others simple, all gently arcuate, ol)lique, and distant ; the veins of this area are represented by exceedingly heavy lines in Mahr's illustration, but as he makes no mention of any difference between them and the others, this is probably an error. The anal furrow is very strongly arcuate indeed and deeply im- pressed, terminating, probabW, a little before the middle of the wing; the anal veins, according to Mahr, are ten in numl)er, but man}' more are represented in his figure, which is carefully followed in our plate; these are all arcuate, regular, simple, and, in striking contrast to the other areas, closely crowded.
The wing is of medium size, the length of the wing being 15.5 mm., while the entire length of the wing is probably about 23 mm. ; its breadth is !) ram., and the breadth to the length as 1 : 2.55. From Mahr's statement that the anal field is concave, the under surface is evidently exposed to view, and the wing is therefore a right one. \v It is remarkable for the great extent of its anal area, by which it is readily separated from all the species of the genus in which this area is known, and for the clo.se proximity of the veins in this area as contrasted with their wider separation in the rest of the wing ; in the uniform belt-like nature of the mediastinal area it resembles several of the species, particularly G. clathrata, G. intermedia, and G. Mahri ; from the first of these it is quickly distinguished by the distance of the branches of the mediastinal vein, in which particular it more nearly resembles the other species ; from G. Mahri it differs greatly in size and in the convexity of the costal margin ; and from G. intermedia in the early division of the externomedian vein and the strongly- curved internomedian vein.
A single specimen, from an argillaceous schist between the third and fourth veins of the Ilmenau coal basin, Manebach. Upper carboniferous.
100 S. n. SCtTDDER ON PALAEOZOIC COCKROACHES.
G-erablattina clathrata. PI. 3, fig. 4.
Blattina clafhrata Heor, Yiertelj. naturf. Gesellsch. Ziirlch, ix, 288, 294-96, pi., figs. 3, 3% 3"'; — Gold., Faun, saraep. foss., ii, 19.
Fore wing. The extreme tip and most of the anal area are wanting, and the inner mar- gin is also broken, so that the precise form is uncertain ; it is, however, tolerably broad, and the oos^tal border rather strongly and regularly arcuate, much as in the preceding species, but with a very .slight humeral lobe ; the principal veins are all almost similarly arcuate, originating near the niiddle line of the wing, and running subparallel to the costal margin ; the branches on either side being very frequent, long, and straight, and, parting from their stems at an equal angle, give the wing a peculiarly simple appearance. The mediastinal vein runs nearly parallel to the costal margin, but is more distant from it in the middle than at the base of the wing, is bent at the origin of its first branch, the humeral lobe being devoid of branches, begins to approach the margin a little beyond the middle of the \x\ug and terminates at the very end of the fragment, or probably about midway be- tween the middle of the costal border and the extreme tip of the wing ; it emits about a dozen closel^'-crowded, straight or nearly straight, simple or occasionally apically-forked, oblique and nearly parallel branches, the direction of the apical not diverging greatly from that of the basal branch ; the area is very broad, occupying nearly one-third the breadth of the wing. The scapular vein, appearing to originate from the same stem as the externo- median and to separate from it in the middle of the basal half of the wing, runs close and parallel to the mediastinal, until that vein turns toward the costal margin ; it retains there- after its former direction for some distance, and then turns very slightly and gradually up- ward, and terminates just before the tip ; in this apical portion it emits three closely approximated branches, the first next the last branch of the mediastinal vein, and basally forked, the others simple and soon parallel to the main stem. The externomedian vein does not fork until past the middle of the wing, and, just this portion being destroyed, it is impossible to give a precise statement, but in any case the distribution of the veins is peculiar, for the three or four straight and simple branches, which occupy the tip of the wing and run subparallel to the scapular branches, spring, in the apical fourth of the wing, from a vein which runs almost exactly parallel with the costal border, and m continuation of the main externomedian vein ; while the other three or four branches, which strike the apical part of the inner margin, run parallel to the internomedian branches, and are much longer than the other externomedian branches, running parallel to each other in a straight and simple course, and originating, in some indeterminable manner, scarcely beyond the middle of the wing. The internomedian vein is rather strongly and very regularly arcuate, terminates a little nearer the apex than the mediastinal area, and emits about ten nearly straight, very long, parallel, oblique veins, the first doubly forked, the others simple ; the area at its broadest occupies considerably more than half the breadth of the wing. The anal furrow is well impressed, strongly arcuate, apically nearly straight, terminating not much be3'ond the ba.sal third of the wing ; one or two fragments of anal veins next to the furrow are preserved, running parallel to the same.
The wing is of rather large size* one of the largest of the genus, the fragment measuring 32 mm. in length, and 13.5 mm. in breadth; the whole wing is probably 35 mm. long, according to Heer, the breadth being to the length as 1 : 2.6. By some accident it has
I
S. n. SCUDDEfi ON PALAEOZOIC COCIvIlO ACHES. 10 1
been represented upon my plate as inaj^nifuMl slightly less than twice. From Ileer'a de.ncriptioii of the reticuhitioii, j)rol)al)ly tla- upper .•surface is rxpt)se(l, and the winj^ iH that of the left side; all the interspaces, according' to lli-er, are fdled with a very fine network, as in Oryrtohl. retUitlnld, consisting of polygonal cells, forming from two to four rows in each interspace, whence the specific name.
The species is peculiar for the regular distrihution of the hranchcs, parting in a uniform manner on either side of the principal veins ; and for the uiuisual distinction of the uj)per and lower branches of the e.vternoiiiedian vein, which take the direction, — the Uj)per of the scapular, the lower of the internomcdian branches. In the great breadth, length, and uni- formity of the mediastinal area, this in.sect resembles .several of tin* species oi' (ierablattina. but especially G. iioldaihcry'i and G. 3Iiihri. In the form of the wing it most resembles the former species, from which it is readily distinguished by its larger size, the much greater extent of its internomcdian and much .smaller extent of its anal area. From Gerabl. inter- media, with which it agrees to a certain extent in the apical divi.sion of the scapular and externomedian branches, it is readily separateil by the far more crowded neuration and the larger size of the wing.
The single specimen comes from the coal-measures of Manebach, in Thiiringen, as.so- ciated with loaves of Pecojiteris arhorescen.i. Upper carboniferous.
Gerablattina intermedia- PI. 3, tig. 11. Blattina intermedia Gold., Faun, saraep. fo.ss., ii, 19, 24-2G, 51, taf. 1, figs. ID, 10'.
Fore wing. The wing is of an obovate form, its regidarity only lost by the prominence of the anal angle and the relatively diminished size of the humeral lobe; the costal border is considerably arcuate, but the humeral lobe so little developed as to be less full than the inner angle ; the inner margin is gently arcuate, and the tip broad and broadly rounded ; the veins originate from about the middle, perhaps above the middle, of the base, and are gently arcuate at their origin. The mediastinal vein, subparallel to and rather distant from the costal margin, turns rather rapidly toward it somewhat beyond the middle of the wing, and terminates in the middle of the outer half of the wing, emitting seven distant, arcuate, obliqiie, parallel, simple branches ; the area occupies a little le.'JS than one-third the breadth of the wing. The scapular vein runs parallel to the costal mar- gin until it branches in the middle of the third quarter of the wing, beyond which it curves toward the margin, and half way to it emits a second and only other branch, which is simple, the first being forked. The externomedian vein, which appears to be coalesced with the preceding in the basal fourth of the wing, runs parallel to the internomedian, and does not fork until it has reached the apical fourth, when it only emits from its upper sur- face two simple, short, and straight branches, which, with the main vein, occupy the tip of the wing, and leave a wide space between the scapular and externomedian veins. The internomedian vein is rather gently arcuate at the base, and beyond nearly straight, in- clined doAvnward, terminating a little before the tip of the wing, and emitting half a dozen or more distant, straight or gently arcuate, simple or apically forked, oblique branches.
The wing is of medium size, measuring 22 mm. in length and lU mm. in breadth, the breadth to the length being as 1 : 2.2. If the upper surface is exposed, it belongs to the right side. The anal area is lost, but otherwise the wing is perfect, and in certain places,
102 S. II. SCUDDER ON PALAEOZOIC COCKROACHES.
savs Goldonberg, one may see with a lens a delicate polygonal reticulation in the inter- spaces, which he represents as formed of ver}'^ closely approximated cross lines, often con- nected near the middle by oblique cro.«!S lines, so as to form elongated intcrdigitating cells.
This wing is peculiar, as Goldenberg remarks, for the very slight development of the scapular and externomedian veins, and especially for the apical division of the latter. He might also have added, its open neuration. In comparing it with '•Blatiina jlabellata Germ.," Goldenberg doubtless had in mind our Gerahl. 3Iunsteri, with which it no doubt agrees in general features, but is at once distinguished by the peculiar marks of the species just referred to; it is, however, more closely related to a species described by Goldenberg at the same time, Gerabl. scaberaia, which also has very sparse neuration. It differs from this, however, in the character of the mediastinal branches, which are for more longitudinal in Gerabl. scaberata, and some of them also forked, while the division of the scapidar and externomedian veins in that species is even simpler than here. In the apical division of these two veins just mentioned it is related to Gerahl. clathrata, but the smaller size and openness of the neuration at once separate it from that species:
The single specimen comes from a bluish bituminous shale at Wemmetsweiler, near Saar- brucken, Germany. Middle carboniferous.
Gerablattina scaberata. PI. 3, fig. 3. Blatiina scaberata Gold., Faun, saraep. foss., ii, 19, 25, 51, taf. 1, fig. 8.
Fore wing. The fragment preserved is exceedingly imperfect, and all that can be said of the form of the wing is that its costal border, away from the two extremities, is nearly straight or scarcely arcuate. The neuration of the wing, however, is suffi- ciently preserved to indicate its probable place in this genus, and to distinguish it from the other species of the same. The mediastinaal vein runs parallel tb the border in the basal third of the win^, then approaches it very gradually, terminating in the middle of the apical half; it is very distant from the margin, the area probably occupying about one-third the width of the vnng ; it emits half a dozen straight and very long, longitudinally obhque veins, some of the basal ones rather deeply forked, the others simple, and all distant. The scapular vein terminates just before the tip, is nearly straight from beginning to end, and probably emits only a .single, and that a simple, branch at the middle of the outer half of the wing ; for there is hardly space for more. The extei-nomedian vein runs in a straight course down the middle of the wing, and can hardly fork more than once,^ and that beyond the middle. For the internomedian vein also runs in a straight line along more than half the wing, and must terminate scarcely below the tip ; only one branch of this vein can be seen, and this has an unusually longitudinal trend, like the branches of the mediastinal vein.
The wing is of tolerably large size, the length of the fragment being 25 mm.; its breadth, 7.5 mm.; the probable length of the wing is 30 mm., but its breadth can only be conjectured. The base, almost the whole of the lower half of the wing, and a large part of the tip are lost. If the upper surface is exposed, the wing is of the right side. Gold- enberg mentions that no reticulation can be discovered, but that the interspaces are sprinkled with small raised points.
' Id the plate the branch of thb vein should have been given in dotted lines at the base as well as beyond.
S. II. SCTDDKR ON TALAKOZOIC COCKROACIIKS. 103
Tlio wing is peculiar for the longitudinal flirection of the hranclies of tlie nu'ili.u-^tinal un<l intornomedian veins, and also for the siniplieity of the scapular and externoniedian liranch- ing ; the latter, indeed, is only inferred, l»ut reasonal>ly so. from the openness of the exist- ing neurafion. the small space left for branches, and the extreme straightness of the prin- cipal veins, which is another peculiar feature of the species. It is more nearly related to the preceding .species than to any other, but is readily distinguished from it by all the features above named, and by the straightness of the costal margin.
The single specimen was found in a bluish bituminous shale from the cuhii of the .\lton- wald mine, near Saarbriicken, Germany. Miildle carboniferous.
Gerablattina Geinitzi. I'l. "J, lii:. II.
Blattina Geinitzi Gold., Neues Jalirl). f. Mineral.. 1S(;!I, l(i()-01, t.if. .{. fig. ■j;_lb.. Faun.
.saraep. fo.ss., ii, I'J.
Fore wing. The wing is of peculiar form, the costal margin being straight nearly to the tip, while the inner border is rather strongly arcuate and the tip well roumled ; Golden- berg considers the humeral angle as complete, and therefore states, as another point in con- trast to the form of the wing in other ancient cockroaches, that it does not project so far basally as the anal angle; but this would hardly seem consistent (to the extent figured) with the use of the "wing, and we are therefore forced to believe the wing imperfect. The veins originate from the middle of the up})er half of the ba.se, and do not curve upward. The mediastinal vein, owing to the straightne.^s and l)asal contraction of the costal margin, is nearer the margin basall}- than beyond, pursuing an arcuate course, (irst divergent from, afterwards convergent with the margin, and terminating only a little before the apex, or at the extremity of the straight portion of the margin ; the area is widest in the middle of the wing^ where it is less than a fourth of the entire width of the wing, and is fdled with frequent, longitudinally oblique, simple, arcuate veins, about eight in number. The scap- ular vein is remarkable for its excessive simplicity, following close to the media.stinal vein, and forking once only and close to the extremity, beyond the origin of the last mediastinal branch. The externoniedian, on the contrary, has a broadly sinuous course through nearly the middle of the wing, and although it begins to fork before the end of the basal tliinl, it only occupies, with its three branches, the extreme apical border of the wing ; the branches are equidistant, the last emitted before the end of the middle tliird of the wing, superior, longitudinal, and closely crowded apically, the first one (in the only specimen known) simple, the next simply, the last doubly forked. The internomedian vein is subarcuate. or bent in a sense opposite to what is usual in palaeozoic cockroaches, the ba.sal half being nearly straight and bent downward, the apical nearly straight and sublongitudinal, termi- nating just before the tip, where the, scapular vein ends, and emitting about eight crowded, subarcuate, simple or forked veins, the apical much more longitudinal than the basal. The anal furrow appears to be lightly impressed, gently arcuate, terminating a little before the middle of the wing; the five anal veins are at first simple and arcuate, like the furrow, afterwards forked and straighter.
The wing is of small size, measuring 14 mm. in length and 4.75 mm. in breadth; or the breadth to the length nearly as 1 : 3. If the upper surface is exposed, the wing is from the right side. Goldenberg makes no mention of the surface characters. The wmg is
104 S. II. SCFDDER OX PALAEOZOIC COCKROACHES.
unusuallv porfoot. but in-ol>al)ly the basal portion at the luimeral lobe is wanting. It is peculiar for the straightness of its costal margin as contrasted with the fullness of the inner margin, for the basal narrowing of the mediastinal field, and for the extreme apical simjilo forking of the scapular vein. In the first and last of these features it is undoubt- edly allied to the preceding species, but is readily distinguished from that by its narrower mediastinal field, as well as by abundant division of the externomedian vein, the smaller size of the wing, and the much more crowded ncuration. Gerabl. Miinsteri has a some- what similar scapidar vein, and also has a crowded neuration, but it also has an extremely wide mediastinal field, in striking contrast to this species ; its straight cosl^al margin also at once separates this species from Gerabl. 3Ii'tns(ei'i, as indeed from all the other uumentioned species of this genus.
The single specimen found comes from Lobejun, German3\ Upper carboniferous.
Gerablattina Miinsteri. PI. 2, fig. 12.
Blattlna flahellata Germ., Verst. Steink. Wettin, 84-85, tab. 31, fig. 5% 5"; — Gieb., Ins. Vorw., 315. Not Bl. flahellata Germ., Miinst. Beitr. (for which see Etobl. flahellata).
Fore wing. The costal margin is rather strongly and regularly arcuate, while the inner margin is straight ; and the wing, being broadest at the end of the basal third, tapers very regularly thereafter to the tip, which is broken, but probably well-rounded ; the veins orig- inate a little above the middle of the base, and curve a little upward at first. The medias- tinal vein is arcuate at base, straight and subparallel with the costal margin bej'ond and past the middle of the wing, curving gently toward the margin, which it does not reach until about the middle of the apical fourth of the wing ; the area is very broad, being fully two- fifths the entire breadth of the wing in the middle of the latter, and emits a large number, a dozen or more, of nearly straight, mostlj^ simple, occasionally forked, branches, the basal ones transversely oblique, the apical longitudinally oblique. The scapular vein is very sim- ple, broadly sinuate, follows the course of the mediastinal vein, and, passing nearly through the centre of the wing, forks once in the middle of the apical half of the wing, and occupies only an extremely narrow area on the extreme apical portion of the costal margin. The externomedian vein appears to be coalesced with the scapular in the basal fourth of the wing, but both before and after its separation follows exactly parallel and close to the inter- nomedian vein, which terminates probably almost as near the apex as the scapular vein, leaving for the externomedian vein only the very apex of the wing ; it begins to branch a little before the middle of the wing, and emits, at equidistant intervals, three longitudinal branches, the middle one arising in the middle of the wing, and simple, the others simply or doubly forked, so that the apex is crowded with veins. The internomedian vein is rather strongly arcuate at base, then runs downward in a nearly straight line toward the middle of the apical half of the inner margin, until nearly the end of the middle third of the wing, when it turns suddenly outward, and runs parallel to the inner border, doubtless afterwards approaching it, and probably terminating only when the apical margin is reached ; it emits about eight straight, oblique veins, the short apical ones only slightly more longitudinal, all simple excepting one which is compound, and fills the apical part of the regular portion of the area. The anal furrow is distinctly impressed, rather gently and regularly arcuate, and
S. II. SCUDDKU OX TALAKOZOR' COCKROACHES. 105
termiiiiiti's a little Ik-voikI the basal tliinl of tin- wiii^; the anal veiiiH. six in iiuinln'r. are 6iin])le and similarly arcuate.
The wing is .somewhat below the medium size, till" fVa^^inent being 17. 2o mm. long ami 6.5 mm. broad; probably the real length of the wing is IK.') mm., and the breailth to the length as 1 : 2.80. The upper surfaee of the wing appears to be e.xposed, and is that o( the left .side. Germar speaks of the ijrincipal media-stinal and inlernomedian veins as delieiite.
Germar confounded this species with that formerly described by him in Miin-<ter's Heitriice under the name of Bl.JlaheUata. It is indeed very close in general appearance, but if the figure given in Miinster's Beitriige is correct, two species belonging to dillerent gen<'ra are indicated. The principal diilerence is to be found in the upper half of the wing. In J'Jlohl. fluhcUnln (as (irst described, and as we have restricted it), the mediastinal area is very nar- row, and the vein terminates at about the middle of the costal margin ; in Gcrabl. M'n- steri. on the other hand, the area is very broad, and the vein terminates only just before the apex. In J'J/ohl.JlabeUafa again the .scapular area is extensive, and filled with many veins; in Gerabl. Miinsteri, the scapular vein is simply f(jrked once. Or, to ])ut it other- wise, the branches of the basal half of the mediastinal vein of Gernhl. Miinsteri are tran.s- ferred. in Etohl. Jlahdhita, to another .short principal vein, running above the medisustinal, and which does not exist in Gerabl. Munsterl ; while the scapular vein of the latter, amal- gamated at base with the three-branched externomedian vein, is to be considered, in Etubl. JlabeUata, as the basal branch of a four-branched externomedian vein. The close resem- blance of the externomedian anil internomedian areas in the two wings would have led me to consider the illustration in Miinster's Beitriige as simply faulty, were it not for the following considerations : First, Germar makes no mention of any such error, but merely quotes the reference in his synonymy. Second, there are several points of difference besides those pointed out; for instance, the shape of the wing, which is less tapering in Etobl. JlabeUata, with a less arcuate costal, and a more arcuate inner margin ; the com- pound branch of the internomedian vein, found just beyond the middle of the wing in Gerabl. Jliin.'iteri, is represented in Etobl. JlabeUata by a pair of forked branches, having a w'idcly distinct origin ; the simply forked vein which I have considered the scapular in Gerahl. Miinsteri originates from the externomedian vein much nearer the base than in Etobl. JlabeUata; and the borders of the broken tip do not agree in the two wings. Third, if they are to be considered the same, the correct drawing is certainly the later one, but the structure of the mediastinal vein is circumstantially described, as well as figured, in both of Germar's works, in each case corresponding to the illustration in the .same work; yet the structure of the wing of El obi. JlabeUata is wholly in keeping with that of the genus Eto- blattina, which comprises the largest proportion of the European palaeozoic cockroaches, and is indeed very closely related indeed to that of Etobl. ajflnis and Etobl. anthracophila, as we have already pointed out ; and were it not for the remarkable similarity of the distri- bution of the nervures referred in Etobl. JlabeUata to the externomedian vein, it scarcely seems probable that any doubt would arise concerning the distinction of the two species. Unless Germar's original types exist, and can be verified, it seems questionable whether the point can really be decided.
Germar, in his Wettin fossils, compares this species to Etoblattina anafjlyptica, which he says it closely resembles, so that one might take it for a small specimen of the same, but as we have seen above, the Wettin species must be placed in Gerablattiua and not in Etoblat-
MEMOIE9 BOST. SOL'. XAT. HIST. VOL. III. H
106 S. II. SCUDDEH OX PALAEOZOIC COCKROACHES.
tiua. It is related to Gcrahl. Geinltzi by the simple structure of the niediastinal vein, and the branching of the internoniedian, but is at once distinguishable from it by the extreme breadth of the meiha-stinal area, and by the general shape of the wing. In the distribution of the externomedian veins it also resembles Gerabl. prodticta, but it hardly resembles it in any other feature, unless it be the shape of the wing. The structure of this same vein separates it from all the other species of the genus. Giebel plainly describes the Wettin species, and mistaking the scapular vein for the iirst branch of the externomedian (since they are united at the base) considers the internoniedian as entirely wanting, and suggests tlint it should therefore form a peculiar genus.
The single specimen comes from Wettin. Germany. Upper carboniferous.
G-erablattina producta. Fl. 3, fig. 2.
Blattina euglyplica pars Gold., Neues Jahrb. f. Mineral., 18G9, 162-63, taf 3, fig. 9 (nee. 8).
Not Bl. etiglypiica Germ, (for which see Etohl. eughjptka). Compare also synonymy oi Etohl. Dolirni.
Fore wing. The wing is rather broad and subovate, the costal margin strongly and reg- ularlv arcuate, contracted at the humeral lobe, the tip well rounded and the iniler border nearly straight. The veins oi'iginate considerably above the middle of the wing, and are scarcely turned upward at the base. The mediastinal vein, however, curves upward nearly as much as usual next the base, where it is unusually near the costal margin ; but beyond the base it is straight, and follows nearly parallel to the costal margin until past the middle of the wing, when it bends very slightly toward the margin, and terminates in the middle of the outer half of the wing ; it emits about eight sti'aight, oblique, mostly simjile veins, and the area at its widest is scarcely one-quarter the width of the wing. The scapular vein is nearly straight from one end of the wing to the other, and terminates just above the extreme apex, separating an uj^per third of the wing from a lower two-thirds ; com- mencing to divide at the middle of the wing, it emits four straight, obliquely longitudinal, superior branches, the first forked beyond its middle, the others simple. The externo- median vein is also nearly straight, but diverges a little from the preceding beyond the basal third of the wung, and tei'minates below the tip of the wing, and a little farther from it than the scapular vein ; it commences to branch a little beyond the basal third, and emits about four straight, longitudinal, forked or simple branches at subequal distances all the way to the end. The internoniedian vein is somewhat peculiar; straight, or perhaps a little arcuate at the base, it bends downward toward the lower outer angle of the wing in the second fourth of the same, and then takes a longitudinal course nearly parallel to the inner border, which it retains to the end, being throughout this portion of the wing slightly broader than the mediastinal area, or a little more than half the width of the combined intemomedian and anal areas near the base ; on account of the length of the apical por- tion of this area, I have proposed the above specific name ; the vein emits about eight simple, oblique, straight, arcuate or sinuous, rather distant branches, the apical ones much more longitudinal than the basal. The anal furrow seems to be lightly impressed, rather gently and uniformly arcuate, and terminates at about the end of the middle thiid of the wing; the three or more anal veins are similarly arcuate, simple, and unusually distant.
S. II. SCUDDElt ON PALAEOZOIC COCKROACHES. ](I7
The wing is of medium size, heing liH.') mm. long anil II. "J') mm. liroad, tlie lin-iidlli to the length being its I : 2..jj. The wing is a right wing, viewe<l iVoin iibove, exhibiting no cro.ss venation.
Goldeni)erg describi'd {\n< insect as identical with h'tabl. Dufiriiii. and ii-rtrrcd both to Etohl. €ii(j/i/jitica. This species, however, diilers l'n)m both of them in the greater length of the mediastinal area, the later branching of the .^-apular vein, and the earlier bramhing of the externomedian vein. From I'Jiohl. niijh/j)titii,iuu\ to u le.s.ser degree from Htohl. J)ii/inui, it diflers in the unusual form of the internomedian area, one of the characteristic marks of this species ; while the wing is also much broader in proportion to its length than in those species, and diflers considerably in form from Klohl. cinjlyj/tira. The diflerences between the other two species are stated in the proper place. The larger size, narrower mediastinal area, and ovate rather than tapering form, as well as the more complicated scapular vein, distinguish this .species from Genibl. Mdnnterl, to which it appears to be most nearly allied. In the narrowing of its mediastinal area at either extremity, in the character of the exter- nomedian branches, and to a certain extent in the form of the internomedian area, it is to be compared also with Gerahl. Ge'initzi ; but it diflers very much in the form of the wing as well a.s in the character of the scapular vein. From the species which follow it diflers to such an extent in the extended production of the internomedian area, as by no means to be confounded with them.
The single specimen comes from Wettin, Germany. Ujiper carboniferous.
Gerablattina GennarL PI. 3, fig. 6.
Blattina sp. Germ., Verst. Steink. Wettin, vii, 87, tab. 31, fig. 9. Blntta Germari Gieb., Ins. Vorw., 321.
Blattina Germari Heer, Viertelj. naturf. Gesellsch. Ziirich, ix, 288; — Gold.. P\iun. saraep. foss., ii, 19.
Fore wing. The wing is slender and tapers considerably, besides being slightly curved ; the costal margin is very strongly and regularly convex, the inner margin straight or very slightly concave and a little convergent with the costal border, narrowing the roundc^d tip unusually ; the veins apparently originate near the middle line of the wing, and curve up- ward a little at the base. Be3"ond the base the mediastinal vein runs longitudinally in a straight line to the middle of the wing, at a great distance from the costal margin, which it reaches at about the middle of the outer half of the margin ; this area at its broadest occu- pies more than two-fifths the breadth of the wing. The scapular and externomedian veins appear to run together, and in very close proximity to the mediastinal vein, as far as the mid- dle of the wing, and then divide, the scapular running to the apex of the wing and dividing, so that about hall" a dozen veins strike the costal margin. The externomedian vein, having but a narrow space to expand in, appears to emit only a single forked branch or two from near the middle of its free course, furnishing about five veins to the extremity of the inner margin. The internomedian vein, also running so close to the mediastinal in the ba.sal half of the wing as to occupy the middle line of the wing, and crowding the middle pair of principal veins together, turns toward the inner margin more slowly than does the medias- tinal toward the costal border, and, having throughout a broadly arcuate course, strikes the inner margin a little before the apical sixth of the wing ; it emits four straight, oblique,
108 S. II. SCUDDER OX PALAEOZOIC COCKROACHES.
siniplo or apioally forked hraiu-lio.^. The anal furrow is well improssed, strongly and regu- larly arcuate, and terminates near the middle of the Aving ; the anal veins that can be seen are simple, closely approximate, and similarly arcuate.
This is one of the smallest species, measuring only 11.5 nun. in length by 3.75 mm. in breadth, the breadth being to the length rather more than 1 : o. If the upper surfiice is ex]iosed, it is a left wing. Germar does not describe it, believing the neuration too imper- fect for determination ; but it is suliioiently preserved, to judge from his illustration (on ■which this description is based), to determine its generic and specific relations with a reason- able certitude. The form, excepting perhaps at the base, is well preserved, and this separates it at once from all known species. In size it agrees only with Etohl. jicirvula and Etobl. insignis. from which it is at once separated by the extent of the mediastinal area. The mediastinal branches are obliterated, as well as the base of those of the scapular and exter- nomedian areas, but the extent of the mediastinal area, and the common distance from the ba.se at which the scapular and externomedian veins divide, show that it belongs to this genus ; while by the close approximation of all the principal veins in the basal half of the wing, as well as by its size and form, it is readily distinguishable from all the other species of the genus. It has no very close affinities to any of the species, although perhaps nearest to Gcrahl. Mahr'i. beside which we have placed it.
One specimen, Wettin. Germany. Upper carboniferous.
Gerablattina Mahri. PL 3, fig. 14.
Blattlna Mahrl Gold., in Mahr., Neues. Jahrb. f. Mineral, 1870, 284-85, fig. 2% 2"; —Gold.
Faun, saraep. foss., ii, 19. Compare also synonomy of Blattina elongata.
Fore wing very slender and somewhat tapering, the costal margin rather gently arcuate on the basal third, beyond nearly straight, the inner mai'gin, at least in the middle, straight. The veins originate below the middle of the wing, and are strongly arcuate at the base. The mediastinal vein follows closely the curve of the costal margin, showing no tendency to approach it throughout the fragment, that is, probably, as far as the middle of the apical half of the wing ; it probably terminates only just above the tip, and emits about ten straight, oblique, equal, very distant, simple branches ; the area occupies nearly or quite a third of the breadth of the wing in its apical half. The scapular vein is closely parallel to the medi- astinal, but very distant from it, running scarcely above the middle line of the wing ; it forks once in the middle of the wing, and, to judge of the openness of the neuration, prob- aVjly not again, the two forks probably enclosing the extreme tip of the wing between them. The externomedian vein is distant from the scapular vein, but not so distant as the former is from the mediastinal ; beyond the base, which is lost, it is straight and longitudinal nearly to the middle of the wing ; just before this it is bent rather abruptly and slightly downward, and runs nearly parallel to the internomedian vein, emitting near together, just beyond the middle of the wing, two superior, longitudinal, simple, straight branches. The internomedian vein is very gently and uniformly arcuate, and being also as distant from the externomedian as the latter from the scapular vein, the area is unusually narrow and slender, the vein probably terminating a little before the middle of the apical half of the wing ; it emits half a dozen nearly straight, oblique, mostly simple, parallel, and distant
S. II. SCUDDER 0\ PALAEOZOIC COCKROACHES. 109
branohe.s, the second only apically forkid in the specimen, and, so far a.« preserved, the only forked vehi in the \vin<^ ; tlie anal furrow is .slij^ht, rather gently arcnate. aj)ically straight, terminating at the end of the ba.sal third of the wing.
The wing is a very large one, the fragment measnring •!(» nini. in length, ami 1"» nini. in breadth; the whole wing is probably 47 nun. long, so that the l)ri'adth is to the length as 1 : o.l. Goldenberg estimates the lengtli at 4") nun. The basi- is broken oblii|uely. so that the anal veins are absent, and a considerable portion of the apex is wanting, particidarly ne.\t the inner margin. If the upper surface is exposi-d, the wing is of the left side ; the veins are very prominent, and the interspaces are filled with a close, irregular net work of delicate cross veins, particularly distinct in the interspaces on either sitle of the Hrst inter- nomedian branch.
This species is peculiar, both for the sparseuess of the neuration, and for its extreme simplicity, only one of the many brancdies preserved being forked ; it is al,«o much more elongated than mcst of the .species, an<l has an excessively long meihastinal area, reaching nearly to the tip of the wing, and, notwithstanding the slenderness of the scapular area, throwing the externomedian branches wholly upon the inner side of the apex. In the slenderness of the wing the preceding very much smaller species approaches it. and in sim- plicity Gerabl. iceisnirma seems nearly allied, but it is readily distinguishable from both by the extreme length of the mediastinal area.
The single specimen was obtained in the •' upper division of the Tlnu-ingcn carboniferous series," at Manebach, in the neighborhood of llmeuau. Upper carboniferou.s.
Gerablattina •weissiana PI. o, (ig. 1.
BlaUina englyptica var. weissiana Gold., Neues Jahrb. f. Mineral., 18G9, 10.3. taf. .3. fig. 10;
— lb.. Faun, saraep. foss., ii, 19. Blattina icelssiana Gold., Faun, saraep. foss., ii, 26, 51.
Fore wing. Only a part of the upper half of the wing being preserved, its form cannot be stated, but the co.stal margin is strongly and regularly arcuate, and the tip apparently well rounded ; the veins are arcuate at the base. The mediastinal vein runs entirely parallel to and not very distant from the margin until beyond tlie middle of the wing, when it grad- ually approaches it, and terminates in the middle of the outer half of the wing ; it emits nine or more straight, parallel, rather longitudinally oblique, simple branches. The scap- ular vein also nnis parallel to the co-stal margin, and terminates just before the extreme tip ; it begins to divide at a little distance beyond the middle of the wing, and in quick succession emits three nearly longitudinal branches, whose course cannot be traced far beyond their origin. The externomedian vein diverges slightly from the preceding in the basal half of the wing, running in a nearly longitudinal course about as far from the me- diastinal vein as the latter is from the margin; it probably terminates not much further below the tip than the scapular above it,^ and only the extreme apex is therefore occupied by this vein and its two branches ; these branches are longitudinal, and arise near together, one at, the other a little beyond, the middle of the wing, and seem to crowd this part of the wing with veins more closely than elsewhere. The iuternomedian is represented by
' Wrongly represented on our pl.-ite by the outside mark, as if the internomedian vein belonged to this area.
110 S. n. SCUDDER ON PALAEOZOIC COCKROACHES.
Goldcnborg as straight, and no interior branches are preserved ; a simple snperior branch, rnnning parallel to the main stem, is represented as arising at the end of the middle third of the wing.'
The wing is a largo one. the length of the fragment being 33 mm. ; its breadth, 10 mm. ; the probable length of the wing, 35 mm. ; its breadth, perhaps 12.5 mm. ; making the breadth to the length as 1 : 2.8. Goldenberg gives the probable breadth as 15 mm., and the breadth to the length as 1 : 2.4, and this breadth is represented by the dotted lines on our plate, where Goldenberg is followed. The straightness, however, and the slight obliqnity of the internomc^lian vein, render it prol^able that the internoniedian area was a narrow one, more as appears in Gerabl. balteata, for instance, and the longitudinal direction of all the veins and all the branches render it all the more probable ; for longitudinal branches in the internoniedian area, are generally correlated with a narrow area ; there is no reticulation in the interspaces, and the wing, if the upper surface is exposed, is of the left side.
The extreme base, the whole of the anal area, all of the internomedian area below the main vein, the neuration of the apical third of the wing, and the lower half of the margin of the entire wing are destroyed ; enough, however, remains to indicate both the generic and specific alliances of the insect, and to show that it is certainly distinct from any other described form. Goldenberg's first reference of the insect as a form o^ Etohl. ewjlyptlca was natural, from the general resemblance of the neuration to what is found in that insect; but the much greater length of the mediastinal area, not to mention the more apical division of the scapular vein, at once foi'bids such a reference. In the form of the wing and in the general distribution of the veins it most nearly resembles, perhaps, the American Gerabl. balteata, but the far more apical division of the scapular and externomedian veins, and especially of the former, sepai'ates it at once. In these points it is more closely allied to Gerabl. Mahri, but the wing cannot be so slender as there, nor so large, and the medias- tinal area is much shorter.
Goldenberg considers this species allied to Etobl. euglyptica and Bl. lathiervis on account of the uncommon breadth of the veins, and to the liassic Legnophora Girardi on account of the smoothness of the margin, which the veins do not quite reach.
The single specimen comes from Briicken, Canton Waldmohr, in the Rheinpflatz. Upper carboniferous.
Gerablattina balteata, nov. sp. PL 6, figs. 9, 10. Blattina sp. Font.-White, Upp. carb. flora W. Va., pi. 22, fig. IG, IG^ [ined.].
Fore wing. The form of the wing cannot be definitely stated, as a large part of both base and apex are wanting ; the costal margin, however, is moderately and regularly convex, and the inner margin nearly straight, and parallel to the former, indicating a moderately slender wing of a somewhat ovate shape, tapering at either end, and largest near the mid- dle. The veins are arcuate at the base, and probably originate near the middle of the wing. The mediastinal vein runs subparallel to the costal margin, but is straight to just beyond the middle of the wing, when it curves gradually toward the costal margin, and
' Two are incorrectly represented on our plate, following Goldenberg's first representation of the same.
S. II. SCUDDRU ()\ I'AI.AKOZOR" COC'KROAt'lIKS. HI
tcniiiiiiitos near the end of the lu'uMIc tliinl of tlio winj; ; in tlie fni;;iiieiit, wliiili represont*^ all i)iit the basal fourth, there are about eif^ht feeble, simple, gently arcuate, rather dintinot, lunjritudinally oblique branches, and the niiildle breadth of the area is waretdy lesn than one-fourth the width of the win-;. The scapular vein, in the ba-sil third or fourth of the win<f, runs in very close proximity to the mediastinal vein, then diverjres from it, beiuf; directed toward the a})ex of the wing; but a little past the middle it returns by a broad curve to its former trend, and terminates j)nil)aiily just before the extreme tip of the wing; in the fragment it eniit.s four branches, and in the apex, which is «lestroyed, it probably liad one or two niore ; the first of these four is thrown olf where the vein diverges from the me<liastinal, viz., a little beyond the ba.sal third of the wing; and tins branch continucH 8ub])arallel to the mediastinal vein, but is compound, f(ukiug once next the second forking of the scapular vein, each fork again diviiling at unequal distances before reaching the border ; the other branches are simple, and originate at une(|ual distances apart, the second in the middle of the wing. The externomedian vein follows very nearly the same sinuous course as the scapular, but constantly a little divergent from it, and widely distant from both it ami the internomedian vein ; it emits its first branch midway l)etween the first two branches of the scapular vein ; this forks at least once, but probably only once, at les-s than half way to the apex ; a second branch, not shown on the plate, and obscure upon the fossil, arises opposite the fifth internomedian branch, but only its base is preserved. The internomedian vein, so far as it is clearly preserved, is straight, and consideral)ly oblique, being parallel to the general trend of the middle portion of the externomedian vein, and, in this portion of its course, it emits five equally and widely distant, generally forked branches, which are oblique at origin, and excepting the first, very stronglv arcuate beyond, becoming nearly longitudinal ; directly beyond the origin of the fifth t>rauch, or just at the end of the middle third of the wing, the vein itself becomes longitu<linal, and runs scarcely convergent with the margin, probably ending in the middle of the apical third of the wing,* and thereafter emits one or two more simple branches.
The wing is of medium size, the fragment measuring 19 mm. in length and 1<I nun. in breadth ; probably the entire length of the wing was 25 mm., making the breadth to the length as 1: 2.5. The upper surface of a left wing is exposed, and the more es.sential parts of the neuration are present, although the entire anal area, with the corresponding upper portion of the base, is gone, together with a large fragment from the apex of the wing. The most characteristic feature in the wing, one found apparently in no other palaeozoic cockroach, is the peculiar limitation of the cross neuration to broad, piceous belts, which follow the veins and their branches throughout all parts of the wing sufficiently preserved to see it, excepting the branches of the mediastinal vein ; they are apparently worn from all but the basal portion of the scapular and externomedian veins, to the extent represented in the plate ; but, wherever they can be seen, follow each of the veins and their branches with extreme regularity and nearly equal width, so as to cross the interspaces where these are narrow ; the cross veins in these belts are very delicate, crowded, elevated, a little irregular, but usually transverse to the interspaces, and only to be .°een by the aid of a magnifier ; between the bands, which are about 0.75 mm. in breadth at the widest, no
' The out^iilo mnik on tlio plate (fig. 9), rppreseiitins be removed consiiientblj- further toward the tip of the wing. the termination of the internomedian area, .«hoidil tlierefore
l\-2 S. II. SCUDDER ON PALAEOZOIC COCKROACHES.
trace of trausvorso markings can bo soon. This peculiar structure is well Ijrougbt out in fig. 16*, of Fontaine and White's plate, but the figure of the wing, fig. 10, represents the course of the neuration as entirely wrong.
The species is, of course, based upon the wing described above, but another fragment of a wing (PI. G, fig. 10) has been found by Professor Fontaine ; and, notwithstanding it occurs in a considerably lower deposit, and represents a part absent from the other wing (thus sup- plementing it. but at the same time affording no common ground for structural comparison bcvond the size), we must consider it as belonging to the same species, on account: first, of its size, which agrees perfectly with the other fragment; and second, from the fact that each of the veins is accompanied by a black belt, although without the addition of the transverse veins. The fragment is that of an entire anal area, and shows that the anal furrow of this species was very deeply impressed in its basal half, more gently in its apical, was rather stron'^lv arcuate and a little bent in the middle, but probably terminated a little beyond the middle of the basal half of the wing, being unusually short; the anal veins were simple, the first three rather distant (but the first very close to the anal furrow), scarcely raised above the surface, and bent in the same sense as the anal furrow, being subparallel to it; the other three or four are gently arcuate in an opposite sense, delicately elevated, and closely crowded. The length of the fragment is 7.5 mm.; its breadth, 3.5 mm. The black belts accompanying the veins are a little narrower than in the other fragment. The surface expo.sed is also that of a left upper wing.
This species is sufficiently distinguished by the banded neuration of the wings to separ- ate it from any other. The distribution of the veins, however, shows that it falls into this genus and has certain special affinities with Gerabl. Mahri and G. weissiana ; from the former of these it differs very much in the greater brevity of the mediastinal area ; and from the latter it is distinguished (there are few points of comparison, from the fragment- ary nature of G. weissiana) by the much earlier origin of the first scapular branch. It has closer affinities, in most of the broad features of its neuration, with the other American species of the genus, G. fasciata, but to the fine subdivision of the veins of the latter it has nothing to correspond ; neither has it in the length and multiple division of its scapular vein, nor in the basal union of the principal veins, nor in the structure of the anal area.
The first and principal fragment described above was found by Messrs. Fontaine and White at Cassville, Monongolia County, W. Va., in the roof shales of the Waynesburg coal, or the very highest of the beds of the upper productive coal sei'ies, in the nomen- clature of the first Pennsylvania survey, or the beds termed Permo-carboniferous by Pro- fessor Fontaine. The other fragment comes from Bellaire, Ohio, near Wheeling, W. Va., associated with plants of the upper productive coal beds, in shales twenty feet below the Pittsburgh bed of coal, which lies at the base of the upper productive coal series, and clearly within the carboniferous series proper. Professor Fontaine, who kindly sent me the specimens, writes me that the two localities are eighty miles apart, and sejjarated by three hundred feet of strata. Upper carboniferous ; Permo-carboniferous.
S. H. SCUDDKIi ON I'AI.AKOZOIC COCKK()A( IlKS. 113
G^erablattina fascigera. I'l. (i, (ij,'>i. 1, -j.
Jihittiti'i fascitjera Sciidd., I'nto. Host. sof. n.it. hist., xix, 2.'5S-;;'.i; — II. . Kiitom. iM)t«'H,
VI, oo— oO.
Fore wing. The wing i.s hroad mid nearly eqnul, tlic hniiieral Idl.e lull, the cr.stal margin very gently and very regularly eonvex, the inner margin nearly straight until the apical third of the wing, where it is roundly licnt and thu.s narrow.s the wi-ll-rounded api-x ; the veins originate below the middle of the wing, and all hut the mediastinal and the anal veins from a single root considerably he-low the middle, from whence they curve ratlier strongly upward. The niedia.stinal vein is very I'aiutly preserved, and runs suhparallel to the costal border, with a similar arcuation. to the middle of the apical half of the wing, and then curves toward it and meet.s it at the extrendty of the fragment, or bevond the middle of the apical fourth of the wing;' it emits a very great nund)er of clostdy crowded branches, which are only visible in the apical half of the area, nowhere visible throughout their length, both their bases and even the principal vein itself being obliterated, anrl the course of the vein only indicated by the position of their outer extremities; enough remains to show that they are generally simple (in a single instance a fork is seen), straight or faintly arcuate, the convexity away from the costal margin and obli(jue, the apical ones becoming slightly longitudinal ; in the middle of the wing the area occupies somewhat le.s.s than one-fourth the i)readth of the wing. The common stem from which ari.se the scapular, externomedian. and internomedian veins and the anal furrow, runs in a straight line parallel to the nearly obliterated mediastinal vein until just past the middle line of the wing, at about the middle of the ba.sal third of the wing, Avhen they all divide simul- taneously, excepting the two lower, which do not separate at once from each other. Be- yond this common point of departure, the scapular vein is at first gently arcuate, shortly afterwards, after its first branch, nearly straight, running throughout parallel to the costal margin, but at a wide distance from the mediastinal vein, and terminates at the tip of the wing ; it is, however, slightly arcuate, in an opposite sense to its first arcuation, between each pair of branches, the main stem and each branch appearing, almost equallv, a.s forks of the preceding part of the main stem; these branches are four in nundjer; the first differs from the rest; it parts from the main stem a little bcjond the basal third of the wing, soon becomes nearly longitudinal, but gradually approaches the media.stinal vein, and finally forks, the two branches of the fork closely resembling branches of the media-s- tinal vein; the second branch of the scapular vein arises a little beyond the middle of the wing, the fourth midway between this and the apex, and the third midway between the two; the second is doubh'. the third simply forked, and the fourth simple; the apical shoots of these branches strike the margin of the scapular area at increasingly wider inter- vals, the lower interspaces being similar in width to those of the inner margin. The exter- nomedian vein, beyond the point of common origin,^ runs m a nearl}' straight but faintly wavy course nearly along the middle of the wing, parallel to the preceding, and has similar arborescent but inferior branches, also emitted at irregular intervals ; the first, which is doubly forked, is emitted at the centre of the wing ; the second and third, which are sim-
' The mark separating the mediastinal and scapular areas * Represented on the plate a little incorrectly, as it should
is placed a little too far toward the apex in the plate. be united at its base with the scapular vein.
KEUOIRS BOST. SOC. KAT. HIST. TOL. m. 13
114 S. H. SCITDDER ON PALAEOZOIC COCKROACHES.
plo. are thrown oft", one opposite the first fork of the first branch, the other opposite the last branch of tlie scapular vein ; there is also the commencement of an oblique, stout cross-vein opposite the basal branch of the scapular vein, I'uiining half way to the second branch of the internomedian vein, almost precisely similar to what occurs in Etohl. venusin and in Arch, acadiaim. both, like this. American species, and members of the same sub- family. The internomedian vein and anal furrow part from each other almost immediately after their common departure from the miited vein, and the internomedian then runs in an irregularly straight line, subparallel to the externomedian vein, and terminates a little further from the tip than the mediastinal vein ; it curves downward a very little at the origin of its third branch, so as to be a little more distant from the extei'nomedian between its third and fourth branches than before ; it has in all five branches, which originate at subequidistant intervals, the last of which is simple, the others more or less deeply and simply forked ; they are all more or less arcuate and somewhat longitudinally oblique. The anal furrow, from the common origin of all the veins, is straight, very deeply impressed on the basal half, somewhat longitudinally oblique, and terminates in the middle of the inner margin ; ' the anal veins are very independent of the anal furrow, consisting first of a pair of compound veins arising from the extreme base of the wing at the origin of the common stem of the principal veins, and running in an obliquely longitudinal course to strike the apical half of the margin of the anal area, and leaving a wide interval at the base between them and the common stem and the anal furrow ; and in the angle four closely aj^proxi- mated. straight, similarly oblicjue, simple veins.
The wing is a large one, measuring 35 mm. long as fur as preserved, and 15.5 mm. broad; the entire length of the wing must have been o8 mm., and the proportion of the breadth to the length as 1 : 2.5. The wing is perfect, except a slight fragment of the tip and a little piece of the base of the anal area. The specimen shows the upper surface of a left wing. The surface is covered with a very delicate network of raised veins, which are arranged more or less irregularlj^, transverse to the interspaces, in a broad marginal band around the apex and inner border of the wing, and as an entirely irregular polygonal retic- ulation upon the disc ; no network can be seen, probably from poor preservation, upon the mediastinal area.
This species was wrongly compared by me to Etohl. 2:)rimaeva, with which it has very few special points in common, and from which it is widely distinct in the structure of the medi- astinal and anal veins. It seems to belong certainly in the genus Gerablattina, but forms perhaps a distinct section, difiering from all others in the extreme multiplicity of the medias- tinal branches, in the ba.sal coalescence of the other principal veins, in the arborescent division of the scapular and externomedian veins, and in the longitudinality and dichotomy of the anal veins, and their wide separation from the anal furrow. In the broad features of its neuration, however, and particularly in points of division of the scapular, externo- median, and internomedian areas, it resembles most and to a considerable degree the only other American species of the genus, G. hnlteata, but it differs from it in all the points above mentioned, and in lacking the banded ornamentation of the veins.
The single specimen found was obtained by Mr. R. D. Lacoe, at Pittston, Penn., and lies on a piece of black carbonaceous .shale coming from the interconglomerate beds of the true
' The termination of the anal area is marked in the plate on the wrong side of the anal vein.
S. 11. SCUDDKR ON I'Al.AKOZOIC COCKROACHES. 11')
coal measures at tlie autidinal next north ol" tliat in wliieh the PittMton HpecicH of Lithoniy- lacris oeoiir, anil also on the sontli-ea.st side. Lower earhonil'erous.
Hermatoblattina nov. gen. (?/>;ia, Blattiiiii). Bltillinit Auct. (pars).
The two species which form this genus differ in the nature (if the nicdin.stinal area in the front wings ; in one it is nearly one-third the breadth of the wing, e(jual nearly to tlie extremity, and terminates close to the tip of the wing; in the other it is fidly a third the breadth of the wing near the ba-se, and diminishes regularly to the extremity, whieli is somewhat beyond the middle of the outer half of the wing ; in both the vein is gently sinuous and the branches frequent, obliipie and generally sinipic The scapular vein, although begiiuiing to branch liefore the middle of the wing, has oidy two or three branches, which are inferior, diverge l)ut .slightly, and may or may not fork, so that the area occupied by the vein is slight, and termijiates at the tip of the wing. In consc<|uence of the inferior position of the branches, the equal interspace between the mediastinal and scapidar veins is marked by oppositely diverging branches. Tlie externomedian vein is very similar to the .scapular in extent, place and mode of branching, but the i>ranelies may be either superior or inferior, but always fall upon the margin below the apex of the wing. The anal and internomedian areas are very broad at base, occupying nu)re than half the breadth of the wing, but narrow rapidly, the internomedian being considerably arcuate, and terminating not very far from the apex ; the branches of the externomedian are as oblique as those of the mediastinal area, and although very long and straight, fork very little. The anal furrow is not very pronounced, more or less arcuate, and terminates not far beyond the l)asal third of the wing ; the anal veins are subarcuate, subparallel. frequent and simple. Nothing is known of the genus but front wings, which are unusually stout, the breadth being contained in the length scarcely more than two and a quarter times ; with the possible exception of Petrablattina, the average form is stouter than in any other genus, although other genera contain stouter species.
This genus is peculiar for the inferior position of the branches of the scapular vein, a characteristic it shares only with Oryctoblattina, from which it is readily separated by the slender development of the same vein, and by the diflerent nature of almost all of the others. But for the inferior position of these branches of the scapular vein, it could hardly be separated from Gerablattina. From Archimylacris and Etoblattina it is distinguished hy the breadth and extent of the mediastinal area. From Anthracoblattina it is again separated by the inferior position of the scapular branches. The limited extent of the combined areas of the scapular and externomedian veins readily- distinguish it from Progo- noblattina, while the totall}- different nature of the externomedian vein in Petrablattina permits of no confusion with that.
The two species belonging here come from the old world, and are of large .size.
Hermatoblattina ^emmetsweileriensis. PI. 4, Gg. 14.
Blattina wemmetsioelleriensis Gold., Faun, saraep. foss., ii, 19, 24, 51, taf 1, fig. 9.
Fore wing. The wing is broad and nearly equal, almost imperceptibly diminishing in size up to the apical fourth of the wing ;' the costal margin is very gently and regularly
' Tliis scarcely appears on our plate, where the apical half of the costal margin is a trifle too full.
110 S. H. SCUDDER OX PALAEOZOIC COCKROACHES.
convex, the inner margin straiglit. and the apex well rounded, no doulit, Init In-okcn in the specimen. The veins probabl}'^ originate a little above the middle of the wing, and are gentlv arcnate at their base. The mediastinal vein runs parallel to the costal margin, but beyond the middle of the wing scarcely recedes from it, afterwards curving very slightly upward, and striking the apical border not a great way above the tip of the wing; it emits a large number, thirteen or more, of rather frequent branches, most of which are simple (the penultimate doubly forked), parallel, the earlier ones oblique, the later longitudinally^ oblique ; the area is a little more than a fourth the width of the wing in the middle. The scapular vein runs closely parallel to the mediastinal throughout its course and emits, at equal distances apart, three inferior, apically forked branches, the first scarcely beyond the basal third of the wing, the third somewhat before the end of the middle third of the wing, and all with their forks crowded closely together into the space between the tip of the mediastinal vein and the extreme apex of the wing. The externomedian vein, on the other hand, runs close and parallel to the internomedian vein ; but it also has three branches, which are slightly further apart thanin the preceding, but originate almost exactly opposite them, the last simple, the others compound, filling the area with veins as closely crowded as in the pre- ceding area ; the branches being superior while those of the scapular area are inferior, brings the branches opposed to each other in a sense the reverse of what is commonly found in palaeozoic cockroaches, and gives the wing a peculiar appearance. The internomedian vein is gently and decreasingly arcuate from the base outward, and is very regular, but, at the origin of its last branch, takes a direction a little above its former course, the branch and the apex of the vein making common forks of the preceding part of the stem ; it terminates before the apical sixth of the wing, and emits eight equidistant, simple or forked, straight veins, all but the last of which are oblique ; the vein originating above the middle of a broad wing, and extending so far toward the tip, gives this area a great extent, making it not a little remarkable that some of its basal branches, all of which are more distant than the mediastinal branches, should be simple, and so very straight. The anal furrow is apparently deeply impressed at base, pretty regularly and very strongly arcuate, terminat- ing a little beyond the basal third of the wing ; the anal veins, nine in number, are, so far as preserved, simple, straight, and closely crowded toward the inner angle, gently arcuate and more distant next the anal furrow.
The wing is a large one, the fragment measuring 34 mm. in length and 16 mm. in breadth ; the length of the wing can vary little from 37 mm., making the breadth to the length as 1 : 2.3. It is almost completely preserved, a little of the extreme base and tip only wanting. If the upper surfoce is exposed, the wing is from the right side ; the reticulation is mostly effaced, but with a lens one may see exceedingly delicate transverse wrinkles, giving the wing a shagreened appearance.
Goldenberg compares this species with Etohl. primaeva, with which, however, at least above the internomedian area, it has very little in common, and from which it differs greatly in shape ; the other species of the genus agrees far better with Etohl. primaeva. This species differs from Herm. lehachensis in the structure of the mediastinal area, which is here almost efjual, and in the distribution of the externomedian branches, which are superior and not inferior.
The single specimen was found in a bluish Ijituminous shale in the neighborhood of Wemmetsweiler, near Saarbriicken, Germany. Upper carboniferous.
S. n. SCUDDKU ox I'ALAKOZOIC COCKKOACIIES. 117
Hermatoblattina lebachensis. I'l. 4, ti;.'. 11.
Iilatt'uia hhacliensis Gold., Silziingsl). iiiiitli.-iiiit. ('I. k. Akiul. Wiss. Wit-ii., ix, ."JS (iinde-
scriljcd). JiJnttina lebachensis Gold., Paliu'ontojfr., iv, 22, 'J.l, taf. (>. lij,'. 7 ; — Il>.. Ko.>-.><. Ins. Saarltr.
6, 7, taf. 4, fig. 7; — lb., Faun, saraep. fos.s., ii, 110, li7, i")l, taf. 1, lijr. -0 ; — (lii-lt.,
In.s. Vorw., 310; — Gein., Geol. Stelnk. Doiit.«chl., 100.
Fore wing. The extreme base and a considerable part of the apex of (lie wing In-iiig lost, its form cannot be given in detail; but it is remarkable for its great breadth near the biise, due to the unusual convexity of the ba.sal half of the costal margin, which is a little exaggerated in tlie plate ; beyoml this fulness the costal margin is straight, and gradually approaches the inner margin, which is itself very gently and regularly convex, so that the wing tapers considerably beyond the ba.sal third. The veins appear to originate not far from the middle of the base, perhap.s a little above it, and have a long bttsal arcuation. The mediastinal vein is very broadly and gently sinuous, straighter than the costid margin, so that the mediastinal area, which terminates just at the tip of the fragment, and probably Hot much before the apical sixth of the wing, narrows toward either extremity from the middle of its basal half, being at its broadest about one-third the width of the wing ; it emits eight distant, straight branches, all excepting one which is forked, simple, the ba.sal one transversely, the apical ones a little longitudinally oblique. The scapular is throughout close and parallel to the mediastinal vein ; it seems to be coalesced with the extemo- median vein in the basal fourth or third of the "wing, and to have three inferior, simple, longitudinal, arcuate, apically distant branches, the first arising beyond the ba.sal third of the wing and reaching the extreme tip, the last arising at about the end of the middle third of the wing. The externomediau vein is very broadly and gently sinuous, running down the middle line of the wing, terminating just below the tip, and emitting three inferior, simple, gently arcuate, sublongitudinal, apically distant branches, arising almost opposite those of the scapular vein. The internomedian vein is strongly and regtdarly arcuate, apically straight or .slightly arcuate in a reversed sense, terminating about opposite the end of the mediastinal vein, and emitting half a dozen rather closely approximate, very long, oblique, straight or sinuate simple branches, the penultimate, in the individual figured by Goldenbei-g in his Fauna saraepontana, ending in the preceding branch.' The anal furrow is lightly impressed, gently convex, and terminates a little before the middle of the wing ; the anal veins, five or six in number, are simple, not very closely crowded, and similarly arcuate.
The wing is a large one, the fragment measuring 28.5 mm. in length, and 10 nun. in breadth ; the length of the wing may be anywhere from 32 to 30 mm., so that the breadth is to the length as 1:2- 2.25. The wing is fi'om the left side, and the upper surface is exposed ; the recticulation of the wing is composed of polygonal, mostly tetragonal or pentagonal, cells, forming a network which may be seen with the naked eye, and are more delicate on the disc than near the apex.
' In his first description, Goldenberg describes the six in- his second description, based apparently on the same speci-
ternomedian branches as all simple excepting the fourth, men, he describes thcni a.-! all simple and figures them as we
which is forked ; and he fi;^ures them as all simple and run- have here described, ning to the margin excepting the third, which is forked. In
lis S. H. SCUDDER ON PALAEOZOIC COCKROACHES.
Goldenberg compares the species to Etohl. euglyiitlca, from which he says it differs in its hirger size, broader mediastinal area, hu-ger number of branches in the anal area, and a wider iutei"space between the scapular and internomedian areas. The differences between the two species in every part of the Aving are so great that it is difficult to see any special point thev have in connnon, excepting the simplicity of the internomedian and anal branches, which is connnon to a great number of forms. Goldenberg subsequently com- pares this species to EtoJil. auagh/pfica, with which it agrees better both in shape and in neuration, but it is still larger than that species, and differs besides in the brevity and non-production of the internomedian area. It much more closely resembles Etohl. pri- maeva than either, although still widely distinct from it. From the only other species of the genus it is distinguishable by the brevity and unequal breadth of the mediastinal area, the inferior origin of the externomedian branches, and the tapering form of the wing.
Several specimens must have been found in the iron-stone nodules of Lebach above Saarlouis, German}-, as Goldenberg remarks that it appears there to be common. Dyas.
"We come now to the more aberrant forms of this group of carboniferous cockroaches, the preceduig genera being more closely allied to each other than to either of the groups which are to follow, and which comprise between them but five species.
Progonoblattina nov. gen. (-puymo^, Blattina). Blattina Auct. (pars).
In the genus now under consideration the mediastinal vein of the front wing runs par- allel and near to the costal border, occupying, even in the slender species, less than a third of the breadth of the wing, and terminating only a little beyond the middle of the costal margin ; its branches are frequent, oblique, gently arcuate, and simple. The .scapular vein is of much greater importance, commencing to branch far toward the base of the wing, emitting ^ve or six forking branches, and terminating only just before the tip of the wing; the branches are superior, but longitudinal or scarcely oblique, and at the termination of the mediastmal vein the are aoccupies about half the breadth of the wing. The exter- nomedian vein early divides into several principal branches, which are very similar in nature to those of the preceding vein, and occupy on the margin a similar extent ; ac- cording, however, to the cui*ve of the main scapular vein, this area may occupy, with its many doubly forking longitudinal branches, more or less room than the scapular area ; to- gether they occupy the entire apical half of the wing, and more than a third of the basal half. The internomedian vein, which originates in the middle of the base of the wing, slopes in a more or less arcuate curve toward the middle of the inner margin ; it emits only three or four branches, simple or apically forked, and altogether plays a very insignifi- cant part in the wing, the anal furrow, which is slight and considerably more arcuate than the internomedian vein, terminating beyond the middle of the basal half of the wing. The anal veins are more oblique than the anal furrow, not very numerous, subparallel, and .'simple or forked.
Nothing but upper wings are known, and these vary exceedingly in slenderness, one of the two species being the slenderest known species, while the other is a little below the general average.
S. H. SCUDI)P:I{ on rAI.AKOZOIC COCKROACnES. 119
This gemis is readily separated Iroiii all the ineee<liiig by the much jjreater comiuoa expanse of the scapular and externoinedian veins, and the unimportance of the interno- median area; indeed, in these particulars it surpasses any of the ancient j^enera of cook- roaches. From Oryctohlattina it is readily separateil hy the brevity of the mediiustinal area, and by the approximation of all the veins in the basal half of the wiii<.'. The totally diflerent character of the externome(lian vein distinguishes it from I'etrablattina, although it approaches that genus in the aliundance of the neuration.
The two species, which differ widely from each other, are European ; one of them is a large species, the other rather small.
Progonoblatlana helvetica. PI. 3, (!<,'. 10.
Bhtttinn heloetica Ileer, Viertelj. naturf Gesell.sch. Zurich, ix, 287, 201-9.3, pi., fig. 1 ; — lb., Urw. Schweiz., 592, note ; — lb., Monde prim, sui.s.se, 22, fig. llic*''; — Grjld., Faun, .saraep. fo.ss., ii, 19.
Blatta helvetica Heer, Prim.' world Switz., i, 20, fig. IGc"**.
J'ore wing. The wing is pretty regularly elongate-obovate, the costal ami inn-i margins about etjualh- and considerably convex, the apex t<vpering but well rounded. The ba.se of the wing is broken, especially next the margins, so that the medijustinal vein can be traced only a short distance ; here it runs near and parallel to the margin, and by a gentle curve strikes it at the end of the middle fifth of the wing ; the width of the area is less than a sixth that of the wing, and in the portioij preserved only a couple of bi'anches are seen, widely separated at their origin, simple and arcuate, but brought near together by their unusual longitudinality, so that it is doubtful if there are more than five or six branches to the vein. The following areas, as Heer has pointed out, are difficult to separate, from the fact that the base of the wing is lost, and they all divide so early as to exhibit at the edge of the fragment, very near the base, no less than eight nervules between the mediastinal vein and the anal furrow. It would, however, present a structure so abnormal were any but the nervure next the anal furrow to belong to the internomedian vein, that it seems almost certain that we must divide seven of them between the scapular and externomedian veins ; the three lower of these have an oblique course at the ba.se, and are .separated by an unusual width from the upper four, which in their turn have a longitudinal course ; and these two bundles of nervules we may consider as belonging to the externomedian and scapular veins respectively. On this assumjjtion the scapular vein is longitudinal and nearly straight, and terminates just above the extreme tip of the wing ; it has six longi- tudinal branches, three of which originate within the ba,sal quarter, two near the middle and one next the tip of the wing ; the first and last are simple, the others simpl^', the middle one doubly forked ; the basal branches curve very gently upward toward their tip, but the others are wholly horizontal. The externomedian vein is more difficult to define ; the three veins with which it starts from the base of the fragment are very similar in character, and bemg perfectly parallel next the edge (which must lie within the basal fifth or sixth of the wing) it is not clear Avhich should be looked upon as the main stem ; but the main stem ma}' be said to break close to the base into three branches which rmi close together toward the middle of the outer half of the inner edge of the wing ; omitting the upper brauch of the upper vein, each of these three stems forks at or just beyond the eud of the basal third of the wing, and each of these forks again divides at irregular
120 S. IT. SCUDDER OX TALAEOZOIC COCKROACHES.
distances! iVom this point, but most of" tliem not f;ir from the end of the middle third of the wing; the upper stem, however, has an upper branch, which starts in the middle of the wing and is doubly forked, running in a very straight, longitudinal course almost exactly through the middle line of the wing, its first fork near the end of the middle third, the second near the tip of the wing. The internomedian vein is scarcely arcuate, and by an apical fork is thrown a little further out than it otherwise would be, reaching close to the end of the middle third of the wing ; besides the apical fork it has three branches, emitted near together, not far from the end of the basal thii'd of the wing, straight, oblique and apically forked. The anal furrow is not impressed, regularly and considerably arcuate, bears an inferior, nearly straight branch near the middle of its preserved course, and terminates considerably beyond the basal third of the wing ; the anal veins are scarcely so crowded as the others, simjile. foiked or compound, arcuate, and subparallel to the anal furrow.
The wing is a very large one, the fragment measuring 39 mm. in length, and 17 mm. in breadth. The probable length of the wing is 42 mm., making the ratio of the breadth to the length as 1 : 2.5. The wing is from the left side and shows the upper surface, which is covered Avith a network of very numerous, closely crowded, delicate cross veins, visible onh' by aid of a glass. Heer compares the species with Etohl. jjrhnaeva and JEtohl. didyma, but fails to point out its closer alliance to Progon. Fritschii, which he describes immediately afterwards, or to notice the feature which is most characteristic of it, viz., the exceedingly early division of the scapular and externomedian branches, and the nearly uniform longi- tudinal course of all these branches ; no other palaeozoic cockroach has such an abundance of longitudinal veins filling the larger part of the wing. From its congener it is readily distinguished by this feature, and also by the smaller extent of the scapular area as compared to the externomedian, and the far greater size and stoutness of the wing.
A single specimen, found in the anthracitic schists of the lower quarry of Erbignon, Canton Wallis, Switzei-land, is remarkable as the only animal yet discovered there. Middle or upper carboniferous.
Progonoblattina Fritschii. PI. 3, fig. 12.
Blattina Fritschii Heer, Viertelj. naturf. Gesellsch. Ziirich, ix, 287, 293-94, pL, fig. 2; —
Gold., Faun, saraep. foss., ii, 19.
Fore wing. The wing is exceptionally slender and equal, both borders being almost perfectly straight ; the apex and outer half of the inner margin are lost, but the part pre- served is more than three times as long as broad. The veins originate just above the middle of the base of the wings, and have the slightest possible upward curve in passing outward. The mediastinal vein runs subparallel to the costal margin, but always almost imperceptibly approaching it, more rapidly toward the tip, which strikes the margin at the end of the fragment, or a little beyond the middle of the wing ; in the middle the area is a little less than one-third the width of the wing, and it is occupied by about seven longitu- dinally oblique, slightly arcuate, .simple veins. The scapular vein runs close beside the mediastinal through the basal quarter of the wing, then turns abruptly although only slightly from it, and runs in a broad, arcuate curve past the middle line of the wing, to strike the border just above the tip, or where a continuation of its basal course would have brought it ; it has five superior, obliquely longitudinal branches, the first emitted at the
S. II. SCUDPER 0\ PALAEOZOIC COCKUOACIIES. llil
point wliorc it divcrj^cs from its first coursf, which i« <l<niljly forkcMl ; tho ni'Xt, which \h forked, at the end of the basal thinl of the wiiiir; arnl thrt'»« .niniple, more closely approxi- mated veins, at and a little hcyond the middle of the winjr- 'I'he externomedian has an arcuate course, closely parallel to the .scapular vein, through the hiusid third or thereal)out-s ; here it is broken up into three i)rincipal stems, the upper of which runs in a slij^htly arcu- ate course to a point as far In-low the extreme apex a.s the .suipular vein is above it, emit- ting in the apical third of the wing tiiree simple, nearly longitudinal branches, which occupy the apex of the wing ; the middle stem runs close to the preceding, and emits, at one-third and two-thirds way to the border, two superior, simple, straight, and nearly lon- gitudinal branches; the lower is basally forked, the forks resembling the ba.sjd branch of the midille stem. The internomedi.in vein is rather gently and rcgubirly arcuate, termi- nating next the middle of the lower border; it has three simple branches, and one (the first) forked branch, approximate, .straight, and olilique. The anal fiurow is a little umre strongly, but just a.s regularly arcuate, and strikes the margin at the end of the biL«al third of the wing ; the anal veins, four in number, are simple, distant, slightly divergent, and similarly arcuate.
The wing is of medium size, but appears rather small from it.s narrowness, the fragment measuring 22 mm. in length and 0.5 mm. in breadth;' the wing must have meitsured 23. G mm. in length, sn that the breadth was to the length a.s 1 : 3.G. If the upper surface is preserved, it is from the left side. It is very nearly perfect, only a portion of the tip and lower apical margin being lost. The reticulation between the veins is mostly de- stroyed, but with a glass one may see. particularly in the anal area, excessively delicate wrinkles or little streaks, giving a shagreened appearance to the wing, and indicating the presence of closely crowded cross nevu'ation.
Ileer remarks that this species comes next to Gcrahl. Miin.stcri, but it differs more from that than from many other species, such as Etohl. jlahellata and Elohl. affinis ; but even from these it is widely differient in the distribution of the scapular and externomedian branches. From its single congener, Progon. helvetica, it is readily distinguished by its exceedingly different size and shape, and differs also in its broader mediastinal field, the less basal division of the scapular and externomedian veins, and the more oblirpie course of the scapular branches. Indeed, it diflers so much from it, that were it not for its essential agreement in the points in which they both differ from the other palaeozoic cockroaches, it ■would seem more rational to separate them generically ; which a more extended acquaint- ance with palaeozoic Blattinarians may yet compel us to do.
One specimen, from the coal-measures of Mauebach, near Ilmenau, in Thiiringen. Upper carboniferous.
Oryctoblattina nov. gen. {'',f,oxz6^, BInttina). Blaitina Auct. (pars).
The mediastinal vein of the front wings runs parallel and very close to the costal margin, closer than in any other of the genera here described, and terminates only a little before the middle of the outer half of the wing ; it emits numerous branches almost transverse to the wing in the basal portion, but notwithstanding their brevity often forked in this part of the area. The scapular vein is very peculiar ; it begins to branch a little beyond the
1 Heer says 7.5 mm., but his figure represents it as if it were 6.5 mm., anU this is more likely to be correct.
MEMUIS3 BOST. 300. XAT. UIST. TOL. 111. 16
122 S. IT. SCUDDER ON PALAEOZOIC COCKROACHES.
miilillo of the Imsal halt" of the wing, and tlie main stem terminates on the costal margin a little beyond the miiUllo of the apical half of the wing, keeping widely distant from the mediastinal vein throughout its course ; it emits numerous parallel, straight, longitudinal and forking branches, most of which, in the only species known, originate from a vein parallel to the main stem, which is emitted abruptly from near the base of the second branch ; the first branch terminates at the extremit}- of the inner margin, so that the entire apex of the wing belongs to the scapular area, which is the largest in the wing. Tlie externomedian vein bi-anches near the middle of the wing, and before that is equally- separated from the neighboring veins by a wide space ; it has only two or three branches which are superior, and perhaps simple, and they occupy a very i-estricted area, only the apical fourth of the inner margin being covered by their extremities. The internomedian vein is again very peculiar, this being tlie only genus known in which a wide space intervenes between the anal furrow and the branches of this vein ; it assumes to a consid- erable degree the form of the externomedian vein, first branching beyond its middle, and then emitting a very few simple or forking, but inferior branches. The anal furrow is conspicuous, very arcuate, originating in the middle of the base of the wing, and terminat- ing in the middle of the basal half of the inner margin ; it is rendered more conspicuous by the fulness of the anal area, which breaks the regular continuity of the margin at the extremity of the anal furrow, a jjeculiarity occurring in no other carboniferous cockroach ; the anal veins are very few, sinuous, subj^arallel, simple and oblique. The wing is of the average slenderness, the breadth being contained in the length about two and six-teuths times. Nothing is known of other parts of the body.
This most exquisite of the carboniferous cockroaches is very widely separated from the rest. The peculiarities of nearly every part of the wing separate it at once from nearly every other genus ; the extreme narrowness of the mediastinal area, the wide separation of the main veins from one another (accounted for perhaps by the excessive development of reticulation), the independence of the internomedian vein, and the fulness of the inner margin in the anal area, occur nowhere else ; the inferior origin of the branches of the scapular vein are found elsewhere only in Hermatoblattina, and the wide extent of the area occupied b}^ the combined scapular and externomedian branches are reproduced only in the aberrant genera among which it is placed. From Progonoblattina it is separated liy the small space, and that wholly on the inner margin, which is allotted to the externomedian veins, besides the points first mentioned ; and from Petroblattina, its other nearest ally, it is conspicuously distinct both by the nature of the externomedian vein, and by the wide separation of the main veins in the basal half of the wing.
The genus is only known from Europe, and is the only one represented by a single species, which is of rather small size. More than twenty years ago Glebel suggested that this species should form the type of a distinct genus.
Oryctoblattina reticulata. PI. 4, tig. 13.
BMtina reticulata Germ., Verst. Steink. Wettin, vij, 87-88; viii, taf 39, fig. 15% 15''; — Gieb., Deutschl. Petref , 6-37; — lb., Ins. Vorw., 310 ; — Gold., Faun, saraep. foss, ii, 19.
Fore wing. The wing is of a very graceful form, oblong obovate, the costal margin tolerably convex next the base, with a very slight humeral lobe, beyond very gently and
S. II. SCUDDER ON I'ALAKOZOIC COCKROACUKS. VS.]
regularly convex; the inner margin is straight, e.N<'t'|iting for the fulness of the anal arm, but a large fragment of the apex of the wing is wholly lost. The veins originate from a little above the middle of the base, and have a gentle biusal arcuation. The mediiu<tinal vein runs in close proximity and subparallel to the costal margin, constantly but very grad- ually approaching it, emitting numerous oltlitnie luauches; in the basal iialf of the area the branches are lurked half way to the margin, and betweiMi the forks are other parallel, spu- rious branches ; but beyond the middle of the wing spurious and forked branches become alike very closely crowded, oblicjuu, simple branches, which continue along the edge, be- tween the apparent termination of the nuiin vein (about the end of the middle fifth of the wing) and the scapular vein ; in the middle of the wing the area is only about one-tenth the width of the wing. The course of the scapular vein has been described sullirifutiy under the generic de.-^cription ; it will be suflicient to add here that there are al)Oiit half u dozen longitudinal shoots to the oflshoot of the second .scapular branch, and that these become more and more closely crowded toward the costal margin ; and that tht* two prin- cipal branches of the scapular vein originate close together, the secoml forked at some di.s- tance beyond the oflshoot. The externomedian vein is gently arcuate in its basal half. The internouiedian vein closely resembles it, and in this particular this species is widely separated iVum all others ; but it is a little more arcuate, ha,s inferior instead of superior branches, and terminates about the middle of the apical half of the inner margin. The anal furrow is distinct and arcuate, bending downward to the margin more rapidly than usual ; the anal veins are only three in number, crowded clo.se together in the middle of the area, traversing it obliquely, with a .slightly sinuous, obliquely longitudinal cour.se.
The wing is one of the smaller of the medium-.sized ones, the fragment measuring 19 mm. in extreme length and 8.5 mm. in breadth ; it represents a wing of the same median breadth and a length of about 22 mm.; so that the breadth to the length must have been as 1 : 2.6. The wing is from the left side. It is marked by a distinct and exceedingly delicate and perfect reticulation of raostl}' pentagonal cells, two or more rows being seen between the wider interspaces ; but in the nari'ower ones, as between the closely approximated scapular branches, these are reduced to a single .series of tetragonal cells, formed by single, transverse raised lines, as far apart as the interspaces, but still no smaller than the pentagonal cells ; next the border, between the extremities of the mediastinal and scapular veins, these cells form, by the absence of their cross bars, spurious veinlets as long as the apical width of the mediastinal area; between the anal furrow and the nearest internomedian branch they do the same, but the veinlets are longer; and in the apical half of the anal area the same thing occurs on a smaller scale.
This wing is so peculiar that it can be compared with no other. Germar and Gieljcl both describe the scapular vein as the mediastinal, and tiie mediastinal as a delicate, longitu- dinal vein running down the middle of the mediastinal area.
The single specimen described by Germar was found at Wcttin, Germany. Upper car- boniferous.
Fetrablattina nov. gen. {-irfia, Blattinx) Blatt'ma Auct. (pars).
The mediastinal vein runs parallel to and not ver}- distant from the costal margin (the area occupying perhaps one-fourth of the breadth of the wing), and terminates at some distance beyond the middle of the costal border; it is abundantly supplied with straight.
124 S. II. SCUDDER OX PALAEOZOIC COCKROACHES.
oblique, simple or Ibrkeil cross-veins. The scapular vein, contiguous to, perhaps united with, the externomedian in the hasal part of the wing, is of small importance, emitting in the apical half of the wing only two or three branches, which are superior, simple, or furcate, and terminate on the costal margin, the whole tip (in one species at least, and perhaps in both) belonging to the externomedian vein. The externomedian vein is the most peculiar in the wing ; as soon as it is free from the common basal union of all the veins, it curves strongly backward to about the middle of the inner margin, in close prox- imity to the internomedian vein ; and from its superior, now outer, surface emits a large number of parallel, forking veins, which terminate on the apex and outer half of the inner margin of the wing. The combined internomedian and anal areas are very broad at base, occupving fully two-thirds the breadth of the wing, and retain their breadth for some dis- tance and then narrow with excessive rapidity, dividing about equally between them the common space ; the branches of the internomedian vein are five or six in number, straight or arcuate, simple or occasionally forked. The anal furrow is very arcuate, not very prom- inent, and terminates near the middle of the basal half of the wing; the anal veins are fre- quent, arcuate, but not so strongly as the furrow, and simple or occasionally forked. Only ujiper wings are known.
The wings are stouter than usual, although they are not sufficiently well preserved to give any more definite statement than that they are, on the average, stouter than any other, excepting probably Hermatoblattina, and possibly Anthracoblattina.
This genus is remarkable for the close union of the veins at the base, and for the very strong curvature of the externomedian vein, by which it resembles somewhat the anal furrow, and for the contrasted longitudinality of the branches which spring from it. In these particulars it differs striliingly from every other genus, and can be confounded with none of them.
Only two species have been described, one of which is European, and the other, known only by a very small fragment of a wing, American ; they are both of rather small size.
Petrablattina gracilis. PL 4, fig. 4.
BlaUlna gracilis Gold., Palaeoutogr., iv, 23, taf. 3, figs. 3, 3"; — lb., Foss. Ins. Saarbr., 7, taf. 1, figs. 3, 3»; — lb., Faun, saraep. foss., ii, 20, 27-28, 51, taf. 2, fig. 1^ — Heer, Vier- telj. naturf. Gesellsch. Zurich, ix, 288 ; — Gein., Geol. Steink. Deutschl., 150.
Blatta gracilis Gieb., Ins. Vorw., 321.
Fore wing. The wing is of a regular elliptical form, broadest in the middle, tapering more rapidly toward the apex than toward the base, both costal and inner margin equally and rather gently convex, the tip a little pointed, but well rounded. The veins all origin- ate above the middle of the upper half of the base, but, excepting the anal furrow, have no ba-sal curve. The mediastinal vein runs subparallel to the costal margin, but in a straight line, nearly to the middle of the wing, and then curves very gradually to the border, which it reaches a little before the end of the middle third of the wing; the area is a little less than a fourth the width of the wing ; its basal half is filled with closely crowded, arcuate, oblique, simple branches, the apical half with similarly crowded and arcuate, longitudinally oblique, much longer, and usually forked branches. The scapidar, externomedian, and in- ternomedian veins evidently spring from a single stem, according to Goldenberg; the in-
S. n. SCUDDER 0\ PALAEOZOIC C"0(KHOA(I!ES. 125
tornoniC'iHan fust separates itself fritin the others, hut tlie other two ajtpi'ar to ho united ahuost throujriiout the liasal third of tiiewiii;;; the scajmhir vein then turns ohh(piely downwanl in parting; from the mediastinal vein at the end of the hasal foiuth of the winj^, in a direction toward the middle of the outer half of the winj;; hut it very soon jiarta widely from the externomedian vein, and rvnis in a lon<;itudinal, hroadly arcuate course to the costal margin, just hefore the apical eighth of the wing; it emits three long, longitu- dinal, but ohli([uely arcuate branches, simple or deeply forke<l, the first before the sepani- tion of the vein from the externomedian. The externomeilian vein continues the clirection of the united scapular and externomedian veins, following closely tlu- iiiternomedian. and terminating on the inner border, about the end of the mi<Idle fifth of the wing; it emits at a wide angle aliout ten closely crowded, longitudinal veins, many of which fork singly or doubly, nearly all of them broadly arcuate, the upper curving slightly upward, the lower downward, and together embracing a very extensive area, including the entire apex of (he wing. The internomedian vein has a bent, arcuate course, and emits about seven long and simple, sinuous, clo.'^ely crowdeil branches, the marginal extent of this area being rather less than that of the anal area. The anal furrow is distinctly impressed, pretty regularly and very strongly arcuate, striking the margin at about the end of the ba.sal third of the wing ; the anal veins, nine in number, are closely crowded, arcuate, and simple.'
The wing is below the medium size, measuring 18.5 mm. in length and ~.^> m?u. ia breadth ; a little of the base, however, is destroyed, which would add about l.") nun. to the length, making it 20 mm. long," and the breadth to the length as 1 : 2.0. The wing is from the right side, the upper surface exposed, with a swollen anal area ; from the condition of its preservation, it cannot be determined whether there is any interspacial reticulation.
Goldenberg compares this species to Etohl. anaylytica and to "Blattina formosa Heer" from the Lias, but I foil to see the slightest ground for any special comparison ; certainly not with the latter; Avliile the peculiar basal connection of the principal veins, and, above all, the distribution of the externomedian branches, forbid comparison with any palaeozoic form, excepting the following species, from which it differs greatly in the multiplicity of its branches and in its slenderer form. Indeed, in the crowded condition of its venation it alone of all the palaeozoic cockroaches, excepting Etohl. insifjnis, shows any tendency to- ward a thickening of the membrane of the wing, which often appears, in ancient types, to have commenced by the multiplication of nervules.
The single specimen known comes from an ironstone nodule from Lebach, above Saar- louis, Geriuany. Dyas.
Petrablattina sepulta. PI. 0, fig. 7.
Blattina sepulta Scudd., Proc. Amer. assoc. adv. sc, xxiv, B, 111, (ig. 2; — lb.. Can. nat. [n. s.] VIII, 89-90, fig. 1; — lb., Ins. carb. Cape Breton [p. 2] fig. ].
Fore wing. The wing is so fragmentary that it is impo.ssible to say anything more of the form than that the middle of the costal and inner margins are gently convex, the former nearly straight. The veins would appear to have originated considerably above the middle of the base. The mediastinal area occupies in the middle of the wing consid-
' One is incorrectly represented on our plate as forked. tion as 1 : 2.2; but his enlarged figure, presumably the most
- Goldenberg wives the breadth as 9 mm. and the proper- accurate, makes the breadth only 7.6.
126 S. n. SCITDDER ON PALAEOZOIC COCKKOACIIES.
erablv loss than one-fourth the width of tho wing, and thereafter approaches the costal niaririn very gradually, terminating, presumably, just before the apical sixth of the wing;^ in tho frairmont preserved it emits three longitudinally^ oblique, straight branches, of which the first is simple, the second simply, and tho third doubly forked. The scapular vein is straiirht. and parallel to the costal margin, lying close beside the mediastinal vein, and, first, dividing in the middle of the wing, probably terminates before the tip ; its branches, two upon the fragment, are sublongitudinal, at least the first forked. The externomedian vein is strongly arcuate, curving downward to the middle of the inner margin, and emitting eight branches at a wide angle, all of them arcuate, the first nearly longitudinal, the suc- coodint; ones gradually more and more oblique ; the first must originate fiir toward the base of the wing, and does not fork unless near the tip, where it probal)ly does ; the next four branches are all forked near the middle of the wing, and prol)ably fork again apically ; the lower three are simple, so far as they can be traced, and probably remain so; these branches are more distant than those of the upper part of the wing. The internomedian vein is wanting, but four of its branches (perhaps all there are) can be seen, the outermost forked, tho others simple, about as distant as the externomedian branches, very arcuate, and obliquely transver.se.
The wing is a small one. the fragment measuring 6.25 mm. in length, and 5.75 mm. in breadth; probably the length of the wing was 13 mm. and the breadth 6 mm., making the breadth to the length as 1 : 2.2. The interspaces, particularly in the internomedian area, are filled with very frequent cross nervules. The fragment is exceedingly imperfect, not more than one-third (a middle piece) of the wing being preserved ; but, excepting that it wants the anal furrow, this contains the most important part of the neuratiou, which difiers widely from that of any other cockroach excepting the European species with which we have generically associated it ; from this it difiers in its presumably greater comparative breadth, the comparative sparseness of the neuration, and the downward curve of all the externo- median branches ; the externomedian and scapular veins are also certainly separated much further toward the base, if not altogether, and the distribution of the scapular branches is different.
In my fonner de.scription of this insect, so different is the neuration from what appears in other American species, I mistook the internomedian for an anal field, and did not attempt to interpret the other parts of the neuration. I also compared it, with no show of reason, to Elohl. carbonaria, with which it has no special relationship whatever.
The single .specimen known Avas found at Cossett's pit near Sydney, Cape Breton, by Mr. A. J. Hill, C. E.. together with Libellula carbonaria Scudd., and a frond of Alethopteris. It was kindly sent me for. examination bj' Principal Dawson, who informs me that it comes from a rather lower horizon than that in which the Cape Breton species of Mylacris occurred, or in the lower part of the middle coal formation near the upper hmit of the millstone grit. Lower carboniferous.
' In the plate, the line which represents the mediastinal as if it were the continuation of the second forked medias- vein in the middle of the fragment is unfortunately oblique, tinal branch; instead of parallel to the margin, as it should be.
S. II. SCL'DDKU UN I'A I. A !•:()/.( )U' ((HKUOACIIES. 127
ArrKNDix. 'I'lic rollnwiiig s[)e(ues Ciimiot he ilcliiiltc'ly n-li-rrcil tcj aiiv of tin- jin . .■■im^ ^<-in-ia. Blattina TischbeinL I'l. I, li,'. In.
lihitliiKi Tisvhheliii (luld.. \ oiw. Fiiuii. Siiail»r., Kl-l"; — lit., Faiiii. .saraop. f(jHM., i, 1(5-17, pi. -, I'll,', lii; — lb., Fauii. sanicp. fo.s.s., ii, 10, 01.
I'ltrt' wiiii;. TIr' fiaL^niu'iit jtrcscrvi'il is an iiLsignificaiit portion of tlic hif^e, wliicli doon not piMinit lis to .say more ol" its alVniitios than tliat it bclonj^s to the Ulattinariae, ami not to the Mylacridae; a network ofdelieate veins can he seen l)otween the principal iiervnrert.
Hind wini^. A nineh hiri,a'r fraj,'inent ol" the liind win;^ is preserved, eonsistincr. hijwcver, altogetlicr, or almost altogether, of the anal (ielil fully e.\pan<leil, hnt much broken and crushed out of shape, according to Goldenberg ; between the vein.s a very line tran.sverse neuration is preserved, giving the wing a very delicate apjjearance.
A fragment of one of the legs is preserved beside the hind wing; .i hind leg, acconling to Goldenberg, consisting of a part of the femur and til)iae '"with traces of spines." This is the only palaeozoic cockroach described in which mention is made of spinous legs.
Besides the.se, upon the same .stone but separated from them, is the pronotal shield, which, according to Goldenberg, is transversely elliptical, somewhat gibbous, the hind margin nearly straight ; elsewhere, both in front and on the sides, rounded, the surface with some slight cro.ss Autows, its length 8 mm. and its breadth 12 mm. Excepting for its hind mar- gin, its form closely resembles that of JIi/l. fUiUirdcopldlum.
The species prot)ably attained a length, according to G(jldenberg, of o 1 mm.
Several specimens were found in a bituminous shale at Hir.schbach, near Saartiriicken, Germany. Middle carboniferoii.s.
Blal^tina lal^ervis. IM. 4, fig. 3.
Blattina laiinervis Ilecr, Yicrtelj. naturf. Gesellsch. Zurich, ix, 288, 296-97, pi., fig. 4; —
Gold., Faun, saraep. foss., ii, 20.
This is the best-preserved hind wing of a fossil cockroach known, but is still very frag- mentary, nearly the whole anal field (all but a detached fragment), besides the extreme ba.se and a belt across the middle of the wing, being wanting. It is subovate, with a straight or sliglitly concave costal margin and a rounded apex. The mediastinal vein, if the costal portion of the wing is perfect and correctly represented, runs close to the margin, nearly uniting with it in the middle, and then diverges slightly from it, terminating only a little before the tip, and in its apical half emitting several .short, oblicjue branches. The scapular vein runs parallel to the border in the basal half of the wing, and then divides into two compound branches. The externomedian vein is irregular, forking near the ba.se, the upper branch simple and running in an irregularly arcuate course to the tip of the wing, the other forked doubly, with a similar but less arcuate and more regular course. The internomedian vein emits, close to the base, two or three simple branches. The anal area, to judge from the small detached fragment, is filled with parallel, frequent, gently arcuate veins, united, like those of the other parts of the wing, with rather distant cro.ss veins.
jov; S. H. SCUDDER ON PALAEOZOIC COCKROACHES.
formiuii qnatlrato colls -with the lonnitiuliiial veins, ami apparently more distant in the anal area than elsewhere. The veins are everywhere edged with black. Length of fragment, 27."> mm.; hreadth. 10 nnn.
Ileer snirirests that this may be the under wing of Gerahl. daihrata, but the unusual width of the metliastinal area in the front wing of that species does not harmonize well ■with the narrowness of the same area in this hind wing; and it is hardly probable that we shall ever be able to determine where it does belong.
A single specimen, from the coal-measures of Manebach, near Ilmenau, Thih-ingen. Upper carboniferous.
Blattina venosa. PI. 4, tig. 6. Blnttina venosa Gold., Faun, saraep. foss., ii, 19, 25, 51, pi. 1, fig. 7. This species is based upon a single fragment from the middle of a wing, whether front or hind can scarcely- be determined. Goldenberg says it is of a front wing, but there appears to be no reason for his conclusion. There are a pair of branching veins, the main stems running parallel to each other, and the branches divaricating on opposite sides. Goldenberg says the veins are remarkable for their distinctness, and therefore as he makes no mention j of any reticulation or cross venation, there probably is none ; the opeiuiess of the ueura- tion, with the undeviating course of the branches throughout the rather large fragment,] indicate a large species. The two principal veins represented would appear to be the scap- ular and e.xternomedian ; or, perhaps, the externomedian and internornedian. Length of fragment, 18 mm. ; breadth, 12 mm.
The single specimen was found in a soft, yellowish shale near Wemmetsweiler, in the neighborhood of Saarbriicken, Germany. Upper carboniferous.
On PI. 6, figs. 11 and 13, are represented two fragments of wings probably belonging cockroaches, but of which little more can be said. Fig. 11 comes from Cossett's pit No. at Sydney, Cape Breton, and was found by Col. A. J. Hill; it has no natural horde whatever, and may belong to almost any part of the wing; it may perhaps be a portion of an externomedian area, similar to that of Petrabl. sepulta (with which it was found), and in that case would probably represent a distinct species. Lower carboniferous.
Fig. 13 probabl}- represents the central joortion of a wing, the right hand set of branches belonging to the scapular, the left hand set, which are wrongly represented as connected at ba.se with those of the right hand, then belonging to the externomedian vein. The speci- men (No. 2010) came from immediately below vein C at Cannelton, Beaver Co., Penn., and was discovered by Mr. L F. Mansfield, through whom 1 received it. It represents a species of perhaps the same size as Archlm. parallehiyn, and possibly belongs to it; but as no part of the margin is preserved, any attempt to place it is useless. Lower coal measures of Penn.sylvania.
Polyzosterites.
Poly zoster ites Gold., Vorw. Faun. Saarb., 18 ; — lb.. Faun, saraep. foss., i, 18.
Goldenberg defines the genus as consisting of cockroaches in which both sexes are apter- ous, with nearly semicircular, very slightly marginate pronotum, and a flat, crustacean-hke abdomen with sharply edged margin.
S. H. SCUDDER OX PALAKOZOIC COCKROACHES. 129
Polyzosterites granosna.
Adelophthahnus {Earypterux) /jranoxus Mcyor. Palueontogr., iv, 8-1 L'. pi. 'J, li;.'-s. 1, L'. Eitr>ii>lerHx f/rdUDSus Salt.-Woutlw., Chart foss. Crust., pi. li, fij^. l/i.
Poh/zosferifes fjntiinsus itoh\., Vorw. Faun. Siuirbr., IS; — llj., Faun, saniep. I'otw., i, IS, pi. 1, (ijf. 17; — 11)., Faun. .><araep. fo.s.-*., ii, 20, ol.
rioldi-nljcrj; (le.-^cril)es the spories a.** folli)\v.s : —
■ Tilt.' prouDtuin. Ijoneuth which. a.s u.sually, the hcail lio.s oonccaled, i.s Bcnii-elliptical. nar- rowed and rounded anteriorly; it.>* greate.-<t breadth, wliifh falls near the posterior blunt angles, is scarcely less than 28 nun. ; the length does not appear to have exceeded IG nun. The conve.xity is gentle, and the .slightly concave posterior border is accompanied by a feeble margin. The next two thoracic .segments have in general a shape similar to that of the succeeding .segments of the abdomen. All of tlieni are tinnid. not only laterally, but also in front and behind, and bonlered with a slender marginal piece, connecting each seg- ment with the preceding. The abdominal and thoracic segments together form a regular oval ; the pointed, lobe-shaped outer extremities of the .segments become gradually larger and broader toward the extremity of the bod^-, as in living species of Polyzosteria; the last four rings are not so well preserved as the others, and are thrown far out of position, so that the last ventral segment is turned completely around. The thoracic as well a.s the abdominal segments have the dorsal surface covered with small, crowded tubercles, which are most prominent on the more tumid portions, and by the unaided eye can be seen to be of a blunt, triangular form, directed backward. An entirely similar structure may be seen in what appears to be Polyzosteria limbata Burm. Had such an animal been found fo.ssil, it would very likely have been taken for a blind Eur^^pterus, were it not for the form of the extremity of the abdomen, which in all Eurvpteri is linear or linear-lancet .shaped."
•' This fossil was found in the Ei.senbahn.schacht near Jiigersfreude, in an ironstone nodule. Near Altenwald I found also in such a nodule a similar fo.ssil, but not so completely pre- served, which may probabl}' have belonged to another and smaller species of this genus."
Goldenberg figures an articulated fragment found beside the abdomen, and which Meyer, considering the animal as a Eurvpterus. had compared to the maxillipeds or false abdom- inal feet of the modern genus Serolis, but which Goldenberg takes for a Myriopod, like Polyxenus. So far as his illustration goes, it might be taken for the antennae of the insect itself. The form of the last segment indicates a female.
Postscript. November, 1870. — It will not fail of notice how oppo.sed to the drift of this entire e.s.say is the statement of Gerstaecker (Bronn's Kla.-<sen imd Ordnungen des Thierreichs, v, 202) that the cockroaches described by Germar ami Goldenberg from Wettin and Saarbriicken agree in every distinctive family characteristic with those now living (•• stimmen in alien fdr die betreffenden Familien charakteristischen Merkmnlen mil denjenicjen der Jeiztzeit iiberein"). In the same place (p. 291) Gerstaecker remarks that scarcely a single extinct form of cockroach approaches in size the largest living species of the family. Yet, as I have stated, the average size of ancient types may be considered somewhat larger than iu modei'u times.
Gerstaecker (loc. cit. 202, note) considers the wing described by Dohru under the name of Fulgora Ebersi as the hind wing of a cockroach, with most of the anal field destroyed.
MEMOIRS HOST. SOC. N.\T. HIST.
130 S. 11. SCUDDER ON r.VT.AKOZOIC COCKROACITES.
It does not, however, agree at all with the striictiiro of the hind wini::s of palaeozoic eock- roaohes already known.
Only after the printing of nio.-<t of this paper have we had access to a paper by Dr. C. J. Anilrii (Eine Alge und eine Insectenlliigel aus den Steinkohlenformation Belgiens. < SitzAnigsb. niederrhein. Gesellsch. Bonn, 1870, 2T-2S) in which mention is made of the occurrence of the wing of a cockroach in the coal formation of Belgium. The author merely states that an elliptical fragment, representing the margin of a wing, was found, the distribution of the veins in which substantially' agreed with that of " Blattina."
Explanation of the Plates.
All the figures on this ])late ;m<l tlie two following ;ire c;iinor:i ]\K-iil:i coi)ics from other authors; the scale is altered where necessary, so as to be uniformly about two diameters above the natural size; the marks out- side the wing represent the limits of the several areas. They all represent European insects. Drawn by the author.
Fig. 1. Etoblattina anthraco2jhila (Germ.), p. 64. Copied from Milnstei-'s Beitriige zur Petrefacten- kunile, V, pi. 13, fig. 3 ; revei-sed and the border restored.
Fig. 2. EtohUittina affinis (Gold.), p. 62. Copied from the Neucs Jahrbuch fiir Mineralogie, 1809, j)l. 3, fig. 3 ; revereed.
Fig. 3. jLtoblattina carhoitaria (Germ.), p. 73. Copied from Germar's Yersteincrnngen des Stein- kohlcngebirges von Wettin, etc., pi. 31, fig. O*" ; reversed, and the a])ical margin restored. The scapular area, however, is represented as broader than it should be, and the restored outline is probably too contracteil.
Fig. 4. £^tof/la(tinaflaf/ellata{Gtinn.),i>.G2. Cojiied from Mtinster's Beitriige zur Petreflictenkuude, v, pi. 13, fig. 4'' ; reversed, and the border restored.
Fig. 5. ^Etoblattina Dohrnii Scudd., p. 60. Co])ied from the Neues Jahrbuch fiir Miner.alogie, 1869, pi. 3, fig. 8, right wing; reversed. The outside mark, representing the termination of the anal area, should be car- ried one interspace further toward the tip of tlic wing.
Fig. 6. Etobkittina russoma (Gold.), p. 76. Copied from the Neucs Jahrbuch fiir Mineralogie, 1869, pi. 3, fig. 2" ; reversed.
Fig. 7. Etoblattina ? iyisignis (Gold.), p. 82. Copied from part of an original drawing received from Di-. Goldenberg, from which pi. 2, fig. 14-' of his Fauna saraepontana fossilis, i, was taken. The restored tip is inac- curately represented as fully rounded, whereas it should closely resemble the apex of fig. 9. Cf. ])1. 4, fig. 9.
Fig. 8. Ant/iracoblattiiia spectabilis (Gold.), p. 88. Copied from the Neues Jahrbuch fiir Mineralogie,
1868, pi. 3, fig. 7 ; reversed.
Fig. 9. Etoblattina parvula (Gold.), p. 81. Cojiied from the Neucs Jahrbuch fiir Mineralogie, 1809, pi. 3, fig. 6.
Fig. 10. Etoblattina elongata Scudd., p. 80. Copied from the Neues Jahibuch fur Mineralogie, 1875, pi. 1, fig. 2; reversed, and with the basal margin.s restore<l.
Fig. 11. Gerablattina Geinitzi (Gold.), p. 103. Coiiied from the Neues Jahrbuch fiir Mineralogie, 1868. pi. .3, fig. 5.
Fig. 12. Gerablattina Milnsterii Scudd., ]i. 104. Copied from Germar's Veistcinerungcu des SteinkohUn- gebirges von Wettin, etc., pi. 31, fig. S**; the a]>ical margin restored.
Fig. 13. Etoblattina didyma (Germ.), p. 75. Copied from Germar's Vcrstcinerungen des Steinkohlcn- gebirges von Wettin, etc., pi. 31, fig. 3 ; reversed.
Fig. 14. Etoblattina rnanebachensis (Gold.), p. 79. Copied from the Neues Jahrbuch fiir Jliiieraloo-ic,
1869, j.l. 3, fig. 4.
S. II. SCUDDKli ON I'AI.AKOZOIC COCKROACIIKS. 131
Fifi;. 15. Etohhittinn auaghjplica (Oerin.), p. (50. C'opiod from (Jtrinrir'n Verxti-inorunf^cn <Uii Stciiikohlon- gfltirj^cs von Wtttiii, etc., |il. 31, H;jf. 4 ; ivvltso.1, and tin- :i|iii:il iu:irf^iii reslnrt'd. The InutJil curve of llie ni:iin veiii» is not well re|ir<'.senteil.
FiiT. IG. EtohliUlina einjhfiilina ((ii.rn\.), p. GO. Copied fmnj Genu.ir'it Versteinerunjjeil ilea .Slcilikohlen- gebirgcs von Wettin, etc^ pi. 31, fig. y, with the rtj>ical margin rehtored. Cll pi. 4, lig. 7.
PLATE III. See pri'iiiiiinar)' c.\plnnntiuD9 to rintv II.
F'ig. 1. Gvrablattina xctissiana {GiAA.), \^. \0d. Copied from the Nciics Jahrlnich fUr Mincralogie, 18C8, p]. 3, fig. It); with i)art of the inner border restored. Tiie outside mark, imlicating the lower limit of the cxternomedian area is placed much too far from tlie ti[> of the wing; there Nhould he also a ningle hrancii to the intcrnoincdian vein.
Fig. 2. Gtra/iliitdna jirodiicla Scudil., p. 100. Copied from the Neues Jahrhuch fur Mincnilogie, 18C8, pi. 3, fig. 9 ; reversed.
Fig. 3. Gerablattina scnherata (Gold.), p. 102. Copied from Goldenberg's Faun.i saracpontana foRsiliH, ii, pi. 1, fig 8 ; reversed. The branch of the externomedian vein, being conjectural, should have beeei dotted throughout.
Fig. 4. Gerablattina dathratii (Ileer), p. 100. Copieil from the Viorteljahrs-sclirifl dcr naturfonichcndcn Gesellschafl, Ziirii-h, i.x, pi., fig. 3; with the inner and ajtical margin rcstorecl. This figure :iccidentally repre- sents the wing as magnified a little less than two diameters.
Fig. 5. Eloblattitia labucliensis (Gold.), p. 59. Co|iicd from Goldenberg's Fauna saraejiontana fossilis, i, pi. 2, tig. 15 ; reversed.
Fig. 6. Girabhtttina Girmari (Gieb.), p. 107. Co])ied from Gcrmar's Versteinerungcn des Stcinkohlenge- birgcs von Wettin, pi. 31, fig 9.
Fig. 7. Etohhtttina primaiva (Gold.), p. 58. Copied from Palaeontographica, iv, pi. 3, lig. 4*.
Fig. 8. Et'ibkUtina mantidioid.s (Gold.), p. 72. Copied from the Geologic.il Magazine, iv, pi. 17, fig. G. The restored outline of the apical half of tiie wing is undoubtedly incorrect, and the inner margin of the base is represented as much too convex ; a corrected figm-e will be found in the text, p. 73 ; the ouLside nuirk indicating the lower limit of the scapular area should be removed to the apex of the wing.
Fig. 9. Etobhtttina kptophhbica (Gold.), ]i. 77. Copied from the Neues Jahrbuch fllr Mineralogic, 18G9, pi. 3, fig. 1* ; revei-sed, and with the ajiical margin restored.
Fig. 10. Progonoblattina Mcetka (Heer), p. 119. Copied from the Viertclj.ahrsschrifl der naturforschcn- den Gesellschaft, Ziirich, ix, pi., fig. 1.
Fig. 11. Gerablattina intermedia (Gold.), p. 101. Copied from Goldenberg's Fauna sar.aepontana fossi- lis, ii, pi. 1, fig. 10 ; reversed.
Fig. 12. Progonoblattina Fritschii (Heer), p. 120. Copied from the Vierteljahrsschrifl iler naturfoi-schen- den Gesellschafl, Zurich, ix, pi., fig. 2 ; with the apical margin restored.
Fig. 13. Gerab/aftina Gohlenbergi (Mahr), ]>. 98. Co]>ied from the Neues Jahrbuch ftlr Mineralogic, 1870, p. 284, fig, 1 ; with the apical margin restored.
Fig. 14. Gerablattina Mahri (Gold.), p. 108. Copied from the Neues Jahrbuch filr Mineralogic, 1870, p. 284, fig. 2"; with the basal and apical margins restored.
PLATE IV. Sec preliminary explanations to Plate II.
Fig. 1. Anthracoblattina Jiiickerti (GoM.), p. 9(3. Copied from the Neues Jahrbuch filr Mineralogic, 1868, pi. 3, fig. 11 ; with most of the border restored ; probably this represents the wing as bro.ader than it should be.
Fig. 2. Anthracoblattina Beniigii (Dohrn), p. 95. Copied from Palaeontogi'aphica, xvi, jil. 8, fig. 3, with the inner and apical margins restored.
Fig. 3. lilattina latinervis Heer, p. 127. Copied from the Vierteljahrs.schrifl iler naturforschenden Gesell- scliaft, Zurich, ix. pi, fig 4°.
132 S. II. SCUDDER ON TALAEOZOIC COCKROACHES.
Fig. 4. Pttrahhittina ffrocilis (Gold.), yi. V24. Co\wd fnim Palucontogrnpliicn, iv, pi. 8, fig. 3' ; rcvfreccl. Olio of the iniiliUo :»ii:il veins is wrongly represented ns forked.
Fiij. 5. Aiithracohhittiiia porrecta (GeLn.), p. 93. Copied from the Noucs .Talnliuch (iir ]\IiiH'r:ilogie, 1875, pi. 1,^ fig. 4.
Fig. C. JihUtina vcnosa Gold., p. 128. Copied from Golcloiiberg's Fauna saraepontana fossilis, ii, pi. 1,
fig. 7":
Fig. 7. Etoblattina cugh/ptica (Germ.), p. 60. Copied from Gorraar's Yersteinerung(Mi des Steinkohlen- gebirges von Wettin, etc., i)l. 31, fig. T*" (pai-s). Ilind wing; ef. pi. U, fig. 16.
Fig. 8. AuthracohhUtina sopita Scudd., p. 89. Copied from the Neues Jahrliiu-li fur iMiiieralogie, 1875, pi. 1, fig. 1, left wing.
Fig. 9. Etoblattina? insignis (Gold.), p. 8"2. Copied from part of an original drawing rcc.i'ived from Dr. Goldenbcrg, from which pi. 2, fig. 14° of his Fauna saraepontana fossilis, i, w.is taken. Hind wing; cf \>\. 2, fig. 7.
Fig. 10. Jilattina Tischbeini Gold., p. 127. Co|)ied from Goldenber2;'s Fauna saraepontana fossilis, i, ]il. 2, fig. 16\
Fig. 11. ncrmatoblattinahbachcnsis (Gold.), p. 117. Copied from Palaeontograpliica, iv, pi. 6, fig. 7; with the a]nc.il margin restored.
Fig. 12. Anthracoblattina wintcrktna (Gold.), p. 94. Copied from the Neues Jahrbuch fiir Mineralogie, 1870, p. 288, fig. 2 ; with the basal margins restored. The figure is probably too small ; see p. 95.
Fig. 13. Oryctobhtttina reticulata (Germ.), p. 122. Copied from Germar's Versteinerungen des Stein- kohlengebirgcs von Wettin, etc., pi. 39, fig. IS""; with the apical margin restored.
Fig. 14. Hermatoblatlina tcemmctsweileriensis (Gold.), p. 115. Copied from Goldenberg's Fauna sarae- pontana fossilis, ii, pi. 1, fig. 9; reversed. The costal m.argin is a little too full.
TLATE V.
All the figures on this plate are original, and represent American insects. They were drawn on stone by L. Trouvelot.
Fig. 1. Mylacris brclonense (Scudd.), p. 41. Magn. ^; drawn by S. II. Scudder.
Fig. 2. Litlwmylacris angustum Scudd., p. 48. Magn. f ; drawn by J. H. Emerton.
Fig. 3. IJthomylacris angustum Scudd., p. 48. Magn. \; drawn by J. H. Emerton.
Fig. 4. Lilhomylacris jnttstonianum. Scudd., p. 50. Magn. f^ ; drawn by J. H. Emerton.
Fig. 5. JAthomylacris sim])lex Scudd., p. 51. Magn. g; drawn by S. H. Scudder.
Fig. 6. Mylacris atithracophilum Scudd., p. 45. Magn. ^ ; drawn by S. H. Scudder.
Fig. 7. Mylacris anthracophilum Scu^d., p. 46. Magn. \; drawn by J. H. Emerton. Pronotum.
Fig. 8. Mylacris anthracophihim Scudd., p. 45. Magn. -J^ ; drawn by J. H. Emerton.
Fig. 9. Nucymylacris htros Scudd., p. 54. M.ign. f; drawn by J. H. Emerton. The first (inferior) oflTshoot of the first scapular branch should be foiked near the tip, or directly opposite the extremity of the first branch itself.
Fig. 10. Lithomylacris jnttstonianiim Scudd., ji. 50. Magn. \ ; drawn by J. II. Emerton.
Fig. 11. Mylacris ITeeri (Scudd.), p. 43. M.agn. f ; drawn by S. H. Scudder. The uppermost fork of the apical branch of the internomedian vein is not sufficiently longitudinal.
Fig. 12. Necymylacris lacoatium Scudd., p. 53. Magn. ^ ; drawn by .1. II. Emerton.
Fig. 13. Mylacris pennsylvanicum Scudd., p. 44. Magn. { ; drawn by J. II. Emerton. See note to next figure.
Fig. 14. Mylacris pennsylvanicum ScHd<l., p. 44. Magn. f ; drawn by J. H. Emerton. The raediastin.il branch next the humeral lobe should have been omitted from this and the preceding figure; it does not exist. The restored outline of the wing probably extends too far outward.
Fig. 15. Mylacris Mansjieldi Scudd., p. 47. Magn. ? ; drawn by J. H. Emerton.
PLATE VI.
Excepting fig. .5, all the drawings on this plate are origin.al, and represent American insects. They were pl.nced on stone by L. Trouvelot.
Fig. 1. GerabUMina fascigera (Scudd.), p. 113. Magn. ?; drawn by J. II. Blake. The base of the
S. 11. SCUDDP:U 0\ I'ALAEOZOIC cockuoaciiks. 133
extcriioiiieili:iii vein bIiuuIiI liave liueii it'|iivsi'ritiMl an united at tlio hams witli tlie iicApular vein ; the oiitiiiilo ni:iik iii'liiMliiift the c'li'l of tlie sc:ii>iil:u- iirtM is |>hicuil ulij^htly tuo liiyh ; that iii<lic:itiii<j the eii<l of thu anal area is phiceil on tlie wroni; siile of tlie anal furrow.
Fig. '2. Guiibliittiiutf<isri(jtm (Scu.1.1.), p. 113. Magn. \ ; <irawn hy J. H. Hlake.
Fii,'. 3. EtiihlaUinn Lfsqucreuxi Scii<lil., ]>. 07. Mayii. J ; ilrawn hy J. II. Kinerlon. See note tu next figure.
Kit;. 4. J-Jtiibhittiiui Lenfjiiertiu-i Sciuhl., ]>. 07. Magn. J ; drawn hy J. II. Kinerton. One or two bnsal branches of the mediastinal vein are not shown. The origin of the middle extcrnoniedian braueh lit wrongly represented ; .see a eorreeted liyjure of the latter in the text, ji. 08.
Fig. 5. /•SltMittiiui wiissiyuisis {Gvrtu.), \i. 6b. Copied from the Xeiies Jahrhueh fllr Mincralogic, 1878, pi. 3, fig. 1 ; reversed. Camera lueida sketeh by S. II. Seudder. This is a Kuropean speeieo.
Fig. 0. Archi/nyldcris jxinilklKiii Seudd., p. 85. Magn. '{; drawn hy J. II. Kmerton. The inediaKtinnl vein of the front wing should be represented as gradually approaehiiig the eostal map^'in in the basal half of the wing. The mediastinal vein of the hind wing can be seen on the speeimen, miderlyitig the front wing, but is not re]>rcsented on the jilate. The wing is aceomjianied by the pronotum.
Fig. 7. Pttrubliittiiui sijjulta (Seudd.), p. 1'25. Magn. f ; drawn by S. II. Scuclder. Tlie inner margin of the fragment is represented as more eonvex than it .should be; the .short line representing the main medi.'is- tinal line in the middle of the fragment should bo nearly [larallel to the margin, not obli({ue.
Fig. 8. Archi'mi/liicris iian/icttm Seudd., p. 84. Magn. '■{ ; drawn by S. II. Seudder. The middle interno- median branehes are given too sinuous a curve. ■
Fig. 9. Gvritbhittina lialtcata Seudd., p. 110. Magn. if ; drawn by J. II. I51ake. The terminal ])art of the internomeilian vein, as described in the text, is not shown here; the outside mark indic-iting the outer termination of the internoniedian area should be consider.ably nearer the ti]) of the wing.
Fig. 10. GcrubhiUinii bultcata Seudd., p. 112. JIagn. ^ ; drawn by L. Trouvelot. Represents the anal area only.
Fig. 11. Fragment of the wing of a cockroach from Sydney, Cape Breton; p. 128.
Fig. 12. Etohhmina voitista (Lesq.), p. 70. Magn. ? ; drawn by J. II. Blake. The restored outline of the base of the wing very ])robably represents too much as lost.
Fig. 13. Fragment of the centr.al portion of the wing of a cockroach from Cannejton, Penn.; ]>. 128.
Fig. 14. An-himylua-is acadicum Seudd., p. 84. Magn. \ ; drawn by S. II. Seudder.
134
S. II. SCUDDER ON PALAEOZOIC COCKROACHES.
Index of Spkcies.
Antliraooblattina drt'silonsis 92
porrocta "3
Romigii ''^
Ruckerti OC
sopita 89
spectabilis 88
wintcriana 94
Archiuiylacris acadiciini 84
par.-iUclum 85
Blattina l.itinervis 127
Tisibbeini 127
venosa 128
Etoblattiua allinis 62
ana^lvptica G9
antliracopbila 64
carbonaria 73
(liilyma '5
Dobriiii 66
elongata '^"
euglvptica 60
Jlabellata 62
infignis 82
labacbensis 59
leptopblcbica 77
Lesfjucreuxi 67
nianebachensis 79
ni.intidioiiles 72
p.arvula 81
primaeva 58
russoma 7G
Tcnusta '0
Ktoblattinii woissiijonsis . GoiMblattiiia balteata dathrata tuscigera Germari Goinitzi GoUlenbergi intermedia . ^lahri . . Wunsten pi'oduota scabcrata weissiana Hcrmatoblattina lebacbensis wenimetswo Lidiuiinlacris angustuui .
pittstonianum simplex MvlaCris antbracopbilum bretonense . . Heeri .... Mansfieldi . . pennsjlvanieum Necymylacris heros . .
lacoanum Oryctoblattina reticulata Petrablattina gracilis . . sepulta . . Polyzosterites granosus . Progonoblattina Fritschii helvetica
Cj 110
100
lis
107
103
98
101
108
104
106
102
109
117
115
48
50
51
45
41
43
47
44
54
53
122
124
125
129
120
119
The date of presentation of this paper to the Society (May 7, 1879) was accidentally omitted from the title.
ly^-^x
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IV. New axd Interestixg Htdroids from CnESAPEAKE Bat. Bt Samuel F. Clarke, Pu.D.,
PROFESSOR OF NATURAL HISTORY, WILLIAMS COLLEGF, ; DIRECTOR OF THE SDMUER SCHOOL OK ZOOLOOY OF THE JOHNS HOPKINS UNIVERSITY, 1881.
Communicated Jan. 19, 1881.
\V IIILE connected with the Chesapeake Zoological Laboratory in the summer of 1879 I had opportunities for studying some of the Ilydroids of Chesapeake Bay. During the early part of the summer we were stationed at Crisfield, Maryland, and later at Fort Wool, Virginia. Again this summer I have had opportunities for work at Fort Wool and contin- ued the studies begun there m 1879. My time was too limited to permit of more extended work on the hydroids although there was a great supply of new and attractive material. It will be noticed that all of the six forms described are of the gymnoblastic group ; all but one are new species and for one of them a new genus has been established.
The most interesting of the six forms is Stylactis arcje, which has the remarkable habit of dividing its hydranths by a transverse partition, leaving the distal half free, which latter with its two or thi'ee hydrorhizal processes that are developed before the division takes place, floats away free, being carried about by currents ; finally it settles down, becomes attached and by growth and budding gives rise to a new colony. It is another method, in which the hydroids are already so rich, by virtue of which they increase their numbers and their geographical distribution. A second interesting feature of this species is the fact that the gonophores in the female are quite highly developed, having radial and cir- cular canals and may or may not become free.
Calyptospadix is another interesting hydroid, especially in its hydrotheca-like processes of perisarc, which are more like the genuine hj^drothecae of the Calyptoblasts than any thing else known among the Gymnoblastca. The species here described are
Calyptospadix ceridea, gen. et sp. nov.
Eudendriuvi carneum, sp. nov.
Stylactis arge, sp. nov.
Lovenella gracilis, sp. nov.
BougainvilUa rugosa, sp. nov.
Eydractinia echinata Fleming.
136 CLARKE ON HYDROIDS
Caltptospadix gen. nov.^
Trophosome. Ilydrophyton consisting of a branching hydrocaulus rooted by a creeping, tililbrni hydrorhiza. Hydranths fusiform with filiform tentacles ■which are arranged in a single verticil round the base of a conical hypostome. Perisarc developed into large hydrotheca-like processes.
Gonosome. Sporosacs developed on the ultimate ramiili beneath the terminal hy- dranths.
Calyptospadiz cerulea nov. sp. Plate 7, figs. 1 to 9.
Trophosome. n3"drocaulus simple, not much branched, of equal size throughout and attahiing a height of three to four inches ; branches irregularly arranged upon all sides of the stem; those of the proximal third of the hydrocaulus are very short, while those of the remaining portions are the longest in the colony, some of them being half the length of the main stem ; branchlets arranged alternately ; hydranths fusiform with a conical pro- boscis and eight to ten, occasionally twelve, tentacles, the latter arranged in a single verti- cil, pi'otected by cup-shaped processes of the perisarc, roughened exteriorly by circular ridges and which very nearly cover the entire hydranth when it is fully retracted ; perisarc annulated at the bases of the branches and branchlets. Gonosome. Sporosacs developed in clusters of from three to five on the ultimate ramuli just beneath the hydrotheca-like expansions ; a large number of planulae developed in each female sporosac, the spadix unusually large.
Color. The female gonophores, the ova, and the planulae in their earlier stages, bright blue.
Development of gonosome. July and August.
Bathymetrical distribution. Littoral and coralline zones.
Habitat. Spiles of wharf and old shells.
Locality. Fort Wool, Virginia.
It is very interesting to notice the approximation to the calyptoblastic forms indicated in this species, shown by the hydrothecae, which are of fully as much protection to the hydranths as are the sHghtly developed hydi'othecae of many species of Halecium. The reproductive zooids have a perfect chitinous covering, but it is developed around a sporosac and so is not a gonangium according to AUman. This author states that a gonangium is developed about a blastostyle. His definition of the Calyptoblastea is, "A sub-order of Hydroida in which an external protective receptacle (hydrotheca or gonangium) invests either the nutritive or generative buds." According to this, any hydroid having hydro- thecae or gonangia belongs to this suborder, and as this species possesses developments of perisarc, which are so much like hydrothecae that there is only an artificial, no natural, distinction, it foUows that we are dealing with a form that stands very close indeed to the sub-order Calyptoblastea of Allman.
' From za^t/Trrif , covered, and spadix, the hollow process in a sporosac about which the generative elements are developed.
FROM CHESAPEAICE BAY. 137
Eudendriam carneum, nov. sp. I'late 7, figs. 10 to 17.
Trophosome. Hydrocaulus iniich bianchcHl, fascick-d at its base and attaining a heiglit of 75 to 125 mm.; primary branches irregularly arranged on all nides of the hydrocauluH, occasionally some of the branches near the base very large, being little less than the main stem; the -secondary branches or branchlets arranged alternately on the upper side of the branches ; hydranths supported at the summit,s of small ramuli borne on opposing sides of the branchlets and also at the extremities of the branches, branchlets and ramuli ; peri.sarc firm, nearly colorless at the distal end.s, deepening to a dark brown at the base, annulated at the bases of the branches, branchlets and ramuli. Il^ilranths large and usually with about twenty-four tentacles.
Gonosome. Sporosacs in the male, composed of a number of spherical receptacles arranged in a monilii'orm series of from three to five and borne in a crowded verticil. Sporosacs in the female arranged in irregular, elongated groui)s of three to si.\, several of which spring from one side of a branchlet or a ramulus ; the distal end of the ramulus may or may not support a hydranth, each sporosac ornamented by a thickening of the perisarc which leaves only the distal portion thin; this latter part finally breaks away, forming a means of exit for the planula. The different sexes are usually found in different colonies.
Color. Hydranths vermillion, perisarc darkest in oldest parts ; female gonophores red, planidae red, male gonophores red.
Habitat. Attached to spiles of wharves, rocks and shells, in the littoral and coralline zones.
Locality. Fort Wool, Virginia, in the entrance to Hampton Roads.
The rocks forming the piers and also the spiles of the old wharf at Fort "Wool are coated during June, July and August with immense quantities of these showy colonies that form a miniature forest, extending at low tide as far as the eye can reach. The lower parts of the colonies form dense tangled masses all matted together with thick growths of Pero- phora, two or three kinds of sponges, Vesicularia, various forms of Vorticellidae, etc., etc.
The arrangement of the branches and consequently the forms of the colonies vary much according to the surrounding conditions ; if the colony is not restricted the branches diverge from all sides and give a full, well-rounded growth about the main stem ; but they are often so crowded that the branches are twisted and bent round into one plane, looking as though they all sprung from two sides of the stem. I succeeded in raising a number of colonies from the eggs ; the eggs passed into the planula stage, these became free-swim- ming, finally they resorbed their cilia, became attached, and developing a hydranth and hydrorhiza, with a covering of peri.sarc, began the formation of a new colony.
One of the many planulae observed, developed after becoming attached, two hydranths at once ; the two trending away from each other in nearly opposite directions, see Plate 7, fig. 14. So many planulae were developing at the same time that the clear glass dish became dotted all over Avith bright rosy spots where they had attached themselves.
MEMOIRS B03T. SOC. NAT. HIST. VOL. UI. 18
138 CLARKE ON HYDROIDS
Sytlactis £irge, nov. sp. Plate 8, figs. 18 to 20.
Trophosonio. Hydrooaulus uiidevoloped ; hydranths with very much elongated, slender bodies, occurring iu colonics of ten to thirty tentacles, arranged in two verticils below the hypostome, from six to eight in each circlet, those of the lower circlet sometimes shorter than those of the upper one ; hypostome large and rounded at the distal extremity.
Gonosome. Sporosacs developed on the bodies of the hydranths beneath the tentacles ; two are first developed from opposite points on the hydranth and then two others, also opposite one another and on different sides of the hydranth from the first pair, make their appearance ; the gonophores are quite well developed, having a large cavity, and four radial canals connected distally by a peripheral canal; slight processes project from the rim of the bell, which appear to be rudimentary tentacles ; a large number of planulae developed in each female gonophore and these may be liberated while it is attached or after it becomes free ; if the planulae are liberated while the gonophore is attached, the latter never becomes free, but iu many cases the gonophore becomes freed from the hydranth and with its freight of planulae leads a free-swimming life.
Color. The entire colony a delicate opaque white.
Development of gonosome. June and July.
Habitat. On stems of Zostera marinum.
Locality. Crisfield, Maryland, on the Chesapeake Bay.
I became very much interested in this hydroid after seeing under the microscope a gonophore detach itself from the hydranth on which it had developed and swim away free. It accomplished this by a considerable number of very energetic, convidsive con- tractions, which were sufiiciently violent to rupture its peduncle. I had often seen the planulae discharged from the attached gonophores and was much surprised to see in a number of cases, and where the specific identity of the different colonies was undoubted, that the gonophores with their contained planulae became detached.
Another remarkable habit possessed by this species consists in the detachment of the distal portion of a hydranth, which settles down in some new locality and gives rise to a new colony. This takes place in this way : a constriction appears around the body of a hydranth; from a point just above which two or three cylindrical processes are developed which are to serve as a hydrorhiza to the new colony ; the constriction then becomes complete and this short-bodied hydranth is carried by the currents to a consider- able distance, perhaps, before it attaches itself by means of its hydrorhiza, when by growth and budding it soon forms new colonies.
This method of multiplying colonies and of planting them in new and possibly distant places is a new featiu-e in the hydroids. In Schizocladium there is an approach to this same thing, but even in that case the method is distinctly different.
In the possession of gonophores which may or may not become free, we are reminded of the Syncoryne mirah'dls of L. Agassiz, and the facts in this case lend support to the characters claimed for S. mirablUs. I greatly regret that my investigations upon this interesting form were so suddenly terminated. I was obliged to leave the locality where this species is found at a few hours notice, and have never found an opportunity to continue
FROM CHESAPEAKK BAY. 139
my work there. I was anxious to obtain a more detailed knowledge of the Ktructure of the gonophores and to make out if there were any difTerences between the attached and the free forms. To its interest scientificiilly it adds the attraction of beauty, for it is one of the most gracefid and beautiful hydroids I have ever seen.
Lovenella gracilis, nov. sj.. Plato 9, figs. 'J.'i to 39.
Trophosome. Ilydrocaulus very slender, sparingly branched, with one or two annula- tions at the base of each branch and hydrotheca, divided by transverse septa into numer- ous short segments, three between each two hydrothecae ; branches simple and similarly divided as the main stem ; hydrothecae arranged alternately on the stem and branches, hyaline, rather stout, the length not more than twice the breadth, clo.sed at tlie top by a conical operculum usually consisting of eight pieces ; hydranths large and active with a single verticil of ten or twelve tentacles and a large prominent proboscis.
Gonosome. Gonangia developed from the bases of the hydrothecal peduncles, very long and slender, largest at distal end and tapering toward the base, supported on sliort pedicils consisting of one to three annulations; from three to five planoblasts develope<l in each gonangium, aperture terminal.
Planoblasts, twenty-four hours after liberation round and somewhat flattened in outline, microscopic in size ; radial canals four, connected by a circumferential canal at the periphery ; marginal tentacles six, of which two are very large, situated at the peripheral extremities of two opposite chymiferous tubes, the four smaller tentacles disposed one on either side of each of the large ones ; at the points on the margin of the bell where the other two chymiferous tubes join the peripheral canal there are rounded processes which have the appearance of rudimentary tentacles, as yet undeveloped ; lithocysts four in number and located midway between the points where each two adjoining chymiferous tubes connect with the circumferential tube ; the tentacles and the entire surface of the bell are well supplied with nematoc3^sts.
Until we have a more complete knowledge of the Lovenella clausa of Loven and Ilincks, it is a question of doubtful issue as to the relationships and systematic position of this species. The genus Lovenella as characterized by Hincks is distinguished from its allies by the possession of elongated, turbinate hydrothecae, crowned with a distinct conical operculum composed of many convergent segments ; polypites with a large and prominent proboscis. Reproduction unknown. The species L. claiisa has a habit of growth very similar to that of L. gracilis, the opercula of the hydrothecae are usually of eight segments in both species, the tentacles are of about the same number and they both possess the same style of large prominent proboscis. From these various points of similarity 1 con- sider it better to put this new form in this genus rather than to create a new one for it. When the reproduction of L. dausa has been made out we .shall have an opportunity of deciding the true relations of these two forms.
The form of the hydrothecae are similar to those of Leptoscyphus and also those of some species of Campanulina, but from the characters of both gonosome and trophosome, L. gracilis can have no genetic relationships with either of these From a study of the growing
140 CLARKE ON IIYDROIDS
colony it was determined that terminal growth takes place by the development of a lateral bud from a point on the terminal segment just below the annnlated pedicel of the terminal hydranth ; as this process elongates it is divided by four septa into four segments, from the distal one of which a new h3-dranth is formed, so that each hydranth on the main stem has in turn been the terminal zooid of the colony. From the series of figures 29 to 34 on Plate 9 some idea may be obtained of the rate of growth in the hydrocaulus of this species ; figui'c 30 was taken eight hours subsequently to figure 28; figure 31 six hours later ; figure 32 seven hours afterward ; figure 33 after a lapse of four hours and figui'e 34 seventeen hours after figure 31 or forty-two hours later than figvire 33. I also recorded the rate of growth in the hydrorhiza which is indicated in Plate 9 figures 27 and 28 ; the latter figure being made thirty-two hours after the other one. It should be remembered that the colony upon which these observations were made was in somewhat abnormal con- ditions. My specimens were procured from a depth of three to ten fathoms where the temperature was considerably below that of the atmosphere. I was unable to have them in an aquarium with a constant stream running through, and the water being changed but a few times during the day the specimens must have been subjected to a much higher temperature than they are generally accustomed to. It is possible moreover that a more, rather than a less rapid growth may have thus been induced, as it is well known that many hydroid colonies, especially of the Calyptoblastea, will, when stimulated by impure water in aquaria, develop long, slender processes at a very rapid rate. They seem to be endeav- oring to get into a region where better conditions for their welfare exist.
Bougainvillea rugosa, nov sji. Plate 8, figs. 21 to 24.
Trophosome. Hydrocaulus large and compound at the base, tapering to the distal end where it becomes simple, rooted by creeping stolons and attaining a height of three inches ; branches numerous, irregularly arranged, a few that arise from near the proximal end of the main stem nearly equal the latter in length; most of the branches are short and deli- cate, bearing small branchlets which give origin to three or four ultimate ramuli ; hydranths fusiform with a rather small, conical hypostome, protected by an expansion of the perisarc very much roughened by circular ridges, into which the hydranths are partially retractUe ; tentacles short and eight to ten in number.
Gonosome. Planoblasts borne by the hydrocaulus on the ultimate ramuli below the hydranths, having at the time of liberation a deep umbrella, somewhat pyriform ; hypostome short and thick, chymiferous tubes four with circular canals, proboscidial tentacles four, cap- itate, unbranched, marginal tentacles twelve, three of equal size at extremity of each radial canal, where they originate from a common highly colored bulb ; ocelli developed at the bases of those two tentacles of each group which become first and second as one passes roimd the bell from left to right; with increased age they gain in size and the
FKOM CIIESAI'EAKK HAY. Ml
tentacles become elongated but they sliow no indications of developing oiIht tentacles or of producing ocelli at the bases of the thii'd tentacles.
Color. The colonies are light brown.
Bathymetrical distribution. Laniinarian zone.
Development of gonosome. August and September.
Habitat. Growing in large colonies on Aleyonidium.
Locality. Hampton Roads, lower parts of Chesapeake Bay.
The best diagnostic characters of this species are found in the shape of the planobhust and the number of marginal tentacles. All other species of Bougainvillea have primarily but two marginal tentacles in each group. It is very possible of course that the labial tentacles become branched and the marginal tentacles increase in number when they are in a state of nature, but as already remarked they developed no indications of such a change after living in my aquaria for a numi^er of days. The absence of an ocellus from the base of one tentacle of each group is also anomalous.
Hydractinia echinata Fleming. Pl.ite 9, fig. 40.
Some of the outer spiles of the wharf at Fort Wool were completely covered from low- water mark to the bottom with a delicate moss-like growth of a milk-white color, which upon close inspection proved to be colonies of this delicate hydroid. I tried in vain to find any mouths to the blastostyles and finding also that the two circlets of tentacles are of quite diflerent lengths, I concluded that they were specimens of //. echlncdd and not tlm II. poly- clina of Agassiz, although from their habitat and locality one would expect that they might be the latter.
I was imable to find any of the capitate, spiral zooids, but found a great many of the simjile, tentacular forms described by Wright and Ilincks. Among these I noticed one interesting zooid that in its long, slender form was quite like the others, but was provided with an enlarged hollow portion at its distal extremity surmounted by a conical or rounded h}q)ostome and a circlet of tentacles. I was unable to detect any mouth in the hypostome though I spent a number of hours in the attempt. The tentacles were not fully developed ; some of them, five of the nine, being only rudimentary while the other four were a little more than twice the length of the short hypostome and of equal size.
It is worthy of notice that this form is intermediate between the ordinary tentacular zooid and the normal feeding polypite, and thus offers an explanation of the origin of the tentacular members of the colony.
From the fact that these forms have been noticed by Wright, Hincks and myself, and from their existing in such considerable numbers in the colonies found at Fort Wool, I am led to believe that the tentacular zooids are regular, normal members of the colony and not abnormal forms as suggested by Allman.
A peculiar, evidently abnormal form of the feeding polypite I also noticed ; the body was in a greatly swollen condition and remained as represented in figure 40 during the three days that it was under observation.
* A Monograph of the Gjinaoblastic Ilydroids. By J. Allman, F.R.S., etc. Vol. ii, p. 346.
142 CLARKE ON IITDROIDS.
Explanation of Plates.
plate til
•
1. Cali/pto.t^^adix c«.Tuka, x25, poition of a branch.
2. The same, X-5, portion of the main stem. 8, 4. The same, X'lb, portions of branches.
6. The same, X-5, mak' sporosacs ; a, spadix.
6. The same, X*25, female sporosacs.
7. The same, X80, a female sporosae, a, the large spadix.
8. The same, X80, a female sporosac, side view, a, 8])adix.
9. The same, x80, a female sporosac, «, spadix ; b, developing ova.
10. Eudmidrium carneum, x'-5> portions of branches, a, a young hydranth.
11. The same, X'25, a large terminal hydrsmth.
12. The same, X80, female sporosacs.
13. The same, X25, fem.alo sporosacs.
14. The same, X25, an abnormal twin planula or two hydranths developing simultaneously from one planula.
15. The same, X80, a normal planula.
16. The same, X25, a normal planula.
17. The same, X25, a branch with male sporosacs.
PLATE VIII.
18. Sti/Iactis arge, x25, an adult hydranth; a, constriction in stem; b, b, hydrorhizal growths by which the hydranth will attach itself aflor becoming free.
19. The same, x25, a hydranth with female medusoids.
20. The same, XJ, a colony.
21. BougainviUea rugosa, x25, a portion of a branch with hydranths and sporosacs.
22. The same, x25, portion of main stem with hydranths and sporosacs.
23. The gonoclicme of the same, x80.
24. The same individual gonocheme two days later, x80 ; showing the great increase of the tentacles in lentnh but no addition to their number. The oval, granular mass that has become separated from the manu- brium I do not understand ; it may be abnormal.
PLATE IX.
25. LoveneJla gracilis, X25, portion of main stem and hydrorhiza.
26. Tlie same, x25, a hydranth expanded.
27. The same, X 25, the hydi-orhiza.
28. The same, X25, the hydrorhiza thirty-two hours later.
29. The same, x25, terminal portion of stem with lateral bud, the latter to form the next intemode of the stem.
30. The same portion, X25, eight hours later.
31. The same portion, X25, six hours later. j
32. The same portion, X25, seven hours later.
33. The same portion, X25, four hours later.
34. The same portion, X25, seventeen hours later.
35. The same, X25, female gonangium with developing blastochemes.
36. The same, X25, gonangium.
37. The same, X 25, gonangium.
38. The same, x25, gonangium and hydrotheca.
39. The same, X80, blastocheme; a, hthocysts, h, marginal tentacles, c, sporosacs, d, manubrium.
40. Hgdractinia echinata, a, feeding zooids, b, reproductive zooids, c, tentacular zooids, d, chitinous spines, e, an abnormal form of feeding zooid,y, an abnormal tentacular zooid.
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CLARKE ON HTDROIDS.
Explanation of Plates.
plate vii.
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1. Cali/ptogjyadix cerulea, X25, portion of a branch.
2. The same, X~5, jjortion of the main stem.
3. 4. The same, X'25, portions of branches.
5. The same, X25, male sporosacs ; a, spadix.
6. The same, X25, female sporosacs.
7. The same, X80, a fera.ale sporos.ac, a, the large spadix.
8. The same, X80, a female sporosac, side view, a, s])adix.
9. The same, x80, a female sporosac, a, spadix ; f>, developing ova.
10. Eudendrium cariieum, x25, portions of branches, a, a young hydranth.
11. The same, X25, a large terminal hydranth.
12. The same, X80, female sporosacs.
13. The same, X25, female sporosacs.
14. The same, X25, an abnormal twin planula or two hydranths developing simultaneously frc planula.
15. The same, X80, a normal planula.
16. The same, X25, a normal planula.
17. The same, X25, a branch with male sporosacs.
PLATE VIII.
18. Stylactis arge, x25, an adult hydranth ; a, constriction in stem ; b, h, hydrorhizal growths bj rhich the hydranth will attach itself after becoming free.
19. The same, x25, a hydranth with female medusoids.
20. The same, XJ, a colony.
21. Sougainvillea rugosa, X25, a portion of a branch with hydranths and sporosacs.
22. The same, x25, portion of main stem with hydranths and sporosacs.
23. The gonocheme of the same, x80.
24. The same individual gonocheme two days later, x80; showing the great increase of the tent pes m length but no addition to their number. The oval, granular mass that has become separated from th panu- brium I do not imderstand ; it may be abnormal.
PLATE IX.
25. Lovenella gracilis, X25, portion of main stem and hydrorhiza.
26. The same, x25, a hydranth expanded.
27. The same, X 25, the hydrorhiza.
28. The same, X25, the hydrorhiza thirty-two hours later.
29. The same, x25, termmal portion of stem with lateral bud, the latter to form the next inte the stem.
30. The same portion, X25, eight hours later.
31. The same portion, X25, six hours later.
32. The same portion, X25, seven hours later.
33. The same portion, X25, four hours later.
34. The same portion, x25, seventeen hours later.
35. The same, X25, female gonangium with developing blastochemes.
36. The same, X25, gonangium.
37. The same, X 25, gonangium.
38. The same, X25, gonangium and hydrotheca.
39. The s.ame, X80, blastochemc; a, lithocysts, b, marginal tentacles, c, sporosacs, d, manubrium
40. Sydractinia echinata, a, feeding zooids, b, reproductive zooids, c, tentacular zooids, d, spines, e, an abnormal form of feeding zooid,/", an abnormal tentacular zooid.
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V. AucniPOLYPODA, A SUBORDINAL TtPE OF SpINED MriUAPODS FROM TlIK CaUJ1(»N- IFEROUS FoKMATION'. By SaMTKL II. ScUUDEK.
KimJ January S, \sh\.
A-LTj the paleozoic inyriapods which have been published, only fifteen nuininal species in all, have been referred to the Diplopoda or Chilognatha as they are variously termed. Among them are species which seem to bear a very close general resemblance to modern Iulidae,and some of them have even been described under the generic name lulus. Others, however, first made known as inyriapods by Messrs. Meek and Worthen in 1868, in the Proceedings of the Philadelphia Academy of Natural Sciences, and in the same year figured in the third volume of the reports of the Illinois Geological Survey, differ strik- ingly from modern types in the presence of rows of very large forked and branching spines upon the surface of the body. These naturalists were aljle also to .sliow the probability that a fossil from the coal measures of England which Mr. Salter had - referred to the crustacean genus Eurypterus belonged in the same group, and more recently Mr. Henry Woodward has pointed out that not only this form, but another, known since the publication of Bro- die's work on the English Fossil Insects in 1845, and which was supposed by Westwood to be the larva of Saturnia, a genus of Lepidoptera, should certainly be referred to this group of spiny myriapods ; and to the list Woodward has also added another species.
Having enjoyed the opportunity, through the kindness of Messrs Carr, Worthen and Pike,^ of examining a considerable number of specimens of these curious fossils — all from the ironstone nodules of Mazon Creek, Illinois — I bring here the results of ray study, which show that these spined myriapods, while allied to the Diplopoda rather than to the Chilopoda, certainly form a veiy distinct t3'pe, which was no doubt the precursor of the Diplopoda ; and it appears very probal^le that even those paleozoic species which have been supposed to resemble closely the modern lulidae were also spined, and may therefore be presmned to have resembled their evidently spined relations in other points of structure in which the latter are distinguished from modern forms. The reasons for this belief will be given further on.
One main distinction between the two groups, Diplopoda and Chilopoda, into which mod- ern Myriapoda have been divided, consists in the relation of the ventral to the dorsal plates of the body segments. In the Chilopoda tliere is a single ventral plate, bear- ing one pair of legs, to every dorsal plate. In the Diplopoda, on the contrary, there are
» a considerable number of specimens, including some new Carr, Pike, Armstrong and Bliss, advantage has been taken species, having been sent me after the first presentation of of the delay in its publication to introduce into the text this paper to the Society, through the kindness of Messrs. descriptions of all such additions. (Jan. 31, 1882).
144
S. IT. SCUDDER ON SPINED MTRIAPODS
two such ventral plates, each bearing a pair of legs, to every dorsal plate (with the excep- tion of a few segments at the extremities of the body). The Diplopoda are universally considered the lower of the two in their organization and it is therefore not surprising to find that no Chilopoda have been found in rocks older than the tertiary series, while myria- pods with two pairs of legs corresponding to each dorsal plate range back through the entire series of rocks to the coal measures.
This being the ease, in any comparison which we may make between the ancient and mod- ern types we may leave the Chilopoda entirely out of account, and confine our attentioB to the points of distinction between the ancient types and the modern Diplopoda. At iirsi we shall confine ourselves, in speaking of the ancient forms, to the large-spined speciefl alone, man}' of which attain a gigantic size. The head and its appendages, wherein ar€ found the greatest divergencies of structure in the different modern forms, are again so
poorly preserved in the carboniferous species that om comparisons must be drawn almost entii'ely from th« structure of the body segments, which are mainly repetition one of another throughout the body.
In modern Diplopoda, each of the segments of thi body is composed in large part, almost entirely, of dorsal plate forming a nearly complete ring, for it| encircles nine-tenths of the body as a general rule^ leaving scanty room for the pair of ventral plates (see Fig. 1). On the side of the body (Fig. 2) it is perfo rated by a minute foramen, the opening of an odorif- erous gland; usually the ring is nearly circular, but occasionally the body is considerably flattened and the sides are sometimes expanded into flattened lam- inae, with a smooth or serrate margin ; a few spe- cies are provided with minute hairs, sometimes perched on little papillae ; and the surface of the body, ordinarily smooth or at best wrinkled, is occasionally beset with roughened tubercles wliich may even form jagged projections. So far as I am aware, no nearer approach to spines occurs on this dorsal plate than the serrate edges of the lateral laminae, the roughened tubercles or the papilla-mounted hairs. In the ancient forms from the coal measures we find a very different condi- tion of things. The body segments may be nearly circular, or they may be laterally compressed, or, as in many modern types, depressed ; but in all, view°of'a^g^ the dorsal plate occupies at most apparently only ment of a car- two-thirds of the circuit of the body, being met
boniferous Ar- _. n a\ rr\\ ■
chipoiypod. by broad ventral plates (see i^igs. 6, 4). Inis
Fig. 1. Cross section of a modem Diplopod. The lines inside the ring mark the separation of the dorsal and ventral plates.
Fig. 2. Side view of a seg- ment of a mod- ern Diplopod.
Fig. 3. Cross section of a car- boni/crons Archipolj-pod. The lines inside the ring mark the sep- aration of the dorsal and ventral plates.
FROM THE CARBONIFEKOU.S FOKMATIoX. 145
dorsal plate is not pcrroratod lor ibramina rcpuj^natoria,' hut as means uf defence it is armed with huge spines upon either side ; one row (for tliey occur on all the segments) lies above, near the middle line of the body ; another lies low down upon the sides near the lower margin of the dorsal plate ; and a third row is sometimes interposed between them.' These spines are similar in all the rows, but ililler in tlic ditTerent species ; in few prob- ably arc they simple i)Ut provided with spinules to a greater or less extent. In the most bristling the spines are forked at the tip, and besides this have a basal conma of stout spinules ; others have such a whorl of spinules in the middle of the spine ; in nearly all the spines are at least half as hmg as the width of the bo<ly, and sometimes they are nearly as long. These .spines are in themselves very remarkable an<l resemble nothing that I •can discover in modern Arthropoda,'' unless it be certain thorny spines seen in the early stages of .some Crustacea, and especiallv of some found on the tail piece of eirrhiped lar- vae figured by Claus, to which Mr. Alexander Agassiz has called my attention. Some of his own unpublished drawings of the young of our common barnacle exhibit still closer resemblances, although even here it is not very marked. These spines are fixed, and one can readily picture the difference in external aspect between one of these creatures a foot or more in leiigtli, bristling all over with a coarse tangle of spines, and the smooth coiling lulus of the present day. (See PI. 10.)
If we pass, however, to the ventral plates we shall find differences of even greater sig- nificance. In the modern Diplopoda, as already remarked, these plates are minute ; they arc similar in size and form; the anterior one forms the anterior edge of the segment, con- tinuous with that of the dorsal plate ; together, however, they arc not so long as the dorsal plate at their side, and tiie latter appears partly to encircle the posterior phite by reaching inward towards the coxae of the legs ; the legs are attached at tlie posterior edge, and those of the opposite sides are so closely crowded together that they often absolutely touch each other (Fig. 1) ; the stigmata, of which there is a pair to each ventral plate, are placed at the outer edge rather toward the front margin ; they are minute, and have their openings lon- gitudinal as regards the animal, i. e., they lie athwart the segment ; the coxae of the legs of the anterior plate are therefore opposite the stigmata of the posterior plate. No other organs are found upon the ventral i^lates ; one might indeed say there was not room for them. The legs themselves are composed of six cylindrical simple joints, subequal in length, the apical armed with a single terminal claw ; the whole leg is short, rarely more than half as long as the diameter of the body.
In the ancient types all is very different. In the first place the ventral plates, which are of equal size, occupy the entire ventral surface, and perhaps may be said to extend partly up the sides of the rounded body, and no part of the dorsal plate passes behind the
' This is what would be expected from the presence of forked spines, microscopic indeed, fringing the last abdorai-
spines; two such me.Tns of defence should not be looked nal segment of the female, and occurring, he says, only in
for in the same animal; offensive glands are present only the sub-family Diaspinae.
in slow-moving, or otherwise defenceless creatures, as in The spines of these myriapods have nothing to do with
Phasmidae among Orthoptera for example. the barbed hairs on the body of the embryonic Strongylo-
*In one species there is onlv one row of spines on either soma as figured by Jlotsclinikoff (Zeitsch. f. wiss. Zoo!., xxiv,
side, situated where the third row occurs in the trebly spined pi. 26, fig. 1 a.). These latter are comparable with the der-
forms. mal appendages of the embryonic larvae of Lepidoptera
' Since this was ^vritten, Mr. J. II. Comstoek has shown See my Butterflies, pp. 28-32, figs. 36, 37. me his capital drawings of Coccidae and pointed out to me
MEMOIRS BOST. SOC. NAT. HIST. VOL. III. 19
146 S. II. SCIDDER ON SPINED MYRIAPODS
the posterior ventral plate ; thej' are together equal in length to any part of the dorsal plate, the rings of whieli the bod\' is composed being equal ; while in modern Diplopoda tlie dorsal portion of the dorsal plate is alwa^ys considerably longer than the ventral por- tion, allowing the creature to coil ventrally without exposing any intersegmental portion of the back devoid of hard armature ; while in these ancient forms, the animal appears to coil dorsally as readily as ventrally ; at least, when not extended straight upon the stones in which they are preserved, they are as frequently found bent upward as downward — or perhaps more frequently ; and there is nothing certainly in their structure to prevent it. Indeed in one species, E. Jlabellata, the ventral plates seem to be divided on either side in the middle, apparently allowing of even greater flexibility, which the arrangement of the posterior dorsal plates for a terminal flap, apparently for aquatic propulsion, would per- haps require in an unusual degree. Then the legs, instead of being inserted at the extreme posterior edge of the plate, originate from almost its very centre, and are indeed so large that they nearly occupy the whole of it, a thin lamina only being left at the pos- terior edge of the coxal cavities, though a wider space remains in front ; neither are they inserted close together, but are removed from one another by a space equal to their own width, 80 that they have ample play (Fig. 3). The legs themselves (see PL 11, fig. 11) differ from those of modern types in having the second joint as long as the others combined, and the whole leg as long as the diameter of the body, sometimes nearly twice as long ; moreover they are not cylindrical but compressed and slightly expanded, strengthened also on the flattened surface by longitudinal ridges, and have in every respect the aspect of swwiming legs in those specimens in which the appearance of the legs is most clear. No modern aquatic myriapods are known. The spiracles, instead of being minute and hav- ing the position seen in modern Diplopoda, are very large, situated in the middle of each ventral plate (Fig. 4), each spiracle opposite to and indeed touching the outside of the coxal cavity of the plate to which it belongs, and running therefore with and not athwart the plate, i. e. across the body ; its length equals the diameter of the large coxal cavities.
But in addition to these structures, which make up the sum of the furniture of the ventral plates in modern Diplopoda, we find in these ancient types some further interest- ing organs, which are so perfectly preserved that no doubt can be entertained concerning their presence and their adherence to the ventral plates. The coxal cavities are not cir- cular but oval and are situated with the major axis in an oblique line, running from near the middle line of the body forward and outward ; this, and the slight posterior insertion of the legs leave even a wider space between them on the anterior edge of the plates than posteriorly, and this place is occupied by a pair of peculiar organs (see Fig. 3 and PI. 11, figs. 1-4), situated one on either side of the median line at the very front edge of the ven- tral plate ; to these it seems to be impossible to assign any other function than that of sup- ports for branchiae ; they consist of little triangular cups or craters projecting from the under surface, through which 1 believe the branchial appendages protruded ; so far as I am aware, no other organs than branchiae have been found in any Arthropoda situated within the legs, and repeated on segment after segment ; a single exception may perhaps be made of Peripatus, in which Balfour has found segmental organs having their external openings somewhat similarly situated ; but this being the only known instance of their
FKOM THE CAHBONIFEHOL'S FolCMATloN 147
presence in arthropocls ' ; l)ranrliiae also occurrinj^ in not a few inst4iiii .- m .uvr tlie niedio- ventral line of the body than the legs, and bnux'hiae and spiraoles coexisting even in the trne insects, and then in somewhat similar relative positions (thongh the branchiae in these instances have never been found next the medioventral line); and the presence furtlier of swimming legs leading us to presume in these creatures an aifuatic or amphilii- ous mode of life : 1 believe we may fairly conceive these cup-shaped organs to be Ijrun- chial supports, and that we are dealing here with a type of myriapod-< very dilTerent from any existing forms, — suited to an amphibious life, capable of moving and of breathing both on land and in water. Moreover tiie assemblage ol" forms discuvereil in these Ma/(jn ('n-ek beds lends force to this proposition ; for the prevalence of aijuatic Crustacea, of fishes and. ferns indicates, what the presence of marsh-frequenting Hying insects does not contradict, that the fauna and flora was that of a region abounding in low and boggy land an«l pools.
These however are not the only points in which the ancient forms difl'ered from the recent. The modern forms are of uniform size throughout, while the ancient, at leiust when seen from above, tapered noticeably toward either end and especially' toward the tail, the largest part of the body being in the neigidjorhood of the seventh t^) the ti-nth body segmeiit.s, which were often two or even three times broa<ler than the hinder extremity, and considerably broader than the head or the first segment behind it. A single segment seems to have carried all the appendages related to the mouth parts, while in modern types two segments are required for this purpose. This is inferred solely but sulficiently from the tact, even more remarkable, that every segment of the body (as represented by the dor.sal plates), even tho.se immediately following the head, is furnished with two ventral plates and bears two pairs of legs. As is well known, the segments immediately following the head-segnients in modern Diplopoda have each only one ventral plate and bear only a single pair of legs, — a fact correllated with the embry- onic growth of these creatures, since these legs and these only are developed at about the time of hatching. The mature forms of recent Diplopoda therefore here resemble their own young more than do these carboniferous mvriapods, a fact which is certainly at vari- ance with the general accord between ancient types and the embryonic condition of their modern representatives, and one for which 1 can offer no explanatory suggestion worth' consideration.
These remarkable points, in which the structure of the carboniferous myriapods are found to be distinguished from modern Diplopoda, none of which (witii the single exception of the lea.^t important, structurally considered, viz. the spined appendages) have before been pointed out, seem to warrant our placing them in a group apart from either of the modern suborders of myriapods, and of a taxonomic value equivalent to them. For this group, the name Archipolypoda is proposed.
Unfortunately the preservation of the appendages of the head in these ancient types has not proved sufficiently good to allow much comparison between them and modern types. This is the more to be regretted since these parts are those on Avhich we depend largely for our judgment of the relationship of the Myriapoda to other Insecta and to Crustacea. If they were present and clearly defined we may well suppose that they would afford some clew to the genetic connection of these great groups.
' Attention should be drawn in tliis place to Ryder's recent ially of its trache.il system (.Vmer. Nat., xiv, 375), the exter- observations on the anatomy of Scolopendrella, and espec- nal openings of which are "inside the bases of the legs."
148 ^i- n. SCrDDER ox SPIKED MYRIAPODS
Tlioro aro certain features, however, common to most, at least, of these ancient types, which should be mentioned ; these are the great breadth and depth of the head, which is the more remarkable from the tapering of the anterior extremity. In one or two speci- mens also the antennae have been more or less completely preserved (see PL 13, figs. 7, 13, IS), and appear to differ little from their modern representatives unless it be in their greater slenderness and brevity, possibly resembling more the embryonic condition of modern types. What appear to be eyes are also preserved in one or two instances (PL 11, fig. 10, and PL 13. fig. 18), and also present no contrasts worthy of special mention.
Besides these, careful examination has shown in specimens of not less than four species of two genera, the presence of a long and straight unjointed appendage, or pair of appen- dages, upon the under surface of one of the early segments of the body (the fourth, fifth or sixth), which varies in length from one-half the width of the body to more than its width. It is always entirely different from the spines and clearly not one of the ordinary legs. No other external organ is known in this part of the body in modern Myriapoda, excepting the pair of intromittent organs, which are morphologically legs, supplanting them on the sixth segment, and it seems, therefore, highly probable that we have in these ancient types a movable organ of the same nature, but of an exceedingly simple char- acter. Full description of each instance is given in the text.
The results reached by a study of these s^^ined myriapods of the Mazon Creek nodules lead naturally to the enquiry what their relations were to other paleozoic myriapods. In some of these previously studied ^ I have pointed out what I then believed to be for- amina repugnatoria. These are described in Xylobius sigillariae Daws., where one spec- imen is said to have " a .slight circular depression in the centre of one of the frustra . . about half way up the sides of the segment ; it resembles and is found in the place of the lateral pores." Also in X.frachis Scudd., where " a slight depression, probably a lateral pore, may be seen in the centre of one of the middle frustra of each segment" (only two segments were preserved in this specimen). And also in Archiulus xylohioides Scudd., where they occur " from the seventh segment ... at least to the seventeenth . . . and are placed in the middle of the sides of the segments ; they are oblong oval in shape, with their longer diameters vertical ; the mean of their diameters averaged 0.2 mm." in specimens the diameter of whose body is about 4 mm. In a subsequent page of the memoir, mention is made of the " large size " of the lateral pores.
In lulus Brassi described by Dohrn ^ he says he was unable to find any foramina, but states that Kner thought he had recognized stigmata on some segments above the legs ; " er glaubt an einigen Ringen oberhalb der Beine den Abdruck von Stigmen zu erkennen ; gewisse Punkte," adds Dohrn, "an diesen Stellen kann man gewiss dafiir ansehen, wenn schon ihre wirkliche Natur nicht zweifellos festzustellen ist".
Woodward in his description^ of the British Xylohius sigillariae {X.Woodwardi Scudd.) says: " each segment of the body, wherever sufficiently well preserved to show it, bears upon its lateral portion a slightly raised whart, indicating the position of the pores, stomata or tracheal openings." These are figured in his plate, in fig. 11a, as nearly one-eighth the diameter of the body.
' The Carboniferous Myriapods preserved in the sigillarian ^ Verh. naturli. Ver. Rheiiil., [3], v, 535-53C, taf. 6.
stamps of Nova Scotia. Mem. Bost. Soc. Nat. Hist., Vol. ii> 3 Trans. Geol. Soc. Glasgow, ii, 236, pi. 3 (1867).
pt. 2, No. 3 (1873).
FROM TIIK ( "AlilJoMI'KROirs FORMATION. 149
The great size of these lateral marks struck ine, at the time my jjuper was written, as inconsistent with their reference to the foramina rcpugnatoria, but there (li<l not then seem to be anything else to which they could be compared. A re-examination of a few specimens of. the sigilhirian myriapods in my possession, coupled with the statements of Woodward and Dulirn, load me now to the conclusion that these marks are the scars or bases of spines, which appear as warts or tubercles in man}- of the Mazon Creek myria- pods, or, in casts or views of the interior surface, as pits of greater or le«.s dimensions. Their position would entirely accord with this. Add to this the fact that all of these lulid-like carboniferous myriapods had a decidedly fusiform body (some more than others) tapering somewhat toward the head and a great deal toward the tail ; and that the legs where preserved are of unusual length — Ijoth of these features peculiar to the spined myriapods of the Mazon Creek nodules : and I think we may fairly consider it probable that they too possessed some at least of the other features characteristic of the latter, and should be hypothetically classed, until proof to the contrary is found, among the Archipo- lypoda.
In this paper however no further attention will be paid to these smaller lulidiform types, Avhich were not improbaldy wholly terrestrial in habit, and may very likely have formed a distinct family of Archipolypoda, to which I have already applied the term Archiididae, and which, in addition to the characteristics mentioned in the paper upon them, were not improbably distinguished from the Mazon Creek myriapods, to which the family name of Euphoberidae may be given, in the absence of branchiae.
It only remains, before proceeding to the discussion of different forms of Euphoberidae, to point out that we have in these Archipolypoda still another proof of the close alliance of the fauna of Europe and America in paleozoic times. The genera Xylobius, Acanther- pestes and Euphoberia, including ten of the twelve species of myriapods found in American carboniferous rocks are all represented in the coal measures of England. I shall be able in future papers, from material already in my hands, to point out among other insects addi- tional evidence of great interest in this direction, and shall hope at no distant day to offer lists of the cai'boniferous insect faunas of Europe and America in pai'allel columns, so as to bring clearly to the 63-6 this prominent feature of early insect life.
The number of forms of Archipolypoda represented in the carboniferous rocks has proved unexpectedly great. By the kindness of several friends, mostly residents of Morris, from whence the ironstone nodules, in which most of them were foimd, come, I have been able to study twenty-six specimens, which with tlip eight jireviously known belong to twelve distinct species and four tlifferent genera. Tlie genera are distinguished in part by the form of the segpients, and in part by their armatui-e ; Acantherpestes having three rows, Euphoberia two rows, and Amynilyspes one row of spines on either side of the body, while in Eileticus, spines are absent and their place supplied by a series of warts. Euphoberia is far the most abundant in species, Acantherpestes having only two, and Amynilyspes and Eileticus one each.
I I f I }
J^J9J$A
.lA
148
S. II. SOrDDER ON SPINED MYRIAPODS
Thoro arc certain foaturos. liowovor. oonmion to most, at least, of these ancient t3-pes, wliioli should be mentioned ; these ai*e the great breadth and depth of the head, -svliich is the more remarkable from the tapering of the anterior extremity. In one or two speci- mens also the antennae have been more or less completely preserved (see PI. 13, figs. 7, 13, 18), and appear to differ little from their modern representatives unless it be in their greater sleuderness and brevity, possibly resembling more the embryonic condition of modern types. What appear to be eyes are also preserved in one or two instances (PL 11, fig. 10, and PI. 13, fig. 18), and also present no contrasts worthy of special mention.
Besides these, careful examination has shown in specimens of not less than four species of two genera, the presence of a long and straight uujointed appendage, or pair of appen- dages, upon the under surface of one of the early segments of the body (the fourth, fifth or sixth), which varies in length from one-half the width of the body to more than its width. It is alwaj-s entirely different from the spines and clearly not one of the ordinary legs. No other external organ is known in this part of the body in modern Myriapoda, excepting the pair of intromittent organs, which are morphologically legs, supplanting them on the sixth segment, and it seems, therefore, highly probable that we have in these ancient types a movable organ of the same nature, but of an exceedingly simple char- acter. Full description of each instance is given in the text.
The results reached by a study of these spined myriapods of the Mazon Creek nodules lead naturally to the enquiry what their relations were to other paleozoic myriapods. In some of these previouslj- studied ' I have pointed out what I then believed to be for- amina repugnatoria. These are described in Xylobms sigiUariae Daws., where one spec- imen is said to have " a slight circular depression in the centre of one of the frustra . . about half way up the sides of the segment ; it resembles and is found in the place of the lateral pores." Also in X.frach(S Scudd., where " a slight depression, probably a lateral pore, may be seen in the centre of one of the middle frustra of each segment " (onlj- two segments were preserved in this specimen). And also in A)-chiulus xylohioides Scudd., where ihey occur " from the seventh segment ... at least to the seventeenth . . and are placed in the middle of the sides of the segments ; they are oblong oval in shape, with their longer diameters vertical ; the mean of their diameters averaged 0.2 mm." in specimens the diameter of whose body is about 4 mm. In a subsequent page of the memoir, mention is made of the " large size " of the lateral pores.
In Iidiis Brassi described by Dohrn ^ he says he was unable to find any foramina, but states that Kner thought he had recognized stigmata on some segments above the legs ; " er glaubt an einigen Ringen oberhalb der Beine den Abdruck von Stigmen zu erkennen ; gewisse Punkte," adds Dohrn, " an diesen Stellen kann man gewiss dafur ansehen, wenn schon ihre wirkliche Natur nicht zweifellos festzustellen ist".
Woodward in his description^ of the British Xylohms sigiUariae {X. Woodwardi Scudd.) says : " each segment of the body, wherever sufficiently well preserved to show it, bears upon its lateral portion a slightly raised whart, indicating the position of the pores, stomata or tracheal openings." These are figured in his plate, in fig. 11a, as nearly one-eighth the diameter of the body.
' The Carboniferous Myriapods preserved in the sigillarian stumps of Xova Scotia. Mem. Bost. Soc. Nat. Hist., Vol. ii> pt. 2, No. 3 (1873).
2 Verh. naturh. Ver. Rheinl., [3], v, 535-536, tat. 6. s Trans. Geol. Soc. Glasgow, ii, 236, pi. 3 (1867).
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The groat size of tliese luteral marks struck ine, at the time my impi-r \vaj« \vritl*'ii, tw inconsistent with their reference to the foriimina repugnatoria. but there ilitl not (hen seem to be anything else to which they couKI be compared. A re-examination of a few spocinicns of.tlie sigiUarian myriapods in my jjosscssion, coupleil witli the utatementK of Wooduiinl and Dohrn, lead me now to the conclusion that thesf marks are tlie wars or bases of spines, which appear as warts or tubercles in many of tiie Mazon Creek mvria- pods, or, in casts or views of the interior surliice, as pits of greater or less «limension«. Their position would entirely accord with tiiis. Add to this the fart that all of thcuo lulid-like carboniferous myriapods had a decidedly fusiform body (sonje m«)re than othon*) tapering somewhat toward the head and a great deal toward the tail ; an<l that the legs where preserved are of unusual length — both of these features pecidiar to the spiiiccj myriapods of the Mazon Creek nodules: and I think we may fairly consider it probable that they too possessed some at least of the other features characteristic of the latter, and should be hypothctically classed, until proof to the contrary is found, among the Archipo- lypoda.
In this paper however no further attention will be paid to these smaller lulidiform types, which were not improbably wholly terrestrial in habit, and may very likely have formed a distinct family of Arcliipolypoda, to which 1 have already' ap|)lied the t<'rm Arcliiulidae, and which, in a<ldition to the characteristics mentioned in the paper upon them, were not improbably distinguished from the Mazon Creek myriapods, to wliicli the family name of Euphoberidae may be given, in the absence of branchiae.
It only remains, before proceeding to the discussion of different forms of Euphoberidae, to point out that we have in these Archipolyjioda still another proof of the close alliance of the fauna of Europe and America in paleozoic times. Tlie genera X}lol)ius, Acanther- pestes and Euphoberia, including ten of the twelve species of myriapods found in American carboniferous rocks are all represented iu the coal measures of England. I shall be able in future papers, from material already in my hands, to point out among other insects addi- tional evidence of great interest in this direction, and shall hope at no distant day to offer lists of the carboniferous insect faunas of Europe and America in parallel columns, so as to bring clearly to the eye this i>romincnt feature of early insect life.
The number of forms of Arcliipolypoda represented in the carboniferous rocks haw proved unexpectedly great. By the kindness of several friends, mostly residents of Morris, from whence the ironstone nodules, in which most of them were found, come, I have been able to study twenty-six specimens, which with tlip eight previously known belong to twelve distinct species and four tlifferent genera. The genera are distinguished in part b}' the form of the segjnents, and in part by their armature ; Acanthcrpestes having three rows, Euplu)l)eria two rows, and Amynilyspes one row of spines on either side of the body, while in Eileticus, spines are absent and their place supplied by a series of warts. Euphoberia is far the most abundant in species, Acanthcrpestes having only two, and Amynilyspes and Eileticus one each.
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150 S. II. SCUDDER ON SPINED MYRIAPODS
OiniER M Y R I A P 0 D A .
Suborder ARCHIPOLYPODA.
Paleozoic nivriapods, with a fusiform body, largest near the middle of the anterior half or third, the head appendages borne upon a single segment ; each segment behind the head composed of a single dorsal and two ventral plates, the dorsal of nearly luiiform length superiorly and inferiorly, occupying most of the sides as well as the top of the body ; desti- tute of foramina repugnatoria, and divided into a ridged anterior and flat posterior portion, the anterior provided with longitudinal rows of spines or tubercles ; the ventral plates occu- pying the entire ventral portion, each bearing a pair of long jointed legs, and furnished outside of them with large spiracles, the mouth transversely disposed.
Family Euimioberidae.
Archipolypoda armed with very large forked or branching spines, occasionally reduced to tubercles, running in several uniform rows along the back or sides of the body, and attached to the dor.sal plates ; the legs compressed, the second joint much longer than any of the others and the whole adapted to swimming ; those of opposite sides well separated at base, and having between their insertions a pair of branchial appendages.
Genus AcA?rrnERPESTES (axa^Oa, ?pxu).)
Acantherpestes Meek and Worthen, Geol. Surv. 111., Ill, p. 559 (hypothetical).
Spines bifurcate at tip and arrayed in subdorsal, pleurodorsal and lateral rows. Segments three or more than three times as broad as long.
The name Acantherpestes was suggested for one of the species which falls within this group by Messrs. Meek and Worthen, in case it did not agree with the genus Euphoberia (to which the species itself was referred with question marks) in having two ventral plates corresponding to each dorsal plate. This it does possess, as indeed the very figure they pre- sent .shows, two pairs of legs being pictured as corresponding to each dorsal plate. Not- withstanding this, and notwithstanding the impropriety of suggesting hypothetical or con- ditional names for animals whose affinities are not clearly understood, the name is a good one, and rather than burden our heavily taxed science w ith synonymy, it is brought into requisition.
Acantherpestes major.
PI. 10, 11, figs. 1^, 6-8, 10, 11.
Euphoberia ?? major Meek and Worthen. Amer. Journ. Sc. Arts, [2], XLVI, 25-27 ;
—lb., Geol. Surv. 111., Ill, 558-559, fig. (1868).
The figure was reproduced by Woodward in the Geol. Mag., X, p. 105 (1873), and also in his Monograph of the Merostumata, p. 172, fig. 62 (1872).
The specimens upon which this species was founded were very fragmentary, the one fig- ured consisting of only seven segments with a part of one spine, the spine-bases and sev- eral imperfect legs. Two other specimens have been placed in my hand by Mr. J. C. Carr,
FROM THE CAUliONIlKKOUS FOHMATIkN
161
AcanltiojjiMtc* tiuijur.
one of which is very perfect and of enormoiis «i/.(.\ and whioli was firnt nhown me hv I'rof. J. W. Pike ; the other though only fraguienUiry is the mure intc-reHlinj,' hecuune it exiiihitjj tlie ventral plates more clearly than any other specimen uf Arcliipoly|><>dii yi-t diH<oviTL'd. A third specimen with it,s reverse, reprcsenlinj,' a younger individual, luw mure recently been placed in my hands hy Mr. Pike.
In the specimen figured in the Illinois Keport, and which hy the kinilne.H.s of Proft-Nhor Worthen we are able to reproduce here, we have a lateral view, apparently of the ante- rior part of the cylindrical body a little curved downward, in which the scan* of the lower Bpines and the mammiform bases of the other series are present, besides one or two of those of the uppermost row upon the furtiier side of the body. The width of the body shows how huge tlic creature must have been. Judging by compar- ison with the most complete one I have seen, it must have been three decimeters or just about one loot long ; " it probably attained a length of 12 to ]•") inches" say the describers. The seg- ments, which are about three times as broad as long, are divided transversely into two parts, the arched anterior portion a little longer than the flat posterior part and bearing the spincH. The surface is apparently smooth. The spines are altogether wanting beyond their bases with the exception of a single fraginent in the uppermost row ; and this is evidently one of the basal spinules and not the spine itself, being comparatively small, simple and conical. The bosses and scars, however, show that there was a subdorsal row of spines tolerably near the mediodorsal line, another at the lower portion of the dorsal plate and a third pleuro- dorsal row considerably nearer the former than the latter. The legs are mostly broken off near their bases, but two or three are longer, and one is represented in the figure (not men- tioned in the text) as complete, being regularly' conical, shorter than the body, and divided into five nearly equal joints ; I cannot doubt tliat this and the apparent joints of the other legs are either given quite inaccurately or that at all events the marks do not represent the joints of the legs. The length of the fragment is 62 mm. and its width 21 mm.
The most complete specimen seen (PI. 11, figs. 6-8, 11), exhibits a .side view of apparently the entire creature, the greater part of the body in a straight line, but the anterior part curved a little upward ; along the entire upper line the spines of the subdorsal scries may be seen, many of them very perfect ; the position of the other rows may be traced by the pitH in the body itself, while legs, many of them almost perfect, may be traced along nearly the entire lower margin. The body is cylindrical or nearly cylindrical in form, pcrhap.s a little higher than broad, tapering forward from the seventh or eighth segment so as to be from one fifth to one fourth smaller ; and backward from the twelfth or thirteenth seg- ment very uniformly and gradually, so as to be at tip only about one half the greatest breadth. The whole length of the body is 207 mm., its greatest breadth 16 mm. There can hardly be any doubt that the whole animal is preserved. The rapidly tapering form of the extreme hinder extremity with the change in the characteristics of the spines make it certain that the body ended here ; at the front extremity the first segment has every
152 '*'• "• SCUDDER ON SPINED MYRIAPODS
appearance of being (he termination of the body, and an appendage, presumably an antenna or a part of one. is attached at the upper margin of the front ; it would also l)e in keeping with the general form of these aninuUs as shown by the study of all the species if this anterior segment were the head.
This head segment is only about half the size of one of the nearer body segments, round- ed, higher than long, the front rather flattened, and bearing in front, aboye, a straight antenna composed apparently of three joints, the basal joint equal, small, cylindrical, slen- der, longer than broad, the apical oblong ovate, twice as broad as the others and four or five times longer than broad ; the whole antenna is 6 mm. long, of which two thirds belongs to the apical joint, whose greatest diameter is 0.9 mm. From the lower outer angle of the head prpjects a bundle of spines (?), which afterwards diverge into three nearly straight rods ; they evidently do not belong where they are, but their structure and surface appear- ance give them the aspect of spines and not of legs ; the triangular offshoot from them appears to have no connection with them, but to be an accidental mark in the stone.
The segments of the body behind the head are forty in number, and of a similar size ; where the body is broadest the length of the segment is 5.5 mm., and this proportion of length to breadth holds tolerably well throughout, the segments being about three times as broad as long. They appear to be strongly arched and more equally than would appear to be the case in the next specimen to be described, although some segments seem to present an anterior, broad, rounded side where the spines are seated ; certainly the segments are deeply and coarsely incised. A large part of the body and of the spines (PI. 11, fig. 8) are covered with circular flattened raised disks of a yellowish color (PI. 11, fig. 7), with a slightly raised rim and either a depression or a slight elevation at the centre, crowded closely together and appearing as if formed of the dried up contents of the body ; the outside of the spines seem to show them quite as much as the inside of the same ; indeed the out^^ide of the spines appears to be entirely made up of them. They are usually about 0.5 mm. in diameter, but a considerable number are smaller and show no structure ; the head, antenna and the trifid appendage of the head are all furnished abundantly with them, but they are entirely absent from the legs.
The only spines that are preserved belong, apparently all of them, to the subdorsal row, but the openings into the hollow interiors of those which are necessarily concealed mdicate clearly that there are three rows upon either side, arranged exactly as described in the specimen figured by Messrs. Meek and Worthen. The spines of the subdorsal rows (PI. 11, fig. 8) are cylindrical, equal, hollow throughout, rather longer than the diameter of the body, rather deeply and equally forked at tip, so as to appear Y-shaped, the branches not very divergent; at the base, (in the anterior part of the body), or near the same (in the pos- terior part of the body), is at least a pair, but more probably a whorl, of subsidiary spines springing from the main stem ; anterior and posterior spinules are preserved at the base of nearly all the spines, but there are also indications of others which lie interiorly and exte- riorly, and which necessarily cannot be very clearly exhibited in a fossil like this ; such an indication appears at the base of PI. 11, fig. 8, representing the spine enlarged, where a rounded hollow seems to prove a spinule in addition to those in front and behind, as clearly as the other pits in the body walls indicate the position of the principal spines ; they appear i to originate at the very base of the spine throughout the body and to be less divergent
FROM TIIK ( AKI50NIFEKOUS FUUMATloN, I53
than the other spimile.s ; of the front ami hind spinules, the posterior is gononiUy lonj^iT uuil slenderer than the anterior, and situated higher upon the stalk ; the double set of hok-M next the base of the legs in several segments of the Ixjdy indicaU-s that this wjls the ciijmj also with the lateral spines ; these spinules are longer on the p;^>sterior part of tiie body than on the anterior, and have about the same angle from the main stem jls the terininiil forks fiom each other. The spines occur, one to a segment in each row, on every Keginent behind the head ; on the penultimate and antepenultimate the main Hpiue Heems to end where the spinules spring out, and the latter are of unusual length ; on the hist segment the same arrangement occurs, though the spinules are very short. The main spines are of uniform size throughout most of their e.\tent, but enlarge slightly above where thev fork, and l>elow where the spinules diverge ; the spinules are generally Uipering an<l pointed, but in the front part of the body tlie anterior and posterior ones are stout, ollen nciircely taper, and are bluntly tipped. The length of the spines is from rj-i;5 mm., and they are 1.0 mm. in diameter in the middle.
The legs • (PI. 11, fig. 11) are better preserved than in any other of the Archipolvpodii examined ; the creature is crushed in such a way that one sees in a groove, running beneath the dorsal plates for the greater part of the body, the interior surface of the biusal joints of the lower lying legs (the remaining portions of which are buried in the matrix), and just below these upon the plane of the dorsal plates, the exterior surface as well as all the rest of the legs of the upper lying or nearer pair.s. They consist of six joints. The first is about twice a.s long as broad on a side view, narrowing a little at either end ; it is about as broad as possible, the series occupying almost the entire space below the segment.-* .so aH to crowd against each other ; it is apparently a little compressed, the outer surface furnished with a distinct longitudinal carina at both anterior and posterior edge and furnished also with a very prominent and stout median longitudinal carina, which is generally a little curved ; corresponding to which on the inner face is a rather deep and very abrupt sulca- tion. The second joint is very different ; it is laminate, nearly equal, considerably nar- rower than the basal joint, very long, being more than six times as long as broad ; it has a distinct median carina, at least on the outer side, or perhaps the slightly convex sides are pinched or angulate along the middle; in. some instances the one, in others the other appears to be the case, even on adjoining legs. The third joint exactly resembles the sec- ond, except in being .shorter ; it has about the same width, and the .same median carina, but it is only about half as long again as broad, equal, quadrate and laminate. The fourth joint is of the same length as the third, but slenderer, a little tapering and with only slight trace of the median carina. The fifth is as long as the fourth, continues the gentle tapering of the leg so as to be nearly half as broad as the second joint, and has no carina. There ia pretty certainly another still slenderer and apparently cylindrical joint of about equal length beyond this, but it is only preserved in one or two instances and in part. Nothing positive can be a.sserted of the claw, but one leg appears to have a single slender gently curving claw of considerable length. The legs are at finst sight apparently shorter at the two ends of the body than in the middle, but this is due simply to imperfect prcserva-
' Between the tips of two of the legs may be seen a crushed considered by Dr. Dawson (Proc. Bost. .Soc. Nat. Hi»l., moUuscan sliell, having the appearance of a minute Planorbis, XXI, 157) as Spirorbis (Microconchus) carbonarius.
MEMOIRS BOST. SOC. NAT. HIST. VOL III. 20
154 S. II. SCUDDEE ON SPINED IMYRTAPODS
tion. nioasuromont^ of the second joint showing no difference whatever. The length of the first joint is 2.4 mm. ; of tlie .•second 7.75 mm.; width of same 1.2 mm. ; length of third joint 2.2 mm.; of fourth joint 2.2 mm.; of fifth joint 2.2 mm.; of sixth joint 2. mm.; of the whole leg as it lies on the stone 21 mm. So far as the legs are preserved there are two pairs to every dorsal plate ; the stone is broken away next the last two segments so that they do not show there, one only appearing on the penulthnate, none on the last segment ; the same is true in front, so that none appear on the first .segment behind the head, and only one on the second segment ; but this one is placed posteriorly, leaving room for an additional one in front of it on the same segment.
Along the ridges which separate the bases of the two sets of legs (of opposite sides) from each other can be seen remnants of the branchial cups to be mentioned further on, but in a fragmentar}'^ and often somewhat disiilaced condition ; enough however to show clearly to one who has studied the specimen next to be described that they were present here throughout the greater part of the l)ody, as they can be traced in various parts.
Both relief and intaglio of tliis specimen are preserved and have helped to reconstruct the mj'riapod as we have attempted to depict it. They belong to Mr. J. C. Carr of Morris, Illinois, from whom, through the kind intervention of Mr. J. W. Pike, in whose hands I first saw it, it was received for study.
Notwithstanding its far greater incompleteness, the next specimen (PI. 11, figs. 1-4) of this species to be mentioned rivals the one ju^t described in interest and importance, on account of its perfect exhibition of the ventral plates. It consists of only a few segments from the stouter part of the body, probably presenting an oblique view, mostly dorsal, with a cast of the same. In the breaking of the stone, the part representing the former under crust of the animal has in a small part of the fossil parted from the upper crust, so that in looking upon the dorsal surface one sees also, in the central part of the fossil, the interior view of the ventral plates ; and its cast represents, no doubt with tolerable faithfulness, the appearance of the under surface of the ventral plates. The body is a little curved and the posterior segments parted from one another. The convexity of the iipper surfiice of the body well appears, but the form of the body cannot further be told from this specimen. The fragment is 67 mm. long as it lies, but this should be reduced to about 58 mm. to allow for the displacement of the posterior .segments. It is 17-18 mm. broad and shows no sign of tapering; probably it is a fiMgment from the broadest part before the tapering had com- menced ; on that supposition its size indicates a creature rather larger than the complete specimen last described, but not so large as that described by Meek and Worthen. Eleven segments arc present, four anterior ones in their natural relations showing the dorsal plates; then three, also connected with one" another anl the preceding, but of which the dorsal plates are gone, revealing the inner surface of three pairs of ventral plates ; and finally four more dorsal plates separated from one another by more than their own length. The dorsal plates are from •3.7-5-4.5 mm. long and therefore about four times as broad as long, their anterior half bearing a broadly rounded, elevated, transverse ridge with mammiform knobs which are the broken bases of the spines ; the posterior edges of the segments are also a little thickened and .slightly elevated, giving the appearance of a slight transverse ridge at this point. The surfiice appears to be almost or quite smooth ; in one or two points a delicate granulation may be seen under a strong lens, and next the hinder edge of
FROM THE CARDONIFEROUS FORMA TION. I55
some of the segments there appears to be a fecbk" wrinklin;^ or fiiint cornijjution of the mir- facc. In {general only the ba.ses of tlie spiiu-s art' prt'st-nt. whii-li ho fur an ciin he ilctcr- miiK'd sliow 11 disposition very similar to what i.s sei-n in the otlu-r spL-cinienM, hut uxhihit more clearly than tlu-y the relation of the subdorsal st-ries to ouih other lu* to iliHtaiiee, showing that they are almost as far removed from eaeh other as tlii-y each are from the pleurodorsal series ; one or two spines also of this latter series remain and by their Mtructure show that they probably did not difTur at all from those of the other series, unless possibly they were slighter and shorter.
The legs do not appear, but on the ventral plates their insertion is plainly visible ( IM. 11, figs. 2-3), showing that the basal joints were probably obliquely appres-ieil, for the e<jxal cavities are obovate ami directed toward the anterior outer edge of the ventral plate next in advance of that on which they are seated ; they are also .seateil a little posteriorly upon the ventral plate, for they reach its posterior edge, but are separated from the anterior bor- der by about one third their own .shorter diameter; those of tiie same ventral plate arc also separated from each other by a space equal to at least their own longer diameter.
In tlie flattened part showing the ventral plates, these extend just as far laterally as the dorsal plates, and the distance from the outer edge, which is preserved upon one side, to their median line is even greater than to the median line of the dorsal plates, showing cerUiinly that they had a wide extent and covered at least the entire under surfiice of the body ; they were of equal size throughout, narrowing only at their extreme lateral extension where they appear to have been rounded. Their length is 2.1^3 mm. Outside the base of each leg and abutting upon it are the large oblong-ovate spiracles (PI. 11, figs. 2-.'3), ruiuiing transversely to the body, and showing as a deep groove with a very thin laminate ridge along the middle ; they are 2.5 mm. long, 0.6 mm. broad. Lying next the front edge of each ventral plate and on either side of the medioventral line of the body, almost altin- gent at their slightly swollen b;ises, are the branchial cups (PI. 11, figs. 2-4), which appear from within as sun'ven pits, rounded triangular in form, two sides of the triangle being formed by the median line of the body and the front edge of the .segment, the latter being the longer; all the angles are well rounded ; the floor of this pit is flat, but depressed around the edges, so that the deepest part forms a groove just at the base of the bounding walls ; the surface of the floor has in some a spongy aspect with an appearance of converg- ing laminae, but this is not clear ; these branchial pits are a third as broad again as long, being 1 mm. in breadth and about 0.75 mm. in length. When viewed from the cast show- ing these organs as they probably appeared upon the outside of the body (PI. 11, fig. 4), they appear as crater-like elevations, the rim of which is suboval rather than triangular, with the posterior inner angle of the boundary wall somewhat higher and thicker than the rest ; the floor presents nearly the same aspect as in the other face.
This specimen was sent to me by Mr. Pike after I had seen and studied the large and perfect specimen last mentioned. In studying that I had become convinced of the po.ssible aquatic life of the creature from the structure of the long paddling legs, and sUited my belief at a meeting of the Boston Society of Natural History held October 20th last. It waa therefore with no small pleasure that I subsequently found my conclusions supported in so remarkable a manner by the discovery of these structures on a second individual of the species. Another specimen received from Mr. Carr is as small as that last mentioned and
156 S. II. SCUDDER ON SPINED MYRIAPODS
more imporfoct. consisting of only a dozen segments or less of the front portion, with scarooly any ajipendagcs. It is of particular interest, however, from partially preserving the oye of one side (Pi. 11, fig. 10) ; it forms an oval boss 3 mm. long and 1.5 mm. l)road, gently elevated above the principal curve of the head, situated low down on the anterior portion of the head, its longer 'diameter vertical; it is covered with nearly hemispherical, low, circular warts about 0.16 mm. in diameter, crowded rather closely but not attingent, and scattered about over the whole convexity with a slight indication of serial arrange- ment. The length of the fragment is 36 mm. and its breadth about 10 mm.
The last specimen I have to mention was sent to me b}' Mr. Pike and represents the larger part of a young individual curled in a broad sigmoid curve. Sixteen or seventeen consecutive segments besides the head are preserved, all poorly ; the spines and legs are ever3"where fragmentary and add nothing to the other specimens ; the diameter differs only a very little at different parts, though the usual enlargement of the segments a little way behind the head is indicated. The head itself appears to be larger than the segments behind it, but is very badly preserved. The points of interest in it are : fir.st, that the basal joints of a leg may be seen on the first segment behind the head ; second, that the ventral plates, where seen, are divided by a distinct suture into anterior and posterior portions, as does not appear in the other specimens where ventral plates are preserved, but as occurs in some specimens of Euphoberia ; and third, that from near the posterior extremity of the sixth (?) segment behind the head, there projects downward a long, straight, stout, cylin- drical, bluntly terminated rod, as long as the width of the body, the apical apparently a little stouter than the basal half, suggesting, as in other cases to be mentioned, an intro- mittent organ. The length of the specimen as it lies is 83 mm.; if straightened it would measure about 97 mm. in length; its diameter is 11 mm.; and the length of the rod men- tioned 10 mm.; the greatest diameter of the latter is 1.25 mm.
This species differs from the next to be mentioned in the much less rapidly tapering form of the body, in the proportionally shorter segments, and in the character of the spines, which in this species are longer bodied, rather less divergently and much more equally branched at tip, and are furnished with basal spinules of a remarkable character which are not apparent in the other.
Acantherpestes Brodiei Scudder.
PI. 11, fisr. 5.
"Caterpillar" Westwood in Brodie, Foss. Ins. Eng., xvii, 105, pi. 1, fig. 11 (1845). Earypterus ? [Euphoberia) ferox (pars) Woodward, Geol. Mag., X, 109-110, fig. 10 (1873).
Arlhropleura ferox Woodward, Monogr. Merost., 172, fig. 63 (1872). Euphoberia ferox Roemer, Leth. geogn., pi. 47, fig. 4 (1874). Not Earypterus ferox Salter.
This species has been known through Brodie's Fossil Insects for many years, but it is only recently that its relationship was determined. This is partly due to its fragmentary nature, for it is pretty evident from what we now know of the spined myriapods of the carbonifer- ous period that the specimen is considerably imperfect, the head (and perhaps two or three
FROM TnE CARBOXIFEROUS FORMATION. \r,'j
segments more) being absent from tbe front end and a considerable number of noginent« at the tail end. It presents a dorsal view of ten seguient.s in the stout^T part of the hotly, enough however to show that it tapered somewhat toward the head and very eonsiderahly beliind the thickest portion of the body, so that the hinder portion seen in only half as broad as the broadest, only six or seven segments distant ; the body has every appearance of having been cylindrical; the fragment is 55 mm. long and 18 mm. broad in the wideflt part. The .segments show a well arched transverse ridge on the anterior portion, which seems generally to occupy much the largest part of the segment.s, but there is an irregular- ity about this in the engraving which would seem to be defective ; its a whole they are from three to four times as broad as long. The three rows of spines are clearly marked, partly by the spines themselves and partly by the tubercles which mark their former origin ; these show the rows to have been equidistant from one another, the subdorsal rows being an far apart as either from the pleurodorsal ; the spines are preserved only in the latcnd rows ; these appear to be uniform, subcylindrical, nearly or quite half as long as the width of the segments (counting to the forks of the spines), expanding at the tip and bearing a couple of stout spinules, the hinder and longer of which is as long a.s tiie b(jdy of the spine, taper- ing and pointed, directed slightly backward, and acconling to Westwood " evidently artic- ulated" at the base ; the front and shorter spinule is short, tapering and pointed, directed a little forward. There is no appearance of any basal thorns.
This species may be easily distinguished from A. major by its decidedly more Uipering body, comparatively shorter and broader segments and the character of the s]>ines, which not only appear to lack the basal thorns, but are very unequally forked at the tip.
The specimen comes ft'om the carboniferous rocks (ironstone ?) of Coalbrook Dale in Kng- land, and is in the Hope collection at Oxford.
Genus Euphoberia. (lu, fo^cp6=:.)
Euphoheria Meek and Worthen, Am. Journ. Sc. Arts, (2), XLVI, 25 (1868). — /?»., Gcol. Surv. 111., Ill, 556.
Spines spimdiferous, but with a single pointed tip, and arranged in subdorsal and lateral rows only ; segments less than three times, generally about twice, as broad as long, rarely less than twice as broad as long, and then only upon a few segments of the body.
Euphoberia ferox. V\. 1-2, fig. 23.
Eurypteriis ? {Arthropleura) ferox Salter, Quart. Journ. Geol. Soc. Lond., XIX, 86-87, fig. 8 on p. 84.
Eurypterus ? {Euphoberia) ferox (pars) Woodward, Geol. Mag., X, 109, fig. 8 on p. 105. — lb., Mongr. Merost., 172, fig. 62 (1872).
Half a dozen segments of the body, seen from above, are all that are preserved of the single known specimen of this animal. The body is equal throughout, but is perhaps broader than high, subcylindrical according to Salter, the surface rugose. Each of the segments is
158 S. II. SCUDDER ON SPINED MYRIAPODS
diviilod into an anterior and jiostorior portion, the ibrnier apparently elevated, spiuiferous, occu]\\ing iVoin two-thirds to three-fourths of the entire segment, which as a whole is scareely twice as broad as long. The four rows of sjiincs are represented as if at about equal distances apart, those of the subdorsal row indicated only by their bases ; those of the lateral row appear from the figures given to be almost a mere lateral expansion of the edge of the dorsal plate, apparently depressed, forming a laminate compound spine, con- sisting of a main flange, two-thirds as long as the width of the segment, broad at base and bearing there a triangular, anterior, pointed spinule of considerable size, beyond narrow- ing and tapering and at the same time curving a little backward to a sharp point, bearing however midway a triangular pointed spinule, veiy broad at base and nearly as conspicu- ous as the main spine itself; so that it might be said to be apically forked as in the pre- ceding genus. Salter says that these lateral spines " have at their base, front and back, two other smaller spines," but only an anterior one is figured. '* The length of the frag- ment, including five rings" — the sixth is detached — "is 14^ inch; and the breadth of the axis, without the long forked spines is |ths inch. The forked spines are |ths of an inch each."
Locality : North Straffordshire, in ironstone.
This specimen was considered by Salter as '• the central lobe of the abdomen of a trilo- bate Eurypterus or allied genus," and like Westwood in speaking of the last species, he says " it would strike an entomologist as a fossil caterpillar of the Saturnia genus, so strong is its resemblance in size, form and ornament to the larvae of that group." It differs from the other species of Euphoberia in its size, its remarkably depressed spines with very large spinules both at base and in the middle, and appears in these two points to approach Acantherpestes, on which account we have placed it nearest them in this list ; its subdorsal spines could hardly have been of the same character as these lateral spines in every respect ; and if they did not, this would prove an additional distinction from the other species.
Euphoberia horrida, nov. sp. PI. 13, figs. 11, 12, 14.
Messrs. Armstrong and Carr have each sent me a specimen and reverse of an unusually large species of Euphoberia, with highly developed spines, to which the above name may be given. Mr. Carr's specimen (fig. 11), is the better preserved and the more perfect. It apparently represents nearly the entire animal lying partly upon its side, so as to throw the legs upon one side and the subdorsal .spines upon the other, but exposing part of the dor- sal surface also ; toward the hinder extremity the legs appear on both sides ; the body lies in a rather strongly sinuous curve, the two extremities broken off, each probably close to the tip, at the edge of the nodule. As it lies it is 107 mm. and if extended would be 119 mm. long, so that its total length must have been at least 130 mm; its width anteriorly is 8 mm. ; at the greatest 4.5 mm ; at the posterior extremity' 10 mm.
About twenty-eight segments are preserved, and there may not have been more thaa three or four and probably were not over five or six more. The first five or six segments preserved are of equal size, then the body enlarges a little for six or seven more, then diminishes again, and continues to do so with, considerable regularity to the hinder i
FROM TIIF. ( AUMOMl'KUors lnl;.M aTIOX. 159
extremity, which is hardly niuiv than hall" as hroad its the front extremity, and a little leHH than hall" as hroad as the middle of the hody. The swollen portion uf thehody in therefiire unnsually distant from the head. In several places near the middle and at the anterior extremity of the body the original texture of the dorsal plates Heems to he prenerveil (fij^. 14), showing that the surface was covered with minute and rather sharply elevated circular papillae, aijout 0.035 mm. in diameter and pretty uniforndy distriliuted at distances averaging about 0.1 mm. apart ; otherwise it appears to be smooth; but the surface of the ventral plates is very finely and transversely striate.
The junction of the dorsal and ventral plates can be seen high up upon the sides of the body as it lie.s, jus represented in figure 11, the line of .separation being a straight one. The segments, as represented by the dorsal plates, are about twice as broad as long in the middle of the bodv, which has the appearance of being somewhat contracted and thus shortening the segments, but in front and i)eliiiiil they are proportionally longer, being Ie.>;s than half a8 broad again as long. The dorsal plates are diviiled transversely into two e([ual portions, the front portion being elevated, selliform and spiniferous, the hinder half depre.««fd and nearly flat.
The .spines of only one serie.=i, apparently the subdorsal, are preserved, but in liiis throughout nearly the whole length of the body ; each is situated on a somewhat elevated boss wliich merges into the spine, but at base is as broad as the entire front half of the dorsal plate and develops anteriorly the nuiin spine, a stout, cylindrical, erect, straight stem, slightly inclined backward, which in its middle divides into two portions, a compara- tively small, short, conical, pointed thorn, continuing very nearly the erect line of the main stem but inclined slightly forward, and a similar but very long and slender pointed thorn, as long as or even longer than the main stem, directed backward at a considerable angle and also slightly curved in the same sense, .«o as to make the entire spine about half as long as the width of the body in the broadest portion of the same, or about two-thirds ita width in the other portions. In addition to this forking of the main stem, the bos.s e.xpands at its posterior extremity, at the hinder lower elevation of the selliform dorsal plate, and bears the spinules which in other species .seem to cluster more strongly to the very base of the main stem of the spine; these spinules are two in nimiber, straight, ver- tical or inclined backward a little, the anterior much longer than the posterior, both slender, nearly equal, tapering only next the pointed tip. arising from a very short main stem which is even stouter than the main stem of the spine proper, the tip of the longer spinule reaching about as high above the body as the fork of the main spine.
The legs are preserved throughout the greater part of the fragment, but so indistinctly that in no case can the joints be determined with any precision ; they appear in general to be divided much as in Acantherpestes major, but they are proportionally slenderer than there, as is the case with all other species of Euphoberia ; they are slightly shorter than the width of the body excepting near the slender hinder extremity, where they do not diminish in size and length so rapidly as the segments, and are therefore propor- tionally to the width of the body longer than elsewhere ; they appear, as in Arnnl/icr- pestea major, to have a median carina, to taper gradually, especially in the apical third and to be either bluntly pointed at the tip, or, in other places, rounded. The legs are
ICO
S. H. SCUDDER ON SPINED MYRIAPODS
about 7 mm. long iu the front part of the body, 9 mm. in the middle and 5.5 mm. at the posterior extromity. The spines are about 5 mm. long.
Mr. Armstrong s specimen represents nearly as largo an individxial as the preceding, but it is not so well preserved, nor is the fragment so great, being composed of thirteen or fourteen segments besides the head, and exhibiting a dorsal view, but with some of the ventral plates exposed. The fragment is 72 mm. long, stretched in a straight line, 8.5 nnn. liroad in the broadest part (near the middle of the fragment), from either side of which it diminishes rei^ularly and very slightly so as to be about 6 mm. broad at the segment behind the headland 7.5 mm. broad at the end of the fragment; it is largest and about equally large from the fourth to the eleventh segment behind the head. The spines, the lateral rows of which are exposed along either side of the body, are exactly similar^ in structure in every particular to those of the preceding specimen, but are a little longer in proportion to the width of the body than there, beuag 6 mm. long where the width of the body is a little more than 8 mm. Signs of the position of some of the close y approx - mated subdorsal series may also be seen. Excepting at the hindmost end of the fragment, the segments are everywhere scar<^ely half as broad, again as their length. No legs are visible, but on one side of the fourth (or fifth ?) segment behind the head is a straight, equal, apically pointed, compressed, unjointed rod, carinate along the middle, as stout as the stem of the spines, nearly three-fourths as long as the width of the segment on which it is seated, and projecting from it at right angles (fig. 12). Probably, as in other cases to be given in other species, it is the intromittent organ ; it is 5.75 mm. long and 0.6 mm. broad ; as the first segment preserved is not unquestionably the head, the segment on which the rod is situated is of course uncertain ; the reasons for supposing it to be the head are that the body appears to terminate there, just before the edge of the stone, and that the seg- ment itself, while bearing no appendages, is, as is the case with the head in specunens of other species of Euphoberia, more deeply impressed and extends further on one side than on the other of the fossil. No characteristics beyond this can be made out.
This species differs from the other of the genus in its greater size, and from the next, to whioh it is most nearly allied, in its proportionally longer segments and in the more extended development of the basal posterior spinules of the spines of the body, which in this species are more widely separated from the main stem than usual.
£aphoberia armigera Meek and Worthen. PI. 12, figs. 1, 2, 3, 5, 6, 13 ; — pi. 13, figs. 7, 8, 10.
Euphoberia armifjera Meek and Worthen, Amer. Journ. Sc. Arts, (2), XL VI, 25-26 (1868) ; — /&., Geol. Surv. IU., UI, 556-558 (pars), figs. C, D on p. 556 (1868) ; — Wood- ward, Geol. Mag., VHI, 103-104, pi. 3, fig. 7, (1871).
To this species I refes two specimens and reverses received from Mr. Carr, two others | with reverses from Mr. Armstrong, another with reverse from Mr. Bliss, another, also with ' its reverse, from Mr. Worthen, a fragment sent by Mr. Pike, and the two figures C and D of Meek and Worthen's illustration, though it is possible that fig. C may be distinct.
FK'oM 'IIIK CARBOXIFKKors ITMiMATIOX. li-,I
Tlie specimen figurcfl in iIk' Illinois report under the letter D, here reprtnluce*! in fifrure 6, by favDr of Mr. Wortlun, and whit-h is copied by Woodward lus above ri'ferri'<I to, exhibits an inferior side view of the entire animal extended in a struif^lit line. From thin it seems that the tapering form of the creature does not appear on a si«ie view, and it i« even drawn as enlarging toward the head, which is considerably larger than any other part of the animal ; toward the hinder extremity, however, it tapers gently ; " the entire length i« 3,C inches and its breadth about O.'J inch." The head is '* seinicinular. as wide as any part of the long slender body. It is not in a condition to .show the eyes, nor are any remains of mandi- j^-^ -' ^ j
bles, antennae or other append- nv,-,:
ages preserved." It is repre- *
, , , ^, . . Fig. 6. Eunhoberia aniiiijera; »i<rurc 1) of Mwk and Worlbi-n.
sented as less than twice as
broad as long. The segments are apparently nearly forty in number jjesides the head ; c)f the ventral plates " as many as about seventy-five or seventy-six may be counti-d." The segments themselves are represented as only .slightly and uiiiforndy arched on a side view, and appear to be scarcely more than twice as broad as long. Acconling to the autliorn, the surface of all their specimens, this included, show " a minutely granular appearance ;" but they figure only that of one of the others, with which I have a specimen agreeing, which seems to l)elong certainly to a distinct species, much more granular than those I would refer to this, and I therefore doubt whether the .same description should apply to all of Meek and Worthen's specimens. The spines are all represented in dotted lines and it is impossible to say how much of them is intended to represent what can be seen on the specimen. They are lepresented on every segment behind the head. The legs are also mostly given in dotted lines, there being only one exception, where it is given fully as long as the .width of the bod\' and composed of four equal joints ; the text, which refers to them all, says •' five gradually tapering joints." On the ventral plates little round openings are marked a little above the bases of all the legs, and aljove them smaller dots ; the former, say the authors, may be the point of attachment of the legs ; the others they compare to spiracles.
The second specimen figured by Meek and Wor- ' '5;J^.,^:T^!rA^M V. then, marked C on p. ojO, and rei)roduced here, in
^fSffiil^nm fig. 7, is the posterior portion of a similar animal, pre-
^^jy??^!^?^^^^^?!!^^ senting the same view as the last mentioned, but bent
^^•-vi?-. '^'^^ abruptly downward at the posterior end ; it i.s much
^^^^r~^ 'V'JM more tapering at the hinder end than at the other,
^^^^^ being at this part only a little more than half as large
vi^"^ as the broken anterior end ; although imperfect, it is
Fig. 7. Euphoheria armi<;era; fig..C o{ larger than the othcr and nearly as long. It ha,s Meek and Worihen. twenty-three .segments, which are uniformly arched
on a side view, and not more than twice as broad as long. The same statement concern- ing the surface sculpture may be made of it as of the other specimen. The spines, many of which of the subdorsal (?) series are represented, are rather .short and stout, generally less than half as long as the width of the body, but as they appear to originate on its
MEMOIRS BOST. SOC. NAT. HIST. VOU III. 21
16i
S. n. SCUDDER ON SPINED MVRTAPODS
furtlior side their bases may not show, in which case they are longer ; they are tapering anil sharply pointed and bear anteriorly, not far before the tip, a small, delicate, pointed sninulo ; thoy are represented on every segment but the last. The legs which the text doscrilies (for all the specimens) as fivo-jointed are three- or four-jointed in all figured, the joints of otjual length, the whole leg moderately stout, tapering, and slightly longer than the width of the bod3^ Similar circular holes are shown above the bases of the legs on each of the ventral plates, as in the last specimen mentioned, and like them probably represent the bases of the nearer pair of legs, all of which are wanting.
This specimen differs from the last mentioned in the greater length of the dorsal plates, and in a more conspicuous tapering of the body posteriorly on a similar view ; but it prob- ably should be considered as of the same species.
The third specimen which I would refer here is one which I have received from Mr. CaiT, and first saw through the kindness of Mr. Pike (PI. 12, fig. 1). It lies flat upon its back, w'ith the lateral spines projecting equally on either side ; a fragment on a higher level at one side shows a few legs, proving that we have here the inner view of the dorsal plates. It is nearly straight and nearly or quite complete. It has the appearance of being unnaturally flattened so as to preserve slight indication of its probably nearly cylindrical form, but its position gives the best view of the form of the animal ; it is largest at the end of the first third of the body or from the twelfth to the eighteenth segments ; in front of this it tapers very gradually and regularly, so as to be about one fifth smaller just behind the head, while the head itself, as in the first specimen mentioned, is again broader ; posteriorly it gradually tapers more until the hinder fourth is reached ; this is of nearly imiform width and a little less than one-third smaller than the broadest part ; in the form of the front of the body therefore it more nearly resembles the first specimen mentioned (D, fig. 6, supra), while in that of the posterior extremity it is like the second specimen (C, fig. 7, supra) ; the length of the animal is 105 mm.
As to the head (PI. 12, fig. 3), it is rounded in front and very short, being much shorter than the body segments and as broad as they, but even broader than those nearest to it ; it bears posteriorly a narrow, prominent, transverse ridge which appears to bear on the left side the scar of a subdorsal spine, but situated, like that of the next segment, far toward the side of the body ; something which looks like a spine, but which may be an antenna, projects forward and outward from the outer front angle of the head ; it is straight, tapering, rather regular and bluntly pointed, as long as the depth of the head ; no joints can be seen in it. The segment immediately behind the head is very pinched, not half so long as the head, and bears lateral as well as subdorsal spines ; the lateral spine is not i-epresented oia the enlarged drawing of this part. The other segments are similar to one another and number thirty-seven, including all but the head ; prob- ably they include the whole animal, although the hinder edge of the creature is broken, and there may be one or two more segments ; this number it will be noticed agrees very closely with that of the finst perfect specimen mentioned. The average length of the body segments Ls nearly 3 mm. while the average breadth is about 5.5 mm., the segments being about twice as broad as long, in which it agrees again very well with the other specimens described ; this proportion holds well throughout the body, the broadest segments measur- ing about 7 mm. and their length about 3.5 mm. ; while at the tail where the width is 4 mm.
FROM THE CAKBONIFEROUS FOUMATION. 153
the lenj^th is barely 2 mm. The se;;iiu'iit.s althuii^fh imu-h ilatU-iieil in preniTviition hIio*, l)articuhii-ly in the hirger parts of the body, distinct signs of having been ridged on the anterior half which bears the spino8, a feature not Heeii, where we r^hould the more expect it, in the figures given of the lateral views of the two other specimens.
The head is delicately granulateil, the granules oblong with their longer n.vc« longitu* dinal, and showing a tendency to run together in wavy l»ut generally straight longitudinal ridges ; these markings however are rather faint and dull ; similar granulation appears ob.scurely in one or two of the segments behiml the head, but shows no tendency to u long- itudinal arrangement. The same circular disks which were de.scrilied in*the large speci- men oi' Acantherpestes ^nry or appear here also all over the body, but the material of which they are formed has generally cracked e.xtensivcly in an irregular manner, so that they are not .so conspicuous ; those of average size have a diameter of about 0..'J."> nun.
The subdorsal row of spines appears only by the little pits upon the surface, which show that these rows are placed a little nearer together than either of them to the lateral row». The spines (PI. 12, fig. 2) are preserved in the lateral rows on one side nearly throughout the body, on the other in the anterior third ; in their length they .show a constant relation to the size of the segments, and are present on all the segments behind the hea<l, excep- ting near the tail where they are lost. They are more than half as long as the .segmentH on which they occur, very broad at base, rapidly narrowing at first, especially on the hinder edge, and then taper gently, with a slight backward curve, to a delicate pointed tip ; they are not compressed or depressed but circular in cross section, and bear at the ba.se posteri- orly (only seen in this specimen on one side of the body) a posterior, basal, triangular tliorn directed backward and outward ; it is stout, conical, pointed and nearly half a.s long an the segments ; its absence from the spines of the right side is due no doubt to tife position of these spines, and the spinules might be found attached also to them by cutting the stone ; besides this basal posterior thorn, there is an anterior delicate .spinule on the middle of the spine plainly visible, at the base of which the spine ha,s a slight bend back- ward in most cases ; this is not shown in the one selected for enlargement (PI. 12, fig. 2), nor is it brought out in the drawing of the natural size ; from certain appearances it l<joks as if there were, at the point where this anterior spinule arises, not merely this one spiinde, but a circlet of them, three or, counting the extremity of the spine as one, four in numl)er : one anterior as described, minute, pointed, hardly directed forward ; the posterior or spine proper, which is nearly as long as the basal part of the spine, tipering regularly and pointed, directed only a little backward, divergent from the first at an angle of about 45°, and occasionally very slightly curved backward ; still another sujierior (or interior) one is indicated by a slight mark, seen in the enlarged drawing as a dark spot at the base of the anterior spinule, indicating the base of a spinule ; and possibly, to match it, one on the opposite side, of which of course no indication could well appear.
The only appearance of legs is in a short fragment at the middle of one side which slopes down toward the body, w^here three sets of two each appear ; they are of equal length, and therefore are probably complete, for the stone is not split on a different plane from that in which they lie until some distance beyond their extremities ; they are therefore very much shorter than in Acantherpestes major and considerably .shorter than the width of the body ; the first joint appears to be broken off at the edge of the stone ; the second
1(',4 S. IT. SCUDDER ON SPIXED MYRIAPODS
is o(|ual in length to the remainder of the leg (though this point is obscure and doubtful), slondor and compressed, with only a faint sign in one of any carina, equal in width through- t)ut. and about six or seven times as long as broad ; the rest of the leg tapers to a bluntly rounded p int. with no possibility of making out distinct joints from the obscurity of its preservation ; on two, a tapering, curved claw appears to be present, not sharply pointed, less than 0.5 mm. long ; the entire leg is 5 mm. long and its greatest breadth 0.4 mm.
The next specimen referred here, and which was received from Mr. Worthen (PI. 12, fig. 6), presents a nearly straight and uniform ventral view. There is no apparent sign of taper- ing toward the head, the anterior half being nearly uniform in size ; behind this it tapers gradually and uniformly, so that the hinder end is about two-tliirds the width of the anterior half The length of the creature is 98 mm., its greatest breadth 6 mm., narrowing to 4 mm. at the tjiil. The head and first segment (PI. 12, fig. 5) ai'e together represented by a deep and large, well rounded depression, in the intaglio half, as broad as the segments behind it, and together much more than equalling two of them ; the head would appear to have been much broader than deep and higher than broad, drooping and passing below to a lower plane than the rest of the body, and with the next segment forming a compact globe ; next the lower front edge of this globe is a slight rounded dejiression (indicating a slight boss in the living creature), on which are half a dozen ovate wartlets or granules which may indicate the eye, but it is too vague for any assertion.
The segments" are many of them obscure, but appear at first sight very numerous, numbering some sixty or seventy, but as these are the ventral plates the real number is only half of this ; the whole body is blurred in parts, rendering it difficult or impossible to be more precise ; these ventral plates average 1.5 mm. in length, and where tliey are distinct, as in the broadest part, they are four times as broad as long ; they are well arched transversely, indicating a well rounded body, and have their anterior half stoutly ridged. They show in places series of short, longitudinal, slightly oblique, slight and irregular corrugations. Traces of the insertions of the legs can be seen on many segments, situated in the centre of the front margin of the depressed portions ; above them (that is, toward the spined margin) there is a slight trace here and there of stigmata, but I have not been able, so poorly preserved is the fossil, to detect any of the crateriform bran- chial cups, described in AcantheijJestes major. The subdorsal spines of a single row are present on many of the segments, but poorly preserved, and are small, being only about one-third the length of the width of the segment on which they occur, rather stout at base, beyond this tapering, and curving slightly backward, and at first sight apparently simple ; one, however, fointly shows a part beyond the apparent tip, indicating that the others have been broken ; and as this is provided also with a slight anterior spinule in the middle, and a basal posterior thorn, it agrees entirely with the last specimen described. There are a couple of fragments of legs just beneath the junction of the first and second ventral plates behind the head, situated side by side and touching ; they apparently rep- resent the basal joints. We have "here new proof that the first segment, represented by one dorsal plate behind the head, bore two pair of legs in these myriapods, and the additional evidence derived from the presence of the complete ventral segments to which they were attached. There is besides only a single indication of what may be a leg, which appears at about the eighth ventral plate behind the head, on the side opposite to that to which the
FROM THE CARBOXIFEROUS FORMATION. 1C5
spines are attached (PI. 12, fig. 5); it appears as a strai},'ht, cylindrical, Hiijfhily tiiperinjf, unjointed rod, 4 mm. lonj;, 0..3 mm. broad, the seirment from which it Hprinjrn liciiifj 5.3 mm. broad; it has the appearance of a spine, but is alto;r<'ther unlike any of the otlier spines and probably represents the intromittent organ.
The next specimen to be discussed is a fragment received from Mr. I'ike aller tiii- paper was written, and is introduced here with a figure (PI. KJ, fig. 8) of a portion of it, becHUso it exhibits certain features of the ventral portions .seen on no other exauuned. It repre- sents the posterior half, more or le.ss, of a myriapod, extended in a slight sinuous «'urve, the legs trailing beneath, and a few spines sliowiug above. The length of the fnigment is 47 mm., its breadth in front 4 mm., ami l)ey(jn<l the middle uf its posteri<jr half l.'.t mm.; beyond this it is very obscure, but between these two points it .seems to tjiper regidnrly. From twenty-one to twenty-three segments are preserved. The jointing of the legs iH very ob.scure but appears to be as in the figure, the ba.sal joint seen, undoubtedly the second, being about as long as the rest of the leg ; the legs are about as long its the width of the body, slender and tapering. The subdorsal series of spines, the only ones preserved, are rather small, and show only here and there, and ol)scurely, any subsidiary spinules. What, however, is of the chief interest is the preservation of the ventral plates in an unusual manner ; these are separated from the dorsal plates by a .straight line along the middle of the body, and appear to be four in number to each dorsal plate ; in reality there are two, each being again divided into a pair of subsegments by a transverse line just behind the middle and only a little more faintly incised than the lines of demarkatiori between the plates ; the appendages are borne only by the anterior, larger, subsegment ; these are, so far as can be seen, the legs, which are attached at the extreme base in circu- lar pits ; and just above them the spiracles, .slender, ovate in form, their longer diameters nearly as great as the diameter of the leg-pit and placed a little obliquely but nearly tran.s- verse to the body, the upper end furthest back, thus differing from Acantherpestes only by their slight obliquity. The sight of this specimen inclines me therefore to believe Meek and Worthen to have been correct in referring the openings aljove the leg attachments (see fig. 6,sui)ra) to spiracles, which they speak of as less rounded than the pits .supposed to be the points of attachment of the legs to the body. A similar division of the ventral plates into subequal anterior and posterior portions is evident in other .species of Eupho- beria, as may be seen from the plates.
Mr. Bliss sends an interesting specimen not very well preserved, indeed, but showing some valuable features of the head (PI. 13, fig 7). It represents about twenty segment.s of the body besides the head, lying flat in a straight line, with the latepal rows of spines project- ing equally on either side. There are two peculiarities in it which seem to make it a little doubtful whether it should be referred to any of the species of Euphoberia here described : first, the segments are extremely crowded and very short compared to their breadth, vary- ing from two and a half to three times as broad as long ; second, the portion of the body exposed, though very favorably displayed for exhibiting any such feature, shows scarcely any enlargement of any region of the body ; it does indeed taper slightly from about the eighth segment forward, but so slightly as hardly to be noticed without direct observa- tion ; the margins of the body are, how-ever, poorly preserved and may give it a deceptive appearance ; it differs slightly also fi-om other .specunens of this species in the brevity of
j^.^, S. II. SCUDDER ON SPINED MYRIAPODS
tlu> spines, wliioli are less than half as long as the width of (he body. From the character of the spines, however, the surface character and general appearance of the segments, and the size of the l>oily. it can hardly be doubted that it belongs to this species. No legs are present, but there are two features worthy of note : first, on one side of the fourth seg- ment behind the head protrudes a pair of straight, attingent, tapering, bluntly-tipped, so far as can be seen unjointed rods, directed at right angles to the body and inclined a little f<n-ward. half as long as the width of the fourth segment, and each considerably stouter than the spines; they certainly may be legs though they differ somewhat from them; but appearing at this place only and recalling similar organs in other specimens of Euphoberia one cannot help inclining to believe them to represent intromittent organs, and this sped men has then a special interest from being the only one yet found in which a pair is pre- served ; second, the appendages of the head ; the head is considerably broader than the body, scarcely longer than the body segments, broadly and very regularly rounded in front ; from either side of the front, about midway between the middle and the outer mar- gin, springs an antenna, composed of four joints : the first, of which only the apical part can be seen and that obscurely, seems to be small and cylindrical ; the second, also obscure, is large, stout, cylindrical, perhaps enlarging apically, a little longer than broad, termina- tin-x bluntly ; the third about as long as the second but very much slenderer, cylinl drical, enlarging a little apically, terminating bluntly and followed by an ovate termina joint, twice as long as broad and a little narrower than the apex of the penultimate joint. ' The length of the fragment is 54 mm. ; probably not more than half of the whole is pre- served ; its greatest breadth is 7.5 nun. and just behind the head 6 mm. ; the head is 9.5 mm. broad and 3 mm. long; the whole antenna 3.3 mm. long; second joint 1 mm.; third joint 0.9 mm. ; fourth joint 0.45 mm. ; greatest width of second joint 0.5 mm. ; third joint 0.55 mm. ; fourth joint 0.38 mm.
Another specimen and part of its reverse sent by Mr. Carr represent the larger part of a curved body on a lateral view with a few spines and many legs, none of it very well preserved ; the head is hot reached anteriorly although very few segments behind the head can be missing. Nearly thirty segments are present, representing a large animal, 115 mm. long so far as preserved. The only parts worthy of special mention are the legs, which are in some places very well preserved ; they are very nearly as long as the width of the body ; the first and second segments are of equal width with parallel sides, but beyond this the leg tapers to a point; the second joint is much longer than the others, longer indeed than the third, fourth and fifth together ; the first and third are of equal length and a little longer than the fourth, fifth and sixth, wliich are of similar length ; the first joint is nearly twice as long as broad, the second nearly six times as long as broad, the third twice as long as broad. The legs therefore essentially resemble those of Acan- therpesfes major, differing from them only in detail; the specimen figured (PI. 13, fig. 10) shows no sign of any median carina, which is visible on some of the legs and not on others. The leg measures 7.25 mm. in total length, the first joint being 1.4 mm. long, the second 2.75 mm., the third 1.3 mm., the fourth and fifth each 0.9 mm. ; the last 1 mm. ; the width of the second joint is scarcely more than 0.5 mm.
The specimen received from Mr. Armstrong is very imperfect and adds nothing to our knowledge of the species. It is a nearly entire body of a small animal preserved on a side
FItOM TIIK C'ARBONIFEROL'S FOKMATIoN'. 1G7
view, with both ends drooping hnt neither perfect, none oC tlie Hpinen and only a few ot tlie lej^s partially preserved. The lenj^th of the fragment a.-* it lie.s ix 3:5 nun.; if extended it would prul)al)ly reach oS nun., and represent the full length, nearly thirty ceginentji being ])artially or wholly visible.
All the specimens which I refer to this species come from the carboniferous ironMtone nodules of Mazon Creek, Morris, 111. Those which have been personally exiunined were received from Messrs. Carr, Annstrong, Worthcn. Bliss and Pike.
The species differs from the last mentioned in the .somewhat shorter Kegment.s and lesji highly developed opines ; it is besides .somewhat smaller ; the spines are longer than in the American .species hereinafter mentioned and the shape of the body also diflers.
The Scotch E. Broicnii is not improbably distinct from this, but in said to have no spincH preserved, removing one of the best sources of comparison ; this, judging from the cast I have, seems to be a mistjike, the appendages on the concave side of the hotly having the appearance of being spines, while those of the convex side are certainly legs. If those of both sides are really legs it presents a dorsal (or a ventral) aspect, and must be considered as distinct from tiiis species because it does not taper to any considerable extent. If it presents, as is far more probable, a side view, like those of the specimens of the present species figured by Meek and Worthen, the spines must be incorrectly drawn in Woodward's figure; on the. cast they appear much stouter than the legs (of the convex wide), and appear to be of about the same size as in the present species, but with no basal thorn, or none of any size.
Eupbobena Brow^nii Wooilwanl.
ri. 1-2, figs. 7, 8, n.
Euphohcria Broicnii Woodward, Geol. Mag., VlII, 102-104, i)l. 3, figs. G a.-c. (1871).
The single specimen upon which this species was ba.'jed. gives, according to Woodward a dorsal view of the animal in a slightly curved position ; l)ut judging from a cast which I owe to his kindness, as well as from the features of the animal as figured by him. we must adopt the view that it presents a lateral aspect. Below, i. e. on the convex side, the appendages (legs) are really much longer than those (spines) upon the oppo.sitc side, though similarly figured by him, even in an enlarged view (pi. 12, fig. 7,8); and at this same margin, as in figures C and D of Meek and Worthen's E. annif/era, though not to so great an extent, the pair of ventral plates can be seen against the lower edges of the dorsal plates; and on the posteror part of the body, from which Woodward's figure G'' (pi. 12, fig. 7) is probably taken, only the lateral row of spine-bases can be seen. The body i« flattened and of very nearly uniform size throughout, a little the largest near the .seventh seg- ment and a little tapering posteriorly ; this form would also indicate a lateral view. The body is 90 mm. long and 0.5 mm. broad at greatest. The head is rather broader than the segments behind it, scarcely more than half as long as they, and well rounded.^with a con- striction in the middle, giving it the appearance of being formed of two rounded lobes. No appendages can be seen. The segments are stated by Woodward to be thirty-six in number besides the head. They are composed of two equal parts, the anterior forming an
168
S. II. SCUDDER ON SPIXED MYRIAPODS
nrohoil transverse ridge, undoubtedly that lioaring the spines, the posterior flat ; as a whole, the soijtnonts are about twice as long as broad ; nothing is said by Woodward about the sur- face sculpture, or the spines Woodward says "there are indications of pores and also of tubercles or spines along the dorsal line, but the latter less perfectly preserved." His enlannnl drawing (PI. 12, fig. 7), shows a single row of marks of spine insertions (?) along the middle line of the body, on the depressed portion. To judge from the cast, they seem to be nrmngcd in distant subdorsal and lateral rows, and those of the subdorsal row, as seen be- yond the body, to be mammiform at base, beyond tapering, curved, pointed, and as long as the segments, apparently simple, and originating from the arched part of the segments ; the pit.s figured by Woodward should probably originate from the other half of the seg- meut^s and represent the lateral rows. The legs (PI. 12, fig. 8) are represented as being as long as the width of the body and as composed of three joints, the first and last of equal length and the second as long as the others together ; this can hardly be correct.
The onlv American species with which this can be compared is the one to which Meek and Worthen's name of E. annigera is here retained. I have given under that species the reasons for believing that it is distinct, but this cannot be considered as conclusive until a further study of the Scotch specimen is undertaken.
The specimen was found in a nodule of clay ironstone from Kilimaurs, Scotland, by Mr. Thomas Brown.
Euphoberia granosa, nov. sp.
PI. 1-2, figs. 22, 24, 25, 26 ; pi. 13, tig. 13. Euphoheria armigera Meek and Worthen, Amer. Journ. Sc. Arts, [2], XLVI, p. 25-26 (pars) (18118).— 76., Geol. Surv. 111., Ill, 556-558 (pars), figs. A. B. on p. 556 (1868).- Roemer Leth.geogn., pi. 47, fig. 19 (1876).
The study of the series of specimens that have been intrusted to me, and of the figures and descriptions given by Meek and Worthen, lead me to separate one (A) of those figured by them as distinct from the others, and to place with it some others, for the opportunity of examining which I am indebted to Messrs. Worthen, Carr and Armstrong.
The specin-ren figured in the Illinois report, and which is reproduced in the accompanying wood cut kindly furnished by Mr. Worthen, presents a dorsal view, with a trace also of the
ventral plates of one side of the body in a curved position, neither end preserved, and showing spines upon one side and legs on the other. The body is of nearly uniform size through- out, but tajTers a very little posteriorly. It is not so lai'ge as any of the previously mentioned species, the fragment being about 54 mm. long, and averaging about 5 mm. broad. The Fig. 8. Euphoberia granosa. segments preserved are tAventy-three in num])er, each nearly three times as broad as long, the anterior portion transversely ridged and bearing the spines of both rows, and the narrower posterior portion depressed. The description of the surface sculpture given by Messrs. Meek and Worthen for their species E. armigera seems to me to apply only to this specimen, which they i a/e chosen to represent it (in fig. B) ; they .say " Under a magnifier, the surface . . . shows a minutely granular appearance . . . ; as these granules are seen on the surface of moulds or impres- sions left in the matrix, they indicate the presence of a minutely pitted marking on the fossil itself" The subdorsal series of spines, as indicated by the pits on the surface of the
FROM THE CARBONIFEUOUS P'OUMATION.
109
body are distiuit from each other, ami probably (niite as near the IuUtuI rowH as Uicy ore to each other ; the .spines ol" the subdorsal rows, which only are preserved in their entirety, are less than half as long as the breadth of the body, stout, conical, curvinj; backward, finely pointed, and bear near the miildle a delicate anterior spinule. The le^s are repre- sented as tolerably stout, a little longer than the width of the segments and composed of five ecjual joints.
The (irst of the .spe(;inu'ns 1 imve seen which I refer to this species, and in which we have bolh obverse and reverse (PI. 12, figs. 22, 25, 26), was received from Mr. Worlhen, and shows a partly dorsal partly lateral view of most of the body, the head end mi.ssing, curving upward near the middle so as to be bent nearly at right angles. The anterior half of the fragment is uniform in width ; l)eliind, it tapers slightly and regularly, .so that the poste- rior end is about two thirds as broad as the stoutest portion. The entire length of the fragment is CO mm. and its greate.st width 1.25 nun. There are twenty-seven segments jircserved, varying fi^om 2 mm. to 2.5 mm. in length, i.e. they are about twice as broad an long, or .somewhat broader than that; transversely they are not very strongly arched, indicating a somewhat flattened body; longitudinally they are very strongly divided into two parts, the anterior two-thirds being very much elevated, ridged ami tpiniferous, the posterior third deeply sunken ; between the subdorsal .spines is a .slight, duli, transverse furrow. Over all the segments may be noticed distinct, close granulations, a little coarser on the lower non-spiniferous parts of the segments, and more apparent in the front than in the hinder portions of the body ; they appear in the cast of the upper surface and therefore indicate, as Meek and Worthen say, a pitting of the exterior crust (PI. 12, fig. 24).
The spines of the lateral rows are far down the sides of the body, while the sulnlorsal rows approach them, being .set very widely apart ; those only of the lateral rows are preserved (PI. 12, fig. 24), and are rather more than half a.s long as the width of the body, tolerably stout, tapering, curved slightly backward, and not very sharply pointed; they have a slight anterior spinule springing from the extreme base. The legs are present along the whole under surface, which is so preserved as to show well the basal joint.s ; these are not so stout, compai'ativcly speaking, as in Acantherjje.'ites major, and taper a little, the a<ljoin- ing legs not touching each other at base but .separated by a considerable spare ; the ba.sal joint iij- evidently compressed, subquadrate, with a not very pronounced median carina, terminating squarely, a little longer than the basal breadth, and about 1.1 mm. long; the second joint is long and slender, nearly as broad as the tip of the first and about six times as long as broad ; it is laminate, straight and equal, with a median carina of no very great prominence ; its length is about 2 mm. and its breadth 0..^2 mm ; a third joint is some- times visible and is slightly narrower, and only a little longer than broad, quadrate, appear- ing as a mere continuation of the second ; all the parts beyond are broken off in all the legs, the longest of which is 4 mm. where the body is of the same width.
A second specimen belonging to the collection of Mr. Carr (PI. 13, fig. 13) exhibit,"? on one stone the entire length of the animal, and on the counterpart almost the whole. It lies in a nearly straight line upon its side, showing the spines on one side and the legs on the other, somewhat faintly and imperfectly, but throughout nearly the entire extent of the body. There are nearly forty segments besides the head, but the exact number cannot be deter- mined from the obscurity of some parts. The length as preserved is G3.5 mm. which, if
MEMOIRS BOST. SOC. KAT. HIST. VOL. m.
j-Q S. TI. SCUDDER ON SPINED MYRIAPODS
extendod. would be about 70 mm. ; it is of a nearly uuiform width of 3.1 nun. throughout, but tapers posteriorly especially on the apical fourth, so that the hinder extremity is only 2 nun. broad ; at its broadest part it measures 3.3 mm. ; perhaps by its mode of preservation it does not show the entire breadth, for the legs, which in other specimens of the species are no longer than the bod}-, are here 3.75 mm. long. The spines agree in character with those of the last specimen mentioned, but in only one or two places can the anterior ppinule be recognized. The segments of the body are very badly preserved and are hardly twice as broad as long ; the structure of the surface can nowhere be distinguished, but some signs exist of the marked distinction between the anterior and posterior portions of the segment^! ; the head again is badly preserved ; it is very full in front, and bears a distinct, long and slender antenna, as long as the depth of the head, originating, on a side view, above the middle of the head, and consisting of seven subequal joints ; the first and second are slightly longer than broad, rounded subquadrate, a little larger at the tip than at base ; the fifth and sixth similar but smaller, the last similar but much smaller, and the third and fourth like the basal ones, but longer and more cylindrical, perhaps a little more than half as long again, or twice as long as broad. The whole antenna is 3 mm. long and in the middle 0.3 mm. broad.
Three specimens of this species, two of them with counterparts, are found in Mr. Arm- strong's collection ; one of them with its counterpart shows twenty-three segments of the posterior portion of the body lying in a nearly straight line, partly on its side, with spines on one side and legs on the other. The total length is 60 mm. and the broadest part 4.5 mm. wide, a width which is retained with slight diminution until the last 20 or 25 mm. are reached, when the body tapers more rapidly, and just before the tip is reduced to 3.25 mm. As in the last specimen, the anterior basal spiuule of the spines is rarely visible, and the spines themselves are unusually slender and pointed, and rather more than half as long as the width of the body. The legs are slightly shorter than the width of the body, and the segments, which are much flattened, and poorly preserved, show signs of the granula- tion of tJie surface and the difference of level of the anterior and posterior portions which is characteristic of the species.
The other two specimens referred to this species are very imperfect and add nothing to the points already brought forward.
This species differs from all the others in the coarser pitting of the surface and in the deep and sudden contrast in elevation between subsegments. The segments are also much longer than those of the preceding species, the legs longer than usual and the spines rather shorter, although of the same simple character. The subdorsal spines are separated at an unusual distance, and there is a transverse sulcation between them, in which points it differs markedly from those of all the other species ; it seems apparent, therefore, that it cannot be confounded with the other specimens referred by Meek and Worthen to their original B. armigera. This species also shows scarcely any sign of tapering, excepting toward the hinder extremity and here very gradually ; in this respect it presents features very different from the following species. All the specimens known came from Mazon Creek.
FRO^I TIIK t \l;i;uMi |,|;(»l^ It )|;M A IK )N jyj
Euphoberia Carri, iiov- Rp. I'l. IJ, li--. 4, 'J IJ, 1 111); pi. 13, fi^rn. 1«, 18.
Five .specimens, all sliowiiiir relief ami iiitujjflio, are pre.served. The first (Pi. I'J. l\<^. Itl), is bent into the shape of an L imd presents on the lonj^er anterior linih a doi-Nal view, but the hinder portion is somewhat twistoil iis well a.s hent .so as U} he partly lateral ; l>oth extremities are broken off. The body thns pre.served is largest anteriorly, nearly e«|UJiI on the front half of the frajrment ; Ijehiiid this it tapers at first considerably, aft4'rwanl less raj)i<lly, so that the posterior extrciuity is scarcely more than half as broad as the anterior portion ; the body is very stron<;Iy llattencd. but may have been rounded. The fragment is about 58 mm. long, 0.5 mm. broad in front and ']J) mm. broad behind. There are twenty-four or twenty-five .segnient.s, about twice us broad as long ; there in little sign of any ridging in the anterior part of the body, but toward the posterior part the spiniferous portion is clearly seen to be elevated abov»! the plane of the remainder of the segment. The wliole body is minutely and closely granulateil like a very fine shagreen (PI. 12, fig. 4s showing the first segment eidargcd); there are also .some slight signs of the .same circular disks that have been described in other specimens, and which are of the .same size as in Acnntherpestes major.
The subdorsal spines are placed in contiguous rows, whirh arc .separated by a considerar ble space from the lateral row, where only are any preserved entire, and that only in a few places. They are of more uniform length than the width of the body (PI. ll', figw. 17, 10), being about half as long as the width of the body where the latter is slender, an<l less than one-third as long in the anterior broader part ; they are almost simple, being conical and sharply pointed beyond a more or less mammiform base, curving .slightly back- ward, especially beyond a minute anterior thorn or spinule which springs from the end of the basal third, and is only sliglitly divergent from the main spine. The legs are pre- served at only one part of the fossil, in the slenderer portion of the body ; they appear (PI. 12, fig. 18) to taper throughout and almost unifonnly, or a little more rapidly on the apical than the basal half; there is plainly a median carina, and on some it even extends throughout the length of the leg, but it is impo.ssible to tell where the joints are ; the whole leg is 4.75 mm. long, where the width of the body is slightly less than that.
The second specimen (PI. 12, figs 9, 12) probably presents the animal throughout its entire length, exhibiting a side view of the creature, doubled upon itself downwards in front of the middle, the front portion consideraldy curved and overlapping the other. The body tapers forward, but not very strongly, from about the seventh segment ; the broadest part appears to have continued for about ten or twelve segments (the bend renders this uncertain) and then to have tapered rapidly, for the hinder third is uniform and nearly half as broad only as the broadest part ; the body was plainly cylindrical, about 42 nun. long, 4.25 mm. broad at the broadest part and 2.5 mm. in the apical half.
The head (PI. 12, figs. 14, 15) consists of a single segment considerably appre.ssed, well rounded, not so long as the next segment behind it, but much deeper than it and droop- ing ; what little can be seen of the surface is pitted and rugose ; something which look as if it might be an antenna droops from the upper anterior margin of the head, curved,8 tapering, and apparently rugose like the head, or else broken up into a great number of
17-2
S. n. SCFDDER ON SPINED MYRIAPODS
j»>iii(s ; tlio whole is howovor vorv problematical. The sogineuts are difficult to determine from the doubled position of the fossil, but there are apparently only twenty-eight of them ; m all excepting the broadest part of the body they are. twice as broad as long ; there, 'the\ are a little more than twice as broad as long; the anterior half is transversely ridged and bears the spines, while the posterior half is flattened. Tlie segments in the posterior portion of the body show a very faint, rather coarse and distant, scarcely noticeable granulation, but it is not elsewhere visible.
The subdorsal rows of spines are a little nearer to each other than either of them are to the lateral rows, as indicated by the pits ; the only spines that remain are a few of the sul)dorsal series, near the front and again at the hinder end of the body, all of which are simple, straight, regularly conical, bluntly pointed, and directed l)ackward ; they have no subsidiary spinules, and are less than half as long as the width of the segments on which they are seated ; a single one of the spines (PI. 12, fig. 11) appears double and forked; it is probably due to the accidental presence of a broken spine. The spines originate near the front of the anterior ridged part of the segments. A few legs may be seen scattered along one side of the hinder portion of the body ; none of them are perfect, and all that can be said of them is that they are slender (PI. 12, fig. 10), flattened and tapering, with a median carina, at least on the basal portions ; they are fully as long as the width of the segments to which they are attached ; the longest fragments, apparently showing the tips in natural position, are 2.6 mm. long and 0.25 mm. broad, the segment to which they belong being 2.25 mm. broad. A few legs may be seen depending from the anterior part of the body (PI. 12, figs. 14,15), and have special interest as certainly appendages of the first and second segments behind the head ; one is attached to the hinder part of the first segment, leaving ample room for another in front of it, and there is an obscure appearance of the base of such a leg at its proper place, having the same form and general direction as the hinder one ; in addition there is a third leg at the anterior edge of the second seg- ment of exactly similar appearance ; these legs are perhaps imperfect, but they are as Ion"- as the width of the segments at this point, compressed, tapering, straight and of moderate stoutness, with a slight indication of a median carina ; joints cannot be made out ; they are 3 mm. long and 0.5 mm. broad at base.
The third specimen (PI. 13, fig. 16) also represents the entire animal, bent in the middle and showing a partially side view, so that the legs appear on one side and the spines on the other. There are from thirty to forty segments besides the head, the exact number being indeterminable ; the larger part of the body includes the first sixteen segments ; with the seventeenth the body begins to taper considerably for several segments, and then narrows very gradually to the hinder extremity, which is only a very little more than half as broad as the broadest part ; in the broadest part the segments are rather more, in the narrower part somewhat less, than twice as broad as long. The specimen is 48 mm. long, 3.25 mm. broad in front, and 2 mm. broad behind ; in some places the surface appears to be closely and rather minutely granulated. The only spines preserved are some of those of the sub- dorsal row on the A'ider part of the body, where they are slender, conical, pointed, curved backward, as long as half the wndth of the body, generally furnished with a minute ante- rior spinule about the middle of the spine, wdiich is directed upward or scarcely forward ; the spinule Ls not half so long as the thickness of the middle of the spine, and is indeed
FROM THE {'AKBONIFKUoirs FoKMATIoN j-j
somotiines wanting. TIr- li-jrs aiv also prt'si-rvi'.! in tli.- .siin<- pint of the IhhIv uikI iiul elsewlitTc anil are consiikiably .•^liortt-r than tlit- width t>l' the hodv. Itv'iu^ (Uilv from \i.2G to 2.0 nini. long, where the body is eon.-^ideial.ly hioader. It ^hollld alho he noted tliut the eegnient behind the head bears not only a spine but apparently at lenut one jmir of iej^ while on the second and each of the succeeding segnient.s (wo pair.-* of legu are pn-M r\.d.
But the greatest interest in this specimen is found in the head and \U appfn<la^ri v It is very short, with a well rounded front, and e.xtends downward, a.n in tin- preceding fperi- men, consideraldy i)eyond the general lower line of the body. At its nppi-r outt-r limit one gees a rounded oval space covered with a cluster of aliout a dozen large prominent hemui- pherical wartlets, each separated from the others by nearly its own diameter, and which together represent, apparently, the eye. It will be noticed that it appears on the upiK-r part of the head and not, as in a specimen of Acanf/u'rjMntcs iimjar, on the lower part. Projecting beyond the lower edge of the front is seen a long and slender jointed organ, which seems to l)e an antenna, agreeing in a general way with that found in E. yrnnoMa. It is about as long as the legs, nearly ecjiial, perhaps a little larger in the middle than at the two ends, moniliform, composed of live subetjual, broad, obpyrifonn joint**, a little longer than broad, besides a much smaller, roundish oval, apical joint. The whole length of the antenna is 2.6 mm. and it.s middle width 0.3 mm. (IM. ]'■'>, fig. IS.)
This specimen differs from all the others in the greater length and slenderne.»>< of the subdorsal spines, but agrees so well in its other characteristics that there are hardly valid grounds for its separation from them.
The fourth specimen is the largest of all though not very perfect; apparently the whole creature from head to tail is represented. It is 75 mm. long and appears to have about 33 or 34 segments besides the head, but some of the po.sterior segments are very obscure, making the exact number uncertain ; the body tapers forward from altout the fifth seg- ment, but onh" slightly ; l)ack of this as far as the sixteenth segment or thereabouts, they are of nearly equal size, and then taper again a little more rapidly; but not so much .«o as usual in this species, although the hinder half of the body as a whole is only just half the breadth of the front part, the breadth in the front portion being 5.8 mm., in the middle of the hin- der half 2.9 mm., at the hinder extremity 2.5 nim., and on the fir.st segment behind the head 4.2 mm. The body is preserved on a dorsal view and the segments of the broader portion are a little more than twice as broad as long. Tiie spines are very small, shaped as in the first specimen described, and not more than one-fourth as long as the width of the body in its broadest part. The legs are only to be seen in a few places ; on the seg- ments directly behind the head they are about three-fourths as long as the wiflth of the segments, while near the miildle and a little behind the middle of the bod}' they are nearly as long as the width of the segment bearing them.
The head is about as long as the segments ne.xt it but much broader; indeed nearly twice as broad, being 7.5 mm. broad, with a well rounded front. No traces of any ajjpen- dages can be seen. The second and third segments behind the head bear each two pair of legs, and the first segment a spine. This and all the specimens hitherto mentioned were received from Mr. Carr.
The last specimen to be mentioned (PI. 13, fig 17), and which belongs to Mr. Armstrong, is a mere fragment of the head end of the body, showing about seven segments besides the
17 1 ■ S. II. SCUDDER ON SPINED MYRIAPODS
head, upon a side view. 'Pho tVagmont is ICi mm. lony;, somewhat curved, and shows spines upon one side and some legs upon the other. The spines are small and obscure, 1 mm. long nnd scaicelymore than one-fourth as long as the width of the body. The legs are more distinct and are considerably longer than the width of the anterior segments where only thev can be seen : a single unusually stout pair is attached to each of the first two seg- ments behind the head, much stouter than, though of the same length as, the legs behind tliem, i>robably from being preserved on a front instead of a lateral view, thus indicating the possible paddle-like condition of legs, which appear to be very slender ; whether there are other legs attached to those segments is uncertain ; these legs ai-e 3.5 mm. long, as long a.s the width of the body at this point.
The head is considerably larger than the segments Ijchind it and droops as in the second sjiecimen described, falling consideral)ly ])elow the level of the )x)dy. As there, the front is full and well rounded, and terminates below in a beak-like projection, forming a very pointed and slightly recurved lij). From the lower poi'tion of the front, at the base as it were of the lip, projects the single, basal, joint of an antenna, which is somewhat obovate in shape and 0.5 mm. long.
This .species is remarkable for the suddenness with which, and extent to which, the Iwdy tapers ; the hinder half as a whole is only about half as broad as the front half as a whole, and somewhere about the middle of the body nearly the whole alteration in size occurs, falling often upon three or four segments. In the character of its spines, it is closely related to the preceding species, but the subdorsal rows are not nearly so distant from each other. It is also related to the same species in the form of the segments as a whole, but differs in this resjiect from the two following species, in each of which the segments have a peculiar form, and where also the outline of the entire body is different.
The opportunity of studying this species is due mainly to the favor of Mr. J. C. Carr, of Morris, 111., for whom the species is named and to whose cabinet four of the five specimens belong. The remaining one belongs to the collection of Mr. P. A. Armstrong. They occur in the ironstone nodules of Mazon Creek.
Euphoberia flabellata, nov. sp. PL 13, tig. 15.
Through the kindness of Mr. Pike I have been able, after the other species had been studied, to examine another and tolerably well preserved specimen of this group of myri- apods, which can be referred to none of them. It lies upon its side, coiled into the commencement of a very open spii-al, and although preserving none of the spines and only a few of the legs, and these imperfectly, it is interesting from the good preservation of the hinder segments, and the exhibition of the dorsal and ventral plates abutting against each other along a line passing nearly down the middle of the exposed surface.
The entire body is preserved in its continuity and consists apparently of thirty-five seg- ments besides the head. The body tapers forward from the eighth segment or therealjout-. and rather rapidly, so that the anterior extremity, including the head, which does no appear to be larger than tlie segments next it, is scarcely one-fourth tlie width of tin eighth segment; behind this, however, it apparently tapers scarcely at all, until near tin hinder end, when the last six or eight segments, and especially the last four, rapidly narrow ; the dorsal plates however do diminish in size from near the middle of the body backward.
FROM TlIK CAnUOXIIKROrs FORMATION. i;-,
leading to the presumption, that, if hetter displayed, the creature would sliow the u*uai appearance of a swollen .second fourth of the l)ody. The dorsid plates are very iiuieh larger in the front than in the hiiul part of the animal, and are nearly ([uadrate or even slightly broader than long (as exposed), while in the middle they are of eijual U-nglh and breadth, and posteriorly are longer than hroad. This refers however only to the plates jw they are shown above the line which appears to separate, along the side of the body, the dor- sal and ventral plates ; but in the hinder third of the body, or the last dozen segments, one sees far below this line the true roinided lateral edges of the seginent.s ; between the two very diflerent margins the ventral jilatcs appear, and continue forward nearly to the head, with occasional indications of the division line between con.secutive d(»rsal plates seen through them, or through which the ventral plates are seen ; a.s in many other foswils, both carboniferous and tertiary, the sutural marks of both an originally uiulerlying and an overlying cbitinous mass appear upon the same surface, so as fre<iuently to render it quite uncertain which was originally superincumlicnt. Judging from these appearances the dorsal plates, perhaps only when ilattened, were four or five times l)roader than long, and in front of the last six segments regularly and fully rounded ; in these last six .segments, the anterior half i.s*rounded fis before, or very nearly .so, but the outer hinder angle is pro- duced, bearing a triangular process which extends to the middle of the succeeding segment ; together they give a straight margin to the sides of the body at this point, and evidently form by their combination a terminal flap, since the triangular proce.ss closes the lateral excavation which the rounded front angle would otherwise create (whence the specific name); a rapid forward and backward movement of this part, after the manner of macruran Crustacea, would propel the creature backward in the water; and we have .seen that the structure of these myriapods allowed so much freedom of movement between the joints, as to render it no great surprise to find a movement so peculiar for myriapods to- day indicated by the special structure of the segments. It adds too another fact in support of the theory that these were aquatic or partially aquatic animals.
Perhaps a similar flexibility of the body is indicated by a feature .seen in the ventral plates, which seems entii-ely diflerent from anything hitherto found in the Archipolypoda. These plates, as stated, are visible along the inner side of the body throughout a large part of its length, two to each one of the dorsal plates ; and along the middle of their course they are broken by a longitudinal suture, {i. e. transverse to the segment), which is only not con- tinuous from one plate to the next on account of the lateral sliding, due to tlie curled jwai- tion of the animal ; where it becomes straight, at the tail, these Ijrcaks are also continuous ; in one instance, near the middle of the body, the ventral plate is again broken by a .second suture next the dorsal plate, but no similar case is noticed elsewhere. Such a fracturing of the ventral plates has nowhere else been seen in these ancient myriapods from Mazon Creek, although in several the parts equivalent to these are amply exposed ; but their regularity here is such that it cannot be looked upon as accidental, but only as an inherent structural feature, and reminds one of the repeated and regular fracture of the dorsal plates in Xylobius, where I have shown this peculiarity to be a feature of the entire genus.
Next the outer side of the coiled specimen one sees, partly on one stone, partly on its counterpart, a partial duplicate as it were of the fossil, a feature which I have seen in
17 11 S. II. SCITDDER ON SPIXED MYRIAPODS
other fossils, and for \vliifli I scarcol}- understand how to account ; it is as if a cast of the creatnre had been t;iken. left connected at one edge, then turned over on this edge as by a huige, without rupture, and laid down beside it ; for here, and always, if I rightly recollect, it is concave while the fossil proper is convex. But here at least it does not perfectly re]H\it the parts which lie beside it, especially in that portion of it which I have had drawn, and which is on the half of the stone on which the fossil lies in relief; for the structure of the surface is quite diflerent, and is unifonuly flat (excepting for the general concave curve of the whole) instead of showing the irregularities of the bosses on which the spines rest, noticeable in the fossil itself ; this surface is finely and regularly striate in a transverse sense, a feature which no doubt belongs to the surface of the fossil at this point, since it is found elsewhere, but which does not appear here on the sijecimen proper. This fine transverse striation of the surface is a marked feature of this species, and seems to be confined to the dorsal plates, although in the portion of which we have just spoken it extends over a great breadth, a})i)arently as great as the entire sujjposed width of the dorsal plates, instead of being limited to the narrow breadth of the portion truly exposed at their side. The fine striation seen over the lower half of the body apically is either adventitious or it belongs to some similar cast as this puzzling duplicate ; it lies beneath the body in a different axis, for the lines are oblique to the true plates of the fossil, whether dorsal or ventral, and extend slightly beyond their actual limit.
Xo spines are preserved, but their position can be detei'mmed to be the same as in other species by the bosses which mark the bases of the upper series, and in a few places by the small ijits which mark the casts of the underlying spines of the lower series, seen through the segments above. Neither can the legs be made out, but only faint indications of them here and there of no value.
There is however an additional though problematical feature in this fossil, of much interest. Below the sixth segment behind the head, but still at some distance from it and therefore not necessarily connected with it, is the imjn-ession of a long and slender, sti'aight, rod-like body, consisting of a close series of delicate transverse impressed lines, cut by a central longitudinal impressed line ; it is half as long again as the width of the exposed dorsal plates at this point, and nearly or quite as slender as the legs must be. Taken by itself, it would appear of little importance, detached as it is from the body ; but considered, with somewhat .similar instances in other species of a long and straight appendage to seg- ments at about this point, it cannot be denied that it may indicate an iutromittent male organ at this point.
The length of the body, if uncoiled, would be about 44 mm. ; its extreme width 4.5 mm. ; its width next the head 1.75 mm. ; and its width at the seventh segment from the tail 3.8 mm. ; the length of the dorsal plates in the middle of the body is 2.1 mm. ; the length of the problematical rod 3.2 mm. The specimen comes from the Mazon Creek nodules, and wa.s sent me for study by Mr. J. W. Pike.
Euphoheria Jlahellata differs strikingly from the other species described in the form of the terminal segments, as well as in the comparative stoutness of the entire body, and its unvLsually tapering anterior extremity and small head. The spines being unknown and no clear indications of the legs preserved, these important features necessary to distinguish a creature of this sort are much to be desired, but the farther distinction of a transversely
FROM THE CARBONIFEROUS FnlJMATIOX. I77
striate surface of the l)ody may be nicntioiu'fl. It would Heem in wnne of itM featuruM to have closer resemblances than other Euphobt-riae to the genuM AinynilvKpet*.
Euphoberia angnilla, n<<\. >[>. I'l. 1'^, lig. -Jii.
The single specimen upon \vliiih tliis species is foumled is very obscure, but differs so much from all the others in the parts (hat ran be made out that it must Ite refi-rre*! to a distinct species. It is probably a complete animal preserved so as to show a dorsiii a>j>ect, bent laterally but not abruptly behind the middle, and the whdle, besides, curved in a sinuous manner. The body is remarkably long and slender, broadest from the seventh to tenth segments, tapering in front somewhat rapidly, so that the heail, whieii is s<iiiiewhat narrower than the segment behind it, is scarcely more than half as broad as the broadest part of the body; l)ehin(l the tenth segment it t<apers very gradually indeeil and with great uniformity over considerably more than half the body, .so that the hinder end is only two-fifths the width of the broadest part; this and its serpentine position give it an ccl-Iike appearance ; the length of the body is about 50 mm. ; its greatest breadth 3 mm. ; its breadth at posterior extremity 1.2 mm. Tlie head, as .stated, is narrower than tlie following segment and of the same length, subquadrate in form with a flatly rounded front ; no appendages can be made out. The segments of the body are diHioult to enumerate, owing to the obscurity of certain parts, and especially at the bend of the body, but there are somewhere between 32 and 36 and probably the number is 34. The bod}^ although almost completely flattened in preservation, does not wholly conceal evidence of a former trans- verse ridging of the anterior part of each segment, not shown in the figure ; probably also the body was cylindrical. The segments themselves vary considerably in their proportions, tho.se at the posterior end being much longer in proportion to their widtli than in the other parts of the body. The last six or seven segments for instance show a gradation from an almost perfectly square form, in the last segment, to a quadrate segment twice as broad as long ; while directly in front of this, and also in the broadest part of the body, they are three times as broad as long.
Marks of the position of some of the subdorsal spines can be made out with difiiculty, showing that these were not di.stant from each other. There is also on one side of the broadest part of the body a faint indication of a simple, straight, short, conical, outward directed, lateral spine, next the anterior margin of two or three successive segments ; it is scarcely more than one-fourth as long as the width of the same segments. No legs are visible.
This species is remarkable for its extreme .«lenderness and the delicate tiipering of the body, and the length of the posterior segments. In all these respects it difl'ers strikingly from all the species described.
The specimen is from Mazon Creek and was submitted for study by Mr. J. C. Carr, of Morris, 111.
Genus Amtxilyspes, nov. gen. (-j.-iyxu, duT-dnfia:.)
Spines so far as known sunple, conical and pointed, arranged in dorsolateral rows only ; segments nearly four times as broad as long, the dorsal plates terminating below in prob- ably free rounded flaps ; the extremities and perhaps the whole of the body more or less onisciform.
MEMOIRS BOST. SOC. NAT. HIST.
17S S- H. SCUDDER ON SPINED MTRIAPODS
This genus, represented by a single species and a fragmentary one at that, is so evidently distinct from Eujihoberia, to which it is most nearly allied, that there can hardly be any question of the undesii'ability of placing it therein even provisionally. Its definite separa- tion will call attention to its distinguishing characteristics and bring to light, much sooner than would otherwise be the case, allied forms in carboniferous beds.
Amjmilyspes Wortheni, nov. sp. PL i:i, ii.i,'s. 1-4, !).
A single specimen and its counterpart represent the antei'ior extremity of the body witl about ten or eleven segments. From these it would appear that the form of the bodj itself did not taper anteriorly, the first three segments behind the head forming with it the common rounded front of the bod}'^, each of the three segments becoming successively narrower and shorter from behind forward, while the head, still narrower but a littk longer, completed the onisciform hood which all combined to form. The body appears toj have been stoutly arched, a little flattened above, the sides and front equally deflected,] and by the compression of the ventral rings perhaps reaching or nearly reaching thej surface on which the creature crawled. With the exception of such modifications as are required for those in front to form the hood, the segments are all alike, each being nearly four times broader than long, and divided about equally into a longitudinally and strongly arched anterior half, and a gently arched posterior half; both portions help to form the deflected lateral lobes, which are triangular, well rounded, and terminate rather in advance of the middle ; at the outer edge of the dorsal field, the anterior lobe bears on each side a spine, straight, erect, simple, scarcely tapering above the basal boss until near the bluntl}' pointed tip, about half as long as the space between the two spines of the same segment; they are borne by every segment behind the head and are just as long on the narrower first and second segments as elsewhere. The head is a little more than half as broad as the entire body, as seen in the specimen simple, and forms the greater part of the front of the hoof-like anterior extremity of the body ; no aj^pendages can be made out.
The length of the fragment is 18 mm. ; its width 8.1 mm ; length of segments 2.15 mm. ; length of lateral deflected lobes 2.5 mm. ; length of spines 2.8 mm. ; breadth of head 5. -4 mm. ; length of the deflected head-shield 2.9 mm. ; space between spines of same segment 5.6 mm.
The single specimen comes from Mazon Creek and was received for study from Mr. P. A. AiTnstrong. I have dedicated the species to Professor A. H. Worthen, who was the first, with Mr. Meek, to detect the myriapodan character of these spined articulates in his Illinois Geological Reports and elsewhere.
Genus Eileticus, nov. gen. {aXr^ruo^.}
Segments longer than in the other genera, being considerably less than twice as broad as long, very few in number, and furnished in place of spines with a series of tubercles, of which there are more than one in the same row upon a single segment.
Although presenting at first glance a very different appearance from the types already described, there seems to be no reason why it should be separated very widely from them ; the spines are merely reduced to tubercles, and this reduction allows their multiplication along any one line, especially when the segments are at the same time longer than com-
FROM THE CARBONIFEROUS FORMATION. I79
mon. As in the other types, we find a pair of leg8 attached to thi- first wgmcnt behind the head and the head composed of only one sej^inent ; such agri'L-im-nt in general features will not pernut a wide distinction, while the minor (lini-rencus which du occur are cert^iinlv of generic value, especially when several are correlated.
Eileticus anthracinos, nov. »[>. I'l. 1:;. ti-s. :., 0.
This species is founded upon a sinj^le individual, exhibiting the lateral and partly don«al view of the anterior portion of the animal; how much is lost posteriorly i-aniiot be positively stated, but the body is unusually stout and short, is largest from the fourth to the eighth segments, and tapers toward either end. slightly in front, rajiidly liehind, so iin rather to indicate that the creature is nearly all preserved ; the body wa.s transversely arched and probably nearly cylindrical. It is 44 mm. long and 7.5 ram. broad in the widest part. The head (PI. 13, fig. 5 ) is very obscure, but it can be stated to have been well rounded in front, very shallow and bi'oad ; the shortness of the head is the more remarkable from its con- trast with the great length of the segments, being not one-third their length ; from the upper extremity of the front projects a very obscure appendage, which Ls nearly as long as the depth of the head, very .slender, regularly tapering to a point, nearly straight, slightly curved forward, and projecting upward and a little forward ; it ha« some appearance of being broken into a large number of joints.
The segments behind the head are only eleven in number ; longitudinally the}' are per- fectly Hat, showing no sort of appearance of an anterior transverse ridge, but they are never- theless composed of two nearly equal parts, a slightly larger anterior part which appears to have been more chitinous, and a posterior more membrauous ; these segments in the broad- est part of the body are 5.5 mm. long, so that they are only half as broad again as long their surface is entirely smooth excepting for the low mammiform tubercles which take the place of the spines, and which appear to be arranged in low lateral and subdorsal rows. In the lateral row there are two to each segment in the .same row, one in either longitudi- nal half of the segment, of which that on the anterior half appears so much more prominent that it may be the base only of a real spine ; in the subdorsal rows, there are three in a row on each segment and confined to the anterior half of the same ; these mammiform elevations are shallow and transversely ova or roundish.
Three or four legs are preserved at the anterior extremity, showing the diplopodous character of the fossil and that the legs were long and s ender ; they are apparently about 6 mm. long where the body is 7 mm. broad, and they are about 0.5 nun. broad in the middle ; they appear to be flattened, but from their fragmentary nature no determination of their jointing can be reached. They are interesting from their attachments, for one of them certainly proceeds from (though it is not in absolute connection with) the anterior part of the second segment behind the head, while one in front of it is similarly relat<.'d to the posterior portion of the first seguiont ; there is also something that looks like the frag- ment of a leg in part of the last, and which, if so, must be a second leg to the first segment behind the head.
This specimen comes also from the Mazon Creek nodules and was communicated by Prof. A. H. Worthen, of Sprmgfield, 111.
lv;() S. H. SCUDDER OX SPIXED MYRIAPODS
It inav ho well, in closinti; this paper, to refer to other m^'riapotlal or supposed luyria- poilal remains from the paleozoic formations. No mention has Ijeen made of one, Palaeo- juliis (li/adicus Geinitz, from the Saxon Permian, because its myriapodal nature has been denied.' and it is now conceded by its author to be a fern, as shown by Sterzel, and in any event is too imperfect to be discussed here. Three species of lulus have also been named (only) by Fric'^ from the Permian rocks of Bohemia. Anthracerpes ty2nis from the Ma/on Creek beds described by Meek and AVorthen,^ w'hich these authors were " rather inclined to view as a nwriapod " Avhen first descriljcd, has been referred to the Avorms, and was afterward so considered by its dcscribers ; it is perhaps very fragmentary and may belong here. Goldenberg desciibes and figures,'' under the name of Athopleurion \_Arthro- pleurion f] inermis, a jointed fossil from the coal measures of Saarbriick, which he considers a crustacean, perhaps allied to Arthropleura, and which may possibly be a myriapod ; it is, however, not worth discussion until something more perfect and somewhat resembling it is found. Finally Jordan has described and figured.^ and Goldenberg^ also, another jointed creature, also from near Saarbriick, which they consider a crustacean, and to which Jordan has given the name of Chonionotns lithanthraca. It is here reproduced in PI. 11, fig. 9. It bears certmn resemblances to these spiny myriapods, and perhaps belongs to Acanther- pestes. It is however a mere fragment, consisting of only five segments, including perhaps the head. The segments are about four times as broad as long, uniform in size, uniformly and not greatl}- arched, with no division into an anterior and posterior subsegment. There is a mediodorsal groove, a row of approximate subdorsal tubercles (broken bases of spines ?) sit- uated centrally on the segments, and a pleurodorsal series of similar but a little smaller tuber- cles showing only on one side. These extend over the four segments behind the front one ; this latter is smooth and w-ell rounded in front, as long as the other segments and may possibly represent the head. The length of the fragment is 14 mm. and its breadth 8 mm. By the presence of two rows of spine-bases (?) on either side above (any lateral series not showing), it must be nearer Acantherpestes than Euphoberia ; provided indeed it belongs in this group at all, which the fragmentary nature of the fossil by no means allows us to assert.
>Cf. Sterzel, Zeitschr. deutch. geol. Gesellscli., 30: 417- ^Faiina saraep. foss., ii, 48, pi. 2, fig. 20.
426;Neues Jahrb. Mineral., 1878, 729-731; see also p. 733. « Palacontogr., iv, 12-13, tab. 2, fig. 3.
^Faun. Gaskohle Bohm., i, 31 (1879). « Fauna s.-xraep. foss., i, 21, pi. 1, fig. 19. "Geol. Surv. 111., ii, 409, pi. 32, fig. 1.
FROM TlIK CAKHOXIFEROL'S FOKMATIOX. HJ|
Exi'LAXATION OK TlIK 1*I„\TES.
Acanthcrpcstes major. Attem|iteil restoralion <jf ii 8].eciiiuii, not <.f th,. lar^iiit »uo, for wlti<li there wm
not rgom on the phiti-. The lioily is inailt- ratlicr too hk-inliT nn"I not itunii-itntiv ta|H'rtnK ; th-- 1 ■ «.l I ■_• v«Ty
iniperfoctly known, is conccalud l>y a ilroo|iing fmrnl of Xmropteriii ('tarknuni I^-w|. Th< ■.i.rf.
eentc'ilas knvintr the water in which it is still swiniining by nieanH of itx himltT h-^, an-l :i~ iii ihi-
trunk of a Lepido.lrentlron (L. vtsd'tutn Lesq.)- Upon the trunk crawls a coikroaeh, Kloblatdna mazonti Seuiltl., while a broken stem of a Calaniites {C. Cintii Brongn.) has partly fallen into a rliimp of ft-ni, Nenroptiri.1 Lotschii Brongn. All the figures are of the natural size, un<l repretivnt iipe<-iL-N fountl in the noilules of Mazon Creek. The plants however, with the exception of the liuit, are anionic tlie rarer ii|K><'ie«. Drawn) bv J. S. Kingslcv.
[Figs, l and 10 are from the drawings of J. II. Blake; figs. .') and !t are copied ; the remainder an- l>v J. S. Kingsley. All the original drawings are from sj)eeiinens in the collection of .Mr. Carr.]
Fig. 1. Arant/urjh'stt's major \. This specimen shows in the inid<lle the interior fnccn of the ventral plates, and elsewhere the dorsal jilates.
Fig. 'J. The same '{. The reverse of the central portions of tig. 1, showing nearly the appearance of the under surface of the body.
Fig. 3. T/te same ^. The central portion of fig. 1, magnified.
Fig. 4. T/te same ^-. A pair of the sujijiosed branchial sujijiorts, as they aj)pear in fig. '2, enlarge .
Fig. 5. Acaitthtrpestes Srodui of England }. Co])ied from I'l. 1, fig. 11, of Brodie's Fossil initecta of the secondary rocks of England.
Fig. 6. AcanthcrjHStcs >naJor ]. The most perfect large sjteeimen that has been discovered.
Fig. 7. The same {. One of the di.sk-like bodies which cover tlie surface of the whole fossil excepting the legs.
Fig. 8. The same J. One of the subdorsal spines of fig. G, on the hinder part of the body; it unfortu- nately does not show the base of the third sj)inule referred to in the text, the original drawing having lKH?n lost.
Fig. 9. Chonionotus lithanthraca of Germany \. Copied from I'alaeontographica, Vol. I\', pi. -, fig. 8.
Fig. 10. Acantherjxstes major \. The head of a third specimen, to show the eye.
Fig. 11. The same ^. Three adjoining legs from the middle of the body of the largo specimen repre- sented in fig. G.
PLATE XII.
[Figs. 7, 8, 21 and '23 are copieil. The others are from drawings by .1. .'^. Kingsley.]
JEuphoberia artnigera \. Specimen from Mr. Carr's cabinet.
The same \. An enlarged sjiine from the above.
The same \. An enlarged view of the head of the above.
Euphoberia Carri \. Part of the anterior segment of the sjiecimen shown in fig. IG.
Uuphoberia armigera ^. Anterior extremity of the sjiecimen shown in the next figiin .
The same. \. Specimen from Mr. Worthen's collection.
Euphoberia Brownii of Scotland. Enlarged view of some of the segments. Copied from the Geological Magazine, Vol. VIII, pi. 3, fig, 6 b.
The same. One of tlie legs still further enlarged. Coj.ied from the same, tig. G r.
Eujjhoberia Carri f The doubled specimen from Mr. Carr's collection.
The same J. One of the legs, poorly preserved, from tlie same specimen.
T/ie same ^. The apparently forked spine of the same 8i>ecimen.
The satne \. The reverse of tlie same specimen.
Euphoberia armigera f Two of the segments of the anterior hilf of the specimen show-i in fig. 6, exhibiting the spines.
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jv;o S. 11. SCITDDER ON CARBONIFEROUS MYRIAPODS.
Fiff. 14. Eiiphobtria Carri ?. The liciul of tlio sinH-inion sliown in tig. 12, enlarged.
Fiaj. 15. The same f . The head of the specimen shown in fig. 9, enlarged.
Fis. 16. 'The same \. The L-sliajied speeinien from I\Ir. Carr's collection.
Fill. 17. The same \. A pair of the spines from tlic anterior end of the last mentioned specimen
Fi<». IS. The same \. One of the legs on the Idnder jiart of the body of tlie same.
Fill. 19. The same \. One of the spines on the hinder part <if the body of the same.
Fig. '20. Euphoherlaaiujuilla f. From Mr. ("arr's collection.
Fi?. '21. £uj>hoben'a Broicnii of Scotland {. Cojiied from the Geological Magazine, Vol. VIII, jil. 3. tig. 6 a.
Fis. "22. £uphoberia ffi-anosa ^. Tlie sjiecimen sliown in fig. 25, enlarged.
Fisr. '23. Eiiphoheria ferox oi England^. Cojiied from Woodward's figure in the Geological Magazine,
Vol. X. p. 105.
Fiij. '24. Euphoberia granosa f. Tlie tenth segment of the specimen shown in tlie next figure, with the spine.
i
Fig. 25. The same \. From Mr. Worthen's collection.
Fig. 26. The same f . " Reverse of the specimen shown in figs. 22 and 25.
PLATE XIII. [Figs. 5, 6, 11, IC, were drawn by J. S. Kingsley ; the others by J. IT. Blake.]
I
Fiff. 1. Amynibjsjyes Worthcni f. Dorsal view of the fossil in relief. From the collection of Mr. Armstrong.
Fig. 2. ITie same f . Dorso-lateral view of the same.
Fig. 3. The same J. Lateral view of the same.
Fis. 4. The same f . View of the cast from above.
Fiff. 5. Eileticus anthracinics f . The anterior portion of fig. 6, enlarged. Tlie fractures in tlie third appendage are accidental and do not represent joints.
Fif». 6. The same {. The entire specimen. From the collection of Mr. Worthen.
Fi". 7. Exqihoberia armiyera. The anterior portion \, showing the head and antennae ; and the suc- ceeding segments of the anterior part of the body ^, showing the spines ; the hinder segment of the more magnified portion is re] leated in the front segment of the less magnified jiart. From the collection of Mr. Bliss.
Fig. 8. The same ^. Three or four segments from the stouter part of the body, showing not only the Bpines and legs, but also the stigmata. From the collection of Mr. Pike.
Fig. 9. Amynilyspes Wbrtheni J. The front spine of figs. 1-3.
Fig. 10. Eujthoberia armigera \. One of the legs, showing very well the division into joints. From the collection of Mr. Carr.
Fig. 11. Euphoberia horridti \. From Mr. CaiT's collection.
Fig. 12. Tlie same f. The supposed intromittent organ. From the collection of Mr. Armstrong.
Fig. 13. Euphoberia granosa ^. The anterior portion of the specimen, showing the head and antennae, the legs, and a few spines. From Mr. Carr's collection.
Fig. 14. Euj>hoberia horrrida Y-. A fragment of fig. 11, from near the middle of the sjiecimen on the right side, to show the character of the surface.
Fig. 15. Euphoberia Jlabellata ^. From Mr. Pike's collection.
Fig. 16. Eujyhoberia Carri f. From ]Mr. Carr's collection.
Fig. 17. The same ^. The anterior portion of tlie body, showing the basal joint of the .antenna. From Mr. Armstrong's collection.
Fig. 18. ■ The same f . The anterior portion of the reverse of fig. 16, to sliow better the head, with its eye and antennae, as well as the legs, the comj^arative breadth of the anterior ones of which is the ojiposite of what obtains in fig. 16.
Note. The introductory part of this paper, nearly as given here, apjjeared in the American Journal of Science for March, 1881.
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scjC'DER on
VI. Some Odservatioxs ox the Embuyolooy of the Teleosts.
By .1. S. KiNGSLEY AND H. W. ( 'oNN. Ri-ad .M.ircli 15, 188->.'*
1 HE following observations on tlio development of a marine bony li-^h were mado at the Summer Laboratory of the Boston Society of Natural History at Anniwiimm, Miuu., (luring the months of June, July and August 1881. Most of the facts here recorded Imvo been witnessed by both authors and in the majority of cases have been repeated many times. The composition of this article is the work of Mr. Kingslcy and when the pronoun " we " occurs in the following pages it indicates the fact that I)otli of its arc responsible for the statements presented, the phenomena which were witnessed Ijy Mr. Conn alone are indicated by the use of his name, while the " I " which will be frequently met in the courHC of the article indicates that Mr. Kingsley alone is responsible for the statement or interpre- tation presented. As we separated soon after the conclu.sion of the observations herein recorded, it has fallen to the lot of Mr. Kingsley to make the comparisons with tiie work of other authors ; and the whole discussion of previous results, with the exception of a portion of the work of Oellacher, has been done by him. The bibliography which follows has been wholly the compilation of Mr. King.sley and embraces only those papers which have been consulted during the preparation of this article. Nevertheless it is hoped that it may prove of use to other students of Vertebrate Embryology. I have adopted the method of referring to these various papers which is used by Dr. Mark in his valuable memoir on the Maturation, Impregnation and Segmentation of Limax ; viz : the name of the author followed by the date of the article in full faced type. Where two or more articles by the same author were published in the same year they have the additional letters ', ", % etft,
BIBLIOGR.VPny.
Agassiz, Alexander E. R.
'76. The development of Flounders <Aincnc.nn Naturalist, x, pp. 705-708 (1876).
'77*. On the young stages of some osseous fishes. I. Development of the tail < Proceeding* of iho American Academy, xiii, pp. 117-127, 2 pis. (1877).
'77^ Sur le developpement des Pleuronectes< Journal de Zoologie vi, pp. 19.S-197 (1877). • Owins to the long delay in the publication of this article for pursuing my investigations I wouM return thankt to Pro- I have had an opportunity to add extensively to it, h.iving fessor Hyatt and Mr. Van VIccic for Uicir kimincM and Um gene over niucli of the ground again during the summer of facilities afforded me during the two aammcn fpcnl at 1882. The additions, however, will .ill appear as foot-notes Annisquam. each with the date 1882. For the opportunities enjoyed
lj;4 KINGSLEY AND CONN
78*. rS!>'"*> t'*''-"' •''-'' ""*]• Abstract < Annals and Magazine of Natural History, Series v, Vol. i, pp. 419- 4-Jl (1878).
7S^ Einliryoloiiy of the Gar Pike<Seieuco News, i, pp. 19-20 (1878).
'79'. On the young stages of bony iishes<Proc. Am. Acad. Arts and Sciences, xiv, pj). 1-25, pis. in-x (1879).
'79*. The development of Lei)idosteus<Proc. Am. Acad., xiv, pp. 65-76, pis. 5 (1879).
'82. On the young stages of some osseous fishes. Part ni<Proc. Am. Ac;rI. xvii, pp. 271-303, 20 pis. (1882).
AlllEUT, IlERJrAN.
'54. BeitraiTc zur Entwickelungsgcschichte der Fische<Zeitsclirift fiir wissenscliaftliche Zoologie, Bd. V, pp. 94-109, pi. VI (1854).
'56. (Same title as '54] 1. c. Bd., vii, pp. 345-364, pi. xviii (1856). BALForR, Feancis Maitland.
'75. A comparison of the early stages in- the development of Vertebrates < Quarterly Journal of Microscopical Science, Vol. xv, p. 207, pi. x (1875).
'76*. On the origin and history of the urogenital organs of Vertebrates < Journal of Anatomy and Physiology, x, pp. 17-48 (1876).
^O"". On the development of the spinal nerves in Elasmobranch Fishes < Philosophical Transactions of the Royal Society, Vol. clxvi, pp. 175-195, pis. xvi-xviii (1876).
'76'. [Abstract of 76^ same title] <Proeeedings of the Royal Society, Vol. xxiv, pp. 135-136 (1876).
'76*. On the development of Elasmobranch Fishes <Journ. Anat. and Phys., xi, pp. 877-411, 517-570; 672-688, pis. XV, xvi, xxi-xxvi, xxix (1876).
'77. [Continuation of 76'']<?. c. Vol. xn, pp. 128-172, 416490, 674-706, pis. v, vi, xv-xix, xxiv, xxv (1877).
'78. A monograph of the develoi^ment of Elasmobranch Fishes. London, Macmillan & Co., pp. xi, -f295, pis. 20, (1878).
'80. A treatise on Comparative Embryology. London, Macmillan & Co., Vol. i, pp. xi -j- 492 + xxn, (1880).
'81. [Same] Vol. ii, pp. xi + 655 + xxn (1881). Van Bajibeke, Ch.
'70. Recherches sur le d^veloppement du Pelob.ate bran (Pelobates fuscus, Wagl.) <Mem. Savants Etrangers Acad. Roy. Belgique, t. xxxiv, pp. 66, pis. 5, 1867 (1870)..
'75. Recherclies sur I'Embryologie des Poissons osseux. Rapport de M.Ed. Van Beneden< Bulletin Acad. Roy. Belgique ii, Serie, t. xxxix, pp. 75-84 (1875).
'76. Recherches sur I'embryologie des Poissons osseux < Mem. Sav. Etr. Acad. Belg. xl, pp. iv-|-66, pis. 3, (1876).
Bacdelot, E.
'73. Observations sur les structure et le developpement des nageoires des Poissons osseux < Archives de Zoologie experimentale, t. u. Notes et Revue, pp. xvm-xxiv (1873). Van Benedkn, Edouard.
'70. Recherches sur la composition et la signification de I'oeuf [etc.] <M6m. (Jour. Acad. Belg. t. xxxiv, pp. 283, pis. 12, 1868 (1870).
'75. (See Van Bambeke '75).
'78. A contribution to the history of the embryonic development of the Teleosteans<Quart. Journ. Micros. Science, xviii, pp. 41-57, 1 pi. (1878). Beooks, William Keith.
'81. Alternations of periods of rest with periods of activity in the segmenting eggs of Vertebrates <Studies from the Biological Laboratory of Johns Hopkins, Univ., Vol, ii, pp. 117-118, pi. viir (1871). Bruch, C
'55. Ueber die Mikropyle der Fische<Zeitschrift f. wiss. Zool. vii, pp. 172-175, pi. ix (1855.) Calbebla, E.
'77. Zur Entwicklungder Medullarohrcs und der Chorda dorsalis der Teleostier und der Pctromy- «)nten<Morphologi6che8 Jahrbuch, Bd. m, pp. 226-270, pis. xii-xiii (1877).
ox THE EMr.UVor.oGY (>K THE TELEOSTS. 185
Foster, Michael ami Balfouk, F. M. '74. Tin- Eli'intMits of Emliryology. VI' London, Mucniillun «fc Co^ pp. six + 272 (lt<74>.
Gaim.hk, Tiie"datu8. Ou the artiliiial n.|)ro(liiction of Fi8hc9<Proo. Clovelaml AcaJemy i, pp. MO-91. 1H54 (1H74).
Gkns<mi, II. '80. Die BIutbiMung auf ilein Dottersack boi Knochonfi8chon<Archiv f. Mikr. Anat. B<1. xix, pp. 144- 146 (1880).
GOTTE, A.
'78. Ziir Entwickelungsgcscliichle tier Teleoslierkieiue<ZoologiMcLor Aujteiger 1 Jahrg. No. 3, p. 62 (1878).
'73. Beitriigo zur Eiitwickelungescliiclito <lor Wirbelthiere. I. Dcr Keiin tlea Forellencif»<Arcb. i.
Mikr. Anat. i.k, j.p. G71»-708, pi. x.wii (1873). '78''. Beitrtiire zur Enlwiekelungsgeschiclite der Wirbelthiere III. Uober die Eotwickeltingder Central- Nervensysteui<Areh. f Mikr. Anat. xv, jip. 139-199, pis. vn-x (1878). Hexneguy, L. F. '80. On some facts in regard to the first phenomena of the development of the omcous fiitho(i<AunalN and Mag. Nat. Hist., v Series, Vol. vi, pp. 402-404 (ISSO) (Extract Bulletin Soc. I'hilomath. de Paris, Apr. 10, 1880).
His, WiLHELM. '73. Untersuehungen liber das Ei uud die Eientwickclung bei Knoehenfischen, 4" Leipzig, F. C. W. Vogel, pp. IV + 54, 4 j.ls. (ls73).
'75. Untersmhungcn Uber die Entwiekelung von Knoehenfischen, besonders Ober diejenigo dca Salmens<Zeitschrift f. Anat. und Entwickelungeschichte, Bd. i, pp. 1-40, pis. i-ii, (1H75). Hoffman, C. K. Zur Ontogeuie der Knoclienfische<Verh. der. k. Ak.ad. v. Wetensch. xxi, p]). 107, jils. 7, (1*''<1).
July, N. '72. Observations on the metamori)hoses of the bony fishes in general and especially on those of a small Chinese fish, of the genus Macropodia, recently introduced into France < Ann. and Mag*. Nat; Hist, iv, X, pp. 403-465 (1X72) [from Comptes Rendus Sept. 30, p. 76C, 1872]. Klein, E. '72. Researches on the fii-st stages of the development of the common trout, S.alino fario<Monthly Microscopical Journal, vii, pp. 192-200, pis. xvi-xvn (ls72).
'76. Observations on the early development of the common trout, Salnio fario.<Quart. Journ. Micro. Sci. XVI, p. 113, pi. VI, (1876).
KUPFFEK, C.
'68. Beobachtungcn tlber die Ent^nckelung der Knoehenfischen < Arch. f. Mikr! Anat., iv, pj>. 209-272 pis. XTi-xvni (l^Os).
'65. Untersuehungen uber die Entwickelung des Harn-und Ge8chlechts-sy8tem<Archiv f. Mikr. Anat. I, p. 233 (1865).
'66. [Same continued] <1. c. n, p. 473 (1866). Lereboullet.
'54. Resume d'un travail d'embryologie corapar6e sur le develoi)pemcnt <lu Brix-hct, de la Perche et de rEcrevisse<Anuales des Sciences Naturelles, Zoologie, iv serie, i tome, pp. 237-2X9 (1N54),
'61. Recheiches d'embryologie comparee sur le d^veloppement de la Truite, du Lezard et du Limu^-e <Aun. Sci. Nat., iv, xvi, pp. 113-196, pis. n-m (1861).
'64. Nouvelles recherches siu- la formation des premieres cellules embryonnaire8<ADn. ;Sci. Nat., v. u pp. 5-41, pi: I (1864).
MULLER, JOHANN.
'54, Uebev zahheiche Porencaniile in der Eikapsel der Fische<Arch. f. Anat. u. Phys., pp. 1H6.190, .pi. vni, F. 4-7 (1854).
Oellachek, Josef. '72°. Beitriige zur Gcschichte des Keimblaschen im Wirbelthiere < Arch. f. Mikr. Anat., viii, pp. 1-27, pi. I (1872).
MEMOIKS BOST. SOC. NAT. BIST. VOL. m. 24
ISO
KI^'GSLEY AND CONN
'~'2\ Boitrii'jo xur Ent wiokclun,s;sgeschichto der KnoclKiifisclio, naeh Boobachtungcn am Bachforcllcneie <Zeitsch. f. Wiss. Zool., xxii, pp. 373.
73. [Continuation of 72"] <1. e. ]>.l. xxiii, ^k 1-115, pis. i-iv, (1873).
OWSJ.VXXIKOW, Pll.
7'2. Ueber dio orston Vorgiintje der Entwiikolung in don Eicn dcs Corcgonus lavaretus<Melange8 Biologiqiics Acad. St. IVtorsbourg, t. ix, p]>. 198-212, 1 pi. (1872).
'74. [Sanic]<Bidk-tin do I'Aead. St. Petorsbourg, t. vii, pp. 225-235, 1 pi. (1874). Ransom W. II.
'G7*. Obsorvations On the ovum of osseous fishes <Philosoj)hioal Trans. Roy. Soc., Vol. clvii, pp. 431-501, pis. xv-xvii (18C7).
'67^ On the structure and growth of the ovarian ovum in Gasterostcus leiurus< Quart. Jour. Micr. Sc ., vn (New Series) ]>p. 1-4, (1867). Reich KKT, K. B.
'56*. Uebor die Micropyle der Fischeier und Uber einen bisher unbekannt.en, eigenthiinilichen Bau dcsNahrungsdotters reifer nnd befruchteter Fischeier < Arch. f. Anat. u. Phys., pp. 83-124, ph. ii-iv (1856).
'56^ tn>er die MuUcr-Wolffschen Korpcr bei Fischenibryonen und uber die sogenannten Rotationcn des Dotlers ini befruchtcten IIechteie<l. c. pp. 125-143 (1856).
'58. Beobachtungen Uber die ersten Blutgefassc und deren Bildung sowie Uber die Bowegung des Blutesiu derselbenbei Fischembryoneu<Studicn a. d. Physiolog. Institut zu Breslau, i, pp. 1-94, 1 pi. (1858). Reixeck.
'C9. Uber die Schichtung des Forellcukeims<Arch. f. Mikr. Anat., v, pp. 356-366, jil. xxi, (1869). Ryder, John. A. -
'81*. . Preliminary notice of the more important scientific results obtained from a study of the embry- ology of Fishes<Bulietin U. S. Fish Commission, i, pp 22-23, (1881).
'81^ Notes on the development, spinning habits and structure of the four-spined stickleback, Apeltes quadracus.<l. c. pp. 24-29) (1881).
'81'. Development of the Spanish Mackerel (Cymbium maculatura) <1. c. pp. 135-165, pis. i-iv [xiii- nv] (1881).
'81"". On the retardation of the development of the ova of the shad (Alosa sa2)idissima) with some observations on the egg fungus and Bacteria<l. c. pp. 177-190) (1881).
'8P. A contribution to the development and morphology of the Lophobranchiatcs (Hippocampus antiquorum, the sea liorse<l. c. pp. 191-199, pi. xvi, (1881).
'82*. Development of the silver gar (Belone longirostris) [etc.] <1. c. pp. 283-301, pis. xix-xxi, 1881 (1882)
'82'. On the nuclear cleav.ige figures developed during the segmentation of the germinal disc of the salmon <1. c. pp. 335-339 pi. xviii, 1881 (1882.)
RUDWAXER, JoSEF.
'76. Ueber die erste Anlage der Chorda dorsalis<Sitzungsberichte der k. k. Akad. zu Wien, Bd. Lxixi, Abth. m, pp. 1.59-165, 1 j)l. (1876). ScH.vPRiNGER, Alois. '71. Ueber die Bildung des Medullarohres bei den Kuochcnfischcn<Sitz. k. k. Acad. Wieu., Bd. uciv, Abth. m, pp. 653-656, (1871). Scott, W. B. '81. Beitrage zur Entwickelungsgeschiclite der Pctromyzonten<Morphologischcs Jahrbuch,vii, pp. 101- 172, pis. vii-xi (1881).
Scott, W. B. and Osborn, Henuy F. '79. On some points in the early development of the common newt <Quart., Jour. Micr. Sci., xix, pp. 449-475, pis. xx-xxi (1879). Stkicker, S. '65. Untersucliungen (iber die Entwickelung der Bachforelle<Sitz. der k. k. Akad. Wien, n Abth 2, pp. 646-554, pb. i-ii (1865). VoGT, Caul. '42. Embryologie der Salmones<In Agassiz, Histoire Naturelle des Poissons d'eau douce de TEurope centrale, 8" with folio atlas of plates, pp. 328, Neuchatel (1842).
ON THE EMBRYOLOGY OF THE Till.. --> I >. ig;
The rggs on which we workml were ohtaiiKMl by siirlac-e Hkimiuiiig and were usually found in ahout equal abundance at day and in the eveninj?, and n.f a rule were rather more al)undant wlien the tide was coming in than when it was running out. One or two evenings however proved an exception to tlie ride, as once witlj about half an hour's skim- ming we found over 70U eggs by actual count. This large number however wius except- ional, one hundred or one hundred and fd'ty being near the average.
The most numerous form of egg and the one on which our ol)servation.s were principally made wa.s perfectly spherical, about a thirtietli of an incii in diameter, jind perfectly transpar- ent. The shell enveloping it(r/i'>rJo« of older authors) was extremely thin and only luider high powers showing a doul>le contour. A Tolles one-tenth objective revealed no traces of any structure in it, nor were there visible any pores such as exist in the eggshells of many Teleosts.' The various preparations of carmine and haeraatoxylin as well jis the anilines very quickly stained the shell, but a prolonged immersion in any staining lluid colored the contents of the cg^^ but very imperfectly and very .slightly, thus ofTering a striking contrast with the eggs of Merlucius which were studied at the same time by Mr. Van VIcck, and which stained ea.-^il}' and well. As our eggs were obtained by skimming and were mature and fertilized, there existed between the shell of tlie egg and the egg proper a narrow space tilled with a transparent fluid in which the yolk floats freely. This space is the breathing chamber of Ransom. The food yolk or deutoplasm comprises the greater por- tion of the egg over one side of which the formative yolk, or protoplasm, is spread as a thin layer. The deutoplasm is perfccth' colorless, free from all oil globules or granules of any sort and of nearly the same refractive index as the salt water in which the eggs were kept, render- ing it an operation of some ditficulty to pick the eggs out of the water in which they were kept, on account of their being nearly invisible. The protoplasm was in the early stiiges" relatively ver}' small, composing less than a twentieth of the bulk of the egg. Like the deutoplasm it was perfectly free from granules or globules of oil or food-yolk but it was of a very pale straw-color and was more refringent than the deutoplasm. With eggs of such transparence one could easily watch most of the changes going on, even in the interior of the egg, while it was on the stage of the microscope, thus affording in this respect a more favorable object than the egg of the trout which has been the subject of so much investi- gation in Europe.
xUpon the above described egg most of the observations were made which form the basis of this paper. When any other form is used the fact will be stated in the text.
We greatly regret that we are unable to identify the eggs on which we worked,^ but all attempts to rear the young fish beyond a few hours after hatching proved futile. We tried, keeping them at the ordinary temperature of the room, keeping them in an ice chest, and in breeding boxes, allowing a free circulation of water, or placed in the water from which the 3"oung were taken, but in vain. Mr VanVleck had no better success with the young of Merlucius.
From the numbers of eggs which we found we supposed that they must belong to some abundant shore fish, and the following observations may aid in approximating the .species. The floimder {Platessa americana) is, according to a letter to Mr. G. Brown Goode, a win-
^ Conf. His. '73 pi. I J. Aubert '54 pi. vi, fig. 1. eggs, which turned out to l)e, as suspccteJ, those of the Cunncr
- During the summer of 1S82 I w.-is able to identify the (Clenolabrus cocruleus.')
ivjji KIXGSLEY AND CONN
ter si>awnin>r lish. The ogcjs of the smelt (Osiuerus) are over twice the size of those on which wo worked. The e^igs of Merliicius, Microgadus, Motella, and possibly of all of the Gadidae have one or moi*e conspicuous oil globules in the deutoplasm. The eggs of the Cunuor {Cteuolabrus coeritleus) taken from the living fish, very closely resemble our specimens in size and appearance, and it seems to us that the probabilities are in favor of our eggs belonging to this species.
()n the other hand one would expect to find (if there be any con'espondence between closolv allied fish and their eggs which, with the possible exception of the Gadidae men- tioned above, has not yet been shown ^) a similarity between our eggs and those of the perch as described and figured by LerebouUet and Ransom. LerebouUet describes the e'fg of the Eui'opeau perch ( '54 p. 241-242) as transparent vesicles containing " glob- ules graiseaux et un grosse goutte huileuse " and also as agglutinated. These features were seen by us neither in the ovarian egg of the Ctenolabrus nor in the ripe, unsegmented e<r>' which we studied. Neither w^ere there present any filiform appendages. Ransom has given a separate description of the egg of the same species, but we saw none of the pores, the rvthmic contractions, nor the micropyle ^ which he figures and describes, nor any such tubes as he shows ( '67' PI. XVI, fig. 26 etc.). The mode of development, especially in the early stages, is also far different from that "of the perch as epitomized by LerebouUet.
The other eggs upon Avhich observations were made were :
1. An egg of similar size and appearance with a large reddish colored oil globule in the deutoplasm.
n. An egg of the same size with several reddish oil globules and a slightly granular protoplasm and deutoplasm.
III. A larger egg, about a twentieth of an inch in diameter with one large oil globule.
III. A large egg, about a fifteenth of an inch in diameter (twice that of our form) and like it in being perfectlj'^ transparent and in possessing no oil globule, though both its pro- toplasm and deutoplasm were slightly granular. In all of these eggs the relative amount of food and germinative yolk were about the same.
These eggs all floated at or near the surface of the water and presented a marked con- trast to those of an Elasmobranch, Batrachian, Reptile or Bird (and which I have never happened to see mentioned as a characteristic of fish eggs) in that the germinative portion is invariably downioard, or on the lower surface of the egg while the deutoplasih is uppermost. This peculiarity renders- it very easy by inclining the microscope, to rotate the egg into almost any desired position with one exception : it does not permit us to obtain a surface view of the blastoderm. Nor could this be obtained by confining the egg, as the slightest pressure almost immediately killed it, rupturing the vitelline membrane and thus contracting the blastoderm so that nothing could be made out of it. The. bad eggs always sank.
' Rviler'i! papers should be consulted in this connection. very minute tubes (or possibly only surrounded by punctae,
'During the summer of 1882 I was more fortunate, having though from what is known of other forms, the former view
twice seen the micropyle. This is shown in PI. xiv, figs. 1 . would seem the most probable). I did not see these tubes
and 2. A shallow depression surrounds the micropyle which except very near the micropyle. The micropyle itself more
its«U, when seen in optical section, is a ■ funnel-shaped tube, closely approximates that of the Herring as figured by Iloff-
it» walls extemling in some little distance beyond the rest of man ('81, PI. i, fig. 9) than it docs those of the more nearly
the egg membrane. Xear the micropyle the membrane is related Julis an<l Crenilabrus as figured by the same author
thickened and in surface views is seen to be permeated by on his third plate.
ox THE EMHKVoI.txJV oK TIIK TKL?:«)STS. \<',i
Tlio snuill size of the ej,'jrs Jiiid their j,n-fat contraetioii in niiy hanleiiiiifi' luediimi (oMuie, chromic, and Kleinenberg's picric acids, liicliroinate of putash and ah-ohul ) prevenlfd the cut- tinji of any satisfactory sections though many attt'm|its were miide. It was also foun«l very ditlicult to keep the eggs ahve for twenty-four hours, and to tliese two cttUseB must ho attributed the fragmentary condition of these notes, of wh«)se shortcomings no one can lje more cognizant tiian the writer. Still in many ways, notably in witnessing the invagiuft- tion of the hypoljlast and the formation of the notochoril, the extreme transparence of the eggs rendered our information on these jjoints llir more satisfactory than any sections could have done, as every step of the process could be clearly seen.
In the following pages the development of the egg will be taken up by stages, each of which is characterized by some prominent feature or by the api)earance of some important organ. From the fact that the several portions of the body are undergoing development at the same time, a perfect chronological arrangement in treating of the siibjcct cannot be maintained, but it is hoped that the general features may be followed in nenrlv their proper order.
These stages may be brielly indicated and epitomised as follows :
I. The maturation of the ovum. We have been unable to obtain anything on this point in our eggs, but introduce some observations upon the eggs of the "Old England Hake," Merlucius.
II. The phenomena of segmentation until the formation of the germ layers.
III. The formation of the three primary layers, the segmentation cavity, the invagina- tion of the hypobla!?t, and the appearance of nuclei in the intermediary layer of Van Bambeke.
IV. The formation of the notochord and neural cord. During this stage the invagina- tion is completed.
V. The tbrmation of the optic bulbs and the segmentation of the muscle plates into proto-vertebrae. During this stage the first appearance of what we call " Kupffer's vesci- cle " and what Balfour regards ('81 p. 61) as the post-anal vesicle, is seen. In the later portion of this stage the splitting of the mesoblast into somatoplure and splanchno- plure begins, while the epiblast in the cephalic region thickens to form the lens of the eye.
VI. In this stage the ears and nasal pits make their appearance and luidergo a j)ortion of their development; the lens of the eye is segmented from the epildast and the first traces of blood vessels were seen ; the segmentation of the muscle plates still continues.
VII. The heart and pericardial cavity begin to be diflferentiated and the former to beat. The blastoderm at this stage completely envelopes the deutoplasm and in subsequent stages will be -spoken of as the yolk sac. The gills bud and the gill-arches and gill- arteries appear in the later portion of this stage. In this stage the first contractions and movements of the embryo are seen; simultaneously with the first beating of the heart.
VIII. During this stage the development of the organs previously outlined progre.sses while the outgrowth of the tail and the formation of the anus are the new features. The fore and hind gut also become prominent and the liiraen in the latter is readily seen.
IX. This stage is characterized by the hatching of the embryo and is reached in from forty-eight to fifty-six hours after the first segmentation furrows make their appearance, a
190 ' KINGSLEY AND CONN
slisiht tliflercnoo in time being notiooablo with a cliange in the teniporaturc. The yolk sac has rapidly decreased in size.
X. The formation of the mouth, the complete dis;appcaraiice of the yolk sac and the depositiini of pigment in the eye.
ThouLrh the processes above outlined and now to 1)C described present many striking diflorences from those which are found in fresh water fishes, they are essentially similar, not onlv in all the eggs of the marine forms which we have studied, buttliey also present many resoml)lances to those of other marine forms as described by Van Beneden, Haeckel, Kupfler and others, though seeming to indicate that there are two distinct types of teleost development, one for the fi'esh and the other for the salt water forms. However, we are not yet possessed of sufficient material on which to base any generalizations, since we know less aljout the development of the Teleosts than of any other Vertebrate type with the exception of some of the lower groups of the old class of fishes.
The description which we give is purposely detailed and may be even prolix, and for these reasons : but few forms of marine fishes have been studied and so detailed observa- tions are necessary to serve as a basis for future comparison; the second is that our paper may be of more aid to American students who as a rule have no such facilities for consult- ing books as have their co-workers in the old world. Besides the works of Alexander Agassiz, Drs. Brooks, Garlick, Lockwood, Putnam, Ryder, and Wyman, referred to in the bibliography, I do not know of a single paper by an American on the embryology of the Teleosts, while all papers embracing any original investigation on the embryology of the other Vertebrates will not exceed two dozen and of these fully one-half were not at their time of publication any contribution to knowledge. With such a poor showing surely any- thing which may mcite to better work may be pardoned.
I. Maturation of the Ovum.
We were unable to make any observations on the maturation of the eggs which we studied,' nor to witness the phenomena connected with the impregnation, but the following
1 During the summer of 1882 eggs were taken from the liv- this operation does not include all of the protoplasmic portion ing cunncr some being fertilized and others not, and from of the egg, a thin layer (exaggerated in the figures) extend- the study of the latter I am able to add a little to the account ing down over the yolk and in all probibility giving vise to of the maturation of the egg and to say a word concerning the the intermediary layer. While this segregation of the pro- formation of the polar globule in addition to the statements toplasm is taking place the aster ajipears, followed by the of the previous year. I would, however, state that it is barely formation of the polar globule. S"liis aster appeared, each possible that the supposed unfertilized eggs were in reality time it was seen, as a true ast(^r, not an amphiaster, but this fertUized, as, for obvious reasons, I cannot say that there were may be the result of the position of the egg, for were an no spermatozoa in the water in which they were kept. These amphiaster viewed in the direction of the a,\is it would pre- eggs in general appearance have been described at the begin- sent this appearance. At the centre of the aster there ning of the second section of this article, and hence tlie appeared the polar globule in a manner almost exactly simi- descriplion need not be repeated here. The features of lar to that so often described in the eggs of invertebrates, maturation witnessed were a disappearance of the nucleus Once on rotating the egg the polar globule was actually and of the strongly refractive globules; then the protoplasm witnessed in its pa?s.agc through the micropyle as shown in began gathering itself together as shown in the figures 9, 10 figures G and 7, its connection with the egg being completely and 11. A slight constriction appears around the central por- severed. At another time I saw a projection which I am tion of the protoplasm which, cutting down and then in, sepa- inclined to reg.ard as a polar globule attached to one of the rates the germinal portion of the egg from the yolk giving resulting cells of the first segmentation (fig. 8, 7). </ ), but. as it eventually the sb:y)e of a button. It is to be noted that the process of formation was not witnessed I am not positive
()\ THE EMBRTOLOGy OF THE TEI.EOSTS. 19|
account of the clianj^es umlergoiie by the e','<,'s of Mciliu-iiH may partially fill tin- ^'ap. The cg'^a in question were taken from the fish ami some were fertilized wliiK- utlu-rs were not. We studied only the latter. Mr. Van Vleck spent his time <m the di'velopniLMit of the former, and it is sincerely to be hoped that he will soon publish his results in «let;iil tut many of them are very interesting and important.
When fir.st .seen the prol6pla.sm of the eg^ of Merlucius was collected at one pole (the lower) and covered about a third of the surface of the deutoplasin as a thin layer. At this time no nucleus ^vas visil)le, though carefully looked for. Soon there appeari'd. at about the centre of the germinatiye disc, the well known a.stcr so familiar to embry- ologists (fig. 3). After about live minutes changes were noticeal)le in the a«ter ; it« ray.s grew shorter, were less distinctly defined, and finally the whole disappeared and no trace of the star could be seen. The length of time from the first appearan<-e of tlii« aster until its complete disappearance wa.s thirteen minutes. Five minutes later the ast4?r reappeared, this time at the centre of the outer surface of the germinal disc where during an interval of about ten minutes it presented the same appearance and went through the same changes as before, at last disappearing as before leaving no trace of its former pres- ence. After twenty minutes more had elapsed it was again seen near the edge of the di«c and on its outer surfiice, where after remaining in sight for about five minutes it again faded from sight. Several additional appearances and disappearances ^vere witnessed but with no differences worthy of note and no further records were kept. These asters made themselves visible ^vith comparative suddenness, while their disappearance was more gradual and is best described by the term "fading out". Close watch was kept for the formation of polar globules but without success.
The foregoing account is by Mr. Conn, but what interpretjition to place upon the numerous appearances and disappearances of the aster I do not know. In another egg of the -same lot I saw the following phenomena :
The appearance of only one aster was noticed and this at the outer surface of the ger- minal disc and close to its outer margin. It was apparently composed of granules of pro- topla.am radically arranged. At the same time of its appearance slightly marked amoeboid movements of the whole protoplasmic area were .seen and which were the most prominent in the neighborhood of the aster and which seemingly proceeded in a slow wave-like man- ner toward the aster as a centre from the circumference. This appearance was noticeil for about five minutes, and as the time progressed the aster gradually faded from the sight as has been described above by Mr. Conn. After its disappearance two very small globules or granules were seen on the surface of the germinal disc in the exact spot formerly occu- pied by the aster (fig. 2). There exists in my mind considerable doubt a,s to whether these granules were the polar globules, arising chiefly from the following reasons : their very minute size, and also from the fact that neither by my.self nor by Mr. Conn was there witnessed anything comparable to the amphiaster (Archamphiaster of Whitman) which
of m_v identification. It may be that ths exclusion of the essentially similar account of the formation of the polar glob- polar globule from the egg is the normal method and this ules and their extension from the egg and, more fortunate would account for the fact that it has so unfrequently been than I, saw all the stJiges of the operation, which were simi- seen in the fishes. AVith the evidence of the present year I lar to those described by Fol and others in the maturation feel tolerably confident that the polar globule of the te.xt of the eggs of the Invertebrata. He however docs not appear (fig. 5 p. g.) \fas in reality such. Hoffman ('81) gives an to have seen the polar globules retained within the egg.
Ipo KINGSLEY AND CONN
acooinpanios the formation of the polar globule in the Invertebrates. The star was always single, nothing comparable to the " Kern-platte " was seen,' and in my egg the elongate irlobules, arranged in the direction of their longer axes, mai'ked the exact centre of the a.^ter. Though watched for a considerable time no further changes were witnessed, and as the C'^iT was not fertilized no segmentation could be expected. No other eggs of so oarlv a stage were obtained.
II. Segmentation'.
But two eggs were obtained by skimming l)cfore segmentation had commenced, the larger portion having the blastoderm Avell segmented indicating a development of from four to six hours. In one of these eggs which I- found (fig. 4) the protoplasm was collected around one pole of the egg, imparting to it a very pale yellowish tinge and gradually fading out so that at about a third of the distance around the egg it was invisible. In this yellowish protoplasm the germinative vescicle or nucleus was visible and in these a single nucleolus. The egg measured .0375 in., the nucleus .0037 in., and the nucleolus .00055 in. Soon several strongly refractive bodies appeared in the nucleus, similar in appear- ance to, but smaller than the nucleolus. An unfortunate pressure of the cover glass then killed this Qgg, preventing any further observations upon it.
Mr. Conn however found a single egg of the same species just as the first segmentation furrow was appearing. He describes the egg as essentially similar to the one which I had, the protoplasm extending down over the yolk in a similar manner. The nucleus, however,' was not visible. The segmentation furrow made its appearance at the centre of the sur- face of the protoplasm and gradually progressed outward and downward until the germinal portion of the disc was divided into two blastomeres. During the later stages of this seg- mentation the line of demarcation between the protoplasm and deutoplasm became more distinct, and at the close of the segmentation the protoplasm is gathered up at one pole of the egg a.s a thick two-celled cushion, as shown in figs. 12 and 13. These changes occupied about a quarter of an hour.
We made more detailed observations upon the first segmentation of the eggs of Merlu- cius, but as Mr. Van Vleck is intending to publish on the development of this form we do not here relate our results, simply saying that they fully agreed with the description above. This segmentation we regard as the first segmentation of the egg. That of separation of protoplasm and deutoplasm cannot be considered as segmentation, since it is one of the features of the maturation of the egg and is accomplished before impregnation.
It is to be noticed that in all the eggs which we studied all of the segmentation furrows, including the first, pa.ss completely through the germinal area and in all the segmentation of "the protoplasm of the egg is complete. Similar results were noticed by Van Bcneden in the egg of an unknown Teleost, and by Haeckel in the egg of ? Motella. On the other hand (Ellacher, Strieker ( Trii(tafario),Yan Bambeke (Leuciscus), aud Carl Vogt (Coregonus) describe the segmentation planes as at first passing only jjart way through the germinal disc.
Returning to our original egg ; from the stage with four blastomeres many observations were made and all features of segmentation were verified and reverified by both of us-
1 See preceding note.
ON TlIK EMKUVoLOGY OF TlIK TKLKOSTS. 19;>
A description of tlio chaii'^'i'.s undL-rgone Ity a single egg will !.»• given in di-tail while the variations presented by others will be noticed as occasion demands. At the ciiise of the section on segmentation, a tabulated account of a few eggs, all apparently of the same species, will be ibund, with the periods of time occupiitl in tin- \:ii;,,i|.4 phenomena of segmentation.
This egg with two blastomercs when first placed nn.i<r liir uu'n.M.ip,- jmd nuclei in each cell, though, judging from the analogies presented by the later stagi-s as well as liy the eggs of Merhu-ius at the same period of development, the nuclei probably did not reappear until some minutes aft^jr the first segmenUition furrow was comjjleted. Soon after this the nuclei disappeared, and in six and one half minutes afterward they were no longer visible, the first external features of cell division were noticed. A slight furrow appeared in the sin-face of each blastomere, their direction being at right angles to the original jdane of segmentation (fig. 13). At first these furrows existed only at the junc- tion with the primary one and were also superficial. They then gradually extendiMl out- wards and downwards from this place until in thirty seconds from their first a])|)earance they had completely separated each blastomere into two. Two minutes later the nuclei reappeared.
In some eggs, between the completion of the .segmentation furrow and the reappearance of the nuclei in the four resulting blastomeres, marked amtelwid movements were observed. In other eggs from the same lot these movements were not noticed until the blastoderm had eight blastomeres. These ama'boid motions were very marked and similar ones were noticed in connection with each segmentation from the third onward. It fs diflicult to describe or illustrate these motions. Processes were sent out by the cells, and furrows appeared cutting into the blastomeres, conveying the impression, the first time that the phenomenon was witnessed, that the cells were about to divide again immediately without the reappearance of the nuclei or the intervention of the usual period of rest. On the contrary, with the reappearance of the nuclei, or very soon after, these motions cea.«ed and the blastomeres acquired their regular cellular appearance and an interval of rest inter- vened before further cell division began.
As was mentioned above, the same amoeboid movements were witnessed at eacli seg- mentation and in all eggs studied, and, though we are by no means positive, it seemed to us that connected with these movements was an increase in the amount of protoplasm and that particles of the yolk or deutoplasm were taken into the blastoderm. Certain obser- vations which we made, but which are not ea.sy to describe, seemed to admit of this and only this interpretation ; and the fact that the blastoderm grows, not only in superficial extent, but also in volume, shows that the amount of protoplasm is in some way increased and thus adds additional weight to the view which we have taken. On the other hand the foct that the cells, after they have reached a quiescent state and have regained their usual smooth contours, exhibited no traces of globules or granules of yolk a.s would have been expected with bodies of such ditYereut refractive indices, would seem to be against this idea. It may be, however, that the deutoplasm undergoes a gradual change, and that portions of it are transformed into the substance of the intermediary layer and that the nourishment of the cells is in turn derived from the intermediary layer. That this inter-
MEJIOIRS BOST. SOC. NAT. HIST. VOL. III. 25
194 KINGSLEY AND CONN
modiarv lavor contains a large proportion of protoplasm is shown by the free cell forma- tion which subsoqucntl}' occurs in it, to be described fiirther on.
It has been impossible to give any adequate representation of these amoeboid move- ment,-* as they utterly surpass any efforts of the artist, but figs. 15 and 17 may serve to convey some slight idea of the appearances. Both are taken from blastoderms of eight cells. In fig. 17 only two cells are shown, each of which is about to segment while two processes are'shown arising from one cell and uniting with the protoplasm of its neighbor. In this case the union was not broken imtil after the segmentation was completed. The other (fig. 13) represents an entire blastoderm of eight cells after the segmentation furrows are complete but before the reappearance of the nuclei.
At the time of the reappearance of the nuclei in the blastoderm of four cells, grooves were noticed extending down from the blastoderm a short distance on the surface of the j-olk (fig. 1-4); but they soon flided out, not lasting over four or five seconds. This phenomenon was noticed at two subsequent stages ; once when the blastoderm was composed of sixteen and once when of about sixty blastomeres. It mijy have occurred at other times but was not looked for ; in fact the times when it was seen were the result of accident, it being incidentally noticed while other changes were being watched.
Concerning the internal features of the segmentation we regret that we can say nothing. Many tunes the nuclei of the blastoderm Avere carefully watched, but all that can b'e said is that they gradually faded away from the sight, growing less and less distinct until at last they were invisible and had utterly disappeared before the segmentation of the protoplasm began. After the cells had divided the nuclei again became visible but rather more rapidly than they had disappeared. In this disappearance and reappearance there did not appear to be any change in the size of the nuclei, but rather their optical properties more and more approximated that of the surrounding protoplasm until at last the microscope was unable to differentiate them. At no time while the segmentation fissures were being formed were the nuclei to be seen. In vain we looked for those interesting features con- nected with cell division which have been described in such detail by Blltschli, Flemming, Klein, Peremeschko, Schleicher, Strasburger and others. Except in the case of the maturation of the egg of Merlucius described above, we have but twice seen anything in the eggs of Teleosts which in any way even approximated an aster, amphiaster or " spi?i- del-kern ".' Once asters were seen in a large proportion of the cells of a blastoderm com- posed of about one hundred segments. The other time a single aster was seen among the free yolk nuclei or rather, as I prefer to call them, the free nuclei of the intermediary layer. In both cases circumstances were such as to prevent any detailed observations upon them, while the little which was seen is of no value standing by itself and hence is not described. It is sufficient to say upon this point of internal features of segmentation that in the earlier stages of division nothing comparable to the phenomena I have seen in the eggs of other forms could be distinguislied without the aid of reagents, which however do not readily penetrate the envelope of the eggs which are studied. The eggs of Mer- lucius afford in this respect a striking contrast, as in them Mr. Van Vleck obtained by staining well marked spindel-kerne.
' The stuilies of 1 882 require the modification of this state- though they did not stain with the more common reagents. ment for I was able several times to see these structures, they The appearance of both asters (//) and spindelkern or aniphi- being well stained by a solution of carmine in acetic acid asters {x) sre shown in pi. 15, fig. 24*.
ON THE EMBRYOLOGY OK THE TELEOSTS. I95
Returninjif to tlie og<? whose sejrmentation we are (liscussiii'r we have to note the suo- cecdinj^ features of division and first tlie cliaii^res in {,'oin;^ from four to ei;^ht eells. In nix minutes after the ajjpearance of tlie nuclei in the four Mastonieres they again lU.sippfar u» before, and fourteen minutes ehipsed hefore any further chanj^es were viwhU*. A depression then appeared at the middle of the inner marj,'in of each cell and gnidually extended outwai'd and downward to the outer surface and to the yolk. These furrowH were parallel to the first and at right angles to the second segmentation furrows and like them cut completely through the protoplasmic i)ortion of the egg. The whole proceH.s of division occupietl hut a few seconds and the nuclei reapju-areil two minutes later and the blastoderm of eight cells was before us.
In the egg which formed the basis of this description the segmentation furrows appeared simultaneously in each of the four cells of the blastoderm and proceeded at nearly regular rates in all. Other eggs agreed with thi.s, but still others (and they formed a large minor- ity) exhilnted at this early period a heterochronous division, as in proceeding from four to eight lilastomeres an intermediate stjige was observed in which for a few moments the blastoderm consisted of six segments, two of the cells having divided slightly in advance of their fellows. In one egg which I studied three blastomeres divided some little time before the fourth, the first three dividing simult<aneously and the result was a blastoderm of seven cells. This egg presented also another jieculiarity in that the nuclei reappeared at nearly the same moment of time in all of the 'cells and before the fourth had divided, and thus the seventh cell had two nuclei and only after the lapse of a minute and a half did this cell divide.
It was at this time, when the egg has eight segments, that we noticed the first traces of Van Bambeke's intermediary layer (figs. 21, 22, 23i'). It was a very thin layer of pro- toplasm extending between the blastoderm and the yolk and at this stage was without the thickened margins and the free nuclei which are present in the later stages. No traces of granulations or oil globules could be seen in it. We would not, however, by the forego- ing account, be understood to say that the intermediary layer made its appearance at this time, but merely that we first noticed it then. Of its time and method of origin we can say nothing except that it certainly was not present at the first segmentation of our eggs.'
As will be seen further on we do not agree with Van Beneden in regarding this inter- mediary layer as the hypoblast, but I am inclined to believe that he is correct in his idea that the tail-like processes of the cells in Ilaeckel's figure of an egg with two cells, in reality represent this intermediary layer. I also agree with the Belgian savant in his opinion that both Kupffer and LerebouUet observed this same inttrmediary layer, the statement of Kupflfer to the contrary notwithstanding. LerebouUet ( '54 p. 200) says " II existe sous le blastoderm une membrane particuliere, distincte, composee de grandes cellules tres pjlles ; c'est d'elle que se formeront les organes abdominaux ". This agrees per- fectly (except in regard to the last poi-tion, the destination of the layer) with the condi- tion of the layer in many of the fresh water fishes with numerous oil globules the " gran- des cellules " being either oil globules or vacuoles. But of this intermediary layer we will speak more at length further on.
'I now think that this statement will have to be modified, from the blastomeres, as the 6rst traces of the intermediary
as I regard the thin portions of protoplasm which are left layer, and the same investigations confirmed me io my bcliet
extending down over the egg at the time of maturation tliat the layer is largely produced by the change of deato-
(fig. 11), and which are also shown in fig. 12 extending out plasm into protoplasm.
196
KIXGSLFA' AND COXN
At no time after eight blastonieres were reaoliod did the segmentation proceed regularly. and with each succeeding segmentation the irregularity became more and more marked until at last, at about that stage when the blastoderm should theoi-etically consist of sixty- four cells, every trace of regularit}^ is lost and each cell divides entirely independently of it.s neighbors, the nuclei appearing in one just as they are disappearing in another, while a tliird is at the same instant dividing. In some eggs this irregularity is noticed at an earlier stage and is much more marked than in others, but in all it soon reaches such an extent that in any case it is difficult to ascertain when the theoretical segmentation is completed.
We have now to describe the division of the blastoderm from eight to sixteen cells. Nine minutes after the last mentioned reappearance of the nuclei, they again disap- peared almost simultaneousl}^, but one or two seconds intervening between the times of the first and of the last. After this disappearance and before the division of the cells amoe- boid movements, similar to those which have been described were witnessed. The cells lost their regular outlines and their smooth contours and became lobulated and fur- rowed. Fig. 17 before referred to represents two cells from the blastoderm. While this amoeboid motion was in progress the segmentation furrows appeared. Fig. 18 will illustrate this division better than it can be described, the two interior cells divided first, then the' other two. and lastly the four corner ones. The fissures in the second began before those in the first were completed and those in three before the segmentation of the second was accomplished. The complete segmentation occupied about two minutes. The planes of division were in general times at right angles with those of the preceeding segmentation and the result was a parallelogram with four cells on a side. The nuclei were again seen four minutes after the segmentation was complete and remained in sight for ten minutes. The amoeboid movements after this segmentation were very strongly marked and lasted for considerable time, and the cells did not attain their smooth contours until about the time when the nuclei vanished. The regularity of the parallelogram was far from being con- stant as frequently one or more cells would segment obliquely and the result would be more like that shown in fig. 19.
From this point onward the segmentation in every egg studied by us was xery irregular, and by various stages of 20, 21, 28, 29, and .30 cells the theoretical 32-celled blastoderm is obtained and a short period of rest (which was not timed but which could not have exceeded three minutes) intervened after which the segmentation proceeded but so irreg- ularly' as to be beyond description. Figs. 20 and 21 will illustrate some of the later stages.
In the following table are given the results of timed observations of the segmentation of several eggs. Several others were studied but without noting the intervals between the stages. The dash ( — ) indicates that stage of development when the eggs were first noted and the figures the number of minutes since the last timed stage.
1 2 3 4 5 6 7 8 9
Nuclei disappear after first segmenta- tion (2 cells) .... Second segmentation (4 cells) . . _
Nuclei reappear ..... 2 3 3
Nuclei disappear .... 6 — — 8 6 — 7
Third segmentation (8 cells) Nuclei reappear .... Nuclei disappear Fourth segmentation (16 cells) . Nuclei reappear ....
|
7 |
|||||||
|
6^ |
7 |
7^ |
10 |
||||
|
2 |
3 |
||||||
|
6 |
|
|
8 |
6 |
— |
||
|
14 |
13 |
15 |
10 |
11 |
— |
14 |
4 |
|
2 |
5 |
6 |
i |
4 |
|||
|
9 |
5 |
5 |
10 |
10 |
11 |
10 |
|
|
9 |
10 |
11 |
7 |
7 |
12 |
||
|
2 |
5 |
4 |
2 |
9 |
11 |
4 |
5i |
oy Tin-: KMi;ijV(M/)r.v of thk tf.i.k. «> r>. I97
After this stage tlie soginontaticn is so irregular tliat it caiiiint he tiinetl.
From the aljove tahle, which is based on eggs of apparL-ntly the same specieH,' it will he seen that there a consiilerable variation in the times whieh were re(|uireil for the same changes in tlilferent eggs but nevertheless in many, well marked periods of rest allcrnatr ing with stages of activity, may be noticed. These periods of rest and activity have recently been commented upon by Dr. W. K. Brooks ('81) an<l have also been notiecd by many of the older embryologists in the eggs of other vertel)rates and also in thoxc; of many invertebrata. I am of the opinion that these periods of (apparent) rest are thus to be explained, that at each one of them the deutoplasin, which I believe to have been taken up by the germinal area, is connected with protoplasm, and that while there is an interval of physical rest, the same time is one of chemical activity. There are several rea-<ons for this belief, but before stating them I wish to obtain further evidence and make additional observations not only on the. eggs of fishes but also on those of other animals.
The phenomena of segmentation in the eggs of Teleosts have been several times described, and the accounts wiiich we have presented to us agree in the main with what has been given above, though there ai'e several- points of more or less importance in which differences are to be noted. The first fact which we would discuss is that the planes of segmentation even at first pass through the germinal area, cutting it completely. This is in strong contrast with the observations of most writers and so far as we are aware occurs in the eggs of all marine teleosts. Every form which we studied presented this peculiarity and the description and figures of Haeckel ' and Viu\ Beneden of the developmi-nt of European marine teleosts. (It might here be remarked that the figures of Haeckel are highly idealistic and show many features which certainly do not exist in nature). On the other hand all writers describing the segmentation of the eggs of fresh water fishes agree in that the first cleavage planes pass but partly through the germinative disc, there remaining a portion next the deutoplasm (vitelline globe) which does not segment until much later. These facts are in strict accordance with the ideas of Balfour that eggs undergo total or partial segmentation according to the relative proportions of protoplasm and deutoplasm. In the eggs of fresh-water fishes besides the vitelline globe there is a large amount of deutoi^lasmic material scattered through the germinal area ; in the eggs of Merlucius there is a very slight amount in the same region, while in the eggs which we studied the protoplasm and deutoplasm ajjpeared to be entirely distinct.
According to ^Vogt ('42 p. 30) the segmentation furrows do not entirely cut through the germinal area of the eggs of Coregonus until a stage with eight blastomeres is reached. To Oellacher we must refer for the most detailed account of the segmentation of the eggs of fresh water fishes which has yet been published. His observations on the segmenta- tion of the eggs of Trutta fario (p. 395 et seq. pi. xxxiii figs. 18-20) agree es.sentially with those of Vogt but from their later date are much more valuable. He lays especial stress upon the fact that the cleavage furrows do not pass at first completely through the germinal portion, and in the later figures (1. c. figs. 22-2G) he shows a layer of unsegmentcd protoplasm underlying the central cells of the blastodenn and continuous with the raargin-
' These eggs as far as the microscope would show were This would explain the great difTcrence in time in certain identical, but there is a bare possibility that Xo. 4 which was changes which here arc very much accellcrated. slightly larger than the rest belonged to a different species.
19S • KIXGSLEY AND CONN
al ones. At a later stage this lower layer of protoplasm becomes segmented. Aside from this difference, which is to be explained by the presence of quantities of yolk gran- ules, the external features of segmentation present no important differences from our reiJult.'j.
The otrgs of Merlucius although tMutaiuing large numbers of deutoplastic globules in the "•erminal portion imdergo a complete segmentation of the protoplasm as in that of the Gunner. There was to be noticed, however a very marked irregularity in the pro- cess of segmentation even from the very first. The blastomeres varied widely in size and the segmentation furrows progressed at varying rates and times in different portions of the germinal area.
Tliough we found it impos.sible to obtain any satisfactory sections of our eggs, their perfect transparency enabled us to see, clearly and plainly, that even the first segmenta- tion furrow extended down to the vitelline globe and that the first two cells as well as the subsequent ones were entirely separated from each other. At no time was there an unsegmented basal portion of protoplasm except that presented by the intermediary layer and peripheral cushion of Van Bambeke.
Kupffer mentions some marked irregularities in the eggs which he studied : in some the second segmentation furrow sometimes was eccentric or occasionally was even parallel to the first. We have seen nothing of this sort in the eggs which we studied.
The theoretical segmentation of an egg is first two meridional furrows and then an equatorial one, but frequently this regularity is interrupted, in fishes noticeably so. If we interpret Haeckel aright, the equatorial furrow is the fourth to appear in the eggs of ?Motella as he figures (fig. 58) a section of a blastoderm of sixteen cells and in it lower layer cells are seen. These figures however show in every line that they are wholly diagrammatic and could not have been drawn from either actual or optical sec- tions. In the eggs of the fresh water fishes it is at a somewhat later stage that the equa- torial furrow is formed and the lower layer cells produced, but even in eggs of the same species there does not appear to be much regularity. In our eggs lower layer cells did not appear mitil the blastoderm was composed of about a hundred blastomeres and even then they did not appear simultaneously in all parts.
III. Formation of the Germinal Layers.
In this section we have to consider the extension of the blastoderm over the yolk from the time of the appearance of the lower layer cells until the formation of the notochord and the neural canal. In it also will be discussed the differentiation of epiblast, mesoblast and hypoblast, and also the phenomena of invagination. Certain of the features here to be described belong in part to the next section, but fi'om the fact that they are first noticed before the formation of the notochord they are best treated here.
Until after the blastoderm has acquired a stage with about a hundred cells it consists, as
before mentioned, of but a single layer, thus offering a marked contrast from the «ggs of
most fishes on which observations have been published. This simple condition of the
blastoderm at this time was conclusively shown by optical sections in which the outlines of
• each cell could be readily traced with a power of a hundred and fifty diameters.
()\ TIIK K.MHUVoLOtJV OF TIIK TELEOSTS. I99
Soon after this iminbcr was reached, hjwer layer cells were noticed. We did not con- clusively settle the manner in which they aro.se but are inclined to believe that the j;reiiter portion arose from the already formed cell elements of the blast4)derm while possibly a small proportion had their ori<:;in in the free nuclei of the yulk. With their formation the epiblast becomes diflerentiated and at first consists of a sinj,'Ie layer of cells. These cell.s in vertical optical .section are lens shaped while the lower layer celN .-ire polygonal in out- line on account of their mutual pressure.
At first the blastoderm fits as a cap over the yolk but soon by the proliferation of ccIIh it acquires a lenticular !<hape and i.s seated in a concavity in the surface of the deuto- plasmic portion of the egg. At this time the intermediary layer (I'arablast of Klein not of His) is plainly seen and its thickened margins {bourrelet peri|iheri«iue of Van Bambeke) is very conspicuous. Regarding the origin of this layer we have nothing new to olTer. Its first appearance was not noticed either as to the exact stage or its to the method in which it arose.' Neither was the time of its disappearance observed ; it wa« visiljle until the blastoderm nearly covered the yolk. When first seen the layer wa« clear and transparent without any traces of granules, vacuoles, nuclei or cells, though at a later stage they were visil)le. The first observer who noticed this intermediary layer was Ix're- bouUet who saw it both in the pike ('54 p. 24S) and perch (1. c, p. 250). lie describes it in the latter as follows : " II existe sous le blastoderme inie mendjrane particuliere, di«- tincte, coniposde de grandes cellules tres pfdes ; c'est d'elle que se fomieront les organes abdominaux"; and in speaking of the pike he says that the vitelline globules are changed to this layer. Almost all subsequent observers have seen this .same layer and have added to our knowledge of it. Our discu.ssion of their results will be taken up in cuunection with that of the germ layers with which it is intimately connected.
At about the time of the diflferentiation of the lower layer cells as well as at later stages free nuclei were seen on the surface of the yolk. These nuclei were irregularly arranged, in fact no traces of any regularity could be discerned except that all were on the surface and now were to be seen on the interior of the yolk. (The term surface here embraces not only that portion which is in contact with the egg membranes but also that on which the intermediary layer rests). In the eggs of Merlucius at a slightly older stage similar nuclei were seen and around man}* of them, especially' those nearest the bhistoderm, the cell walls could be made out, the whole presenting an appearance somewhat similar to that given by Kupffer ('68 p. 217 pi. xvi) in the eggs of Gasterosteus. These free nuclei and cells are not arranged with anything like the regularity of Kupffer's figures. In the Gunner egg I watched the process of cell formation around these nuclei with some care. The nuclei nearest the germinal portion of the egg were the first to become the centres of cells and the formation of the cell boundaries took place in a corresponding direction, that is those portions of each cell wall nearest the blastoderm appeared first and these gradually extended themselves around the nuclei. The whole operation required over half an hour. In the Cmuior but comparatively few of these free nuclei and resulting cells were seen.^
'The observations of 1882 elsewhere detailed alter this representing a portion of the bl.-istoderm and the adjacent
statement slightly. portion of the peripher.il cushion ; in the latter there being
- In 1882 by staining, these free nuclei with all their accom- shown asters, amphiasters, and the proci»s of outlining of the
panying phenomena were seen and studied, fig. 24*, pi. XV, cells.
200 KINGSLEY AXD COXN
As tinio passes tlio blastoderm gradually extends itself over the surface of the yolk until, at a later stat!;e than that described in this section, it completely embraces it, thus forming the yolk sac. AVhen about one-fourth of the surface of the yolk was thus covered, the segmentation cavity was first noticed. No observations were made regarding it.s mode of origin but it was doubtlgss by a lifting up of the blastoderm. In the earli- est stiiges its roof was formed by the epiblast alone, its walls of lower layer cells while its floor was formed by the yolk, or rather by the intermediary layer which rests upon the yolk. The floor at this time was perfectly free from nuclei or cells. At first the segmen- tation cavity is low, circular in outline, with its lateral margins about equidistant from the edge of the blastoderm. The blastoderm continues its extension over the yolk and increases rather more rapidly in one position of the margin than on the others, and at the same time the lower cells encroach upon the segmentation cavity from one side until the cavity becomes eccentric and is placed nearer one portion of the blastodermic margin than to the others. This pushing in of lower layer cells continues until the cavity acquires an arcuate or reniform outline. At this time free cells are numerous upon the floor of the cavity.
This is the first opportunity we have for the orientation of the egg. The segmentation cavity is farthest from the portion of the blastodermic margin where the first outlines of the germ are to appear and so we may now speak of anterior and posterior portions of the bla.stoderm, the segmentation cavity is anterior and the embryonic area posterior.
The invagination of the hypoblast now begins. As before stated we were unable to cut actual sections but the extreme transparence of the eggs rendered this almost a superOuity. Our observations on the invagination were made both by surface views and by optical sec- tions, the latter being in almost every respect equal to actual ones while from the fact that the steady progress of the invagination could be continuously watched in the living egg they presented advantages which no product of the section knife could equal.
At all points of the margin of the blastoderm a single layer of cells may be seen push- ing themselves inward beneath the rest of the blastoderm and separated from the lower layer cells by a well defined line. Between this hypoblast and the yolk is still to be found the intermediary layer. The invagination progresses much more rapidly from the posterior or embryonic portion of the blastoderm than from any other portion of its mar- gin, and at the anterior portion more rapidly than at the sides. Fig. 22, pi. xiv, rep- re.sents an optical section on the median line of an egg in which invagination has just begun, while fig. 23 represents the .same at a somewhat later stage. In this last figure the extent of the lateral invagination is shown by the shaded area. Fig. 24 gives a view of the lower surface of the same blastoderm showing the rates at which the invagination pro- gresses in different parts. (The dotted line indicates the plane on which the section described is taken.) The invagination continues until it forms a layer entirely separating the rest of the blastoderm from the yolk and intermediary layer. Its later stages and the phenomena accompanying it belong more properly to the next section.
Our attention was not especially directed toward the origin of the mesoblast but we are of the opinion that it arises partly from the lower layer cells and partly from the hypo- blast. Whether it arises as two lateral plates, we know not, but at an early stage it forms a continuous layer extending acro.ss the embryonic area as shown in fig. 25. With
I
ox TIIK K.MIiKVoI.OGY OK TllK 'H;i.K(tSTS. 201
the progress of the iiivagiuatioii the scgiuentutioa cavity is oncroached upon by the lower layer cells, its (lour l)ee()iiies covereil with cells, some arising IVoiii the iivpohiiust while others apparently orij^iiiate from the free yolk nuclei, and the cavity i^ Hhortly oljlitcrateil.'
1 admit tliat 1 am in doubt as to the part placed liy the intermediary layer and it^ resulting cells. As before mentioned a portion of tlie cells apparently enter into the floor of the segmentation cavity and are sultseiiuently either eml)race<l in the hypobhist of invagination or are crowded by it into a mesoblastic position. This however accounts for but a small proportion of the cells of the intermediary layer, and it seems to nie proitable that the hypoblast of invagination forms only the dorsal wall of the alimentary truct while the intermediary layer furnishes the ventral portion. This .seems to be in full accord with the formation of the alimentary tract in otiier form.s (e. g. Batrachia) where the ventral portion of the hypoblast is formed by yolk cells.
Regarding the origin of the hypoblast in the Teleosta there seems to be a iliversity of opinion, llenneguy ('80 p. 402-3) describes the invagination in the eggs of the percli and trout, the blastoderm being inllected at its margin and a line or fissure .separating the sensorial [our lower layer cells] from the inflected portion. So far we agree with him. He however states that the epidermal layer is not inflected. In this he agrees with two of the figures of Ilis ('75 pl. ii, figs. 2 and 3) l)ut not with (ig. 1 . Our observations were that the epidermal layer of the epildast alone is inllected. Balfour ('81, 57) says that the yolk cells form the hj'poblast in the smaller Teleost eggs but that in the larger as in those of Elasmobranchs only a portion of the hypoblast has such an origin. We should con- sider our eggs as small. Kupflier with a doubt regards the cells as forming the hypoblast. Professor Van Beneden in his researches on the eggs of an unknown Teleost ('78) arrives at widely different conclusions regarding the origin of the germ layers from those we have formed and we cannot reconcile his results with our observations. We have seen step by step, minute by minute, the progress of the invagination and it scarcely seems possible that any error of observation on this point can have crept in, especially as we witnes.sed the process many times. Yet Van Beneden totally denies that in his Teleost any invagina- tion takes place. It would seem to me that he is wrong from the very stixrt. On p. 52, he considers the egg before the appearance of (our) two segmentation spheres as follows : "Directly after fecundation the eg'^ of the osseous fish divides into two very unequal cells, very dissimilar, differing in constitution and significance ; the one is a germ which seg- ments and from which the blastodisc is derived ; the other is formed by the deutoplasmic globe * * *. This cell is the origin of the endodermic layer of the future embryo." To all of this I must express an emphatic dissent. The aggregation of the protoplasm at one pole of the egg and of the deutoplasm at the other cannot in any way be considered as a segmentation, nor can the deutoplasmic portion be considered as a cell. No one would think of regarding a centrolecithal egg, that of a Crustacean for example, as composed of two cells or the central portion as of a cellular character, yet the homology between the two eggs is easily shown. On the same page he explictly says that the germi- nal portion is the homologue of the ectoderm and the vitelline of the entoderm, a view
> Subsequent studies lead me to believe tliat this stiitemont to this cavity, though I must say that there api)ear many difli- is an error and seem to con6rm the idea of Ryder wilh regard cutties in connection therewith.
MEMOIRS BOST. SOC. NAT. HIST. VOL. lU. 26
202 KINGSLEY AND CONN
which is not warranted without considerable qualincation. It must be understood that I am not criticising his observations on the free cell formation in the intermediary layer and in the volk. nor do I deny that a portion of the hj^poblast may arise from those portions. This free coll formation we have both witnesed in the eggs of several marine Teleosts and wc are wiliinu: to accept his account of their formation but I do deny that the presence of these cells and nuclei can be addressed as evidence that the deutoplasmic glolje itself can be considered :xs a cell and the complete homologue of the hypol)last. On p. 56 he con- < aiders that the hypoblast described by Haeckel, and which closely resembles in its structur and mode of origin that of our fishes, was in reality " composed of cells derived from the intermediary layer." It hardly seems possible that there should be in the eggs of teleost such diverse methods of origin of the hypoblast and that in closely allied forms. ProfeS'l 8or Van Beneden following Haeckel regards his egg as probably belonging to one of th€ Ciudidae. and with this opinion we are inclined to agree. The eggs of Morlucius and o| Morrhua present a striking resemblance to those studied by Haeckel and Van Beneden, and if there be any relation between the characters of the eggs and of the fishes produc- ing them (a point on which we have but slight data) the eggs studied by both probably belono-ed to the Gadidae. Now as we have observed in an egg with a conspicuous oil globule, and as has been traced through with great care by our friend Mr. Van Vleck in the egg of Mcrlucius, the hj'poblast arises exactly as we have described it above.
It would thus appear that Van Beneden has been led into an eri'or either of observation on his own eggs, or of interpretation of the results of Haeckel, regarding this point and we are inclined to believe that the former is the case, for the reason that it appears from inter- nal evidence presented by the article in question that he did not witness continuously the phenomena presented by his eggs. Still there remain certain statements which we can- not reconcile with what we believe to be the facts of the case. For instance the statement on p. 50. '• Tlie blastodisc remains all this time very sharply delimited inferiorly and in no part is there a passage from one to the other (from the upper portion of the blastoderm to the hypoblast). In no part have I found the slightest indication in favor of invagination."
In the earliest stages of the egg the intermediary laj-er is not present but it soon appears and acquires its maximum development about the time of invagination. It appears to arise by an elaboration of the food yolk into protoplasm. It consists in our eggs as in those of Van Bambeke and Van Beneden of a thin layer extending across the egg between the blastoderm and the food yolk, and having a thickened marginal welt. This welt extends down some distance over the yolk and it may be possible that the nuclei of the yolk men- tioned on p. 199 belong in reality to this extension of this layer. Klein ('72) describes this as a ring in the trout as he failed to find the portion extending across between the blasto- derm and yolk.
Most observers have considered the mesoblast as arising as a continuous sheet in the Teleosts but Calberla claims that it is in two halves as in the Elasmobranchs.
We found no traces of the segmentation cavity of Van Bambeke and judging from the irregularity of his figures we are inclined with others to regard it as a product of reagents or the section knife. The segmentation cavity of Von Baer which was found in our eggs is clearly homologous with that of other forms of animals.
ON THK i:.mi5Ijv()I.(h;v of tiik tki.k.osts. 208
IV. NoTOCnOKD AM) NKrUAL CuKI). The origin of tlie notocliord in tlie Vertehnitii has recently been the suhjoet of Home discussion, and tliongh we cut no sections we einleavored to make such observations as would throw some light upon it^j source and the methods of its formation. All of our observations were made upon the living egg, and as we iiave in a single egg watched con- tinuously every step in the j)rocess, and have .several times verified all of our re«ults, we feel confident of their accuracy as far as our fish is concerned. To sum uj) our .>«tudies of this p(Mnt on which we both agree, the notorhord arises f rum (hi' Iti/jiuhlfist, ut first as a longitudinal median thickeninfj of that lat/tr and sahsequentl ij lucunrs segmented off and takes its place- among the niesoblastic tissues.
A detailed account of the evidence on which we base this slatimiut will now be given. Finst an account w-ill be presented of the changes witnessed in a view of the lower surface of the 'bhistoderni and afterward a description of the plieiioinena (jbscrved in optical sections.
Fig. 24 represents the under surface of the blastoderm at the earliest stage at wliich the notocliord was seen in a flat view. The segmentation ciivity (») po.s.se.ses the arcuate outline before described while the shaded portion of the figure indicates the extent to which the invagination has extended. The embryonic area (ea) has encroached but slightly upon the cavity. Another sketch shows the same eniliryonic area on a larger .scale.' In the median line is seen tiie notochord extending not quite half way from the margin of the blastoderm to the anterior extremity of the embryonic area. Anteriorly the notochord is well marked and clearly differentiated from the surrounding tissue.s, Avhile posteriorly this distinctness fades out until at last no line can be drawn separating the chord from the adjacent hypoblast. Anteriorly the cells of the notochord have the same polygonal out- line as have those of the hypoblast, but they are much smaller, indicating that rapid cell division is taking place. As we proceed in our examination, toward the hinder end of the notochord, we find the cells gradually increasing in size and approximating those of the lower germ layer in magnitude until at last no difference can be observed between them. Sometimes a sharp line may be seen cutting across the extreme end of the notochord and slightly in advance of the margin of the blastoderm and separated from it by a narrow strip of hypoblast, as frequently however this arcuate line was absent, but whether pres- ent or not we were never able to trace the notochord quite to the edge of the blastoderm. The margins of the chord at this stage were straight anteriorly but at the hinder end they diverged giving the whole a somewhat spatulate outline. This shape, resembling some- what the appearance of a paddle, the blade behind, was retained until a comparatively late stage in the development.
At tliis stage, though the notochord was in a great portion of its length clearlv and distinctly outlined, not a trace of cells could be sedn extending across the- ventral surface of the chord as would have been the case had it been of mesoblastic origin, for then the hypoblast would have extended over the lower surface.
As the embryo increases in size the notochord becomes longer, apparently growing in both directions but much more rapidly posteriorly, keeping pace with the extension of the
' In draniivr the plate this figure was inadvertently omitted. intelligible without iU It is hoped that the description is SHlBcicntly clear to be
204 KINGSLEY AND CONN
blastoilorm over the volk. At tho same time other changes may be noticed, in full accord- ance with the idea that the notoohord arises from the hypoblast, though they are by no means the sole proof which we have to offer, as will be seen farther on. Near the anterior end of the chord, the cells of the hypoblast may be seen extending themselves across (on the under surface of) the notochord until these hypoblastic processes from either side meet and close in the chord. The fonuation of this bridge occupies Ijut a few minutes and is first completed near the anterior portion, from which it progresses at the same time in both directions, reminding one of the closing up of the medullary groove in other ver- tebrates. It has been impossible to obtain any satisfixctory sketch of this process as seen in a superficial view. The feature of the egg which has already been mentioned, the greater specific gravity of the germinal portion, readily permitted us to trace these various changes on the under surface of the blastoderm.
Soon the cord is anteriorly entirely cut off from the hypoblast and closed in ; this process progresses more slowly posteriorly until finally the notochord is wholly separated from its parent layer and is entirely surrounded by mesoblastic tissues, but at what stage the sepa- ration is complete our notes and observations do not show. It is however before the for- mation of the optic lobes and protovertebrae. For a time the cells of the hypoblast can be distinguished by careful focussing extending across the notochord but soon they become so small that it is impossible to recognize them as such with the highest powers which it is possible to use in such investigations carried on upon the living egg.
This cutting off and closing iu of the notochord has been several times witnessed by both of us and it seems as if there were but little chance for errors of observation, but while this observation from the surface would show that the hypoblast plaj's a part in the formation of the notochord it does not conclusively prove that it is the whole source of the notochordal cells. So far as these already described observations go all three of the germ la3'ers may play a part in its formation and there might be some truth iu Rudwauer's statement ('76 p. 161) that the notochord arises from the epiblast. We have however other evidence which proves to us conclusively that the hypoblast alone gives rise to the notochord.
Returning to the invagination described above ; its later stages and its connection with the formation of the chorda dorsalis may now be described. These various steps have been constantly and consecutively watched by us both in several eggs, not only of the Cunuer but in several other forms, as well as by Mr. Van Vleck in the eggs of Merlu- cius and there exists in the minds of us three not the slightest doubt of their general accuracy.
In optical sections it was seen that the invaginated hypoblast was but a single layer of cells in thickness and at all times was separated from the overlying mesoblast by a well defined line. An optical section, transverse to the longitudinal axis of the embryo, was closely watched and at first the hypoblast was but a single layer of cells deep and every- where of uniform thickness. Soon a thickening was seen in the median line of the hypoblast, extending slightly into the mesoblast and also into the underlying yolk or intermediary layer. This thickening was clearly a jiart of the Ivjpohlast and the meso- hlaat was in no way concerned in its composition, the line of demarcation between the two layers being as well defined as before. Gradually a sharp line appeared cutting the
i
0\ TIIK KMr.KVoT.or.V ol i m-. I ll.KuSTS. 205
thickoning awa}- from the liypohlast (fig. '2'j) and siifccciling this the hypohhist wa.^ seen to extonil itself across beiieatli tlie now formed notociionl (figs, lit'.— 'JS in just the niuii- ner wliich we were led to expect from our observations made from surface views.
It is always dilficult to make out cell limits in optical sections of ef,'<,'s uh small as those on which we worked and hence they are omitted in our drawinj^s, hut it Wiis seen that in this notoehordal swelling of the hypoI)Iast tliat the cells were smaller than the adjacent portion of the layer just as was seen in the surface views.
AVe would repeat and lay especial stress upon the fact that we witnessed, hy cou'^tant and repeated observations on living specimens, every step in the formation of the notoehord, from II hypoblast of but one cell in thickncs.s until the chord was segmented of!" from it» parent la^'cr and eventually entirely enveloped by the mesoblastic tissues, and at no time did we witness the .slightest appearance that could be regarded as evidence that anv por- tion of the notoehord was other than hypoblastic in its origin. The later history of tlic notoehord will be treated under the respective sections of the development of the fish.
Previous to Balfour's first paper (Quarterly Journal of Micr. Science, 1874) all writers on vertebrate development had regarded the notoehord as belonging not only in position hut in its method of origin to the me.soblastic tissues. Dr. Balfour there and also in his com- plete monograph ('70'') showed that in the Elasmoljranchs, at least, the notochonl is a hypoblastic structure in its origin. Following him, Ileusen, in a paper on the development of the rabbit, gives the same general account of the derivation of the chorda dorsalis with only such variations as might be expected in two diverse cla.sse.s of Vertebrata. Calberla ('77) studying Petromyzon, Sygnathus and Rana arrives at similar results and was the first to show that in the Teleosts the notoehord is an endodermal structure. Kudwancr ('70) in a short paper also treats of the origin of the chorda dorsalis, but his article is of little value and his figures are evidently diagrammatic and do tiot represent the true stiite of afiliirs. He derives the notoehord (p. 101) from the outer germ layer or epiblast. More recently Braun, in his paper on the development of Parrots in the Arbeiten a. d. zool. zoot. Inst, zu Wiirzburg (the exact reference to wliich I have not at hand), still considers the notoehord as of mesoblastic origin. All of these observers Jiave worked with and studied sections and hence the discrepancy in their results. On the other hand our observations w^ere made on the living embryo, and hence we saw the organ formed and did not have to call upon the imagination to fill up any gaps and also the sources of error in interpretation were eliminated.
In the development of the neural canal the Teleosts present a marked contra.st according to all observers with the other vertebrates in that it is first formed as a solid cord in which a lumen afterwards appears.
At al)out the same time that the notoehord was first seen the first appearances of the medullary folds were witnessed. Coincident with the invagination of the hypoblast the edge of the blastoderm increases in thickness and this thickening is most marked at the posterior margin in the median line forming what Balfour has called the tail swelling. When first noticed it presented much the appearance of the " stage A " of Dr. Balfour's Ela.«mo- brancli ('70'' pi. vi, fig. A). This soon became elongate and more and more jjrominent until a broad shallow longitudinal furrow finally made its appearance dividing it into two lateral halves. These halves are the medullary folds and are low rounded ridges. With the
20(5 KINGSLEY AND CONN
inoivase in size of the Mastodoriu ami the growth of t!ie now outlined enibiyo, the folds iUitoriorh- came closer and closer together and the medullary groove narrower and propor- tionalh' deeper. It then grew more and more shallow, its decrease in width also continu- ing initil at last the groove was entirely olditerated. This groove is shown in fig. 28.
As before mentioned it wms very dillicult to obtain surface views of the blastoderm and hence our surface observations on the closing in of the medullary folds have not that detail which we could wish. Were an egg so held that the blastoderm was uppermost, be the ]M-e.>^sure never so slight, it almost immediately died and then contracted so that no con- secutive studies coidd be made. Enough, however, was seen to show that there was none of that infolding and direct formation of a neural canal which is so familiar in the other vertebrates. It was not seen whether the modified closing up took place near the middle and extended both ways or whether from the anterior end backward. From what we know of other forms the former would seem the more probable.
Fig. 28 shows an optical section through the hinder part of an embryo of the stage shown in fig. 34. Here the medullary groove is shown broad and shallow, the noto- chord has been separated from the hy])oblast but has not attained its later quadrate sec- tion but still retains the flattened outline ; the muscle plates on either side have not yet been differentiated from the mesoblast, while the hypoblast extends across immediately beneath the notochord and is not separated from it by any intervening mesoblast. In this optical section it was not possible to make out clearly the cell boundaries although the limits of the various germinal layers were readily made out as figured.
As to the method in which the neural canal forms, whether in the normal way by an actual enclosing of a tube of epiblast cells, or as maintained by Calberlaby a lumen forming in the epiblast which is pushed down and not infolded, our observations will not allow us to decide, though I am inclined to believe that the latter is the method, and for this reason. The earliest optical sections of the neural cord do not show any traces of a medullary canal while at a later stage such a canal is found. The same is also true of the brain and the optic lobes. It will readily be seen that, if either of these methods be the true one, the canal so formed is perfectly homologous with the same structure in other verte- brates and hence the actual manner of its formation has not so much importance. It is however interesting to observe that there is the same formation of medullary folds in our fish as are found in other vertebrates, that they arise the same and only differ in the details of the formation of the canal. As was said above these medullary folds exist, but at no time did we see any closer approach to the formation of a closed tube by a longitudinal union of the summits of the neural folds than that shown in fig. 28. Still I am inclined to believe that a large hiatus in our observations may exist here. In a doi'sal view of the tail of an embryo with about twenty protovertebrae a well-marked median line was observed which at the posterior extremity slightly broadens out into a groove, just as would be the case did the neural canal form as in other vertebrates.
Xot having witnessed the formation of the neural canal of course nothing definite was seen of a neurenteric canal of the same character as exists in the Elasmobi-anchs, Batra- chia and birds. In figure 30 which represents the first formation of the neural folds a slight notch is seen at the po.sterior margin of the blastoderm which afterward became much more marked. This notch arises in the same way and to my mind is
0\ TIIK KXIUIYOI.OCV or TlIK TKI.KoSTS. •j(l7
homoloj^ous with tl>e eanul connoctiiij; tin- iK-iiral ami iiliim-iitarv raiuils wliicli luu< rtTfiitly been (Icinoiistfateil to exist in all vertt-ltrate-). An imroitunate arc-iilciit occiirriMl to the egg forming the subject of this figiiie an<l hence no consecutive observations were made upon it. No other eggs in such favorable conditions were found. In fig. 30 1 liave shown the medullary folds extending slightly farther over the (leuto|iliism than iloes thi- rest of the blastoderm, and between them the medullarv groove, the epiblast of which of course forms the lining of the neural canal. Continuous with tiie cpil)last which passed down into the notch l»etween the medullarv foltls is the hypol)last whi< h e.vtends up the under surface of the blastoderm. Whether this notch eventually doses up leaving a tube connecting the neural and alimentary canals I do not know, but it .seems impossible fo escape the conclusion tliat it well represents the neurenteric canal of other forms although the enteric canal of the fish does not at this time have the closed condition which olitains in other forms.
According to various observers, before the fdrmatiou nl" the neural canal tiic e|iiblast separates itself into two layers, an outer or epidermal and an inner or nervou-i layer, the latter being confined more closely to the embryonic area. This diiferentiation we were not looking for and hence no allusion to it appears in the foregoing account of the for- mation of the neural cords ; whether it exists or not we cannot positively say though it probably does and was overlooked in our studies. According to those ob.servers who , make this distinction, the nervous layer forms the Ijulk of the neural canal and Cal- berla('77) claims that a thin layer of epidermal cells penetrates into the nervous layer and eventually forms the epithelial lining of the neural canal, but GiJtte ('78) denies thin and Balfour studying Lepidosteus and the teleosts ('81) has not been able to confirm Cal- berla's observations. It would however seem probable that Calberla is right though farther observations are necessary to settle the point.
Schapringer ('71 p. 555) does not afford an}- information on tliis point, for he merely states that the medullary canal does not form in Itony fishes, as in Birds, Batrachia and Mammals by a folding in of the medullary folds but through a process of .separation on the inside.
According to our observations the method of origin of the neural ridges has an ahno.st exact parallel in that of the Elasmobranch as given by Balfour ('78) and also clo.sely resembles Klein's observations on the trout 'G2 pi. 17, fig. 2. The figures of Hi.s. ('75) in text, and which are copied by Balfour, '81 fig. 33, are greatly different from aiiytbiug which we have seen as will be noticed on an inspection of our plates.
Optic Bulbs and Protovertebrae.
Shortly before the stages shown in figs. 29 and 32 the fore-, mid- and hin<l-brain< arc differentiated and almost immediately the optic lobes begin to be segnionteil off. At this time both the brain and the rudimentary lobes appear to be solid l)odies without any internal cavity nor does there appear to be any trace of the neural canal in the spinal cord. A fissure appears on either side of the brain cutting off a portion which forms the optic lobe. This fissure begins above and behind and gradually extends forward.^ and downwards until at last but a slight connection is left, the rudimentary optic nerve (fig. 36). The fissures progress until at last the nerve going to the right eye is connected only with the left side of the brain while the optic nerve of the left eye arises from the right
20S KINGSLEY AND CK)NN
siile of the same central organ, the condition wliich obtains in the adnlfc fish.. Dnring the dirtorontiations thus described other changes take place, and before the stage represented in IW. 42 is reached the lumen in the brain, optic bulbs, and neural cord appears as shown in figs. 30 and 45.
Svnchronous with the differentiation of the regions of the brain, the mesoblast adjoining the notochord (fig. 32) becomes separated from the rest of the layer as the muscle plates, and with the .reparation of the optic bulbs the muscle plates are divided into protoverte- brae. The first of these protovertebrae to be formed is at about the middle of the body, and the fissures which limit it arise simultaneously. They begin close to the notochord above and progress oytward and downward and at the same time slightly backward. From this central one the formation of the protovertebrae extends gradually in both direc- tions. At the same time the formation of pigment cells is seen. These arise as black dots and gradually increase and change their shape until at last they assume forms like those shown in fig. 51.
Regarding the peculiar structure which from its first describer we may call Kupffer's ves- icle 1 have but little to say. It first makes its appearance just before the stage shown in fig. 34 on the under surface of the posterior end of the embryo and rapidly increases in size untU it acquires a diameter nearly equal to that of the fish. Of its subsequent fate our notes afford no information. Its first appearance is indicated by one or two small globules which soon are joined by others until an appearance like that of fig. 52 is seen. Very soon these globules unite and in two hours the vesicle has the appearance and relative proportion of fig. 53. Fig. 54 shows about the limit of its development and is reached in about five hours from the first appearance of the minute globules.
As mentioned above, this vesicle was first noticed by Kupffer ('08) and by him regarded as a rudimentary allantois. Balfour ('81) regards it as homologous with the terminal vesi- cle of the post-anal gut of Elasmobranchs. On the other hand Henneguy ('80) studying the perch thinks he saw an opening or traces of invagination of the vesicle and would homologize it with the primitive intestine of the Cyclostomi and Batrachia and its opening with the anus of Rusconi, a view which it seems to me is entirely unwarranted by the pre- vious growth of the embryo and by the method of origin and position of the vesicle as we have seen it. The view of Balfour seems much more probable.
The epiblast over the optic lobe begins to thicken to form the lens of the eye when six- teen protovertebrae are outlined. This thickening increases until soon it acquires the character shown in fig. 49 and almost immediately the thickening begins to be segmented off and to make its way into a depression in the optic lobes and to acquire more and more of a spherical character as shown in figs. 55-57. The manner of the involution of the lens and the features connected with it have so often been described that it is unnecessary to repeat them here.
At about this time the mesoblast begins to split into somatopleure and splanclmopleure. This splitting begins at the head end of the embryo and progresses regularly in every direction. This is a true splitting and not as suggested by Mr. Ryder in a letter to the author an apparent one. He interprets his observations as follows : the portion of the mesoblast which extends down over the yolk is that portion which eventually forms the Hplanchnopleure and that the somatopleure gradually extends down between this layer and
ON THK K.MIIKVoI.or.Y OF THE TELEOSTS.
209
the epihlast, and he also ('81) roganls the space into which the soumtAipleure thus forccn itself as the remains of the segnienUition cavity. So far as our e;^gs and our ohservatioiw go there is not the slightest evidence in favor of citlicr view, for the epihlast is everywhere in clo-<e connection with the inesoblast and nothing could he seen in the cnvcl(»pe>t of the yolk which could in any way he interpreted as remains or derivations of the scmentatioii cavity, a cavity of which all tracer are lo<t at an early st ige in the d'Vclopmi'nt. In our G'^'^^ also there was a veritable s[)litting of the me-solda-it a-< will he seen by au iuapuction
of fig. 3(;.'
From this point on my observations are exceedingly fragini-niary and the account would best he confined to little ir.ore than the remaining figures, a course of procedure which will .serve to connect tiie early stages with those of which Mr. Agassi/, treats.
In a side view, at first but two of the prominences of the brain are seen (fig. 33) but soon the third, tlie niid-liraiu. makes itself visilde as shown in fig. 34, and at the latter stage we first fiml tiie traces of the pericardium and the heart {p. fig-. 34). Of the origin of these portions of the anatomy I can say but little. It seems almost impossible U) cor- relate the steps of their development with those found in other vertebrates. At first there appears a mass of mesoblastic ti.ssue arising almost beneath the hind brain and pro jecting into what has previously been regarded as the cavity produced liy the splitting of the mesohlast (and therefore corresponding to the pleuroperitoneal cavity of other verte- brates) but which is regarded by Ryder as the segmentation cavity. (We .shall return to this cavity further on). This mass of cells grows downward and when it comes in c(jntact with the lower layer of celLs (either hypoblastic or sphlanchnopleuric) a lumen appears, the primitive heart. At first this is a simple tube and indeed for a consideraide time retains that character as shown in figs. 40 and 50. When the heart first begins to pul- sate the vibrations are very slow and frequently it ceases beating for some time and then begins again. Coincident with the first j^ulsations, which appear at a little later stage than that represented in fig. 43, the first motions of the embryo are seen, and consist of .slight tremors of the whole body. At first the contractions of the heart produce no currents of blood nor in fact are any corpuscles to be seen. In the eggs of the cunner it is extremely difficult to trace the development of the circulatory .system after this time, only .slight and unsatisfactorj' views of portions being visible, while only once was I able to see anything whatever of the blood vessels of the yolk sac. Of the formation of the corpuscles nothing was seen nor were they visible until a comparatively late stage.
We have seen in preceding pages the method of formation of tlie hypoblast of the ali- mentary tract by an invagination to which are possibly added cells from the intermediary layer. A portion of the hypoblast eventually forms a solid cord e.xtending along l)eneatii the body but of the exact method we are not certain. This cord gradually grows forward ami at intervals a lumen appears, as shown in fig. 33 me., the future cavity of the canal ; this is shown again at a later stage in figure 42, which represents the hinder end of the mesenteron of a fish about as far developed as shown in fig. 43. Though the exact process of the clo.sure of
' The investig.itions of 1882 wliich einbr.-icud tliese points some nioflific.ition, the changes rcquireil .ire far less than thoae le.iJ me to reganl Mr. Ryder's eonclusions more favorably, impltcil in the above paragraph which is ba.tcJ upon sooxe and though I am not ready to accept them wholly without erroneous interpretations.
MEMOIRS BOST. SOC. NAT. HIST. VOL. III. 27
210 KINGSLEY AND CONN
the blastoilorm was not seen, the writer feels confident that the posterior end of the alimentary tract arises in the normal way by an invagination of the epiblast to form the proctodeum (fig. 41) and that the division between the two portion breaks down, the result being as shown in figures 44 and 53. Ryder seems to regard this proctodeum as the neurenteric ca- nal. The steps between these two figures were all seen, but tlie formation of the anterior end of the canal was not witnessed. There are many points of the alimentary tract upon which additional information is needed: the manner of the formation of the mouth, the connection, if any exists, between the yolk sac and the stomach or intestine, and the rela- tions of what is here called the hypoblast of the yolk sac to that of the digestive portion. There are many points in connection with this latter which are absolutely unintelligible to me no matter how looked upon. In fig. 33 this layer is represented as extending beneath the embryo and nowhere united with the alimentary canal and together with another layer starting oflf on its course around the yolk. Now if this be the hypoblast from which the digestive tract arises, some connection would be expected between them though none has been found.
The fins which are first seen in an egg about as far advanced as fig. 51, arise in the cun- ner as a simple outgrowth and not as a continuous lateral fold, as is found in many forms. Tlie first skeletal elements appear as a small body at the base of the fin parallel to the bod}- axis and it is not until considerable later that radial portions appear. This basal skeleton instead of appearing as a pair of rods as described by Ryder was rather a broad plate with a central opening, as if his rods had united at their extremities. Thij same feature was seen in Lophius.
The remaining features of the development so far as I have clearly made them out can be seen from the plates, and my knowledge is too deficient to say more concerning them than will appear in the explanation of the figures. In about two days from impregna- tion, the fish hatches with a lai-ge yolk sac, which in four days more has almost entirely disappeared as shown in fig. 53. The time of hatching I cannot exactly state, in fact it varies considerably with the temperature. Eggs which were impregnated Friday morning at ten o'clock were found hatched Sunday at eleven A. m. (How much before that hour the actual hatching took place I cannot say). The act of hatching was often wit- nessed. The membrane of the egg, yielding to some violent struggles of the embryo bursts open and the young fish emerges usually head first. At the time of hatching the young fish is aljout a tenth of an inch in length and very slender in proportion.
I
ox TIIK i:mijky<ii.(>(;v of IIIK TKI.Kc»TS.
Exi'LAXATION OK Pl.ATKS.
a. imii^. h. />. liiii,l-l)i:iiii. „,,. oil j{l<'l»ulc.
a/. aliiiRiiiary cM-.il. i. iiitiriiif.liary layer (in lifr. p. {H-ricanliiiiii.
no. aorta. 40 jiii,'ular v.iii.) ;x-. 4anliiial v.-in.
au(f. au.iitory vcsi.li-. / ju;,'ular viiii. ;,, y. jM.lar 'kIoIiuIo.
d. blast. mKtiii (in fig. •J4* an /. l.iis. pr. i.rr.ct.*.k-uni.
astiT.) /. /. thiikening of t|.iljla.st for p. t. j.rot..viTti'ljriw.
'"'• buotus C'nvitrii. lens of the i-ye. h. Htfnn.ntation i-avily.
(//. noto(H)r.l. //•. livir. *o. 8..niato|.lfurf.
e<i. i-niliryonic ana. inh. ini.l-brain. sp. Hplaii<'lino|iK-urc.
/■ till- ""?• imsoblast (uusinliron in mi. v. mijiorior vcrUhrii.
/. h. f.in-brain. figs. 3:5 ami 41. g. r. ninuM vlmiohuh.
/.v. Mn vein. h. p. na.sal pits. t. h. tail 8Mollin(r.
//. gills or gill anlii'S. n. <j. neural groove. u. Knp)Ter'.s veHicle.
A. or Ay. hypoblast. o. eye. m. ^. urogenital upparatUM.
Id. heart. op. ojitic vesiele. y. yolk.
211
y. ». yolk sai
PLATK XIV.
Fig. 1. Alioropyk' of egg of Ctenolabrns in section.
Fig. '2. Surface view of same -with surroumling pore eanals.
Fig. 3. Merhieius the germinal disc .ibove showing the arehamphiaster of maturation.
Fig. 4. E:irly egg of Ctenolabrns before maturation and impregnation.
Fig. 5. Portion of germinal area of egg of Jlerlucius with probable j)olar globules.
Fig. 6. Formation of polar globule and expulsion of same through the micropyle.
Fig. 7. The same a few seconds later; in these two figures the details of micropyle are omitted.
Fig. 8. A polar globule attached to one cell of a bhistoderni of two segments.
Fig. 9-10-11. Three successive steps in the formation of the biscuit-like germinal arcii, shown in section, the shaded portion extending out from that region forming a portion of the intermediary layer.
Fig. 1.. Result of first segmentation, the "tails" ou either side the rudimentary " bourrelet peri- ]plieriqne.''
Fig. 13. Prei>arations for second segmentation.
Fig. 14. Ivesulting four segments with the tem|iorary furrows of the yolk.
Fig. 15. Diagram of amoeboid motions in blastoderm of eight cells.
Fig. 1(3. Blastoderm of eight cells showing a common irregularity.
Fig. 17. Amoeboid a]ipcarance of two cells.
Fig. IS. Preparation for dividing from eight to sixteen cells, showing irregularity in time of division.
Fig- 19- Blastoderm of IG cells.
Fig. "20. Blastoderm of 24 cells.
Fig. 21. Optical section through the edge of a blastoderm in a late st.igc of segmentation.
Fig. 22. Beginning, and fig. 23, later stage of inv.ngination of hypoblast. The upper slndcd portion representing the cpiblast and lower layer cells ; s, the segmentation cavity, and the dark narrow line just beneath, the intermediary layer; the broad shaded portion shows the outline of the lateral inv.igination. The black line beneath A, the hypoblast, and e. a., embryonic area is possibly the segmentation cavity of Ryder.
Fig. 24. Bl.astoderm of fig. 23 from above, showing the outline of the segmentation cavity, the line acrosx shows the plane of the preceding section.
PLATE XV.
Fig. 24*. Cells from the margin of bla.stoderm ; and beneath, free cell formation in peripheral cushion ; aiuphiaster x, and an aster b, are shown and also a stage in the fonnation of cell walls.
212 T"K EMBKYOLOGY OV TIIK TELKOSTS.
Fisrs. 25, 26 27. Tliroo stages in fonnation of notocliord shown in (o]itical) section.
Fig. 28. Sanu" at later stage.
Fis;. 29. Siile view of embryo, etc., showing the blastoderm with (faintly) its thickened margin.
Fiii- 30. Oblique view of tail end of tig. 29, showing the neural groove, the tail swelling and the thick- ened margin of the blastoderm, the slight notch in the m;irgin at / s may possibly represent the neurenteric canal.
Fi-jj. 32. Formation of oi>tic lobes and protovertebrae ; the a])parent distortion of the figure is due to an atteni] t to represent the embryo in perspective.
Fin. 33. Staire a little later than 32 showing optic lobe and niesenteron and a few of the anterior proto- vertebrae.
Fig. 34. Still later with fore-, mid- and hind-brain differentiated and pericardial region forming.
Fi<». 35. Splitting of mesoblast into somatopleure and sj)lanchnoj)leure.
Fig. 36. Dors.al view of head a little later than fig. 34 with formation of the lens of the eye and the appearance of the lumen in the brain and o]>tic vesicles.
Fii's. 37, 38, 39. Successive changes in appearance of notoehord.
PLATE XVI.
Fig. 40. Heart and blood vessels in stage nearly correspomling with fig. 51, or shortly before hatching.
Fit;. 41. Plclations of notoehord, .aorta, urogenital canal, nieseiiteron and ])roctodeuni in hatched fish.
Fig. 42. Lumen in mesenteron in embryo about like fig. 43.
Fig. 43. Embryo with the lens of the eye, auditory vesicle and nasal pits well advanced. The blasto- derm has closed and the tail has begun to grow out. Kupffer's vesicle was present but is omitted in the drawing.
Fig. 44. Anal region in hatched fish.
Fig. 45. Details of head in fig. 43.
Figs. 46 and 47. Out-growth of liver in its earliest stage from the side and from beneath.
Fig. 48. Anterior portion of fish two days old from beneath, showing anterior end of urogenital canal. The stomodeum and mesenteron have not yet met. H. W. Conn, del.
Figs. 49 and 50. Fish of .about tour days. H. W. Conn, del.
Hg. 51. Embryo of unknown teleost just before hatching;
Fig. 52 and 54. Two stages in formation of Kupffer's vesicle, u, seen in optical section.
Fig. 53. Fish between four and five days old.
?Jf OLO CY OF TE LE 0 ST S
/
V
r;::;GSirv' ok Embryo.
■■/
A
t^'
J J
7^
f^
X&Kut^s1<y, li EiiUilk
Kj:;:-SLr:' :K r'.MBRYOLOGY OFTjlLEOSTS.
VII. Tin: CAnnoNiFEnors IIexapod Insects of <.i:i \i I!i:ii\in. By Samuel II. Scuudeij.
Read May 21, 18.S2.
xjlLTHOUGH it is very nearly fifty years since Aiidouin first iinnuuiiced the discovery <>!' insect remains in the coal-mea.'inres of England, the nuiiiliLT of known forms from tliut conntry is still so small that they may he counted upon tjie fingers of one hand. The addition of two species to that numher, which I am aljJe througli the kindness ol' Kev. 1'. B. Brodie to make at the present time, is therefore of more tliiin common significance. Each of these, moreover, has a special interest, the one from its striking color-contrasts, the other from its gigantic size ; and both throw so much new light upon the ancient insect fauna of^Great Britain that I venture to pass all the neuropterous forms under review, partly to clear away certain misapprehensions concerning the affinities of tliose that have been described, partly with the view of vindicating the accuracy of Aiidouin's early announcement ; partly also in the hope that this may lead to the discovery of more forms in these older beds, where every addition to our knowledge is likely to be of more than ordinary importance.
Both the additional forms represent genera hitherto unknown, as do also each of those alread}^ described. To the first of the new types we may apply the generic name
Brodia nov. gen.
In this genus the wing is long and slender, shaped somewhat as in Panorpa, slightly pedunculated at the base ; the costal margin is nearly straight, being very gently and and equably convex, the lower margin moderately full, straight along the middle portion. The marginal vein forming the border is stout, armed throughout with short prickles or spines (pi. 17, figs. 5, 6). The mediastinal vein is the most indistinct in the wing and situ- ated at a low level (compare pi. 17, tig. 3 and fig. 4) ; it runs midway between and entirely parallel to the marginal and scapular veins until near its extremity, Avhere it turns upward ver}- gently, terminating in the margin at about the middle of the wing. The scapular vein runs parallel to the margin throughout the wing (as preserved; that i.s, nearly to the tip) and is situated at a high level ; its main branch, which is again at a low level, parts from the vein at an exceedingly slight angle at the end of the basal fifth of the wing, and runs parallel to the main vein, and at a distance from it about equal to tlie distance of the latter from the margin ; this main branch emits half a dozen or more equidistant, oblique veins from its lower side (five are found in the fragment), which run parallel to each other
214 SCUDDKR ON THE CARBONIFEROUS
U>\vanl the outer part of tlio lower margin ; the first of these nervules is at a high level, is thrown oil' near the base in continuation of the base of the main branch and is more curved than the others, its basal direction being less oblique than theirs. The extevnome- dian vein is a simple, gently arcuate vein, running from the base to a little beyond the middle of the lower margin, and emitting from its upper side at the middle of its course a single branch, arcuate at base, which, like the main vein, has a course parallel to the scap- ular brunches ; both main vein and branch are situated at a very low level. The interno- median vein is nearly straight, a little arcuate, especially in the apical half, and perfectly simple, situated at a high level and terminating a little before the middle of the lower margin. The anal vein, neither elevated nor depressed, is forked at the base, one fork run- ning parallel to the internomedian vein in the basal half, and beyond curving downward t.0 the margin, which is slightly indented at this point ; and the other again forking, the forks similar, curving, but very short.
There are several distinct cross-veins in the wing ; one important one, a long and curv- ing vein, connects the externomedian and scapular vein, near the base, and appears to form a downward curving basal continuation of the main branch of the scapular, making it look like a superior branch of the lower vein ; the others are transvei'se and most of them at exactl}- right angles to the nervures, and they are all situated in the dark bands. Besides these, there are a large number of fainter cross-veins transverse to the nervures they connect, pretty regularly and uniformily distributed over the wing below the main scapular vein, forming quadrangular cells which over most of the wing are more than twice as broad as long.
The genus is dedicated to my honored friend Rev. Peter Bellinger Brodie ; as his name will alwaj's be connected with the fossil insects of England, it is fitting that so notable a form as this should recall his eminent services.
Thi.s generic type is an ancient form of Planipennia or true Neuroptera, the structure of whose wings does not agree with that of any of the existing families of the group, but rather shows a combination of features which now distinguish separate families. It has the general aspect of a gigantic Pauorpa, borrowed from its form, its markings, the pres- ence of a few scattered cross-veins, and the course of the mediastinal nervure. When, however, its neuration is carefully observed, the scapular vein is seen to be fundamentally diflerent, although its position and the origin of its main branch is similar ; for, while in both ca.ses the area it occupies is important, in the Panorpina the main branch divides dicbotomously throughout, and its offshoots take a longitudinal direction ; while in Brodia, the main branch emits oblique shoots at regular intervals downward and outward, as it does in other Planipennia, but not in Panorpina. The veins below the scapular are also very different from what they are in Panorpina, and relatively to the rest of the wing much less important.
With the Hemerobina, the wide space between whose marginal and mediastinal veins is filled with numerous oblique and generally forked veinlets, and whose scapular vein has numerous sectors, this ancient type has less to do. In this group the mediastinal vein extends nearly to the tip of the wing, while in Brodia it terminates a little beyond the mid- dle. The Hemerobina, however, differ from other Planipennia in the insignificant part usually
IIKXATOI) INSKCTS OF (MtKAT ItlUTAIN. 2ir>
playo'l by the oxternoint'dian vein, which is rrciiui'iitly ahiio>it fiuiivly hiiuplc or oiilv forked once in the apical half of its course. This peculiarity is horrowed, tliuiiirh hdI in a striking degree. l)y I?rodia, whc^re this vein is forked once near tlje niiddh* ; hut whose branches, widely distant like those of the sca[)ular vein, cover a considerable area.
The more es.sential features of this ancient wing, however, foreshadow the chara«'teristic« <»l' the Sialina. In form, while it is not very dilfcrent, it has none of the arcliing of the costa almost universal among Sialina, and usually accompanied in modern fvpe-« by a broad space t)et\veen the marginal and mediastinal veiiH, imt at all displuvfd bv Hrodin. In the brevity of the mediastinal vein Hrodia resembles the Kaphidiida>, but the nenrn- tion of the rest of the wing is completely dilferent ; while in the Sialina proper the medi- astinal vein always continues nearly to the tip of the wing. The course and distribution of the branches of the scapular vein, however, are of greater importance, and in thirt respect Brodia agrees very well with the Sialina ; again, however, the simnlicitv of the internomeilian vein in Hrodia, where it consists of only a single undivided ray, is very diflerent from that now fouml in Sialina. where it is always divided ami often plays a some- what important part.
Brodia, then, is a planipennian in a t»road sense, refusing to aHiliatc closely with the restricted families of the present day. Nor does it appear to be intimately related to any paleozoic insect yet described. It is also peculiar for possessing a very large numlier of fine cross-veins or wrinkles, besides the stout cross-veins which are scattered here and there over the wing ; the latter are, however, confined to dark patches to be mentioned presently ; while the former are uniforml}' distributed over the wing, subequidistant, and always run at right angles to the nervures they connect, even where, by keeping that course, they strike the often obliquely directed, stouter cross-veins.
In the preservation of its colors (pi. 17, fig. 7), Brodia is the mo.st striking instance known among paleozoic insects the markings are sharply defined and, to judge from illustra- tion.s, more deeply tinted than in Protopluisma Dinnasii recently described by Bnmgniart, who has drawn particular attention to this remarkable feature in the wings; or than in the longer known Gryllacris lithanthraca of Goldenberg. In allusion to this colorational fea- ture, the species may bear the name of
Brodia priscotincta nov. sp.
PL 17, ti-s. :j-7.
The wing is a rather large one, being probably about 5-3 mm. long (the fragment is 44 nun. long) and 12 mm. broad in the middle. Both front and hind margins are very dark colored and are distinctly furnished at the extreme edge with a row of fine bristly teeth, short, stout, triangular, pointed, black, directed outward and forward (or backward), and on the costal edge more clo-sely approximated away from (pi. 17, fig. o)than near(pl. 17. fig. 6) the base ; beyond the base, also, the marginal vein is furnished along its lower edge with a similar armature, only the teeth, here also black, are depressed, directed outward, and not nearly so sharply pointed (pi. 17, fig. 5).
The stone on which the wing is preserved is of a dull, impure gray color fpl. 17, fig. 7), and the hyaline parts of the wing do not differ from it in tint. Nearly half of the wing
216 SCUDDER (.)N THE CARBONIFEROUS
however is of a much darker shade, the markings consisting mainly of three broad trans- verse belts, which cross the wing from the scapular vein to the lower margin, one near the middle of the wing and one near the middle of either half; these, and especially the outer two, are of a distinct though dull umber brown ; the same deep tint is also found throughout the space between the scapular vein and its main parallel branch, but the whole costal margin above the scapular vein is Iwaline; the apex of the wing, which ia lost, was probaljly tipped with the dark color. Of the three transverse belts the outer- most is pretty regularly transverse, its inner margin following an irregular zigzag course, generally at right angles to the costal margin, from the base of the third oflshoot of the main scapular branch to the tip of the lower externomedian branch ; its outer margin fol- lows a similar direction downward from the base of the fourth offshoot of the main scap- ular branch. -until it reaches the second offshoot, when it follows that outward (to the broken part of the Aving). The middle transverse belt is less regular, being nearly broken in the middle, its lower half hardly more than half as broad as its upper half and thrust a little further outward ; the upper half is seated on the extreme base of the upper externomedian branch and, broadening upward, reaches from near the base of the first oflf- shoot of the main scapular branch to nearly midway between the second and third offshoot ; the lower half is equal and tolerably regular, its middle line opposite the lower termina- tion of the outer margin of the upper half, its outer margin terminating below at the tip of the internomedian vein. The inner belt is broken into thi'ee fragments ; the upper, between the scapular and externomedian veins, reaches from where these veins begin to diverge to the extremity of the curved cross-vein uniting the two veins ; the second, between the externomedian and internomedian veins, extends in neither direction so far as the one above, and is terminated outwardly by a distinct and oblique cross-vein ; the third occupies the outer half of the anal area. Besides there are a few dark cloudy spots at the base, one following the lower edgg of the internomedian vein, and others parts of the anal veins. The heavier cross-veins, besides the one referred to in the generic description, at the ba.se of the main scapular branch, are the following : In the scapular area, four equidistant transverse veins between the main stem and the main branch ; two approximate transverse veins between the third and fourth offshoots of the main branch, — both in the outer dark belt and the outer forming its outer margin ; one in tlie same belt in the interspace below, and in continuation of the inner of the transverse veins above it ; one in the middle belt, oblique to the nervures but at right angles to the costal margin, between the scapular and externomedian veins; two others in the same interspace in the outer belt, a little oblique to the nervures, in the oppo.site sense to the preceding ; two others in continuation of these, but transverse to the nervures between the externomedian branches ; another in the same interspace in the middle belt, also transverse ; one in continuation of this, in the interspace below, forming the inner margin of the middle belt, besides another outside of it in the ex- terno-internomedian interspace, both transverse, and one in the same interspace, very oblique, forming the outer margin of the inner belt ; two in the interspace below, one oblique, its lower extreir.ity at the tip of the anal vein, the other transverse, above the middle of the lower spot of the inner belt ; and finally one, very oblique, in continuation of the preced- ing. It thus appears that all the heavy cross nervules fg,ll in the three transverse dark belts and that with few exceptions those which are oblique to the neighboring longitudinal
IIKX.M'OI) IXSKCTS OF (ilCKAT HIMTALV. oj^
nervures arc situated in the interspace between main velnH, wliile tlio-ie wliicli are trans- verse are between branches of a single vein.
The specimen comes from tiie coal measures near Ti|)ton, Staflonlshire, where it wa« obtaineil hy Mr. C. Beale and was kindly sent to me for study by the Hev. P. B. Hrodie, Vicar of lvowinj,'ton, near Warwick, to whom it now belonfr^. The face examined is the upper surface of the right wing, or else the reverse of the luw.-r suilini' nf the lell wing. The .second species may be called :
Archaeoptilus ingens miv. sj). ci ^^'.h. ri. 17, tigs. 10- 12.
The costal margin, or marginal vein, is pretty strongly convex at the base, but beyond is straight ; no other margin is preserved, and only the ba.se of this, but the wide separ ration and straight course of the upper, and the sweeping curve of the lower, veins indicate an immense expan.se of wing both in length and breadth ; all the veins are exceedingly stout. The media.stinal vein is at first directed in a straight line toward (presumablv) the middle of the costal margin, but at a distance of 20 mm. from the base bends very gently and very slightly downward, still continuing a nearly straight course, indicating the extension of the vein to the tip or nearly to the tip of the wing ; at the extremity of the fragment, at about 40 nim. from the base, it lies midway between the marginal and scapular veins ; but previous to this it lies nearer the latter. It lies in a slight depression, a little lower than the level of the interspaces beside it, as well as that of the marginal vein. The scapular vein, on the contrary, though broad and flattened like all the rest, lies at a high level from which the wing .slopes in a rounded curve equally on both sides; it starts from tlic middle of the base of the wing, and follow- ing a course subparallel to the costal margin, especially beyond the extreme base of the latter, moves in a broad inconspicuous curve, apparently reaching the highest point of the curve at the extremity of the fragment. The oxtcrnomedian vein crowds against the scapular at base and, at a distance of only about 10 mm. therefrom, it divi<les into two branches, the upper of which continues the course of the undivided base, but diverges veiy slightly from the scapular vein ; so that at the end of the fragment the two veins are separated by scarcely more than the width of one of them. Like the scapular vein it lies at a high level, but the lower branch, on the conti'ary, falls rapidly beyond its origin, .so as to lie. at the terminal portion of the fragment, at a lower level than the mediastinal vein j but unlike the mediastinal, and indeed all the other principal veins, it is weak, having less than one-fifth the width of the scapular vein ; it diverges with toleralile nipidity from the main branch, and divides equally the space between it and the internomedian vein. The latter vein, again heavy, and also closely crowded at base against the veins above, a.s fiir as the divi.sion of the externomedian vein, .sweeps downward in a pretty strong curve beyond this point, so that at the end of the fragment, up to which it is undivided, it is a.s far from the upper branch of the externomedian, as the scapular is from the mediastinal. It lies again at a higher level, the space between the lower branch of the externomedian and the internal forming a broad gentle arch, lower and less conspicuous than that between the mediastinal and lower externomedian veins, but otherwise similar to it, at the summit of
MEMOIRS liOST. SOC. hAT. HIST. VOL. III.
21S SCUDDKK OX TIIK CAKUONIFEKOUS
wliirh lies tliis vein. Tlio anal vein is not orowdoil against those above it; it has a curve even more sweeping than, but running subparallel to, the internoniedian vein, and emits several similarly ciu'ving branches, of which fragment? of two can be seen upon the stone ; at base it is separated from the veins above by a space several times its own width, and at the extreme base it seems to part more widely from them, and to have its root attach- ments at a considerable remove from them ; the vein itself is neither depressed nor elevated.
The cross-veins of the wing are very conspicuous, especially in the two broad upper intei-spaces ; here they are prominent, in relief, generally simple, occasionally forking, and then rather widely, generally curved or sinuous, subequidistant, and dividing the inter- spaces into cells generally about twice as broad as long. In the mediastino-scapular interspace they are generally regularly curved with the convexity outward ; and the same is usually the case with the other cro.ss-veins of the interspaces below, in all of wliich they are found (even in the slender intersjjace between the scapular and the upper branch of the externomedian vein) ; though here they are much feebler, more numerous, uniform and simple ; they are especiallj' feeble and numerous in the internoraedio-anal interspace, as well as in the slight fragments that remain of the anal area.
Besides these cross-veins are a few others, the nature of which it is more difficult to divine ; such are three short, curving, transverse impressions which cross continuously the base of .-scapular and externomedian veins ; and also a considerable number of transverse impressions on these same veins awaj- from the base generally crossing the vein, sometimes only half crossing it and usually in continuation of the ordinary cross-veins in the inter- space below ; these latter cros.s-veins are not shown in the figures ; they are not con- spicuous in the fossil and appear to be confined to these two veins.
In addition to these points it may be mentioned that the only fragment of a boixler which remains shows that the edge of the w^ing was spinous ; toward the base the costal margin is furni.shed on its convex portion (pi. 17, fig. 11) with frequent .short, oblique, spinous points, which further out seem to be altered to distant, recumbent, outward directed, longer and rather slender spines.
Length of the fragment 4-3 mm. ; breadth 32 mm. ; greatest width of upper interspace 10 mm.
This fragment is remarkable for representing the largest known insect-wing from the paleozoic rocks, not excepting the Acridites formosiis of Goldenberg from Saarbriick, or my Mefjatheiitomnm, pustulatum from Illinois. Certainly not more, probably ranch less, than the fifth of the wing is preserved (pi. 17, fig. 12), but the direction of the veins, their very great robustnes.s, and the extraordinary distance apart of the upper three, are clear indications that the spread of wing enjoyed by this insect was not less than 25 cm., and may have been even more than 35 cm., while the width could not have been far from 6 cm. All the principal veins are a millimeter or more thick.
The specimen occupies the entire surface of a reddish-brown iron-stone nodule and came from the coal measures near Chesterfield, between Shelton and Clayboi-ne, Derbyshire, Eng- land ; it was received for examination from Rev. P. B. Brodie, to whose collection it belongs. The reverse is in the British Museum, from which I have received excellent casts through
IIEXAPOD INSKCTS OK ( MJKAT 15IU TAIN. 219
Dr. Ilciny Wondwaiil. 'I'lie speciiiioii l)ct'<iiv iiu' n-jm'.-iint-^ tin- ii|i]u'r suifacc (tf a Itit wing, or elsi' the reverse of the lower surfaee of a right wiii;^.
Tlie exact position of a Iragineiit a.s small (proportionally speaking) as this would seem to be indeterminahle at first sight; and so indeed it wonhl he, were there not other forniM living at that time, belonging to a group from which this cannot be separated bv anything in the structure of the base of the wing; and yet, as it iliflers strikingly from all of them in certain features, and from its immense size can lie confounde<l with none, it merits di.t- tinct mention and a name. All of the principal veins are present, and from their trend and relative level, and from the width and nature of the interspaces, there can be no (piestion that the insect belongs to the same group as the only other heretofore known nenropte- rous wings fonnd in Great IJritain, viz., Cor^jflaJls Bron(jni(irli Mantell and LithoiiKtnt'tH air- honarlus Woodward, and is only to be separated generically from them. Its proper position can therefore best be determined after the structure of those wings has been discussed, — a point to which we will now direct our attention.
Dr. Woodward is assuredly mistaken in referring Lithomantis to •' the neighborhood of the Mantidiv," notwithstanding that he supports himself by the adherence t<j his views of such able entomologists as Me.ssr.s. Westwood, Waterhouse and M'Lachlan, who can hardly have made a serious studj' of the neuration. It bears indeed a vague resemblance to that of the Mantidae, excepting in the hind wings, where the fullness of the anal area, with its special development of folding rays in the insect of to-day, need not be looked for in its less specialized ancestor; but when the elements of the neuration are examined, the resemblance is seen to be purely superficial. Then it appears that Lithomantis agrees with other ancient types, and not at all with the Mantida\ The front wing of the Man- tida> has a very peculiar and characteristic neuration. The marginal vein forms the front border of the wing, as I believe it never does in any saltatoriul Orthoptera, and always does in the Xeuroptera. The mediastinal vein is shnple, and runs in close proximitv to the scapular, terminating near the tip of the wing. So fur there is nothing essentially difler- ent from the condition of things in Lithomantis; but in the next three veins all is difTerent. To use the specific example {Bhpharis clomina of Afi-ica) given by Mr. Woodward : the scapular vein is perfectly simple as far as the extreme tip, when it divides into three very short nervules supporting the apical margin. In Lithomantis, however, it eniit.s a stout inferior branch near the middle of the wing, which runs parallel or nearly parallel to the main vein, and probably (if it is like its allies of the time) sends off several branches to the lower apical margin. As this is one of the principal veins of the wing, diflerences wliich occur here are significant, and there is hardly any group of insects which has so unimportant a scapular vein as the Mantida?. The diflerences are even more striking in the next two veins, better preserved in the fossil. In Blepharis (and it is much the .same in all Mantidae) the externomedian vein is divided at base into two main stems, the upper of which runs in close proximity to the scapular, and in the outer half of the wing sends downward three or four conspicuous oblique veins, which appear at first glance precisely as if they were offshoots of the scapular, which they are not at all ; they only perform the office of such offshoots in other wings ; the lower branch takes an irregularly longi- tudinal course below the upper branch, and emits similar veinlets to the lower margin ; and the entire area occupied by the two bi'anches of this vein and their offshoots covers
22^ SCUDDER ON TTIK CAT^BONIFEROUS
vorv much the laixor part of tlio wing. The intcrnoinedian vein, on the contrary, is exoi'odinglv simple, being forked only once (often, in other Mantidaj, not at all), and occupies much less space than even the anal area. Now in Lithomantis the case is verv different ; the e.vternomedian vein does not divide at all until near the middle, and then onlv once or twice, its branches covering an area which is certainly much less than a quarter part of the wing ; while the internomcdian vein subdivides numerously, no less than ei-^ht final nervures reaching the margin, and covering an area, certainly as great as, and apparently considerably greater than, that of the externomedian vein. These singu- lar diflerences between the Mantidaj and Lithomantis, affecting the distribution of the throe most important veins of the wing, leave no doubt whatever that the resemblances between the two are only superficial, and that Lithomantis can with no proprietj' be referred to the MantidiB.
What place, then, shoidd be assigned to Lithomantis ? I believe we should compare it with certain other paleozoic wings, and notably with " Corydalls Brongniarti " of Man- tell, to which indeed Woodward has himself compared it ; speaking of their "marked simi- laritv " and giving at the same time an original figure of this interesting fossil (reproduced in pi. 17. fig. 8).
The last insect, as I shall show, should be referred, neither to the modern genus Cory- dalis nor to Gr^'Uacris, but is generically distinct from all modern types, and may bear the name of
Lithosialis Brongniarti.
PI. 17, figs. 1, 2, 8, 9;
This insect is especially interesting from its being the first discovered in paleozoic rocks, and that at a time Avhen, to use the words of Audouin, no fossil insect was known either from the lower oolite, the lias, the keuper, the muschelkalk, or the new red sandstone ; still less in any older rocks. How astonishing then it must have been to find this trace in the coal ! It was at first supposed to be a plant, and as such was sent by Mantell to Brongniart, with other remains from Shropshire. Brongniart placed it in Audouin's hands, and he drew attention to it on several occasions, — before the Entomological Society of France, the Academy of Sciences, and the Assembly of German Naturalists at Bonn, asserting its relationship to Neuroptera, where he placed it in the neighborhood of Herae- robius, Semblis, Mantispa, and especially of Corydalis. Mantell accordingly figured it in 1839, in his Medals of Creation under the name of Corydalis, adding in the second edition in 1844 the specific name Brongniarti. The figure given by Mantell (reproduced in pi. 17, fig. 9) is thoroughly bad, not one of the veins being correctly drawn, and giving an altogether false idea of the wing ; that by Murchison, in the various editions of his " Siluria" (reproduced in pi. 17, fig. 2) is apparently made from the same drawing, and therefore almost equally bad ; the anal veins alone are more correct.
No further notice appears to have been taken of this wing until, in 1874, Swinton, and again, in 1876, Woodward, gave us new illustrations of it, (cf. pi. 17, figs. 1 and 8) which leave little to be desired. Swinton thought he had discovered the relics of a stridulating organ at the base of the wing, and compared it to similar characteristics alleged to be
IIKXAI'OI) IXSK( !>> (i| i.iji.Al l;l;il AIN. UJl
present on the under surlUce of the front winj^ of the ihoilern (irvUacri!?. He iu-conlinj:lv referred tlie win;^ to the Orthoptera. ami even to the rjoeustarian ;^fnu-< (frylla<Tis. This view cannot possibly be niaintained. ami a more unfortunate coniparison eonld hardly have been made. Swinton himself aeknowledjjes that he eouM not sneeeud in fnidin*^ a spcciiB of Gryllacris '-with an effective file," and the si'inldaneeof one he figures cannot be uscril)ed to a stridulatinj; ap|)aratus; for (1) the "file" he lij^ures couM not produce any w»uml when brou;^ht into contact with a similar structure on the op[)osite win*;, since from their course tlie two would not be brought into the jjroper relations to each other, or at least into such relations as they always are brouglit in stridulating Orthoptera ; (2) but it could not be brought at all into conhict with the similar part of the opposite wing, the wing-iuHcrtionK being far apart in Gryllacris, and the supposed file lying at the extreme base of a vein in tiie middle of the wing; (o) if this were a stridulating organ, it would not only lii- in n dillerent area from that in which it lies in all other Locu-tarians. but woulil agree with its place in no other Orthoptera whatever.'
The supposed file in Gryllacris being no stridulating apparatus, any comparisons between it and the fossil from this point of view are of course misplaced ; but, jiside from this, the position and course of the supposed file of the fossil is entirely difierent from that of the supjtosed file in Gryllacris, more indeed as it really is in Locustarians. But a careful ex- amination of casts of both obverse and reverse, kin liy given me by Mr. Woodward, and which show even more details than are given either by Swinton or Wooilward (as. for instance, the spiny nature of the edge of the costal margin), brings nothing to liglit which lends any support to this supposition.
In his comparison of the general nouration of the fossil wing and the modern Grylla- cris, Mr. Swinton's language is vague ; and his conclusion, though evident, is wholly erroneous. It needs only the figures upon his plate to point out the essential dilferences in the neuration. In the first place, a distinction of prime importance appears in the margin- al vein, which forms the border (and is heavily .spined) in tlie fossil, is widely removed from it in Gryllacris, the margin being for.ned of a film supported by superior offshoots from the marginal vein, which of course do not exist in the fossil. In Gryllacris, the scapular vein is crowded into <a narrow space, embracing on the margin only the extreme tip of the wing; while no such contraction appears in the fo.ssil, where the area embraced by this vein must cover the entire apical margin. The externomedian vein <if the fossil is closely crowded against the scapular at base, and parts from it beyond with a sweeping curve (as in most Neuroptera), appearing as if a branch of it; while in Grylla- cris it lies midway between the adjacent veins, an 1 has scarcely the slightest downward tendency, its branches being equally parallel instead of divergent. The internomedian vein in the fossil is widely separated on either hand from the adjoining veins ; while in Gryllacris it is equally crowded with the others. Finally, all the branches of the latter, as well as those of the preceding vein, impinge upon the apical margin in Gryllacris ; while in the fossil they strike the lower border of the wing.
'Mr. R.Etheridge of the British Museum has examined the is in fact only a fracture of the surfwc of the nrKliile. in original speciinea and -'is convinced that not the slightest which the wing i? preserved. Tliis is shown Uth on the foo- trace of any organ, as figured by Mr. Swinton . . . e.\ists on fil and its counlerpart." Geol. Mag. (2) viii. ■>■.•><. note, the specimen in question. The supposed ' stridulating organ'
222 SCTDDER OX THE CAU150XIFEH0US
Tlioso difloronoes. many of Avliich separate also most of the families of Ortlioptera from tlu>«!e t)f Neuroptera. i)rove that the fossil is widely distinct from dryllaeris, which, on its side, has a nenration more nearly allied to that of Nenroptera than, perhaps, any other group of Ortlioptera ; an}' comparison with other Ortlioptera wonld therefore be still • more vain, the nenration of the fossil wing bearing so much closer reseiiihlaiue to that of those gronps to which Andouin at first referred it.
Compared even with Broilia, it will be seen tliat the essential features of the nenration are tiie same, with the single exception of the mediastinal vein, which in Brodia ends on the margin not far from the midiUe of the wing ; while in this ancient " Corydalis " it extends no doubt nearly or quite to the tip. But exactly such a difference as this is fonnd today between Raphidiidiv and Sialidaj, and there can be little doubt that all four of tlie wings which have now been discussed (comprising all the important fragments of wings from the English carboniferous rocks but one — a cockroach) belong to an ancient type of planipennian Nenroptera.
Of these, the two which are most nearly related to each other are, unquestionably, the Cori/(htHK Bronrjnlartl of Mantell and the Lilhomantls c«r6o;ir</-/»s of Woodward. Indeed, the resemblance between them is so close that one would almost consider them as belong- ing to the same genus. The basal narrowness of the margino-mediastinal interspace, however, as well as the considerably greater importance of the internomedian area in Lithomantis, forbid this, though the course and general disposition of every principal vein is nearly identical.
Cori/iI'iJis Bronfjnlartl, then, being generically distinct from its .synchronous allies, and wiilely diflerent from living types, merits a distinctive name, and may be termed Lithosi- alis, to recall its relationship to the forms to which Audouin first compared it. From Lithomantis it differs in the points just rdentioned ; from Brodia in the basal breadth of the margino-mediastinal interspace, the much more numerous branching of the lower veins, ami the greater extent of the mediastinal, besides the more uniform breadth of the whole wing; from Archneoptilus, in the proportionally narrow area occupied at the base of the wing by the uppsr two interspaces, and the far later division of the externomedian vein.
Objection would perliaps Ijc made by some to the retention of Woodward's name of Lithomantis for an insect whose supposed resemblance to the Mantidte is found to be erroneou-;, and which does not even fall within the suborder to which the Mantidte belong ; but, asiile from the fact that it belonged to an age when the characteristic features of Ortlioptera and Nenroptera were more or less blended, its outward aspect is at first glance by no means very different from the insect to which Woodward has compared it ; and the retention of the name has an historic interest which should not be disregarded ; the num- ber of paleozoic insects is not, and is not likely to become, so great as to render the name itself an obstacle to a knowledge and easy recollection of its true affinities.
Attention may here be drawn to the apptirent fact (there are many described fossils which I have not yet studied with sufficient attention to speak in any stronger terms) that while all the carboniferoas Nenroptera of Great Britain belong to a single group, not only is thi.s group not represented (at least at all con.spicuously) in any other locality, whether in Europe or America ; but also the prevailing forms of other coal measures, the Dictyoneurae.
IIKXAl'OI) INSKCTS OF CIJKAT lilMTAIN 223
Ti'rniites, etc., arc entirely alisent IVuiii Kiiglaml. It is a iiuticealile exeeption to tlie prevailinj^ uniforniily of insect type among carhoniferous localities generallv. Tlie same exception tloes not exist ainonj; the araclmitls ami myriapoils of (ireat liritain, as Mr. Woodward has shown in nearly all his papers npon lossil in.seet.s.
Concerning the other hexapod insects described from fJreat Rritain we have here noth- ing to add besides a mere list of all the s[)ecies hitherto recorded, with which this paper is concluded.
LIST OF TIIK (•AIM!i)\[FKIJ)l'S IIKXAl'OI) IXSKCTS or (JIJKAT HUITAIV.
Nel'koi'teka.
1. Lithosialis Brongniarti Scuddkic, <;.ul. Marr., (-2), viii, -JOT-SOO (IS8I) ; — In., ITirv. I'niv. IJiill., ii,
nr. (issi).
Cori/l'tlis (ullicil t") .\.Li)i>L-i.v, Ami. Sue. Kiitoin. Frmcc, ii, IJiill., 7-S (18:{:J) ; — :\I \\r., Woii.l. (Ji-oL, ii,
CSO (1839) ;— Mlk.ii., Silur. Syst., i, 1(14-11(5, fig. a on ]). lO.i (IS.'J'.)) ; — In., Siltiii;i, p. 284, Ii;;. I (1854). Sialid'ie (lielongs to) Pktet, Tiaito Paloont., 2e eil., ii, 377-37H, |il. 4l>, fig. 1 (ls54). Corijililis /?ro/iy/Ma;-<i .Mantki.i., Moil. Cieat., n, 575, 57S, lign. 1"24, fig. 2 (1814); — In., ib., 'J<1 eil., ii,
551, 554, ligii. 181:2 (1854) ; — .Mcucii., Silu^i:^ 3.1 cl., 32il, fos.s. 81:1 on [.. 321 ( 1X59) ;— Swivr., Gcol.
M.-ig., (-2), I, 3-5 (1874). Gnjllwris ( Corijdnlis) Bromjiilarti Swintox, Geol. M:ig., (2) i, 5, jil. 14, (ig. 3 (1874); — Wood w., Quart.
Jonrn. Gcol. Soc. Lon.l., xx.\n, GO, pi. 9, tig. 2 (1876). GryUncris Ihoii;/iuarti Novak, Jahrb. gooL Heiclisaiist., x.x.v, 73-74, \A. 2, fig. 4 (1880).
[Coalbrook D:ilc', Sliropsliirc].
2. Lithomantis cavbDnavius \Vonr)\v. (Juart. .lomn. Gcol. Soc. Lond., .\.\xir, (jO-i54, pi. 9, (ig. 1 (187G); —
Scuui)., Gcol. Mig., (2), vni, 290-300 (18S1);— In., Ilarv. U„iv. Bull., ii, 175 (1881). Archimnntis (err. typ.) carbonnrias Scudd., Mom. Bost. Soc. Nat. Hist., m, 18, note 2 (1879); — In., Arch. Sc. I'hvs. Xat., (.J) III, 303 (1880). • [Scotland].
3. Archaeoptilus ingens Sccdd., Geol. Mag., (2) viii, 295, 300 (1881).
[Near Clicsterficlil, between Slielton anil Clay Lane, Derbyshire].
4. Brodia priscotincta Sccdd., Gcol. M.ig., (2), viii, 293-295, 300, fig. on p. 293 (1881).
[Tipton, StafTor.lshire].
Ortiioptera.
5. Etoblattina mantidioides S. lt)d., Mem. Bost. Soc. Xat. Illst., in, 72-73, ti_'. "n p. 73. |.l. 3, fig. 8.
(1879); In., Geol. Mag. (2) viii, 300 (1881). Bhata sj). KiuKii., Geol. Mag., iv, 389, pi. 17, fig. 6 (1867). JilaUldhuii mantidioides Goldenb., Faun. Saraep. Foss., ii, 20 (1877).
An iinlctenninate fragment of another wing, i)erliaps of the same species, is nKMitioned and figure<l, fig.
7, l)y Kirkliy as above. [Claxhcugh, Durham.]
6. Phasmidae sp., Kikkb., Geol. Mag., iv, 389, j.l. 17, fig. 8 (1867) ; — Sccdd., Gcol. Mag., (2) vm,
300 (1881). [Claxhcugh, Durham.]
COLEOI'TERA.
7. Curculioides Ansticii Bccki,., Geol., ii, 76, jd. 46", fig. 1 (1837); — Agass., Buckl., Geol., Expl. pi.
40", pp. 1-J, ].l. 40 ■, tig. 1 (1838) ;— Manx., Med. Great., 2d ed., u, 555 (1854) ; — Scudd., Geol. Mag., (2), VIII, 300 (1S81). Henila Ansticii Gieb., Ins.Vorw., 143 (1856). [Coalbrook Dale, Shropshire].
The other species described by Buckland as a beetle has been shown to be an araclinid.
( AKliONlFEKOlS INSECTS OF GKKAT RinTAIIS;.
EXTLANATION OF PLATE XVII.
Fill. 1. J.itfiosialis l>roii;/iii'<ir(i j". 'J'lio fiLrnro givoii by Swiiitoii ; ooiiiod from GoiA. Mag., ("2) i, jil. 14, fisj. 3. The arrow points .it tho su|>]hisoi1 tilo.
Fill. i. The same. j. Tlu' figiiro given by Muroliison ; cojiiod from his Siliuia, liil oil., p. :V21. TIk- ligure jjivon by rii't<?t is copied from the s:ime.
Fiir. :5. JJrodia prifcotincta. if. Sliowing simply tlie ueur:iti(>u with the he;ivier cross veins. Dr.awn l)y J. S. Kingsiey.
Fisr. 4. The same. ^. Cross section of tlie same at the point where tlie dotted line is placed in fig. 3, to show tlic different planes at which the veins lie. Drawn by J. S. Kingsiey.
Fin. ;"». 7'/ie same. \''. A bit of the costal margin from near the tij) of the wing, .showing the double row of appmximated depressed teeth. Drawn by ,T. S. Kingsiey. The positions of figs 5 and G iqion the |il,-ile would better have been reversed.
Fi'T. 6. The same. \". A bit of the same margin near the b.ase, showing the single row of more distant and elevated teeth. Drawn by J. S. Kingsiey.
Fiff. 7. The same. \. Tlie whole wing and stone. Dr.awn in color by J. II. Blake.
Fig. 8. Ijithosialis Brongniarti. \. The figure given by Woodward; copied from the Quart. Journ. Geol. Soc. Lond., x.x.xii, pi. 9, fig. 2.
Fi"'. 9. The same. \. The figure given by Mantell ; copied from his Medals of Creation, 1st. ed. ir, p. 578.
Fiij. 10. Archacoptilus ingens. \. Cross section at the point where the dotted lino is placed in fig. 11, to show the different planes at which the veins lie. Drawn by J. S. Kingsiey.
Fig. 11. The same. \. Drawn by J. S. Kingsiey.
Fig. 12. 77t€ same. \. Restored to its presumed size, etc. Drawn by S. II. Scudder.
An abstract of this pajicr was published iu the Geologicai. M.vg.vzixe (2), viii, 293-300 ; July, 1881.
^
.-' . ;<^
q£-
/
fev-
1 ..r^LX?^ ^;^:-
\IU. On the Development of OicrANTnus niveus and its Paiiasite, Teleas.'
I)V lloUAIU) AVKUS. First Walker IVize Essay of the Swicty for 1HK3. rONTENTS.
I. Introduction — Alplia^K'tic list of tlio litrra- g. Formation of Ktonioihu-nni nn<l ]iroct<)-
turc. (laciini.
II. Ue])ro<luctive organs of the feinale. — Origin Ii. Kevoliition.
and Maturation of the Ovum. i. Yolk sac
a. Ovariole. j. Synopsi.s of 6u1)se({uent d<'Velo|iinfnt. See Ij. (iermarium. Germ cells. ]>. 240.
c. \'itellariuni. P'ollicular ci>itl>elium. k. Cells, nuclei and nuclear plienomena.
d. Yolk. I\'. Thcoretieal Considerations.
e. Membranes. ;i. Embryonic niembranes.
f. ^I.'iture egg. Gcrminative vesicle. b. Yolk sac. m. Origin and Growth of the Embryo. c. Dorsal organ.
a. Cell eleinent.s of the fecundated egg. d. Gastrulation and niiiruhitinn.
b. Embryo. V. Parasites.
c. Primitive segmentation. a. Fungi, etc.
d. Embryonic membranes. b. Teleas.
e. A|)|ienrance of apj)endages. VI. Exjilanation of the jilates.
f. Neurulation.
In thi.s thesis I have endeavored to e.'^taltlish, among otlier.';, the fullowino j,f)int-<.
FOK OKCANTIICS.
1. The origin of the ovinn in a germariuni rather than IVom an ovarian ei)illic'liuiii.
2. The process of yolic formation by cell degeneration instead of secretion.
3. The occurrence of a primitive segmentation of the embryo before the appearance of the permanent segments.
4. The existence of a pair of appendages (some of them rudunentary) on each of the seventeen segments of the body.
5. The origin of the dorsal vessel as a paired organ, the lateral halves of which fii.se and give rise to a median tube in the same manner as in some of the worms, and the origin of the blood corpuscles as nucleoli of endodermic cells.
6. The existence of embryonic gills.
7. The lack of any sharp distinction between a cell and its nucleus, and between a nucleus and its nucleolus.
8. The existence of segmental enlargements of the raesodermic somites, similar to those from which the nephridia of worms take their origin.
9. The origin and significance of the embryonic membranes among the Insecta.
10. The origin anji significance of the dorsal organ among the Insecta.
FOR TELEAS.
11. The absence of embryonic membranes.
12. The occurrence of a larval form intermediate between the blastosphere and the Cyclops larva of Ganin.
' The following investigations were carried on under Comparative Zoology, at Harvard College, Cambridge, the direction of Dr. E. L. Mark, at the Museum of Mass.
MEMOIRS BOST. SOC. NAT. HIST. VOL. III. 39
'22C> AYERS ON THE DEVELOPMENT
Alpuabetic List of the Literature.
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2. Bamhkke, Ch.vrlks van.
'7G. Keelierehes siir I'eiubryologie ties Batraciens. I. Ocuf imlr nou feeomle ; II. Oeuf feconde. Bull. lie I'Aca,!. roy. de Belg.', 'i ser., Tom. xli, No. 1, pp. 97-135, 2 i)ls. Jan. 1876.
3. Bexkpex, Ed. vax.
'76. (."oniributions ii I'histoire ilc la vesicule germinative et du premier novau embryonnaire. Bull, de I'Aead. roy. de Jielg., 2 ser., Tom. xli, No. 1, pp. 38-85, 1 jil. S .Jan. 1876.
4. Bexedex, Ed. van.
"76. Contributions to tiie History of the Germinal Vesicle and of the first Embryonic Nucleus. Quart. Journ. of Mier. Sci., n. ser., Vol. xvi, pp. 153-182. PI. xiii. Apr. 1876.
5. Bessels, E.
'67. Studien Uber die Entwicklung der Sexu.aldriiseu bei deu Lcpidopteren. Zeitschr. f. wiss. Zool., Bd. XVII, pp. 545-564. Taf. xxxii-xxxiv. 1867.
6. BoBKETZKY, N.
"74. Zur Embryologic des 0/nscus niurarius. Zeitschr. f. wiss. Zool. Bd. xxiv, pp. 179-203. Taf. xxi and XXII. 1874.
7. BOBRKTZKV, N.
'78. Ueber die Bildung des Blastoderms iind der Keimbliltter bei den Insectcu. (May, 1878.) Zeitschr. f. wiss. Zool., Bd. XXXI, pp. 195-215. Taf. xiv. 6 Sept. 1878.
8. Braxdt, Alex.
'68. Beitriige zur Enlwickelungsgeschichte der Libelluliden und Ilemipteren mit besonderer BerUck- sichtigung der Embryonalhullo derselben. Mem. de I'Acad. Imp. des Sci. de St. Petersbourg, s6r. VII, ToiiLxiii, No. J. 35 pp., 3 Taf. Oct. 1878.
9. Brandt, Alex.
'78. Ueber das Ei und seine Bildungsstiitte. Ein vergleichend-morphologischer Versuch mit Zugrun- delegung des Insecteneies. 210 pp., 4 Taf. Leipzig, Wm. Engelmann. 1878.
10. Brandt, Alex.
'79. Commentare zur IveimI)laschentheorie des Eies. Arch. f. raikr. Anat., Bd. xvii, pp. 43-57. Taf. iv. Aug. 1878.
11. BfTSCHLI, O.
'82. Uel>er eine Ilvjiothese beziiglich der phylogenetischen Herleitung des Blutgefassapparates ernes •Theils derMetazoen. Morph. Jahrbuch, Bd. viii, Heft 3, pp. 474-482. 1882.
12. Claus, C.
'64. Beobachtungen Uber die Bildung des Insecteneies. Zeitschr. f. wiss. Zool., Bd. xiv, pp. 42-54. Taf. vj. 22 Sept. 1864.
13. Claus, C.
'73. Zur Ken-.itniss des Baues und der Elntwickelung von BrancJupus stagnalis und A2niS cancriformis. Abha I llungen der Gesellschaf t der WissenschaftenzuGoUiugen, Bd. xviii,pp. 93-140. Taf. i-viu. 1873.
14. DiETL, M. J.
'76. Die Organisation des Arthropodengehirns. Zeitschr. f. wiss. Zool., Bd. xxvii, pp. 488-517. Taf. xxxvi-xxxviiL 1876.
15. DoHRN, A.
'75. Notizen zurKenntnissder Insectenentwickelung. Zeitschr. f. wiss. Zool., Bd. xxvi, Heft 1, pp. 112- 138. Sept. 1875.
16. FiLippi, F. De
'51. Note sur la generation d'un hymenoptSre de la famille des Pteromaliens. Ann. d. sci. nat., 3e ser., Zool., Tom. XV, pp. 294-297. PI. v, figs. 1-8. 1851. Also Engl, transl. : Ann. and Mag. Nat. Hist., 2d ser.. Vol. ix, pp. 461-464. PI. xvl a. 1853.
17. Flemming, W.
78. Beitrage zur Kenntniss der Zelle und ihrer Lebenserscheinungen. (Sept. 1878.) Arch. f. mikr. Anat., Bd. XXI, pp. 302-436. Taf. xx-xxin. Dec. 1878.
18. Flesimixg, W.
'82. Zellsubstanz, Kern und Zelltheilung. 442 pp., 8 Taf., 24 Textbildern. Leipzig, 1882.
19. Ganin, M.
'69. Boitrage zur Erkenntniss der Entwickelungsgeschiehte bei den Insecten. Zeitschr. f. wiss. Zool., Bd. XIX, pp. .381-451. Taf. xxx-xxxiii. 1869.
20. Gegexbaur, C.
'78. Elements of Comparative Anatomy. Translated by F. J. Bell and E. K. Lankestcr. London, 1878. Macmillan & Co.
I
OF OECANTHUS AM) TKLEAS. 227
'Jl. GUAIIKK, V. .
'77. I)k' Insiittii. 11 Thiil, II Iliillto, jij.. 8+263-G04. ViTgloich. Eulwiiki-liiDijiii'fSfhichU'. (Die Natuik^ufti', Bil. xxii.) *" *" ^
•JL'. Git A II KR, 'T.
'7K. N'orliiuHge Ergcbiiisse einer grosseri-n Arluit Ul>er vir^jloiclii'iido Eiiihryol.H'io ilir IiistiUn, i-to. Anil. r. iiiikr. Anat., Bd. xv, Heft 4, i.j). G30-G40. Oct. 187H. '2:i. Hatsciiek, 1{.
'77. lUitiiitfi- zur Kntwicki'Imigsijesrhiilite di-r Lcpiiloptoren. Ji-iiaiKclii' Ziitnclir., IM. xi, llift 1, I>I>. lir)-14s. Taf. 7-l>. Also separate, 3S pp., 3 Taf. iiiul 2 Ilul/.scliiiitteii. 1H77. 24. Heutwio, O. aii.l K.
'81. Die Coelointheoiie. Versiich einer Erkliining <le8 iiiittleren Keiniblattcs. Jinaimlie Zeilwlir 15(1. XV, pp. 1-1.')U. Taf. 1-3. 1881.
-.'>. KiDD, 1'.
'7.^. t)liservations on spontaneous movement of nuclecili. (^iiart. Jmirn. uf .Mirr Sci ii Her Vol xv ]>]>. 133, 134. April, 1875. , . .,
lit). KoWAl.EVSKI, A.
'71. Kiiiluvologisclie Studien an Wttrmern un<l Arthropoden. (Pr^'8ent6 18 \ov. 1809.) M.'iii. de TAead. imp. des Sci. de St. Petersbourg, s6r. vii, Tom. xvi, No. 12. 70 pp., 12 Tuf. 1871.
27. Leuckart, H.
'55. Uelter die Micropylcr nnd den fcinern Ban der Schalenhaut hei den Insecteneiem. Zugleieh ein Beitr.ig zur Lelire von der Befruclitung. Arch. f. Anat. ii. Physiol., 1855, j>p, l»0-2G4. Taf. vii-xi.
28. Lubbock, .1.
'59. On the Ova and Pseudova of Insects. Phil. Trans., 1857, p. 343. (1859.)
29. LuDwiG, II.
'74. Ueber die Eibildung iin Thierreiche. Arbeitcn aus d. zool. zootom. Institut in Wdrzlmrir, Bd. i, Hcfte v u. VI, jip. 287-51(1. Taf. xiii-xv. Synopsis of same in Ilofinann ii. Schwalbe's J.dires^ ber. Anat. u. Phvsiol., Bd. iii, 1874, Anat. Abth., p. 378-401 passim.
30. Mark, E. L.
'81. Maturation, Fecundation, and Segmentation of Limax campestn's. Bull. ]\Ius. Coiup. Zoiil., Cam- bridge, ilass.. Vol. VI, pt. II, no. 12, pp. 173-025, 5 pi.
31. Mayei:,P.
'70. I'eber Ontogenie u. Phylogenie derlnsecten. (Eine acad. Preisschrift. Jena.) Jenaischc Zeitschr., B.l. X, lip. 125-221. Taf. vi, vi a, vi b, vi c. 1876.
32. Metsciinikokf, E.
'66. Embrvologische Studien an Insecten. 112 pj)., 10 Ku])fertafeln. Leijizii;, 1866. Separate from Zeitschr. 'f. wiss. Zool., Bd. xvi, Heft 4, pp. 389-500. Taf. xxiii-xxxii. 1866.
33. Metschxikoff, E.
'74. Embryologic der doppcltftissigen Myriapoden (Chilognatha). Zeitschr. f. wiss. Zoo]., Bd. xxiv, pp. 253-283. Taf. xxiv-xxvii. 1874.
34. MCller, J.
'25. Ueber die Entwickelung der Eier im Eierstock, etc. Xova acta acad. Caes. Leop.-t'arol. nat. curios., 1825, Tom. xii, pp. 555-672. Tab. l-lv.
35. Packard, A. S., Jr.
'73. Our Common Insects, etc. 235 pp., 4 ]il., 268 woodcuts. Boston, 1873.
36. Packard, A. S., Jr.
'78. Outlines of Comparative Embryology. 243 pp., 1 pi., 267 woodcuts. New York, 1878.
37. I'riesti^y, J.
'70. Hecent Hesearches on the Nuclei of Animal and Vegetable Cells, and especially of Ova. Quart. Journ. of Micr. Sci., n. ser.. Vol. xvi, j>p. 131-152. PI. xi-xii. April, 1876.
38. Hatiikk, H.
'44. Ziir Eiitwickehinffsijesoliichte der ManhviirhgriWe (Grt/llotalpa vulgaris). Miill. An-h. f. Anat. n. Physiol., Jahrg. 1844, jip. 27-37. Taf. 2, figs. 1-5.
39. Strasburger, E.
'82. Ueber den Theilungsvorgang der Zellkerne u. das Vcrhiiltniss d. Kcrntheiluni; zur Zelltheilung. Arch. f. mikr. Anat., Bd. xxi, pp. 476-590. Taf. xxv-xxvii. 1882.
40. TlCHOMIRUFF, A.
'79. Ueber die Entwickelungsgeschichte des Seidenwnrms. Zool. Anzeiger, Jahrtr. 2, no. 20, pp. 64- 67. 3 Feb., 1879.
41. Weismanx, a.
'82. Beitriige zur Kenntniss der ersten Entwickelungsvorgange im Insectenei. Freiburg, 1882. In Beitriige z. Anat. u. Embryologic, etc., pp. 80-111. Taf. 10-12.
42. WHiTjiijf, C. O.
'78. The Embryoloiiv of Clepsine. Quart. Journ. Micr. Sci., n. ser.. No. 71, Vol. xviii, pp. 215-315. PI. xii-xT. July, 1878. Also separate, 101 pp., 4 pi. 1878.
•••>s
AYERS ON THE DEVELOPMENT
OECANTHFS NIVEFS.
The soxually mature ovaries of Oecanthus are bodies about tlie size and shape of an apple seed. Tliev lie in the abdominal eavity above the alimentary canal, and on account of the mass of eggs contained in them completely lill, or even distend this cavity beyond itis normal capacity. They are united anteriorlj' into a common terminal cord which is inserted in the wall of the dorsal vessel, in the thorax above the stomach. The origin and growth of this cord and of the ovaries is best seen in the embryo. From this point of insertion they are directed backwards, downwards and outwards, and terminate in the oviducts. They ai'e held in place by connective tissue filaments, the peritoneal lining and the ramifying tracheal and nerve filaments.
The oviducts extend inward from their origin on the ovary and unite into a common duct, the vagina. At this point of union is given oiFthe receptaculum seminis as a pouch
from the wall of the vagina. At its posterior outlet the vagina is connected with the genital armature. Each ovary consists of from 10 to 20 ^ delicate, thin-walled egg tubes or ovarioles covered by a net-like peritoneal membrane. This net is composed of cell-groups connected by narrower portions of the cellular membrane, These groups are composed of relatively large cells with finely granular, scarcely stainable protoplasm and a central deej^ly stainable nucleus. The ovarian tracheae ramify through- out this coating but do nof connect with the tunica propria of the ovariole. This covering for the sexual organs is continuous with the peritoneum of the body cavity.
Each ovariole^ consists of a double-walled, blind tube divided into two distinctly marked portions. The upper, filamentous part originates as a blind tube in the terminal cord of the ovary and extends with a gi-adual in- crease in size to the upper end of the lower or follicular part, which is funnel-shaped. The size of this terminal, filamentous portion or germarium, as I shall hereafter designate it, varies in cross- section from 12.5 « to 5.6 u. The follicular portion,ormore properly speaking the vitellarium, begins with this funnel-shaped enlargement and extends to its insertion
A. ,Fi?. 1. B.
Fig. 1. A. Female sexual organs, a. ovaries, b. recepta- culum seminis; c. marks the beginning of the terminal filament; d. that of the terminal ligament; e. glimdula appendicularis; /. oviduct: g. vaj^ina ; h. anal stylets; i. ovipositor. Magnified 26 dbimeters. (From nature and after L. Dufour.)
Fig. 1. B. An ovarj' with the peritoneal and the connective- tis-ue coverings removed and the ovarioles separated, a. ter- mii.alfilamerit of the cvariole (Endfaden); b. ovariole; c. oviduct.
Fig. 1. C. Male sexual organs, t. almond-shaped testicle; r. d. vasa defferentia; v. $., vesiculae semiaales; ». anal stylets. (.\fter Dufour.)
' According to Lubbock (28) they are 8-10 in number.
' Havin;^ doubts as to the truth of several points in the theories advanced by Balfour (1), Brandt (9), Gegenbaur (20) and Ludwig (29), I wished to satisfy myself as to the
structural details of the egg-producing and egg-maturing or- gan of insects. With this object iti view I have studied with especial care the ovariole in Oecanthus niveus, Acheta abbre- viata, Periplaneta sp., and Acridium sp. These four forms
OF OKCAXTIirS AND TKI.KAS.
229
into the oviduct. The timic-a piDpriu of the ovariule is a thin, ehistic, Htnictun-k-sM and coh)rless membrane, wliich in the vitelhirium Ibrui-s a tuhe whose diameter varies Irum .00 nun. to I nun.
-«;
Fig. 2. Fig. 3. Fig. 4. Fig. 6. Fig. 6.
Figs. 2, 3 and 6. Ovarioles of Oecan'liiis. X125. 2. dissected in sodium chloride solution; 3. from direction In 0.1 percent chromic ai'iil; 6. dissected in water. Kig. 4. An ovariole of Acheta abbreviata, from a di section in 0.1 percent, osmic acid. X125. Fig. 5. An ovariole of Acridium sp. from a sodium chloride preparation. X125.
The germarium ^ is filled more or less completely with cells of characteristic structure which, as .sections show, have no definite relations to nor connections with the tunica propria ; but, since there is no trace of an epithelial lining throughout the entire course of the germarium, the.se cells may in consequence lie in contact with the tunica.
Since the cells are of nearly the same diameter as the tube in its upper and middle por- tions they are generally disposed in a single row occupying the centre of the tube ; they
possess epg tubes of the simplest type, where one would n.iturally seek for the primitive method of egg formation. The results of my observations differ in two essential partic- ulars from the above mentioned theories, viz: in the origin of t!ie egg and the formation of the yolk. The ovariole in these species varies only in histological details. The four forms represent three sharply defined families of the Orthoptera, and one of thein is closely related to the oldest insects in geological time. For an exhaustive treatment of
the origin of the germ and the formation of the egg, together with a review of the literature and a critical treatment of the theories held at different times on the origin and struc- ture of the insect egg, the re.vlcr is referred to Bramlt (9). For a general and comparative account of the origin of the egg throughout the animal kingdom one should consult Ludwig (29) and Balfour (1).
' See Bessels's (5) account of the origin and formation of ovarian germs in Lepidoptera, also Miiller (34) and Claus (12).
230
AYKIx'S OX THE I)EVE1A>P:\IENT
niav 1)0 flattcMieci against one anotlior l)ut at all times a cell wall is to be distinguished. These cells have large nuclei with prominent nucleoli while the cell substance is found as an exceedingly thin layer covering the nucleus. The nuclear boimdary is even more distinct than the cell boundary. Nuclei in the upper and middle part of the germarium seldom have more than one nucleolus and may be destitute of such a structure, while in the lower part and in the enlarged mouth two or three nucleoli are frequently found in each nucleus. These nuclei are amoeboid, their changes in form being most noticeable in the lower part of the germarium. In pi. 20. figs. 25, 26, 27. and pi. 21, fig. 25 are shown tlie structure and relations of the germ cells to the tunica propria. These germs pa.ss down the tube into the upper end of the vitellarium where they become surrounded bv a greatly increased amount of finely granular protoplasm that is in intimate contact with ("he epithelial lining of the vitellarium. (P1.20, figs. 1, 2, 3, 5, 27; pl.21, figs. 28, 29, 30 and Figs. 2-('i. on p. 229.) This epithelial lining, or follicular epithelium, is confined strictly to the vitellarium, in the upper part of which it is seen as a membrane one cell deep, either lining the walls of the tube or extending between and about the ova, thus separating them from each other and from the tunica. These epithelial cells ai'e somewhat smaller than the germ cells found in the lower part of the germarium, and the relative amount of nuclear and cell substance is different in the two cases. The germ cells have a greater proportion of nuclear substance. The epithelial cells proliferate rapidly and soon increase the extent and thickness of the follicular membrane, which is at all times thinnest at its upper end, where it grows around the ovum in a thin .sheet of small cells. In no case was a cell which from its size indicated its origin in the germarium found in process of division after reaching the vitellarium whereas, in the germarium itself cells in such a condition are sometimes found. As the egg advances toward the oviducal end of the ovariole the wall of the epithelial follicle becomes thicker and more capacious from the increase in the number of cells composing it.
The germinative vesicle, wdiich is the transformed nucleus of the germ cell, becomes vesicular and at the same time acquires several nucleoli, which gradually enlarge but remain connected with each other and with the nuclear membrane by numerous tortuous fila- ments. Sometimes there is a single nucleolus and then the nuclear filaments are much more numerous. The nuclear fibres or tlu'eads are to be seen only aftert reatment with certain reagents (e. g. gold chloride, silver nitrate, osmic, chromic and acetic acids). The germinative vesicle is distinctly amoeboid in the upper follicles but shows this characteristic to a less degree in the two or three folli- cles before the one in which it disappears, while in the latter its amoeboid nature is again asserted. Its membrane is distinct until about the time of its disappearance, which occurs in the following manner. Near the time when the vitelline membrane is secreted, the wall of the germinative vesicle grows thinner.^ It remains sharply marked off from
'. For a comparison of the different stages of this process in other animals see Bambekc (2), Van Bcnedcn (3 and 4), Brandt (9).
Fig- 7. Fig. 8.
Fig. 7. Dinfp-am of the forma- tion of an egg follicle.
1' ig. 8. An ovariole of Oeoan- tlnis from a dissection in distilled water. X 70.
Fig. 8, a . Sec tion passing trans- versely through an epithelial par- tition between two follicles. From an osmic acid preparation of an ovariole of Oecanthus. X 600.
OF < )K('ANTI! US AM) TKI.KAS.
2:]l
I'ip;. 9. Fig. 10.
rig. 9. An oviirinii follicle of ' I ■oantluis in which the gcrmi- imtivc vesicle lies in contacl with the surface of the fulliculur epithelium.
Kig. 10. Same as Fig. 9.
the 3olk but fades into the iiurlear .suh.staiice on tlie iiiiu'i- surface. Tlie inieleohiH and all other nodule.s of nuclear filanient.s or niu-lear .suhstaiice, extend tiieniselveK in the form of very delicate, tortuous threads which in tlie fresh condition give the vesicle a llnelv granular appearance. This process continues until the nieiiiliiani* has become ho thin ilh to be indistinguishable in the fresh .state. It (inally disappears altogether, first at its upper, or .sonietiiiies at its outer, surface. (PI. 20, (ig. 1.)
The germinative vesicle has in the uieaiitiiiic travelieil from itj* 1 y_J ceiiiia! or Hubcentnil position to the siuface of the yolk and lien
\ i^ ]| ill contact with the follicular eiiitheliuiii. The use of reagents caiiweB
a sharp line of demarkation between the yolk and the nutdear Hub- staiice to appear in sections of the egg at this stage. This line of condensed protoplasmic sul)stance apjiears to belong to the yolk. The nuclear substance gradually becomes diffuse in the region of this nienilirane but remains .sharply marked off from the follicular epitlieliuiii. The entire nuclear nia.ss now becomes a finely granu- lar lioinogeneous cloud which spreads out over the surface of the yolk antl in this manner disappears from view. (PI. 20, figs. 28 29.. At the t ime of the disiippearance of the germinative vesicle the egg has acfjurred about one-half of its yolk substance. The latter is aggregated into an ovoid ma.ss. The egg soon secretes about itself a membrane which at this time is to be detected only by treatment with hardening reagents.
The process of the formation of the \olk and the egg membranes (save the vitelline membrane) is a continuous phenomenon. By a process of nuclear proliferation, the folli- cular cells are elongated into a very thick columnar layer. (PI. 20, figs. 1, 4, 13, 14, 18, 20. PI. 21, figs. 24, 2G.) These cells vary in their radial diameter with the num- ber of nuclei present, and the latter vary from one to four in a single cell. The outer or first nucleus is .sharplv marked off from the small amount of cell protoplasm surrounding it, while each succeeding nucleus t)eroines less distinct, until the nuclear outlines are lost in a region of indiiferent granular and filamentous substance, with here and there oil globules and bits of albuminous matter, distinct from the matrix of degenerated cell mate- rial out of which they have been differentiated by some chemical proces.ses. In the upper follicles where the process is just begun the cells commonly po.ssess two nuclei, and in the last follicle, or the one in which the chorion memiiranes are being formed, they also po.s- sess two. if at the beginning, but if at the end of the process, a single, .small, degenerated nucleus, surrounded by a cell wall containing a proportionally large amount of a thin, watery protoplasm. In the follicles between these two extremes, where yolk formation is at its height, there may be as man}- as four nuclei in a cell, each surrounded by a proportionally small amount of finely granular protoplasm. The outer nucleus presents the characteristic appearance of a normally active structure, while the inner ones reproduce successively the characters of the degenerate nuclei of tlie last follicle. Finally, after the chorion is secreted and the egg has passed out into the oviduct, the remains of the follicular epithelium, together with the tunica propria, form a contracted mas,s, — the corpus luteum, — which disappears before the next egg makes its way into the oviduct. In pi. 20, figs. 14 - 17,
ooo AYERS OX THE DEVELOP^FENT
aresiivensm-faoc views of the follionlav epithelium in several successive stages of degenera- tion. PI. "JO, fig. 14 is from a follicle in which the yolk is being deposited ; pi. 20, fig. 15, fivm a follicle in which this proce.ss is nearly completed ; pi. 20, fig. 16, from a follicle where the chorion is being formed; pi. 20, fig. 17, from the corpus luteum. Fecundation probably takes place while the egg is passing into the vagina, since it is hardly possible that the male element could gain access to the follicles before the chorion is secreted.
The e<'-ir 1ms ac»iuired more than half its normal size before any membi-ane is to be di.<tin-4uished surrounding it. consequently it is only in the lower follicles that the process of the tbrmation of the membranes is to be observed. Before the pocket in which the egg lies becomes terminal, the vitelline membrane may be detected as a very delicate, colorless sheet surrounding the ,yolk. The most of the yolk material is already within this mem- brane, but from its subsequent increase in size it must be inferred that there are further additions to its mass by a process of endosmosis. Later there are deposited about this membrane two others, true chorion layers ; both are derived from the same source as the yolk and by a process almost continuous with that which forms the latter. Both the vitelline membrane and the first layer of the chorion form continuous envelopes, but the second layer of chorion is interrupted at the upper end of the egg and in its place is deposited a micropvlar apparatus. Although it is only a modified portion of the chorion and is at its outer and thinner edge in direct continuity with the outer chorion, this apparatus is easily separable as a distinct cap of thickened chitinous processes. Tlie inner layer of chorion, which is deposited by the same cell mass as the outer layer, exhibits but faint indications of the subsequently deposited cap. During the deposition of the layers of the chorion the previ- Micropvlar cap, ously straight egg becomes curved, with its concave surface facing ventrad. soda.''''Tiie''p'n".'iiiae This' curvature fits the egg for the pit made by the ovipositor for its recep- :!"„',fg^,?:f ",;^a"",?,e tion. By examining an infested stem these pits will be seen to be curved.^ byThe ac\Ton of'Jhe The egg having received its protective membranes is ready for deposition, "'■rhrTepap^iae'fur- and the epithelium of the terminal follicle, having now become much "pen aTo"e'^ti'cie"f reduced in thickness by the production of these layers, forms but a loose "'" ^^^^^' sac around the egg. The latter on this account passes into the oviduct. On its passage through the vagina, the egg is coated by a mucous substance which hardens on exposure to the atmosphere or on contact with the pith of the stem in which it is laid. In the latter case it serves to retain the egg in position. The egg coatings, now five in number, may be arranged for convenience of reference as follows :
1. Mucous coating — structureless — secreted by vaginal mucous glands.
2. Outer chorion — produced by the follicular epithelium — presents a series of surface
markings or cracks.
3. Inner chorion — produced by the follicular epithelium — pi'esents a series of surface
markings or ci'acks less numerous and fainter than those of the outer chorion.
■ In the allieJ Acheta abbreviata, the egg is not onrved vided with a niicropylar end (?). The eggs are laid in
and is destitute of a micropylar cap. The eggs are laid in ground which is rc'ndere<l hani by sun-bake, so that the
loose earth among the roots of grass. In Caloptenus insect is compelled to drill special cavities for their reception, spretus, according to Packard, the egg is curved and is pro-
I
OF OKCANTIirS AM) TKI.KAS
233
4. Micropyhir cap — pruihu'cd by the follicular opitla-liuiii at tin- anterior ciid of the
ovariole — possesses a very complicated Htructurc. •'). Vitelline nieniljrane — secreted hy protopla-in of i"^<r — structure similar to ztjna
radlntu of other animals. From the ahove it is seen that the memltranes are derived from three dilVereiit soin-ces — the egg itself, the follicular epithelium, and the vaginal mucous glands. The mucouH coating is very thin when dry ami is only to be detected on eggs treated with caustic Bodn or water; it is most abundant about the mieropylar cap, fre(|ueiitlv filling the spaces between the papillae.
The outer chorion is a dense, tough, homogeneous membrane markeil with a series of parallel and cross surface cracks (PI. 20, lig. 1 1, and Fig. 12, iielow) which are arranged with an extreme irregularity quite characteristic. The diflerent .systems of surface cracks cover limited areas and incline at various angles to each other. This arrangement of parallel and cross lines at varying angles of intersection reminds one of a city map in which the rectangular system of streets for each addition was laid out regardless of the direction in neighboring parts. The surface cracks, or grooves, in this layer vary in their depth, frequently extend- ing nearly through the membrane. In the figure they shoulil be represented by two parallel lines, since they are open spaces bordered on each side by the sharp edges of the mem- brane. The areas are sometimes perfect squares but usually when rectangular they are several times as long as they are broad. This layer tears with a sinuous outline across the cracks and .soliil membrane indiHerently. Until near the time of the revolution of the embryo in the egg, this membrane is intact, and when the egg is ruptured it deterfuines the course of the rupture of the other membranes. Just before revolution the outer layer is burst by the swelling of the egg and exposes the transparent inner layer. The relation of the cracks to the monibrane, and of the membranes to each other and to the egg, is best shown in section. ( I'l. "ill, fig. 2 1.) This lajer is deeply stained in safranine, haematoxylin and picro-carmine. liut remains unstained in other dyes. Its thickness varies
from 3.5 ;/ to 4 u. On treatment A ^ with caustic .soda it swells rapidly.
At first small sac-like elevations appear over the surface of the egg ; these gradually coalescing form a loose sac about the lat- ter and remain united with it at the . mieropylar end where all the layers are more or less fused. During this swelling pro- cess the cracks disappear, the mieropylar i)apillae enlarge, be- come transparent, and .show a distinctly marked, central, curved lumen. If the action of the reagent is continued the inner chorion is affected in the manner described for the outer chorion, also coming away from the egg as a loose sac. Frequently one sees in this inner sac a mass of granular matter. The vitelline membrane does not swell in the alkali, but when brought in con-
MEMOIKS BOST. SOC. NAT. HIST. VOL. III. ^^
Fig. 12. Surface view of the egg membranes and the serosa. From a chromic acid, glycerine preparation. X 400 .
234
AYEKS ON THE DEVELOrMENT
Fig. 13. A livinp; egg treated with caustic soda. Tlio three egg membranes are sep- arated from each other by the action of the reagent. 1. — Vitelline mem- brane. 2. — Second chorion. 3. — First or outer chorion. X 15.
tAct with it. quifkh- dissolves, exposing the egg contents. The folds or grooves of the inner chorion are never so numerous nor so large as those of the external layer. The inner membrane is much thinner than the outer one and quite transparent, so that by the use of caustic soda to remove the outer chorion one is able to make the otherwise opaque ec^g transparent enougli for the .study of the embr\'o in the fresh state. On removing the micropylar cap by means of caustic soda, there appear on the inner chorion beneath this cap polygonal areas with raised edges which fit into corresponding grooves in the inner surface of the cap. The inner chorion is more stainable than the outer, and is sometimes indented opposite the nuclei of the sero.sa.
The micropylar apparatus' belongs chiefly to the outer chorion and some- times comes oft' [with this layer when it ruptures. In the region of its fusion with the outer chorion it is composed of polygonal scales or areas, which 'gradually become more prominent as they approach the apex of the cone. From tlic upper angle of each area is given off" a thickened protu- berance or papilla into which the intermediate canal between two adjacent areas is continued as a distinct lumen. The papillae vary in shape from
simple scale-like patches to nipple-shaped protuberjinces or even funnel-shaped en- largemtuits, pi. 20, fig. 11. They are most perfect about one-third the distance from the apex toward the base of the cap. The apex itself is smooth or is furnished with only a few flat scales. Besides furnishing channels for the ingress of the male element, the micropylar cap serves as a thick, roughened plate, against which the insect may push when ovipositing with- out injury to the egg and without danger that the ovipos- itor slip from its place.
The vitelline membrane is of nearly the same tliickness (4-5 ^i) as the outer chorion and of a pale gray color. On surface view it appears finely punctate, while in optical section it pre- sents a radiate structure entirely similar to the zona radiula of other animals. It is readily stained by any dye that stains cell substance. In the fresh egg it is at all times in close contact with the yolk, but in hardened eggs it does not shrink with the embryonic membranes and yolk, and hence is easily removed with the chorion.
The yolk of the mature egg is composed of two distinct elements, fat bodies and albimiinoid masses. The former are of nearly uniform size and are globular in .shape. The surface of each sphere is differentiated into a thin pellicle, insolu-
■ .See Lcuckart (27) for structure of micropyle and chorion among Insccta.
Diagrammatic sketch of a micropylar scale e> and ita thickened angles a', A'. The double outlines o, 4 represent the edges of neighboring scales separated by a groove. X 600.
Fig. 15.
Fig. 14.
Fig. H. a.— Frag loroen. b. — opticHrsection of anothe'r papi'lla! in this onc"tiie lamen extendi to the vitelline meniljnine but does not pass beyond it. c, d, t and/.— papillae of different forms. X600.
Fig. 15. The anterior end of an ovarian e;g showing the manner of p-owth of the micropvlar papillae. a and b.— two successive sLiges. c— surface view of mrxlified papillae from the lower edges of the rap. d.— tunica propria of the °^*jI J •"<'" •''e upper portion of figure, erroneously marked e) remnant of the cell mass that secreted Ct) the micropylar cap. X 50.
OF OECAITIirs AND TKF.KAS.
235
ble in ether, which siiirounds a greenish-vellow lliiiil readily soluhU' in ether. The albuminoid bodies vary much in size and in their chemical composition. The latter i.s proved by the varying results obtained from the use of* reugent.s. The NUperficiuI layers of many of them difler but little in their cheiuical composition from living protoplasm. Hut since they do not exhibit any of the phy^:ical properties of the latter, their sul>stance must be considered as .something dillerent from protoplasm. The change of the fat into the albuminoid, and of the albuminoids into living pnitoplitsni, is undoubt- edly entirely effected by the chemical or assimilative action of the living protopla.sm of the egg. When treated with osmic, acetic or chromic acf^ the albuminoids are rendered vesicular. They stain deeply in picro-carmine and acetic-acid carmine, but not in cafra- nine or alum-carmine.
In the ovarian egg after the disappearance of the geniiinative vesicle no traces of nuclei are to be found ; l)ut Ijordering certain of the yolk masses there are bands of stainablc substance entirely similar to that which results from the degeneration of the follicular nuclei, except that it is confined to a definite and limited area encircling some of the yolk globules. (PI. 21, figs. 23, 24.) After fecundation no trace of distinct cell elements was found until about the time of the appearance of the bla.«toderm. At this time the yolk masses lie in contact with the vitelline membrane and the blastoderm cells coming to the surface finally form a thin cellular layer between the yolk and the protective coats of the ovum. Eggs were taken from the last ovarian follicle, from the oviduct, and from elder stems where they had been deposited but a few (one to twenty-five j minutes ; they were hardened in a HCl-alcohol preparation, removed from their protective membranes, stained in picro-carmine, sectioned, and mounted in balsam. In none of them were there found more truces of distinct nuclear elements than have been indicated above (pi. 21, fig. 23). The earliest stage in which such elements were to be distinguished .showed a partially formed blastoderm, but from this time onward during the entire development of the embryo there are always numerous amoeboid cells to be found throughout the yolk. In pi. 21, fig. 31 is represented a section through an egg in this stage, treated in exactly the same manner as the earlier stages in which neither cells nor nuclei could Ijc found, in pi.
21. (ig. 47, and pi. 23, fig. 7, are .seen five of these cells magnified 800 diameter.s, showing them to be both naked amoeboid nuclei and amoeboid cells. Pi. 21, fig. 31, shows the manner in which the cells help to form a blastoderm. The cell protoplasm extending out from one surface of tlie nucleus fuses with a simi- lar plate from the neighboring cell. The nucleus ex- tends into this projection and here its memljrane is seen to be ver}- thin. After these cells reach the surface of the yolk they furnish by rapid division a sufiicient number of cells to form a membrane. (Fig. 1 7 and Fig. 12, p. 233, .show the completely formed blastoderm.) The cells first arrive at the surface in the lower part of the egg in the region in which the embryo is to be found at a later period.^ Only part of the amoeboid cells migrate to the surface. The others remain in
' Compare Brandt (10), Bobretzky (7), 'NVcismann (41).
Fig. 17. Surfftce view of fresh serosa from an Oecaiithus treated with acetic carmine. X 500.
23t)
AYKliS OX Till-: DEVELOPMENT
Fig. 18. li-. 111.
Fig. IS. SurHice view of the serosa cells in an uninjured egg of Oecantlins. toplasm of the cells radiates from the central nucleus. X about 150.
Fig. 19. 0[itical section of the protoplasmic network in an egg of Oecanthus.
The pro- XSOO.
the yolk and at once begin to assimilate the yolk matter, changing it into cell protoplasm and nuclear siihstnnce. They increase rapidly by division in a manner similar to the blastodeim cells, hut owing to their high degree of nuclear development they exhibit but a thin nivering of protoplasm. The amoeboid processes ' from each cell extend out amono- the yolk spheres and coalesce with neighboring pseudopodia, so that when the number of such cells becomes quite large there is fully formed an intricate network of proto- plasmic fdaments such as is partially indicated in Figs. IS - 20. The nuclei appar- ently control this network and at times draw to themselves their pseudopodia, sending out new ones from other parts of the surface to unite Avith , some other portions of the common network or to en- gulf and feed upon the yolk globules. When a free amoe- boid cell comes in contact with a yolk globule, it folds or
creeps over it and, in case the yolk body is large as com- pared with the cell, surrounds it by a thin layer of clear protoplasm, the nucleus of which bulges out from the side of the globule but still remains entirely surrounded by a thin layer of cell substance. In sections of hardened and stained eggs these amoeboid cells remind one of certain rhizopods that possess anastomosing filamentous pseudo- podia extending in a radial manner from the entire surfiice of the central mass. In these amoeboid cells the fine threads of protoplasm are comparable with pseudo- podia, and extend in all directions from the protoplasm which surrounds the central nucleus. The amoeboid cells which reach the periphery form a thin continuous cell layer of uniform thickness over the whole surfoce of the yolk, — the .so-called blastoderm.^
A tract of the blastoderm along the median line of the ventral (concave) side, lying nearest the deep or primitively head end of the egg, becomes thickened into a germinal band, which is the first trace of the body of the embryo. This thickening is caused by the proliferation and elonga- tion of the flattened cells of the blastoderm in this region. On sections of this stage the germinal band is seen to be composed of a single layer of
Fig. 20.
Surface view of the edge of the body wall a it is advancing over the volk. From" the cm" bryo figured in pi. 19, fig. 1, in the region crossed by the line b. The space between the body wall anil the line 2, which limits the vcntr^ extent of the yolk, is seen to be more or less covered with amoeboid cells connecting the volk area with the edge of the body wall, 'riie volk mass lies underneath the entire field. ■ X 800.
' Compare Graber (22).
^ The " Keiiiibautblastem " is entiroly wanting.
I
OF OECAXTIirs AM) TKI.EAS. 237
cylindrical cell.><, each of which appears polygonal in surface, view anil has near its centre an oval coarsely granular nucleus. Tliis j)late of cells is about .7 inui. in length (pi. IH, fiffs. 1, 2.) and protrudes beyond the surface of the surrounding bli^t dlcrin. I'iie ventral surface of this geriuiual Ijand is soon covered by a thin cell layer (amnion auct.). This layer makes its appearance at the edges of the band soon after it is formed, an<l gradually e.vtends to the median line where its free margins coalesce. On account of the <|uaiili(y of the yolk and the size of its masses, the details of its growth vary from the usual maimer of fonnatiiiii. This variation is caused, as has l)ccn indicated, by the excessive amount of food-yolk, which takes the form of birge enwclear masses wiiich l)ecome redur-ed in size only hv gradual assimilation within the amoelioid cells. While the germinal band is still a single layer of cells the rest of the blastoderm, at its line of luiion with the band, pushes up from its e<lge in the form of a fold; but as the space between the germinal b;in<l and the vitelline membrane is too narrow to allow the ingrowth of this Ibid in its primitive condition, the lower or amniotic layer is retarded in its growth toward the middle line and only assumes the nature of an embryonic membrane some time after the edges of the upper layer (or serosa) have united, and all traces of its manner of formation have disap- peared (pi. 23, tig. 8). The cells which I'orm the amnion are given off from the lateral edges of the germinal band, and even after the fusion of the free margins in the meilian line this meml>rane lies closely pre.s.sed upon its surface until the appendages by their outward growth push it off. The cells of the amnion finally assume the same polygonal Ibrm as the sero.sa cells, (pi. 18, figs. 4 and 10,) but remain throughout their existence much smaller than the latter. In sections of the germinal band at this stage there is seen to be an irregidar, but usually continuous, layer of cells (mesoderm) lying innnediately l)eneath the cylindrical cells (ectoderm) of the baud. Lying at short intervals from one another are seen large amoeboid cells apposed to, or fused with, this layer of smaller mesodermic cells. These bodies or yolk cells, which have come to the surface from the central yolk ma.ss, are five or six times as large as the mesodermic cells and aiipear to be in process of division. They doubtless give rise to the smaller mesodermic elements. The latter are closely apposed to the uniler surlace of th > germinal band and so llattened tliat tlieir long a.xes are parallel to the surface of the band.
I am at present unable to affirm or deny the existence of the invagination' whicli in most insects leads to the formation of these mesodermic elements, for, although most of the facts relating to this mesodermic invagination seem to point to the conclusion that it is wanting altogether, there are in some sections structural details indicating the possibility of its occurrence in a modified form. The evidence against its occurrence in Oecauthus is as follows : In sections of the egg in which the serosa is continuous over the • germinal band, and the amnion is present only in the form of a few flattened cells pressed closely against the outer edges of the band, the mesodermic elements are seen in respective sections to form eitiier an unljroken line of small cells across the band, or two lines of cells, one on-each side the point at which the invagination would occur. In .some cases only two, three or four cells occur at irregular intervals in the extent of the section. Here and there the large yolk cells are fused with the under surface of the germinal band ; in some cases they are apparently breaking up into cells of the size and appearance of the
^ Compare Tichoiniroff (40).
23S AVKIJS ON THE DEVELOPMENT
inosodonnic element*!. Furlhoj-more, in this stage all the colls of the germinal band arc proviiled with a single nucleus, and no trace of cell proliferation is seen in. any part. As favoriiv the existence of an invagination it may bo observed, that some of the sections show an arran<jfement of the cells which indicates a disturbance in their primitive position. In pi. --. fig- -^' '^ shown this disturbed arrangement. The outer ends of the cells on either side the median line incline toward the latter. Tliis arrangement of the cells is similar to that found in sections of eggs of other insects just before and after the invagina- tion iias taken place. Moreover, the cells of this median region appear to be less regularly columnar than those on either side. By far the greater portion of the mesodermic elements, iiowever. originate from yolk cells which migrate to the region of the germinal band and there undergo division.
The mesoderm has formed a continuous sheet over the inner side of the germinal band before any modification in the form of the embryo appears. The almond-shaped thick- ening' is soon divided into two tolerably well marked regions by the enlargement of the head end. The narrower portion of the germinal band increases somewhat in length and the abdominal end l)ocomes more broadly rounded, so that the embryo presents the appearance shown in jil. 18, fig. 3. The mass of yolk substance during this time has undersroue important changes, due to the greatly increased number of yolk cells, which are to be seen at this stage as grayish masses, larger than the yellow yolk globules and about the size of the albuminoid masses. These occur at irregular intervals and by their trans- parency help to clear up the yolk. The oil globules have decreased in number and size, while there has been a proportional increase in the number and size of the albuminoid bodies.
With the further growth of the embryo the head lobes increase rapidly in breadth, the ectoderm at the lateral edges becomes thicker, and the posterior portion of the embryo becomes spatulate in form with the enlarged part of the spatula forming the ti]). There appears a depression in the middle of the forehead which helps to make more conspicuous the bilateral .sjMnmetry of the head region. It indicates the position of the future labrum and forms the inner boundaries of the two cephalic ganglia, which are developed on either side of this depression at a much later stage. Almost simultaneously with the appearance of this depression, two lateral folds are formed in the spatulate portion of the embryo (pi. 18, fit'. 4), which, besides emphasizing the bilateral symmetry of this part, serve respec- tively to mark off the maxillary and thoracic regions, thus leaving the abdominal region con- spicuous from the absence of any such differentiation of its surface. The general shape of the folds may be compared to a figure made up of the Arabic numeral 3 for the right fold and the same figure reversed for the left fold. The anterior por- tions of both folds are tliicker and approach each other closer than the posterior portions. Tiie folds are thickest and most sharply defined in the maxillary region. At their origin, apparently within the bounds of the head folds, they arise sharply from the general surface of the embryo i.v"2i! outline of gradually increasing in breadth until near the middle of their length, yJi'Jnlp^clnii.'rvo." The and then a.s gradually decrease until they pass into the thoracic folds. fs''di's'hi'^\k''m:tked? The latter are of the same breadth throughout their extent and ^n^utiine of .a trans- fade insensibly into the surface of the abdominal region. SVtWs's'tage.'^xfio.
OF OECANTIIUS AND TKI.EAS. 239
At this stage the amnion forms a complete covering over the Hurface of the emhryo. The tliickeneil outer edges of the head fohl are at this time continuous liehintl with the oilier edges of the germinal band, hut they gradually grow in toward'* the median line (pi. 18, fig. 5), and are at the same time hent forward toward-* the n-gion c)f the future mouth. The rounded angle made by the posterior end of the head fold is the lirst inrlica- tion of appendages (the antennae). The anterior ends of the maxillary f)lils fuse and, owing to the proportionately more rapid growth of the t!ioracie-ab lo:uiual than of the cephalic region, the connecting portion of these'folds lies posterior to the antennae and forms a transverse elevation extending entirely across the embryo behind the cephalic region, forming the anterior limit of the maxillary region. It will be noticed that it i.s an unpaired structure. In tlio stage represented in pi. IS, fig. 0, the maxillary and thorai;ic constrietions have l)ecome more sharply defined, since the folds have travelled to, and now form theedgesof, the embryo, but the strictly alxlominal region has not kept pace in its growth with the anterior regions. The embryo is now composed of four well marked regions : cephalic, maxillary, thoracic and abdominal.
The cross fold between the cephalic and maxillary regions grows fainter in the median line, and there arc gradually raised from the surface live pairs of protuberances (pi. IS, figs. 8 and 0). These ten prominences which arise within the region of the maxillary and thoracic folds appear simultaneously. The forces producing them also cause a general elevation of the lateral walls of the body above the surface of the germinal band. By the elongation of the embryo that now takes place a space is left between the anten- nal folds and the first pair of maxillary appendages, the floor of which is at first perfectly level, but somewhat later is pushed up in the manner described for the five succeeding pairs. The prominences arising in this space are first sharply defiucfl on their posterior borders. Whether this pair of prominences arises within the area marked off by the anterior maxillary fold is still uncertain. At least they arise very close to, if not out of, the fold itself. With its disappearance, the lateral thickenings of the maxillary and thoracic regions become marked into segments b}' the appearance of four pairs of marginal notches, so that the maxillary region is divided into two, and the thoracic into three, sharply marked segments. These notches extend themselves across the embryo in the form of shallow furrows meeting in the median line. Later the abdomi- nal region becomes segmented in the same manner but the notches are never so distinct as in the anterior portion of the embryo. «
The abdominal region has now increased in lengtii until it is nearly as long as the rest of the embryo ; its posterior part is broadened into a caudal enlargement, while its very tip is produced into a Fig. 22. Ventral and side view3 small papilla. The head region meantime undergoes marked
of :\ii nbnormallv shaped embryo. , ni •••/» iiiii
X 40. " changes, tor there occurs an invagination or tlie lateral ectoder-
Fig. 23. .\bdon,inai region of j^j^, ^^,^]i j,^ fj.Q„^ ^f ^lic basal end of thc antcunal fold. In this
an ombrvo of the same degree of .... ., , . .
development as the one shown in manner the Hmits ot the aiitcunal and brain regions are sharply pi. IS, fig. II. X 25. defined. While this invagination is progressing the lateral edge
of the ectoderm in front of it becomes differentiated into a superficial, limited, crescentic thickening and a deeper continuous layer.
!40
A VERS ON THE DEVELOPMENT
Tho folds wliii>h projoot inward from the antonnal region at length extend far forward and unite in the median line, thus bounding a V-shaped area the apex of which is near the front end of the embryo. Near the angle of this depressed area there appears a shallow, cup-like cavitv. — the beginning of the stomodaeum.
The maudil)les are now seen as definite oval prominences, while the five jiairs of appoidages posterior to them appear in optical cross-section to be composed of two concentric circles of cells. This ap])carance is produced l)y the two apposed cell layers, ectoderm and mesoderm. The appendages grow out perpendicularly to the germinal band, but later are deflected towards the abdominal region until they finally come to lie in a plane parallel with the longitudmal axis of the body. At an early stage they are some- times to be seen slightly bent toward the head (pi. 18, fig. 9). As the appendages grow out, the egg begins to increase in volume and the cracks in the chorion grow less distinct. Soon after the mesoderm has extended into tiie liollow appendages, there appear successively a varying number of aljdominal protubei'ances exactly similar to the maxillary and thoracic appendages in their earliest stage of growth. Of these only two pairs ever reach an}' considerable degree of development, they are the first and the last abdominal. The fbruier grows to the length of the mature mandibles and then ati-ophies. It varies in shape from a finger-like process (pi. 18, fig. 17) to a lobed outgrowth,and in the later stages is covered by the last thoracic appendage. The last abdominal appendage is the primitive anal stylet and acquires a very complex structure which will be described in con- nection with the hatched insect.^ The intermediate prominences never pass beA'ond the simple knob-like stage. The mesoderm extends into all of them as an inner la3-er apposed to the ectoderm, such as has been described for the maxillary and thoracic appendages.
About the time of the beginning of the invagination for the stomodaeum, there may be detected both in fresh and in hardened embryos a more or less sharply defined linear depression (the Primitivfurche of Hatschek), extending the entire length of the embryo. It is most distinct in the maxillary and thoracic regions and grows gradually fainter as it advances toward the tip of the abdomen just before reaching which it bifurcates, and the resulting lines, after extending for a short distance along the region of the caudal enlarge- ment, approach each other and by their coalescence surround a pear-shaped, depressed area. This line first appears in the thoracic region and grows both ways. It ends in front just behind the mouth opening, while its posterior cup-like termination indicates the posi- tion of the future proctodaeum. The line itself is the suparficial indication of a longitudi- nal invagination to form the nervous .system. The evidences of this invagination, which appears thus early in the development of the embryo, persist for a considerable time.
The upp,er lip appears simultaneously with the invagination for the stomodaeum and arises a.s a flap or fold in the median line between the bases' of the antennae, from the
Kig. 24. A lateral vieiv of a young e.ii- bryo still within the fresh egg. Certain bodie* apparently of a protoplasmic na- ture are seen at the head end of the egg; no nuolearstruclufe yum di»tingusliable within them. X^O.
' Compare this embryonic stage with the active larva of Lisyra fuscata, a Neuropteron which has all the segm^.-nts of
the body provided with articulated appendages.
OF OKCAXTIirS AM) TKI.KAS.
241
region where the antcniril folds iinitLHl. It projects backw.irJ an<l downwarJ so as to partly cover the mouth opening. Tiie caudal enlargement is now greatly changed in its relation to the embryo. It has up to this time been lying in the same plane with the body of the embryo, but by some means at present unknown it is reflected toward tho head, so that it.s dorsal side is uppermost and the ventral .surface of the last 3-5 seginenLs of the abdomen lie in contact with the ventral surface of the preceding segments. It forms in this stage a ^ -shaped fold.
The amnion is now seen springing, not from tlie tip of the abdomen, but from the region of the last pair of abdominal appendages, the anal stylets ; in otTier words, the posterior end of the abdomen has grown backward beyond the limits of the amniotic membrane and lies free in the yolk. Since the force which causes the folding seems to act through the amni- otic layer, it is apparent that this free abdominal tip will not be changed in direction but will be merely drawn forward and displaced to a plane ventr.d to tiie body of the e:ubryo, with whi'jh it remains parallel. The pear-shaped depression in which the nervous invagina- tion of the median line terminates behind has, by gradually deepening, extended back to the tip of the abdomen, and it is the blind end of this pocket which fijrms the tip of the last a of the §. (See pi. 18, figs. 19, 20, 21, 22, 29; pi. 22, figs. lS-21 and 2G.
The intimate connection of this pocket, or proctodaeum, with the invagination that forms the nervous system is worthy of notice. Compare Ganin (19, pi. xxxi, figs. G, 9, lU-12, Platygaster).
After sprouting out from the body the appendages grow rapidlj- and soon show con- strictions near their bases. In the case of the mandibles and maxillae the free ends also become lobed. (PI. 18, figs. 20-22.) The three oral appendages are trilobed ; the lobation is most prominent in the second maxillary and least in the mandibular ajipendage. The primitive appendage is first divMed into two lobes and the inner of these becomes secondarily divided into two. The antennae and thoracic appendages grow with equal rapidity until the time of revolution, when the antennae suddenly commence an extremely rapid growth and soon acquire a length equal to twice that of the body. During this rapid growth there is a gradual decrease in the diameter of the appendage, and constric- tions appear in its walls at irregular intervals. The upper lip is now a broadly ovate flap and entirely conceals the mouth opening. The first pair of abdominal appendages has reached it~s maximum development (pi. 18, figs. 22 and 23), whereas the last abdon;inal pair is scarcely more advanced than the nine intermediate rudimentary appendages, which are now prominent elevations of the bodj' wall and show the mesodermic or inner layer and a central lumen, when seen in optical section.
The stoniodaeum has so far advanced as to project some distance beyond the iinier wall of the body, its blind end lying free in the yolk. It is a circular tube with a distinct lumen extending from the mouth opening to the blind end. Its wall is composed of cylin- drical epithelial cells. The proctodaeum has grown but little in length, and, like the stomodaeum, its free blind end extends into the yolk, while its lumen communicates by means of the anal opening with the amniotic cavity. Its anal end is bordered on either side by the enlarging anal stj'lets.
In cross sections of embryos of the stage represented in pi. IS, fig. 17, the median line seen en the ventral surface of the embryo is shown to be the outer ends of cells whose
UEMOIKS BOST. SOC. NAT. HIST. VOU HI.
042 AYERS OX TIFE DEVELOPMENT
nuoloi hiivo mi.fl:rate(i to the dorsal eiuls of the cells (pi. 23, figs. 9-12), while the walls of their ventral einls have Ijeen so compressed as to produce in this manner the peculiar fibrous structure of the ventral portion of the invaginated area. (Compare Hatschek, 23, Tjif. II, fig. 2.) There are dillerentiated on either side of this central, invaginated portion two limited tracts of cells within the ectodermal layer, which ultimately go to form a part of the nervous system. These* two tracts have been designated Seitenstriinge by Hut.sc'.iek. These '-lateral cords" are composed of large cells with scarcely distinguishable cell walls, which enclose large spherical nuclei containing from one to five nucleoli and their svstenis of radiating nucleolar fibres and granules. The nucleolus is usually angular or bai^shaped and eccentric in position. The nuclei of these ganglionic cells are from three to five times the diameter of the nuclei of the ordinary ectoderm cells.
The structural conditions to be seen in sections have been described, in the case of the earliest stages of the germinal band, in connection with the account of the origin of the mesoderm. 1 have not been able to trace the origin of the lateral cords of the nervous system back to such a definite tract of cells as Hatschek has in his studies on Bombyx chrysorrhoea. On the contrary, in sections of the germinal band before the appearance of the median invagination there are to be seen, in the region of the future side cords, two lateral grooves. The cells in these regions have the characters of the cells invaginated for the middle cord and they thus indicate the origin of the two lateral cords as invaginations of the .superficial ectoderm, and not as linear tracts of cells budded off from the inner ends of the epithelial cells of the germinal band, as Hatschek has figured and described for T.iepidoptera (loc. cit., pi. i, fig. 6, p. 8). The sections of the stages in which these cells a.s.sume their characteristic appearances show them occupying the region of the future lateral cords, but not confined within such definitely marked areas as Hatschek figures. Before the appearance of the appendages the mesoderm is seen to lie as a continuous, thick layer of cells apposed to the germinal band. This condition persists in the abdomi- nal region after the thoracic appendages have grown out, but disappears before the invagi- nation for the nervous .system has extended itself into this region. (PI. 22, figs. 27 and 28.) It divides into two lateral plates as the invagination advances. In their outer halves these lateral plates of mesoderm are split into two sheets which contain between them the primi- tive body cavity (pi. 23, fig. 13,1 and figs. 11 and 12, be), but the latter soon disappears by the fusion of its walls. The separation of the splanchnic and somatic layei's of the meso- derm occurs before the invagination for the middle cord, but after the formation of the lat- eral cords of the nervous system. The primitive body cavity exists in the form of a pair of tubes extending from the head region backward for a greater or less distance ; but on account of the retardation in the development of the abdominal mesodermic plates, the body cavity of the thoracic i-egion has been changed by the process of segmentation into a number of clo.sed sacs' before the cavity has appeared in tlie abdominal region. The body cavities of the opposite sides do not communicate, although the mesodermic plates have not been divided in the median line. Subsequently the niesoderm occupies the lateral region of the germinal band and is entirely lacking in the region of the middle cord. After the
' The posterior wall of each sac is continued backward rior wall of the mesodcrniic segments of worms. The fate for a thort distance in the form of a short pocket, reminding of these pockets is not yet known. one of the enlargements in the splanchnic half of the poste-
OF OECANTIIUS AND TKI.KAS. 248
completion of the nervous invajriiiiitioii the ineaodenn a^ain imitoH in the middle line, iind later becomes separated into its pernianeut .somatic and splanchnic layers.
The cavities of the cup-like pockets of mesoderm extending into the appendages are at first in direct communication with the yolk cavity, but they soon become cut ofl' from the main cavity by cross partitions of mesoderm which close the opening by an auiudar con- 8tricti(m. {i'\. IS. figs. 17, '20, 21, 24; pi. 22, lig.s. 2:5-2.'); pi. 2:5,' figs. 11, 12, l;j.) The mesodermic lining of the antennae and upper lip is entirely similar U) that of the other appendages. In the case of the upper lip, however, the formation of the ingrowth is somewhat dilferent : the me.sodermic sheet is pushed off from the ectoderm by the ingrowing stomodaeum (pi. 23, fig. 13) and, a.s the latter extends inward Uiking a longitudinal direction, the mesoderm grows arouml it from its dorsal side, the two nieso- dermic folds coalescing in the median ventral line ; from this portion of the mesoder^ic layer the lining of the cavity of the upi)er lip is dcrivi-d. In the head region the ecto- derm is thrown into folds by the proliferation of the cells of certain tracts. These thickened tracts give rise to the cellular ina.ss of the supra-oesophageal ganglia.
The fibrous portion of the brain as well as that of the ventral cord is un<loubtedlv fur- nished Ijy the cell walls of the ganglionic cells (pi. 22, lig. 2). In pi. IS, fig. 24, are shown the internal ectodermic folds of one side of the head, o. being the lumen or cavity of the head from which the mesodermic elements have receded ; ftP. the lower fold lying against the invagination sk. of pi. 18, fig. 15; fcP. the upper, outer fold which, to judge from its size, probably gives rise to most of the brain mass. Contrary to the observations of Hatschek (23, pp. 9, 10), I find the mesoderm extending into the head region, where it is also provided with a body cavity (pi. 23, fig. 13.1). In pi. 22, figs. 18, 11), 20, 21, 22, are shown sections through the end of the abdomen and the proctodaeuin of an embryo of about the stage outlined in pi. 18, fig. 21. The proctodaeum projected beyond the end of the dorsal cj of the ^, and consequently the first few sections pa.ss through the procto- daeum alone. In figs. 18 and 19, pi. 22, the mesoderm is seen as a crescentic layer only partly surrounding the thick ectodermal wall of the proctodaeum on its dorsal side, whereas, a little farther from the end (fig. 20) it has nearly enclosed it. In fig. 21, the region of the free end liaving been passed, the amnion is seen in .section extending over the anal stylets, while the mesoderm is confuied to the ventral surface of the germinal band. In the case of the proctodaeum, as was also seen in that of the stomodaeum, the mesoderm grows around the invaginated mass from the dorsal side and its limbft coalesce in the median ventral line. Sections through the maxillary region at this stjige (pi. 22, fig. 23) show the first maxilla to be a three-lol)ed, much broadened appendage.
For convenience of description, I will first give a .sketch of the development of the embryo during the third stage as a prelimiiKiry to the more detailed account of the devel- opment of the organs. The general relations of the embryo to its membranes and to the yolk mass at the close of the second stage may be briefly stated as follows. The egg has increased much in volume and the outer chorion has ruptured, exposing the inner layer. The emljryo extends along the concave side of the egg for two-thirds of its length, with its abdominal end folded upon itself in a ^ fold, from the ventral arm of which the amnion extends over the ventral surface of the embi-yo as an entire sheet, united with the embryo along its lateral margins and the dorsal edges of the head fold (pi. 20, figs. 7 and 8). On
244
ayp:rs o\ the development
tho concave side of the egg this amnion intervenes between the ventral, or outer, surface of the einlirvo and the serosa, while on the other side the yolk intervenes between the deep, or dorsal surlace and the serosa. The amnion and serosa are not united at any point, but may lie in contact. The stomodaeum and proctodaeum extend into the yolk, but end blind! v. The embryo is a closed sac, as it has been since the union of the two lateral folds of the amnion. The serosa now fuses with the amnion lying over the region of the forehead, but the two Layers remain separated for the remainder of their extent. The resultinir membrane becomes first very thin and finally ruptures, so that the anniiotic cavitv communicates freely with the space between the vitelline meml^rane and tlie serosa, but does not open into the serosal cavity, neither does the latter open into the vitelline cavitv. (Compare Brandt, 8, Calopteryx, Hemiptera parasita.) By the contraction of the internuclear protoplasm of the serosa (this process may possibl}'- be aided by the exer- tion^ of the embrvo itself, since at this time traces of muscular fibres have made their appearance) its cells, which at first form only a single layer, are greatly changed in their mutual relations, and the serosal sac is changed into a bag, the walls of which are greatly thickened and furnished with an opening at the end where the fusion with the amnion has taken place. This is the earliest stage in which I have observed the external opening of the yolk sac. In the meantime, the embryo has (pi. 20, figs. 8 and 9) partly everted itself through the opening, and the .serosa is thickened at the apex of the egg. The shortening of the serosa consequent upon the contraction of its cells is the mechan- ical force which, applied to the inner surface of the embryo through the yolk mass, causes its eversion through the ruptured wall. The upper lip protrudes first and is soon followed by the head, antennae, and maxillae. The embryo now lies curved across the lower blunt end of the egg with one-half of its body uncovered by the amnion ; the other half still lies within that membrane and retains its terminal flexure (pi. 20, fig. 9). The head now moves upward on the opposite, or convex, side of the egg and the embryo again assumes a position parallel to tlie long axis of the latter. But compared with its first position the embryo lies on the opposite side of the egg and faces in the opposite direction. The abdomen is now straio-htened out and the proctodaeum projects into the yolk, which has in the meantime partlv descended into the cavity between the ventral and dorsal walls of the embryo.
At this time the ventral portion of the embryo is composed of three layers : ectoderm, mesoderm, and endoderm. (PI. 22, fig. 1.) The ectoderm of the ventral side is highly differentiated. From it have arisen, in addition to the ventral wall of the body and its appendages, the nervous system, and the epithelial lining of the fore and hind gut. It gradually becomes less complex toward the dorsum, where it is an exceedingly thin cellu- lar membrane in the condition of a syncytium. The ir.esoderm extends as a more or less complete layer over the inner surface of the germinal band into the pleural, and later into the dorsal, region. The endoderm, as a distinct layer, is limited to a sac-like sheet extending over tlie ventral surface as far posteriorly as the blind end of the proctodaeum, over which it folds and is finally lost in tiie yolk. Anteriorly it curves around the stomodaeum and ia continuous with the yolk-sac, which still projects beyond the body walls. The com- pleted dorsal wall is first formed in the region of the proctodaeum, and from that point the closure gradually extends forward until the wall encloses the constantly decreasing yolk-.sac.
OV OKCANTIIIS AM) TKI.KAS. 245
The heart is forinetl in coniiectioa with tlie coalescence of the mesoderinic plates in the inediitn dorsal line and is to be detected as a ilislinct thin-walled tube opposite to, or sliglitly in advance of, the anterior edge of the thickened ectojermic layer. It is formed in the head rej^ion only after the yolk-sac has passed entirely within the body. When the heart is partly formed, the mesoderinic plates anterior to their point of union form in the livin;^ embryo two pulsating membranes which, to judjjv- from I)ohrirs(l.j) oljservu- tions on Clryllotalpa, dilYer in their formation froai the iio:n(jlu;^ou< membrane in the latter insi.-ct. I have not obsorveil pulsations in the dorsd mesoderuiic layer aft-'rfusiunol the two plate-s, such as Dolira has described for (iryllotalpa ; Ijut before the coalescence takes place the free edges of the lateral plates are thrown into wave-like motions at each pul.sation of the formed portion of the dorsal vessel. The pulsations origiuate from the contractions of the segmental muscles in the pjsterior abdominal region, wliich drive tlie corpuscular fluid forward through the heart to the point of bifurcation, from which the lluid passes through the channels in the edges of the plates, and over the exposed surface of the yolk between tliem. Each pulsation occupies 1} seconds in traveling from the tip of the body to the umbilicus of the yolk-.sac. The pulsations occur in series witii int'jrvals of repose between them, which sometimes last for three or four minutes. The pulsa- tions of each .series follow each other regularly at the rate of one per .second, .so that while one wave of pulsation is progressing through the free edges of the mesodermic plates another one has originated in the posterior end of the dor.sal vessel.
The secretion of a cuticular covering by the ectodermic layer begins first on the ventral surface of the body. The appendages appear to be simultaneously enveloped by the secretion, which closely encases them ; however, soon after the closure of the dorsal wall and the secretion of the cuticula in this region, the whole layer becomes distended with a fluid and is thereby removed from the body. At the ends of the appendages tiie cuticula is swollen into a bulb-like enlargement which allows a free movement of the tip of the growing limb ; this is especially noticeable in the antennae, which at this time are rap- idly increasing in length. The embryo soon comes to fill completely the cavity of the egg ; the legs are now folded upon themselves, pi. 19 figs. 4 and o ; the antennae curve around the end of the abdomen and reach nearly to the head on the dorsal side. The embryo lias attained its full size and is enveloped by two cuticdar layers, — tlie primitive layer surround- ing the body like a loose sac, and the secondary cuticula closely investing the h^-poienuis. The outer layer shows only a few irregularities of surface, vviiile the inner layer is pro- duced into innumerable spines, bristles, and hair-like processes. (PI. 19, figs. 14 and 15.) The mouth parts have grown shorter and stouter, while the cuticula of tiie mandibles and the inner lobes of the maxillae has become much tUickened to form the biting mouth parts. The yolk has been consumed during tliis interval of growth and the digestive tract is completed in all its essential parts. The body walls have become thinner as the internal organs acquired their relative proportions, so that they now consist of a thin hypodermal layer surrounded by its tough cuticula. The food supjily being exhausted, the embryo bursts its membranous coverings and becomes free.
The foregoing summary of the changes through which the eaibryo pisses from the time of revolution until it leaves the c^g will be of service in properly connecting the following detailed account of the development of the separate structures of the now comi^licated
246
AYEHS OX THE DEVELOPMENT
auiiiKiI. In orilor to simplity the mat tor. 1 will treat each of the following subjects in a separate paragraph.
1. Alimentary System.
a. Prootoilaeum and Malpighian tubes, b. Mesenteron, pyloric caeca and yolk.
c. Stomodaeum and salivary glands, d. Corpus adiposum and pigment bodies.
2. Circulatory System.
a. Heart and blood corpuscles, b. Lateral and ventral blood sinuses.
3. Respiratory System.
a. Embryonic gills, b. Tracheae.
4. Nervous System.
a. ^'cntral cord. b. Brain, c. Suboesophageal ganglion and conunissural cords.
d. Dorsal cord. 0. Sexual Organs.
a. Germinal cells, b. Ovaries and Testes.
6. Germinal Layers.
a. Ectoderm, its origin and derivatives. b. Mesoderm, its origin and derivatives (splanchnic and somatic layers), and body cavity, c. Endoderm, its origin and de- rivatives.
The PROCTODAEUM has the shape of a pocket at the time of revolution but it soon elon- gates into a tube ending in an enlargement resembling the cap of a mushroom (pi. 18, fig. 26 ; pi. 19, fig. 1 ; pi- 22, fig. 1 ; Fig. 26). It is composed of two separate layers, an inner epithelial, derived from the ectoderm, and surrounding this a muscular layer derived from the splanchnic layer of the mesoblast. The latter is con- tinuous with the muscular coat of the mesenteron and stomodaeum. When the tube has elongated so that its enlarged end lies within the fourth or fifth segment of the abdomen (counting from behind forwards), there arises near the free end in the median dorsal line a small, trilobed, hollow bud of the ectodermic layer, opening into the lumen of the tube. Each lobe grows rapidly into a small tubular organ, the primitive Malpighian vessel. Each of Fig. 25. these bifurcates at some distance from the proctodaeum, so that there are ulti- w^tionof'^J^ mately six of the tubes. The one lying in the median dorsal line grows back- ^o^ ^th"th^ ward for some distance along the proctodaeum ; the two lateral tubes curve in mesenteron. X ^j^j.jQyg directions through the body cavity. At the time these vessels appear the proctodaeum is connected by a dorsal mesentery with the heart. (PI. 23, fig. .5.) The lumen of the proctodaeum is at first circular in cross section, but as the layers thicken the epithelial lining is thrown into si#c equal longitudinal folds, which in the anterior part of the tube at this stage almost obliterate the lumen. These folds are par- allel and extend the greater part of the length of the tube. The lumen of the proctodaeum becomes continuous with that of the mesenteron only some time after the muscular layer of these two parts have united. At the time of hatching all traces of the union of the parts have disappeared, but in cross section the mesenteron is still much larger than the proctodaeum.
OF OECANTlirs AM) TKI.KAS. 047
Tho sTOMODAErM (pi. 10. fifrs. 2, 4 and i:> ; pi. '2'2, i\^. 1; Fij; li-')) early awHumcB a tubular couditiou, but it does not unite witli the nie.><enteroM until alU-r the closure of the body walls. It e.xtends from tiie mouth opening back into the region of the .second thoracic segment, and in its growth piishe» itself into the mesenteron, carrying before it the wall of the mid gut. The portion of tiie mesenteron which projects in front of the post^'rior end of the stomodaeum is subsecpiently converted into the pyloric caeca of the adult uiiinuil. Like the proctodaeuni. tlie stomodaeum ends blindly at first, but its cap is not so marked as that of the former. At the time of revolution there appears a pocket in the median dorsal line OpticnrT«Kiitni sec- simili^i" to that formed in the proctodaeuni for the Mal|)ighian tubes. beZe°L'''>n.ipiKhu.'!! The fate of tliis pocket is unknown. Upon the union of the st(,mo.l.ieum vessels BrUe. X250. ^^.jj|j (|jg nicsentcron, the alimentary tract is converti^'d into a continuous tulie. Tn cross sections of the embryo one finds the epithelial layer of the stoniorlaeum thrown into six longitudinal folds, which at first nearly fill its lumen ; but by its sub.se- quent increase in circumference they are reduced to ridges along the inner surface of the canal. In the anterior portion of the stomodaeum the dorsal fold is larger than the others and is freciueiitly liilobed. (Compare the sectioiLS shown in pi. 21, fig. .'17 ; pi. 22, figs. 11, 1;'); pi. 23, figs. 1, 2, 4.) The stomodaeum passes through the nervous cord between the brain and first ventral ganglion. The invagination for the alimentary tract having taken place before the formation of the nprvou.s cord, the latter is in consequence cunipellcd to grow around the stomodaeum in order to unite with the brain. The stomodaeum forms, by an enlargement near its posterior termination, the proventriculiis.
Although the s.\livarv glaxd.s arise as invaginations of the ectoderm (pi. 2'i, fig. 1) of the ventral surface of the mandibles, yet they soon come to unite with the oesophagus by a common duct (pi. 18, fig. 10) and, from the subsequent shortening of the oesophagus, to empty into the floor of the moutli. The invaginated portions extend upward toward the donsal line of the body in the form of a solid, curved rod of tliin-walled spindle-.shaped cells. The nuclei of these cells are equal in size to those of the ganglionic cells and besirles exhib- iting a distinct nucleus, they are connected with the central fibre of the rod by what is apparently a portion of the nuclear membrane. The rods are ultimately directed backwards and reach into the abdominal cavity. A short distance back of their union into a common duct, each gland bifurcates. They never become convoluted as do the Malpighian vessels. Before hatching, all trace of their origin has disappeared. No evidence of the existence of the sjnnning glands of other groups was found at any time, although I have carefully stud- ied my preparations of the early stages for the invagination in the upper lip from which they arise, and tho.se of later stages for the glands themselves. The uniform result ha.s been the failure to detect any structure that could be interpreted as belonging to these organs.
The part of the mesexterox (pi. 19, figs. 4 and 5 ; pi. 22, fig. 1) which is first formed within the body of the embryo is a .sheet-like extension of endodermic cells along the germinal band in contact with the yolk. It is pushed away from tho head region by the growing stomodaeum and from the posterior abdominal region by the proctodaeum, so that it is confined to the thoracic and anterior abdominal segments. In the region of its con-
248 AVKRS ON THE DKVELOriMENT
tact with the proetoilaeuin tho walls of the mcseutorou are tlirowa into folds. At present I am nnablo to say whether these folds go to form diverticula of tho mid gut or disappear altogether. Tlie large yolk cells which, as has been stated, appose themselves to the ger- minal band to form tho mesodermic elements are not all employed to form the middle germinal layer, but some of them become arranged as a superposed layer, — the endoderm. At an early stage one cannot distinguish between these cells, whether they are to form mesodermic or endodcrmic elements. Previous to the time of revolution the mesenteron is formed slowly, but after this act it rapidly becomes a definite sac enclosing the yolk mass. The anterior end of the mesenteron is in connection with the serosa sac, and since the latter passes bodily into the embryo, its cells grade so insensibly into those of the walls of the mesenteron that it becomes difficult to distinguish the place where one begins and the other ends. After revolution the yolk passes from the yolk sac into the mesenteric cavity through a circular opening in the body wall (i. e. amnion) back of the head. (PL 19, figs. 1.2; pi. 22, fig. 1.) It is forced into the body of the embryo by the contraction of the walls of the j'olk sac. As a consequence of this continued thickening and contrac- tion, many of the nuclei of the serosa cells are set free from their cells and pass with the yolk uito the body through the circular pore back of the head. After passing this point some of them find their way at either side of the oesophagus into the body cavity, while others go directly into the open end of the heart; the majority of them, however, pass with the yolk into the enteric cavity and aid in the assimilation of this mass. The remnant of the yolk sac is seen for a time as a plug-like projection from the median dorsal wall behind the head. It ultimately passes into the body cavity and is absorbed. When within the embryo there is a faint lumen between the apposed walls of the yolk- sac, which is continuous with the cavity of the mesenteron. (PI. 19, figs. 4, 5 ; pi. 22, fig. 1 ; pi. 23, fig. 2.) Up to the time of hatching the mesenteron is more or less distended with yolk matter and its walls are in consequence very thin, but as the yolk is assimi- lated the walls become thicker and the diameter of the tube is mucii diminished.
Owing to the rapid growth of the embryo after revolution, the yolk mass is quickly taken within the body walls. The greater part of it is consumed before the walls are closed. The assimilative function is so active that the amount of food prepared exceeds the amount that can be made use of by the growing tissues, and in consequence this surplus is stored up in two dorso-laternl fat bodies (pi. 19, fig. 1), which lie on either side of the heart and, extend from just back of the head to the tip of the aljdomen. These bodies are yellow, reach their greatest development soon after the closure of the dorsal wall and have entirely dis- appeared at the time of hatching. In pi. 19, fig. 12, is shown one lobe of the corpus adi- posum of the left side. It is an irregularly shaped lobe composed of loosely connected grayish corpuscules. The lobes, one to each segment, project outward from the longitudi- nal connecting body. Within the grayish mass are numerous yellow fot-drops and an irregular network of black pigment. The muscular wall of the mid gut is formed b}^ the splanchnic mesoblast before revolution. About the time of revolution, however, there is deposited upon this layer another, which at first is very thin and irregular. After the dorsal wall of the abdomen is closed over, the mesoderm is quite well formed in the region of the proctodaeum. (PI. 22, figs. 1, 9.) The cell walls are very indistinct (if present at all) and cannot be made out on specimens treated with osmic-acetic acid solution. The nuclei vary in size but are usually soiuewhat larger than the nuclei of the surrouuding
OF OECAFTIirs AND TKI.KAS.
10
splanchnic mesoblast. The prcitophisin of the eiKlixh-riiiic cells furnis an irregnlar mitline on the inner surface of the layer. Here ami there may he seen the larj^e emlodermio nuclei which iiave come to the surface of the yolk mass to fuse with the inner wall of the mesenteron anil to furnish l)y subsequent division the nuclei of other cells. The splanch- nic mesoblast has been separated into two parts, a muscular layer in contact with the endo- dcnn, and an epithelial layer of exceedingl}- thin flattened cells continuous with the liiiinj^ of the body cavity. The cells of tlie epithelial layer are spindle-shaped in cross section anil occur at irrej^ular intervals. (PI. 22, fig. il.)
The formation of the IIEAKT does not begin until after tlie revolution of the i-mliryo. It is first to be distinguished in the al)dominal region al)oiit the time of the closure of the dorsal ectoderm. With a magnifying power of 12;j diameters it appears (pi. I'.t, figs. 4, 5 ; pi. 22, fig. 1 ; pi. 2'!, fig. o)as a delicate tube with here and there nuclei lying in contact with its wall, but when more highly magnified the wall is .seen to be double. In the for- mation of the heart, the lateral plates of mesoderm grow upward around the mesenteron, and as their edges approach the median dorsal line there is seen to be in each a tube. These two plates coalesce in the median line and their tubes unite into one — the hi-art. or dorsal vessel.
The mesoblastic plates are not divided in this region into splanchnic and ."-omatic layers until after the formation of the heart.' (PI. 22, figs. 10, 11, 12, and 14; jd. 21, figs. 32, oo, 34, 35, 3G, and 41.) In cross sections ol the (nibr\oin the stage represented in pi. 22, fig. 1, the origin and formation of the heart ma}- be traced satisfactorily, and, as has been ,';hown above, it does not differ from the formation of tlic bean in Lumbricus as described and figured by Kowalevski (Ice. cit. p. 25, pi. 7, fig. 23). In this stage the heart is a V-shaped organ, with the stem of the V directed backwards, but as the limbs of the V approach each other they fuse and in this manner form the single tube of the dorsal vessel. The formation of the permanent vessel keeps pace with the growth of the dorsal ectoderm from behind forwards.^ The histological elements composing the heart in Oecanthus deserve especial men- tion. The primitive tube of each me.soderraic plate is formed by a row of cells, each one of Avliich becomes (^ shaped, and then by the fusion of the lips of the (^ it acquires a (^ J) shape. (PI. 21, figs. 33 and 36.) Those are the muscle cells of the wall of the heart. The nucleus lies in the outer part of e.ich cell. In .some sections the me.«odermic plates appear to be composed at their upper edges of amoeboid cells, .so that in some parts the heart does not have any structural connection with other portions of the body at this stage. In such a section the wall maj^ be destitute of nuclei, and the heart then appears as a single-walled, round, oval or D-shaped vessel. Its cavity, before and after the fu.sion of the two parts, is filled with the same coagulable fluid that fills the body cavity. Mesoderinic cells, such as compose the wall of the heart, are found free both within and without the vascular cavity at this stage. It is probable, however, that all these
an.
Fig. 27.
Diagram of the half-forraeil
heart, an. its posterior end.
1 Compare Biitschli (11). the he.irt is foniieil first in the he.id region and extends into
- Compare the account by Claus (13) of Branchipus where the abdomen at a later period.
32
MEMOIRS B03T. SOC. NAT. HIST. VOL. III.
250 AYEKS OX THE DEVELOPMENT
cells assist in forming the walls of the blood canal and do not become blood corpuscles. There are sriven ofl' from either side of the heart two thin sheets of mesoderm (pi. 23, (ig. 2), one above and one below the middle line. These unite at a short distance from the vessel on either side, but immediately diverge again into, what appear, upon cross section, to be a pair of more or less circular vessels extending in a plane parallel to, but below, the heart. In the membrane thus stretched between these vessels and the heart there are usually a number of nuclei having the same size and appearance as those in the wall of the heart. From the outer sides of these lateral tubes, mesodermic elements diverge in the form of a vary- ing number of sheets (in some instances there are as many as four, but more commonly onlv two), which join the somatic huer of the mesoderm. After the formation of the heart there appears in the thoracic and maxillary regions below the nervous cord a tube of about the size and shape of the dorsal vessel. (PI. 21, fig. 41.) It is a ventral blood sinus similar to the two latero-dorsal tubes just described. In jLhe postei'ior abdominal region, about the time of the appearance of the Malpighian vessels, the heart is connected with the proctodaeum by a dorsal mesentery similar in structure to the .sheets just described. In embryos treated with osmic-acetic acid the heart, like the body cavity, is at this time found to be filled with a finely granular substance, probably coagulated plasma, which appeai-s grayish in reflected light and is faintly stainable. (PI. 22, fig. 10.) During the contraction of the yolk sac most of the nuclei of the serosa cells which are then set free pass into the mesenteron, but, as has been stated in a previous paragraph, some of them pass into the body cavity and after further transformation find their way into the heart. These serosa nuclei become large and vesicular during the decline of the yolk sac, and their nuclear substance breaks \ip into several irregular masses connected together by a few coarse filaments and numerous granules. In this stage they are freed from the sur- rounding cell, the protoplasm of which during this time has become thin and watery. The nuclear membrane is seen to be a delicate, structureles.s, scarcely stainable vesicle surrounding the nuclear substance. If the nucleus passes into the mesenteron with the yolk, it does not undergo any marked transformation and may either disintegrate or pro- liferate and form, by collecting protoplasm about itself, from one to several amoeboid endodermic cells. If, on the other hand, the nucleus passes into the body cavity (pi. 22, fig. 1) it becomes more vesicular, its membrane much thinner, while nearly all of the stainable substance is promptly concentrated into the nucleolar masses, and ultimately all of the nuclear substance goes to form from one to three spherical bodies which are sur- rounded by the common memjjrane. These bodies are blood corpuscles and are free nucleoli immediately on the rupturing of the vesicle which surrounds them. (PI. 22, figs. 1 and 3.)
The invaginations of the ectoderm which form the tracheae do not occur so early in Oecanthus as they do, according to Kowalevski(26), in Hydrophilus, neither do they occur on the ventral surface of the segments, as Kowalevski has represented in his pi. 8, fig. 10. On the contrary, one does not find the tracheal pockets until after the embryo has revolved in the egg and the dorsal wall is partly closed. They then appear as invaginations of the pleural region.
There are to be seen in sections of the head segment, at the time when the invaginations to form the salivary glands are well advanced, small infoldings of the ectoderm similar in posi-
OF OKCAXTIMS AM) TKLEAS. 251
tion to the invii^ination-i of the thoracic and ahdoininal se;^inent«< which form the tracheae; but at present I am unable to say whether these inj^rowths form any portion of the tra- cheal trunks, as they do in Lepidoptera according to Hatschek, or Ix'come transfornu'd into cliitinous rods forming part of the internal skeleton of the head, as TirlKjmirofl" ha-s (lescribeilfor IJombyx mori. They prol)ably (lisa])pear altogfther, as no trace of them was to be fouml in sections of an embryo ai)out the time of hatching. A final decision on this point is reserve<l until fiuther study can be made. In the embryo at the time of hatching there are two main tracheal tuln's which extend along the sides of the body from the end of the abdomen where they are smallest, into tlie thoracic 8egment,s. The stigmatic openings, as well ns the tracheae which supply the organ.^ of the body, are all connected witii these trunks.
Tlie respiratory function of the eml)ry() is first indicated at tlic time of revolution bv tlie appearance of paired lateral outgrowths of the ectoderm from the pleural region of the first abdominal segment. These gills or respiratory organs come to lie just behind, but dorsad of the base of the third thoracic appendage. (PI. 19, figs. 1, 17 ; pi. 22, figs. 13 and 14 ; pi. 2o, fig. 29.) In outline they are broadly oval or kidney-shaped and are united to the ho(]y by a short peduncle springing from the centre of that face of tlie disc which is in contact with tlie body of the embryo. These folds are cellular structures and at diflerent periods are solid or hollow. The cells of the folds early lose their ectodermic characters and become somewhat larger than those of the adjacent body wall. In the fresh condition they appear enucleate and coarsely granular, but upon treatment with osniic ora cetic cid a nucleus is distinctly visible. In surface view there is to be seen a clear central area which indicates the position of the internal cavities of the gill. These cavities are contin- uous with the body cavity and probably- serve as channels through which the va.scular fluid circulates. They vary in shape and relative proportions. The relations of these append- ages to the body is best seen in sections. (PI. 22, figs. 13, 14.) The out-growing llap is here seen to project over an invagination immediately below it and in some instances to become apposed so closely to the body wall as to convert the open pocket into a closed canal. In its middle part, where the fold fuses with the body, its cells are se])arable into two irregular layers which correspond to the two primitive plates of the fold, Imt they fuse completely, or become widely separated, in the free portion of the pad. These append- ages reach their greatest degree of development soon after the revolution of the embryo, and then gradually atrophy, entirely disappearing before the complete closure of the body walls. In sections of the gill organ before its atrophy (or absorption) one finds both dis- tinct canals and lacunar spaces (pi. 22, figs. 1-3, 14), which radiate from the point of connec- tion of the pad with the body, and these together with the arrangement of the cells give the radiate stucture characteristic of the fresli gill. The canals are generally circular in section and pursue irregular courses throughout the cell substance, while the .spaces are developed by the separation of adjacent cell walls and are irregular in outline and occur at varjaug distances from each other. The gill pad is essentialh^ a single-layered sac, with a much constricted neck, evaginated from the pleural region of the abdomen- The pro- truding organ is flattened against the body of the embryo and by this means the cells are rendered spindle-shaped. The nucleus of each cell lies in that part of its cell which is farthest from the constriction of the organ. The cell waU gradually tapers to a point and ends near
252 AVERS ON THE DEVELOPMENT
the neck. The cells arc bent in various waj's depending upon the relations of their nuclei to the wall of the pad. The only larval organs wliic^h in any way resemble these are, so far as I am at present informed, the peculiar mushroom-shaped bodies described by Rathke (oS. pp. 27-32. Taf 2, figs. 1-5) for Gryllotalpa. The author considered them to be resj)iratory in function but he was not able to establish his interpretation.
The central nervous systesi, which made its appearance early in the development of the embrvo. is still muted with the ectoderm at the time of revolution, but with the comple- tion of this act. which seems to add a new impulse to the development of the entire organism, the ganglionated cords that form the nervous system of the thoracic and abdom- inal regions become cut off from the superficial ectoderm and lie free within the body cavity. The median cord, which was formed by a modified invagination of the superficial laver of the ectoderm, immediately fuses with the lateral cords along its dorsal and lateral surfaces, but its ventral surface still forms a portion of the ventral surilxce of the body of the embryo. By the overgrowth of the superficial cells on either side of this cord it becomes inclosed within the body. These three parts of the nervous system now form a single nodidated rod which has no structural connections with the rest of the body, nor with the brain. Since the enlargements of the two lateral cords occur at regular intervals and opposite ea«h other, each segment of the young embryo is furnished with two ganglia, but when the median ingrowth passes between and fuses with them, they become structurally connected by two l)undles of fine transverse filaments which arise out of the substance of this invaginated part. These bundles of fibres do not remain distinct but soon fuse, after which they are seen to connect the central portions of the ganglia. Between the succes- sive pairs of ganglia the median ingrowth atrophies, and at the time of the closure of the dorsal wall of the body there is seen between the connecting cords of two adjacent pairs of ganglia, a .small triangular or cylindrical mass of cells, concerning the fate of which I am not absolutely certain. I believe, however, that they go to form a part of the inter- nal skeleton. The chitinous rods in the thoracic region to which the muscles of the legs and wings are attached probably arise from the remnants of this median invaginaiion, but in the abdominal region they may disappear entirely without giving rise to such structures.
The two lateral ganglia of each segment ultimately become fused into one, so that on di.ssecting out the nervous system of the embryo represented in pi. 19, fig. 4, all the gan- glia presented the appearance represented in pi. 19, fig. 9. They are ovoid bodies con- nected by two longitudinal commissures which at this stage are so short <as to leave the ganglia in contact with one another; later these long commissures increase much in length and the ganglia thus become widely separated. Before hatching the three ganglia of the maxillary region (i. e. the primitive pairs of ganglia supplying the mandibles, the first and the second maxillae) fuse into one mass^— the suboeso2)ha(jeal ganrjUon. This nervous centre Is the largest in the body with the exception of tlie brain, which it nearly equals in size. In pi. 21, fig. 39, is figured a section through this ganglion before the fusion of its fibrous portions. The fibres of the longitudinal commissure are similar to
' Oratior (21, page 428), says that in insects the ganglia of does not afTirin, however, that lie has himself observed this
the mandibnlar segment become the commissural cords, to be the case. It is improbable that there exists in differ-
while the sulKiesopbageal ganglion is coniposcJ of the prim- ent insects such a diflerencc in the manner of the formation
itire ganglia of the first and second maxillary segments. lie of the commissural cords and the suboesopliageul ganglion.
OF OKCAXTIirs AM) 1 Ki.i: AS.
253
those of the cross coinmissurt's ami arist- from thu gaii^'lioiiic culls of the lateral codIh. In longitmliiial sections of the conl (pi. L'l', fig. 1 ) one limis the longitiiiliiial coiiiiuissiires extending as iinl)roken Ijnndles of fil>re.s from the hrain to the last altdominal Hegment. The portion in the hrain i.s of two or three times the size of that in the hind ahdominal region. In transverse sections {pi. 23, figs. 1 and 2) it forms a varying proportion of the cord, dependent upon the part of the ganglion through which the section pas.ses a,s well iw upon the region of the l)ody from which it is taken. During its passage through each ganglion it sutlers a slight enlargement, which is auginenteil hy the decu.ssation of lihres from the adjacent surfaces of the two long commissures through the cross connni.s.sures. The fibres of the longitudinal and cro.s.s commissures remain distinct from cue another until quite late in embryonic life, when the peripheral filjre.s of the long commi.s.>tureH become woven among some of the fibres of the cro.ss conuni.ssures. (PI. 22, fig. ().)
The BK.\ix (pl. r.l, figs. G, 10 ; pl. 20, figs. 22 and 2.>) is developed as two .separate kid- ney-shaped lobes from the internal cell mass of the ectoderm of the head folds, and hence corresponds in its origin to the lateral cords of the thoracic and abdominal regions, but the invaginated median element Ls lacking here, and the union of the two lobes is on this account accomplished only at a very late date. The union of the brain with the ventral nerve cord is accompli.shed .shortly before revolution. The posterior portion of each lobe is pro- longed backward for a short distance and unites with the anterior ends of the lateral cords which are prolonged as far as the upper border of the oesophageal opening. The union of the two lobes of the brain is accomplished by the coalescence of outgrowths from their median surfaces near the posterior end of either lobe. In cross sections of the brain (pl. 22, fig. 1 ; pl. 23, figs. 1, 3, 6, 15) the fibres are shown to be limited to the central portion of the mass of ganglionic cells, while in the ventral cord they lie dorsad to the centre. The mo.st of the fibres in the brain appear to form concentric layers, the remainder curving about in all directions, giving the fibrous mass the appearance of a felt work in which a few of the fibres are larger and more sharply defined than the others. In
the ventral ganglia the fibres are arranged principally in the direction of either the long or the cro.ss commissures. Tl'.e fibres of each cross commissure are collected into two' bundles more or le.ss clo.sely tmited, depending upon the development of the embryo, while those of the long com- missures remain permanently distinct from one another. The nerves of the adult insect are, in their ba.sal portions at least, simple outgrowths of the fibres of the cro.ss commissures, each with a sheath of ganglionic cells. At the time of the closure of the body wall, they are finger-like pro- cesses and they, like the outgrowing ocellar and antennal nerves, project in pairs from either side of the ganglia. (Pl. 20, figs. 22 and 23.) The ganglionic cells give rise to the fibrous portion of the nervous .system, probably by the prolongation of their cell walls into filaments. Pl. 22, fig. 2, shows the nucleus of a single ganglionic cell, from the periphery of which fine filaments radiate and pass into the
1 Compare Bobretzkj- (6).
Fip. 21-
Ventral nerve cor<l and other structures as seen from above. The piiiglia are connected by a ma*s of cells below the fibres, /.c. of the figure. The 1. com. probably cont^iins most of the commissural fibres. The ganglia are entirely covered by a reticulum witliin the meshes of which are seen fat bodies. Along the median dor-al line there is seen a del- icate tube cont.iining a non-corpuscular fluid. Six tracheal branches extend over the surface of the pinglion- On either side of which are seen the lateral blood siuuses. From a living embryo, X 400.
2o4
AVKKS ()\ TlIK DEVELOPMENT
liln\>us portion of tho brain, leaving a cavity abont the nnclcns and its radial fibres. The nervons cord in the hatched embryo embraces 17 pairs of ganglia. Nnnibcring from before backwards, 1, forms the brain ; 2, 3, 4, the suboesophageal ; 5, 6, 7, the thoracic ; 8-17. the abdominal ganglia. During embryonic life the brain shows no traces of the spe- cialized parts (e. g. calicos, trabecnlae, central l>ody, etc.) fonnd in the adult. In pi. 22, fig. 1, are figured three pairs of large nuclei which occur in the adjacent walls of the suc- cessive thoracic ganglia. Pi. 22, fig. 7, represents these nuclei more highly magnified. No nuclear membrane is distinguishable. The nuclear substance appears finely granular in the sections, and near the centre of each of the luiclei occupying the anterior edge of a gan- glion is a bar-shaped nucleolus, while the nuclei lying in the posterior edge of a ganglion possess several small round nucleoli. The significance of these nuclei is unknown. The optic lobes (pi. 20, figs. 22 and 23) are first seen as rounded projections on the outer sur- face of the hind part of each half of the brain. By a gradual growth they appose them- selves to, and finally fuse with, tho much thickened ectoderm near the base of the antennae.
Before the diflerentiation of the optic lobes of the brain, the ectoderm just posterior to the base of the antennae is raised into a pair of lenticular elevations which ultimately form the ectodermic parts of the eye — i. e. the cornea, lenses, rods, and retina. (PI. 23, fig. 16.) The cells in this elevation are at first colored with a brown pigment, but the color disap- pears about the time of the closure of the dorsum. The surface of the elevation becomes papillate by the project! n of the cells which form the simple lenses. This condition persists (pi. 20, fig. 47 ; pi. 25, fig. 31) until after the first ecd^^sis of the hatched insect, when the cornea becomes smooth and glassy.
The following table is self explaining : —
A. Ectoderm. —
Origin. From tlie superficial cells on the dorsal side of the egg in the future ceiihalic region.
B. Mesoderm. — From indifferent yolk cells ; from the inner ends of the cells of the germinal band (?).
C. Endoderm. —
From indifferent yolk cells ; from the s\i])erficial cell layer — the bl.astoderm or yolk sac.
Fate. It becomes the " hypoderm " of the body and its appendages, — the gills, wings, and ventral appendages, — .also the nervous system, the trache.ie, the epithelial lining of stomodaeum and proctodaeuni,the salivary glands and the Malpighian vessels ; and forms by secretion the cuticula of the first three structures.
It becomes, muscular layers of the enteric tract, sexual organs, heart, segmental muscles, peritoneum, and segmental organs (?).
It forms the epithelial lining of the mesenteron and furnishes the cor- puscles of the vascular fluid.
The germs of the sexual organs do not appear until after revolution and the beginning of the formation of the dorsum. (PI. 22, figs. 1, 4, 5). They are first seen as two irregular groups of amoeboid cells, belonging to the splanchnic layer of the mesoderm on either side of the dorsal vessel. Later they assume the form of spherical masses, which soon elongate, becoming first oval, then cylindrical and finally pear-shaped. The ovaries at their ante- rior ends become small and rod-like, and the anterior end of each rod is connected with
OF OECANTIIUS AND TKI.KAS. ^r^g
the mesodermic element-^ lyinLC aloiii,' tlio wall oCtlit' lu-art. In llu- iMilarj^tMl j)orti«)ii oCtla' mass there appears a space eoinpanitively free from <^eniiiijal cells but CiHimI with a finely granular protoplasm ; in this area are to be seen a few nuclei — with peculiar bar-shaped nucleoli — which are much larger, and also more sharply defined, than tlie nuclei of the remaining germinal cells. Tliese are the nuclei of the primitive ova and probably give rise to all of the ovarian germs. At a later date each ovarian body is fliflJ-rentiateil into
fifteen or twenty ovarioles — which include the greater part of the cell nuiss an<l an
oviduct which is formed as an out-growth from the hind end of the mass. The details of the tul)ulation of the ovarian masses and the distrii)utiou <d"the germinal cells reciiiire fur- ther study.
At the time of revolution the appendages exhibit traces of their future subdivisions. The antennae are about one half as long as the eml^ryo and are comparatively thick. The mandil)les are much l^roadened and slightly trilobed. IJoth [)airs of maxillae are distinctly trilobed and are much longer than the maudildes. The three pairs of thoracic appendages are of nearly equal length, but the third pair exceeds the other two in bulk. The biusal joints of all three pairs are considerably enlarged, but their tips are as yet rounded. Soon after revolution they increase rapidly in length and become sharply bidentate. The first pair of abdominal appendages have nearly disappeared, while the anal stvlets, or last pair of abdominal appendages, has grown to the length of the mandibles, and at the close of eml)ryonic life have acquired considerable size and are covered with hairs.
After the yolk sac is formed a cuticula is secreted about the embryo, but it does not quite reach to the edges of the yolk sac and is much thinner on the sides than on the ven- tral surface of the embryo. This layer is soon cast off and a second one .secreted. From the latter are derived the thick chitinous parts of the mandible and maxillae, the onychia and tibial spines of the legs, and the balloon shaped processes of the anal stj-lets. With the growth of the embi-yo, the maxillary and mandibular regions of the bodv are <''reatly sliortr ened, their dorsal portions disappearing alto^'ctlier and their ventral portions fusin"- with the oral region. Both pairs of maxillae become somewhat reduced in size and with the mandibles completely cover the mouth opening. They are in turn covered by the broad labrum, which has now been reduced to a thin chitinous flap. (PI. 19. figs. 7, 8 ; pi. 20. fiirs 45, 46.) ° '•-.„•.
After the secretion of the second layer of cuticula the surface of the body is thickly beset with bristly hairs. They are especially developed upon the antennae and anal sty- lets. On the inner surfaces of the basal portions of the latter are seen two vesicular bodies (pi. 19, figs. 14, 15, 16) which from their structure and position can be only modified hairs. They appear after the first ecdysis and then only one upon each stylet. Subsequently they increase in number, probably with each ecdysis, until in the adult insect one finds on each from ten to fifteen such bodies. The cuticula at the base of the orgiui is raised up in the form of a vase, from the depth of which the stem of the balloon takes its orifin. The latter is filled with clear vesicular bodies during the period of embryonic life but appears to be entirely empty in the adult.^ At the time of hatching there are no traces of wings, but later these appear as flat outgrowths of the dorsal ectoderm and in the man-
* These org.ins m.iy possibly be homologous to the sense p,ire Paclcird's description of those met with in Blatta. organs found outhe anal stylets of other Orthoptera. Com- Amer. Nat. vol. iv., p. 620.
256 AYERS ON THE DEVELOPMENT
nor of their fonn;ition closely resemble the ventriil appendages, except that they are rot^riotoil in their growth liv the cuticiihi and only increase in size at each ecdysis. The ectoderm of the insect has now lost its cellnlar character and constitutes a syncytial layer in close contact with the inner surface of the cnticula.
The serosal membrane of Oecanthus affords excellent material for studying the structure of the cell and the changes which its different parts undergo during the process of division. In Fig. 17 is represented a portion of the fresh serosa, treated with dilute acetic acid. The reagent is just beginning to affect the cells. Adjacent cells are joined together by intra- cellular matter which is to be considered as belonging to the cell substance. Near the cen- tre of each cell is seen tiie usually spherical nucleus. Before the reagent had affected them, these nuclear bodies appeared to be filled with a finely granular protoplasm, — often showing a bipolar arrangement, — which contained from one to three highly refractive nucle- oli. Sometimes a small area was to be distinguished about one, or each, of the nucleoli. The boundary of the nucleus, although sharply defined against the cell protoplasm, seemed to fade insensibly into the nuclear substance. After the action of weak acid the membrane showed a sharj) double contour and the nuclear substance became more coarsely granular. Some of the nucleolar bodies are seen to be centres from which the nuclear substance radiates either in the form of distinct fibres or as rows of granules. Many of these rays are finally deflected toward, and centre in, the opposite pole. In nuclei in which two or three of these bodies are present, there are frequently seen two centres of radiation between which lies the third nucleolar mass. This third body corresponds, in its rela- tive position to the centres of attraction, with the so-called Zellplatte in the process of cell division. (Fig. 17 ; pi. 21, figs. 15, 16, 17, 20, 22.) In other nuclei there is seen a distinct spindle structure, at either end of which are placed the nucleoli which thus form the centres of radiation. (PI. 20, fig.s. 32, 33.) The stages in this process of nuclear division are evidentl}^ very similar to those which have recently been described for ce?Z-division by numerous writers.^ One sometimes finds within a single cell wall two nuclei lying in con- tact (pi. 20, fig. 31), — each of which contains a nucleolus with radiating filaments similar to those of the single nucleus, — and in such mutual relationship as to indicate that they had arisen by a process entirely analogous to that of cell division.
The nucleolar bodies lie at opposite poles of the nucleus but are always surrounded by the nuclear substance and hence do not come in contact with the nuclear membrane. The granules of the substance lying between them are disposed in straight lines which are separated by tracts of clear protoplasmic substance, while from numerous points on the periphery of the polar corpuscle tlie nuclear substance radiates either in the form of dis- tinct fibres or rows of granules. (PI. 20, fig. 33.) PI. 21, fig. 47 is a section through the nucleus of a blastodermic cell, exhibiting two nucleolar bodies, which lie within a space free from nuclear granules or filaments. The bodies are separated by a thin layer of nuclear substance, which is probably an optical section of the nucleolar plate. The body of the nucleus is filled with fine tortuous filaments of nuclear substance.
' I cannot assert positively that the spimlle figures which It is more lliaii jji-obeible that such is the c.tse, since in ;i single
I have seen in the nuc/ei of serosa cells of Oecanthus arise in preparation of serosa are to be founil nuclei exhibiting all
the same manner as in cells or produce the same effect upon the stages in the i)lienoniena of spindle -formation and division.
Ducleasas they do upon the cells in other instances, since I Compare Flumming (17, 18), Priestly (37), Strasburger (39)
have Dot observed the sequence of phases In any one nucleus. and the synopses of these papers by Mark (SO).
OF OECANTIirs AND TKI.KAS. 257
In tlie nuclei of the epithelial cells from the follicles of the ovariole of Oecimthus (pi. 21, figs. 43-00; pi. 23, figs. 17, IS, 20) the nucleoli vary greatly in shape and nmnlier. There maybe a single spherical or «luinh-he!l shaped nndeoUis, or the latter may assume the con- dition of a thick rod. It may l)e lacking fntircly or may consist of a central body with few or many, small or large, radiating threads. Whenever more than one nucleolar htjdy in present the nucleus is more or less elongatetl and usually shows some indications c»f approaching division. The occurence of anything like a symmetrical nuclear spindle is rare in such cells. The arrangement of the nuclear substance in the form of filaments in exceedingly various, but out of all the material studied, I have not been aide to trace any definite cycle of conditions througli wliich the nuclear filaments pa.ss during the division of the nucleus, such as has been de.scril)cd by Flemming, Strasburger and others for both animal and vegetable cells. However, many of the stages which I have observed corre- spond to those given in their schemes of cell division. The most common form of filament as a short, tortuous, refractive thread, which is woven into a filamentous ma.ss so as to be traceable for only short distances in any direction. This thread may appear moniliform or continuous.
The filamentous structures of the germinative vesicle at various stages in the growtli of the ovum, although characteristic, do not differ in essential particulars from similar struc- tures in tissue cells. In the follicular epithelium the threads are frequently arranged in loops at the periphery of the nucleus while at their central ends they are connected with the larger masses of nuclear substance, — nucleoli, — from which they may be said to spring.
The physical and chemical conditions of the yolk nuclei differ considerably from those of the nuclei of tissue cells, as is at once apparent upon treatment with reagents. The yolk nuclei are larger than any others in the embryo and are less numerous. They multi- ply much faster, but their descendants usually differ greatly from them, as for example when a single yolk nucleus by rapid proliferation gives rise to many mesodermic nuclei. When treated with osmic acid and Beale's carmine the nuclear matter separates into two distinct parts, the nuclear fluid and the nuclear substance. The latter is usually contracted into an irregular mass near the centre of the nucleus, but the compactness of this central mass depends entirely upon the kind and strength of the reagent used. If the reagent is too strong, the nuclear substance will be entireh" torn away from the membrane and be contracted into an apparently homogeneous mass, but if a weak solution is used many of the filaments will still retain their connection with the nuclear membrane, whereas the cen- tral mass will appear finel}^ granular with here and there filaments stretching out toward the periphery of the nucleus. The spaces between these radiating filaments are filled by a feebly stainable substance, the nuclear fluid. The nucleoli do not stain so deeply as the filaments, and the membrane stains scarcely at all. The size and condition of the nuclear filaments vary greatly in different nuclei and, consequently, one infers in different stjiges of tho growth of the same nucleus. The nucleolus is not always present, but when it is, the nuclear filaments are usualW seen to be more closely intertwined in its vicinity than in other parts of the nucleus. The nucleolus may appear filamentous or homogeneous in its structure ; in the latter case the nuclear filaments have no connection with it. Sometimes the nucleolus may be enveloped in a clear mass of protoplasm in which no filaments are to be detected. Such nucleoli are probably the homologues of the polar corpuscles which
MEMOIRS HOST. SOC. NAT. HIST. VOL. III. 38
258 AYERS ON THE DEVELOPMENT
appear in the process of segmentation. There exists this striking difference between the two cases, that whereas in most cases the nucleoli (polar corpuscles) are placed in the cell proto|ilasm. in the case of the serosa nuclei the corpuscle lies within the membrane of the nucleus, and the division of the latter does not at first seem to affect the condition of the cell.' (PI. 20 figs. 30, 31.) Such a cell immediately after the division of the nucleus is practicallv in the.condition of a syncytium. The relations of tlie nucleolus to its fibres and to the nuclear fluid are distinctly shown in sections of eudodermic nuclei. (PI. 21, figs. 5, 11, 12.)
As regards the origin and significance of the primitive germinal layers among the Insect,a, I am still in doubt. Balfour's interpretations and general conclusions (loc. cit., Vol. I. p. 378 ; Vol. II, p. 278) I cannot accept since they seem at variance with the facts. The author considers the superficial cell layer existing at the close of the formation of the blastoderm equivalent to ectoderm (epiblast) and the inclosed yolk mass as essentially endoderm. But when we consider the role and subsequent fate of these two layers it at once becomes apparent that such a view does not accord with the fiicts, for the blastoderm ultimately forms the entoderm (mesenteron), and the ectoderm, arising from a small area of thickened cells on one side of the blastoderm, encloses the yolk and endoderm by a genuine epiboly.'^
It is, however, with some hesitancy that I expose the following tentative views on the subject, with the hope that, if they do not at present afford an entirely satisfactory and complete explanation of the facts, they may at least help toward the solution of the diffi- cult problems of the origin and significance of the embryonic membranes and the germinal layers in the Arthropoda, and in this way serve, perhaps, to throw some light on the phy- logeny of the group.
How did the embryonic membranes (amnion and serosa) arise ? What is their function ? Is their present function the primitive one ? The answer to these inquiries undoubtedly lies in the clear comprehension of the relations of the embryo to its food supply — the yolk. That the cellular embryorric membranes could have originated for protection, or from an early ecdysis is, to say the least, highly improbable. Among the Insecta the egg is furnished with a protective membrane — usually in the form or a chorion — before leav- ing the body of the parent. The presence of an unusually large amount of yolk matter, fundamentally changes the manner of cleavage in the egg of the Arthropod.^ After the forma- tion of the blastoderm the yolk is inclosed in a cellular membrane which is, strictly speaking, a food sac or stomach ; functionally considei'ed it is consequently endodermic, not ectodermic, in its nature. The ectoderm arises, as has been said, in a limited area on one side of the
• In most animals the polar corpuscles arc formed just at stance (e. g. most animals and plants) ; or the)- may lie at a
the outer edge of the nnclcar membrane and exert an attrac- distance outside the membrane and inllucnco botli nuclear
tion in all directions , through the nuclear substance, pro. and cell protO])lasm (e. g. Limax; see Literature, 30). Since
ducingthe spindle phenomenon and through the yolk, produc- these jiolar corpuscles are essentially nuclear in their origin
ing the astral structures. In some cases (e. g. Limax) they the last two cases are to be considered as derivatives of a
are formed at a distance outside the nuclear membrane and primitive form, in which the corpuscles are internudcar.
never come in contact with it. There are, then, three posi- ^ The so-called endoderm, on the other hand, remains
tions which the polar corpuscles may assume. They may lie througliDut its existence an inert mass of food substance
entirely within the nuclcir membrane, the latter app.arently between the particles of which numerous imliffcient celts are
letting a limit to its influence (e. g. Oecanthus) ; tliey may found.
lie in contact with the outer surface of the nuclear membrane 'In Oecanthus there is no trace of yolk segmentation. and exert their influence through both nuclear and cell sub-
OF OECANTIIUS AND TI.I.KAS.
259
egg, and by a siibsoqiicnt growth entirely siiiround-^ tlie endoilerniie sac itnd its contents. This process is modified, however, by the inlerpohition of tlie so-called embryonic membranes. Since the endodermic sac is so extremely large — as compared with the size of the embryo — that the latter could not easily inclose it by a simple epiljoly much before the time of hatching, it is apparent that any modification of the j)rimitive process which will enable the emliryo to enclose the yolk earlier will l)e advantageous to the animal by shortening the developmental processes. Hence, the lateral edges of the band-like endtryo instead of epiboli/.ing the yolk have acquired through adaptation the tendency to grow ventrad instead of dorsad, so that on the completion of the amnion, the embryo i.s devclopjd inside out, with its dorsum (the amnion) covering the ventral surface of the germinal band after the fashion of u membrane.
That the cavity inclosed between the so-called amnion and the germinal ban<l is really external to the endjryo is evident from the fact that the external ends of the stomodaeum and proctodaeum connnunicate with it. The fusion of the two edges of this anmion in the median ventral line, may take place simultaneously with that of the sercsa, or it may take place quite independently of the serosa and at a later period. The embryo may, or may not, become entirely disunited from the endodermic sac (now serosa), and hence may be related to it in one of three ways. It may Ije in contact with, it may be fused with, or it may lie entirely within, the sero.sal sac. This process is capable ol being explained in two ways. Either the yolk mass would not allow the dorsad growth of the lateral edges of the germinal baud, or it is strictly an adaptive response of the embryo to changed conditions of environ- ment. The latter is probably the true cause of the unique phenomenon of an animal under- going development inside out, and its object can only be the swallowing of the food stored up fur its nourishiiient. The amnion and serosa fuse in the head region of the embryo. This fused membrane -soon ruptures, so that the sac-like embryo, which up to this has had no structural connection with or control over its food sac, becomes united with the sero.sa into a double sac, a sac within a sac.
The endjryo now everts itself through tliis opening ami lies outside of the yolk sac, which in the meantime has assumed a position dor.sad to the embryoi The amnion now forms the dor- sal and part of the pleural walls of the embryo and at its ceph- alic termination is continuous with the yolk sac. The yolk to- gether with the greater part of the cell elements forming the wall of the yolk sac is soon enclosed within the body of the embryo. The remnant of the yolk sac remains for some time as a plug- like projection from the median dor.sal line inunediatel}' l^ehind the head, and is the homologue of Kowalev.'^ki's dorsal organ.
Since the appearance of Kowalevski's paper on the embryonic development of Hydrophilus, in w hich he first makes known the existence of a dorsal organ among insects, the conjectures as to its probable significance have been various. The follow-
Fig. 29. Dinprmmmatic reprcsent.it relations of the mcscTiteron
1 of the stomo-
daeum, and proctodaeum after tlie closure of the liody walls dorsal orpin or pluR. Com] sectionsof an embryo. X50.
closure of the body walls over the injr explanation of its Origin and function is a necessarv corollary
dorsal orpin or pluR. Compiled from _ . . ..... . . ".
from the previous explanation of the embryonic membranes.
260
AYERS OX THE DEVELOPMENT
A-* h:i< already been shown for Oecanthus, the embryonic moinbranes (especially serosa) final! V assiiine the condition of the dorsal organ of IlydrophiUis, with this notable excep- tion: the organ does not extend the entire length of the uiesenteron, nor does it possess a distinct luuKMi, but as tlic soquol will prove the diderence is only one of degree and not of kind.
lirielly reviewing the fiicts in the two cases, we find that in Ilydrophilus there is a fusion of the serosa and aninion and a subsequent rupture of tlie fused membranes in the median ventral line.* Fig. 30.
r J -.-'. Fig. 32.
^.gattmo.
Fig». 30-34. Diagrammatic illustrations of tho formation of ICowalevski's dorsal organ. Fips. 35-37. Diagrammatic illustrations of the varying relations of the embryo to its yolk sac.
By the contraction of the serosa the amnion is pulled off from the ventral surface of the bodv 'fig. 31) and goes to form the dorsum of the embryo after the serosa has contracted into a thick rod and has passed into the mesenteron. The serosa first forms a thick plate on the dorsum of the embryo (fig. 32 and Kowalevski, 26, pi. 8, figs. 14, 15, 16). This plate is in union Avith the body wall at its edges, and by the upgrowth of the walls it becomes longitudinally folded on itself forming a tube open at the head end. (Fig. 33.) This end is the last to be covered over by the dorsum. (Fig. 34.) It finally loses its connections with the body walls and undergoes disintegration within the mesenteron.
In Oecanthus the membranes fuse at or near the head, and by a self eversion through the opening caused by their rupture the embryo comes to lie outside of the amnion and serosa. The latter now forms a yolk sac, which by a gradual contraction, as the yolk is absorbed, comes to lie within the body, being last seen just back of the head. (PI. 19, figs. 1-5, ; pi. 22, figs. 1, 11 ; pi. 23, fig. 2 ; pi. 25, fig. 31.) It is always in connection with the mesenteron and its thick walls finally disappear by a process of disintegration.
Although Brandt (8) makes no mention of the function or fate of the thickened serosal yolk sac which he so frequently figures (loc. cit., pi. 2, figs. 15-22; pi. 3, figs. 32, 34, 38), there can be no doubt that it is the same structure that exists in Hydropliilus and Oecanthus.''
' Kowalivski leaves this point in doubt since lie w.as ancert.-xin as to the fate of the amnion. He states that it is either ruptured or absorbed. From its fate in other insects
the former seems more probable tlian the latter.
2 Compare also Metsehnikofr (.3-2) pi. 2.3, fi-s. 15, 19-23; pi. 2U, figs. 9-27 ; pi. 27, figs. 20-28 and pi. 30, figs. 20-34.
OF OECANTIirS AM) TKI.EAS. ' 261
From these figures it is apparent that in many it" n(jt all insi'cts the serosa ancl amnion play the same r^)le that they do in Oeeantlms. i. e., the serosa fiinelioin iis a yolk sac wliile the amnion is the dorsal wall of the inseet. Hence the so-called dors.il organ is but the remnant of the yolk sac.
Note. — In tin' lii^lit of the itii|Mii-t»iit iliscovorifs in tin- oinbryolo-ry of Traclii-atn inailo liy the late Professor lialfour (F. M. Halfoiir — Tlie Anatomy anil Development of I'eri|>atiis Cajiensis. Quart. Joum. ilicr. Sei., n. ser., No. xc, Ai>ril 18m3, |>|>. •Jl3-:;5y, jd. .\m-.x.\) the process of ^astriilution in Oeeantliua is more satisfactorily e.x]>iaineil. In Oecantlius the original blastopore or j^astrula mouth, cxistini^ near the head eml of the egjj after the formation of the blastoderm, elongates with the formation uni| growth of the germinal band into the form of a shallow furrow (the so-called niesodermic groove of insecto). It does not form, as in Peripatns, a slit-like opening within the limits of the germinal band, the lips of which coalesce in the median line leaving at either extremity of the bbistopore an o|>cning into an archenleric cavity — Balfour's so-called mouth and anus, — but the posterior o|)ening begins an a shallow pocket and opens into the archentcron at a very late period. The mesoderm arises in the region of the primitively circular mouth and grows backward, following the course of the groove in the germinal band. The anus conscipiently is a part of the blastopore while the mouth is a secondary forma- tion. The embryonic mouth persists until near the time of the closure of the body wall over the <Iorsum.
These views may be stated as follows : —
1. At the close of lilastoderm formation the aicheiiteric cavity is completed, and its mouth is on the dorsum of the cephalic region (compare Oniscus, Jlj-sis, Scorpio, Libellula, Caloptery.x and Ilcmiplcra par- osita), hence the blastoderm ecjuals cndodenn, not ectoderm.
2. The ectoderm arises simultaneously with, if not previous to, the endoderm; but, instead of surround- ing the entire endoderm, it covers only a small area on the dorsal side in the region of the gastrula mouth. Subsequently, however, it surrounds the archenteron and it also becomes incomplete at, the circular gastrula mouth, where it unites with the endoderm.
3. The mesoderm arises before the full com])letion of the gastrula as an unpaired plate in the region of the fusion of ectoderm and eniloderm, i. e., near the lips of the gastrula mouth, and grows both backward anil dorsad between the ectodennic and endodermic layers.
4. The so-called niesodermic inv.igination is to be considered as connected with the blastoj)orc — jierhajjs in some cases the only indication of the previous existence of a gastrula mouth.
5. On account of the pressure of an unwieldy mass of yolk these processes are somewhat modified, but not so completely as to lose their identity. On this account the completion of the gastrula is retarded until the organs of the embryo are well advanced.
In Scorpio, Mysis, and Oniscus, the blastopore is dorsal in position.
TELEAS.
A parasitic Icluieumon lly, probably of the genus Teleas, infesting the eggs of Oecanthus, presents highly interesting stages of development which were first made known by Metschnikofl' in 1866, and were more fully described for Teleas and a number of related forms 4)y Ganiii about two years later. The results of my study on Teleas differ in some points from those of Metschnikoff and Ganin on species of the same genus. De Filippi(16) has described the embryonic changes of a Pteromalian, parasitic in the egg of a curculio (Rhynchites). which, to judge from his figures, closely resembles Teleas in its j-ounger larval stage.
Metschinoff (32) gives a short account of the development of a species of Teleas infest- ing the eggs of Gerris lacustris, of which the following is a brief summary. The earliest observed stage was that of the stalked egg iu which the blastoderm (Keimhautj was already
262 AYERS OX THE DEVELOriMENT
formed. This blastoilciin was composed of cells resulting, in his opinion, from a total seg- mentation of the egg. It surrounded a central cavity which Metschnikoff considers liomol- oijous to the segmentation cavity of Copepods and certain Daphnias, and therefore he gives it as his opinion that this cavity existing in Teleas is a genuine segmentation cavity. At the close of segmentation tliere lies outside tlie blastoderm a cluster of round cells which later form about tiie embryo a membrane analogous to tlie " anuiion " (equivalent to tiie serosa of authors) of other insects. When this membrane is fully formed the embrvo is seen to be a round, laterally compressed body. A median furrow now appears causing a division of the embryo into synnnetrical halves, the so-called Keimwiilste. The embryo elongates and becomes kidney-shaped, the farrowed face remaining convex, tlie opposite one becoming concave. While the embryo still consists of a single layer of cells, the head region is diftei'cntiated, and the continuation of the above mentioned fur- ■ row into this region gives rise to two well-marked head folds (Kopflappen). With the further growth of the embryo its head broadens and its posterior end becomes conspicu- ous! v narrower. The cells of the dorsal wall become broader and thinner, while those of the ventral wall remain cylindrical and, on the whole, increase in thickness, so that one may now for the first time speak of a germinal band (Keimstrcif). With still farther devel- opment there is formed on the head a transverse fold, the lateral edges of which are especiallj- well marked and are afterwards converted into the pointed jaws, while the median part of the fold is only faintly indicated and finally disappears altogether. The central cavity now becomes filled with small round cells which are derived from the ven- tral plate and soon form the mesenteron. Invaginations at either end of the embryo form the stomodaeum and proctodaeum. The latter remains unconnected with the mesenteron during the whole of the first larval period. The hind part of the embi-yo grows rapidly in length, whereby it is considerably narrowed and finally is converted into the long, pointed tail. A muscidar system is developed in the embryo, now a larva, and a cuticular covering is secreted about the body. This cuticula is armed with bristles, disposed on both sides the equator of the embryo and they are moved in only one direction by muscles. The embrj-o now comes out of the " amnion '' and feeds on the yolk of the host egg. The ger- minal stripe remains in the larva as an undifferentiated band of cells from which (but only at a much later period) the ventral portion of the nervous system is formed ; whereas the youngest larva is already furnished with a bilobed brain mass. MetschnikofF's endeavors to determine whether an amnion (Deck- or Faltenblatt) was present or wanting proved entirely fruitless. •
Ganin (ID) studied the development of several genera of the Pteromalidae, among others a species of the genus Teleas. The following is an abstract of his observ;itions on that species. The author takes exceptions to Metschnikoflf's view of the existence of a central cavity in the segmented egg of Teleas and, although not having seen the segmentation of the egg in this species, he still believes that it ought to agree closely with Platygaster, Polynema and Ophioneurus, where the result of segmentation is an outer layer of small cells surrounding a solid mass of large " central cells." He goes so far as to say that the production of a segmentation cavity in the egg of Teleas as the result of a total segmentation is, at least for him, inconceivable. Ganin claims that Metschnikofi's observation regarding the origin of the mesenteron is also erroneous, since he believes that
OF OECANTHUS AND TELEAS. 203
it arises from the large " central cells," which at first constitute a solid cylinder, in which a central cavity is afterwards developed. The proctodaenui and stoniodaenin arise here, as in the other Pteronialidae, by invaginations of the hypodermic layer at either end of the body. The earliest stage observed by Clanin was what he called the first larval form. It bears a very strong resemblance to the first larva of Platygaster ; the cephalo-thoracic por- tions especially are to be compared. The only internal organ possessed by this larva is ;i mesenteron which ends blindly liehind. Its wall is composed of comparatively lari^e cells, and is destitute of a muscular layer. The cuticular covering of the body is furnished with two sharp, curved jaws, an npper lip (located far back of the mouth opening near the junction of the cephalo-thoracic with the abdominal portion of the body), a tail and two transverse rows of bristle.s back of the head region, one on each side of the body. These bristles are structureless prolongations of the cuticula and are long enough to reach to the end of the tail. The author observed them in motion but could not distinguish the muscles described by Met>chnikofT. The Uiil is composed of two conjoine 1 parts and diminishes constantly in size with the growth of the larva. On the transition to the second larval stage it disappears. The thin, structureless cuticula is thickest on the head. On the ven- tral side of the latter is seen the mouth opening, circular in form. It lies in the median line between the jaws and is bordered by a sharp outline. The proctodaeum does not appear in the first larva and the muscular .system remains but poorly developed. There are a number of tail- and jaw-muscles. The body cavity contains numerous amoeboid cells which are believed to be the indifferent embryonic cells left from the central cell ma.s3 after the formation of the mesenteron, although in Platygaster similar cells are claimed to arise from the hypodermis. In Teleas the latter is of uniform thickness at all point-s of the surface. When the first larva passes into the second larval stage the h3'podermis in the tail region is invaginnted and forms a proctodaeum as in Platygaster. It then thickens along the whole ventral line and forms a germinal band which is continuous posteriorly with the undifferentiated walls of the proctodaeum. This process is the result of a rapid cell proliferation in this region. In the dorsal part of the head region the germinal band curves into a pair of very thick head folds which are separate from each other as well as from the hypodermis of the dorsal region. The folds give rise to the supraoesopha-'eal ganglia. The lateral portions of the germinal stripe furnish the muscular system. Sali- vary glands appear at first as solid cords of cells derived from the anterior portion of the germinal stripe. They subsequently develop a central lumen, ending blindly behind but opening out in the mouth region. The eggs of Teleas are very small, transparent, and colorless ; they possess no yolk.
These are the main facts which the author gives with regard to the development oi Teleas, he, however, believes on grounds of relationship and for a jjrior'i reasons that the development of Teleas corresponds in all essential particulars with the facts obtained in his researches on Platygaster, Ophioneurus, and Polynema. He states that the embryonic membrane which he has called amnion is not homologous with this membrane in other in- sects but is to be' compared with the skin developed on the dorsal side of some low worm- like Acarians (Pentastomum) and the larval skin of crustacean embryos (loc. cit., p. 44G).
In order to avoid confusion it will be necessary to observe, that Ganiu's first larva of
■ Packard (35) says: "may possibly be."
204 AYERS OX THE DEVELOPMENT
Telcas is oquivaloiu to tho tliird stage ^^•hi('h I have tbuml jiarasitic in the eggs of Oecan- thus nivou^.aml is the same as the hirva oI'Metschnikotf ; i'lirthennore that Ganin's second larval Ibrni is only my '• third stage " in process of ecd3sis. For an excellent summary of Ganin's entire paper one may consult Balfour (1). Packard has given a more detailed extract in (35) and (36).
The earliest stage^ of the parasite found in ihe eggs of Oecantlius was that of the com- pleted blastosphere (pi. 23, figs. 23, 31). This perfectly spherical body consists of a shell of small, short, cylindrical cells which encloses a colorless, finely granular fluid, possibly a nutritive or yolk matter. At this stage theic are no cell elements except those which form this shell (Blastoderm of Metschnikoft' — Embryonalanlage of Ganin). Soon amoe- boid cells are budded off from the inner ends of these cells and make their way into the contained fluid. They are usually much smaller than the cells of the blastosphere and are irregular in form. Some of them appear destitute of any nuclear structure, but most of them possess a small, sharply defined, eccentric nucleus. On one side of the blastosphere the cells in a linear tract elongate causing a spindle-shaped ridge to be formed on the sur- face. This increases in size until it is quite prominent, when there .appears a median furrow dividing it into symmetrical halves or folds. At each end the folds are continuous with each other by means of a narrow, curved cross-fold. The growth of the folds is accom- panied over the whole of the inner surface of the blastosphere by a cell proliferation which is most active along the region of the folds or germinal baud. There now appear at the starting point of the folds two pairs of prominent thickenings (pi. 23, fig. 27), the head folds. The anterior of these is the larger and ends abruptly in the germinal band. From this point backward the band gradually thickens into an evident prominence (pi. 23, fig. 27) which probabl}- marks the boundary between the thorax and abdomen. It is now bordered on each side by shallow furrows, produced by thickened bands running outside of and parallel to it. The germinal band extends over half the cir- cumference of the blastosphere which now begins to elongate into the spindle-shaped larva. In the meantime the amoeboid cells collect into a mass in the centre of the embryo and form the endoderm. In pi. 24, fig. 1, is shown the relation of the parasite to the host in this stage, while in pi. 23, fig. 3-5, is shown a cross section of a blastosphere magnified 800 diameters giving the mutual relation of the elements composing it In the young blastosphere the elements are very small, thin-walled cells with the longest diameter radial to the sphere (pi. 23, fig. 23); as seen from the surface they are polygonal in outline ; upon treatment with osmic or acetic acid they become spherical. In the youngest stage following segmentation, they are arranged in a uniform layer with no appreciable difference in the size of the cells ; soon, however, the cells in certain tracts begin to increase in size and to proliferate, giving off from their inner ends amoeboid cells which go to form a layer of cells of irregular sizes and shapes just beneath the ectoderm. As soon as proliferation begins, the cells lose their uniformity of arrangement and cohesion, the least pressure being sufficient to displace them. In sections of this stage are found cells of the size and char- acteristic appearance of ectodermic cells lying just outside the ectodermal layer, although
' The egg has not been seen but is pi-ob.-ibly of the usual proiluct proves. Allowing the contents of tlic sphere to be pedunculate form, with the colorless yolk not gathered into genuine yolk-niatter, there is no evidence that the segmenta- olk masses. The segmentation of the egg is total, as the tion may not have been "superficial."
OF OECANTIirS AND TKLKAS. 2G5
in the frosli state no snrh ot'lls are ti) be seen. These occur at irre^'iil.ir intfrvali and are fuiiinl only when tlie bhistosphere shows traces of liavin>:; been ruptured by tlie swell- ing iiilluenee of reagents. (I'l. 'J.'5, fig. oO.) In all stagi's the parasite is surrounded by ii ina.xs of clear protoplasmic substance which has been aHected by the presence or secretions of the parasite. On sections of the first stage one finds surrounding the blastosphere, but at some distance from it, a thin wall of condensed albuminous matter containing within its substance no indications of cell structure. This layer cannot be made out in the fresh state. It is not found in .sections of the two sub.scquent stages of the parasite. There are no other layers to be found enveloj)ing the parasite in an}' stage ob.><erved.
This stage ' agrees perfectly with that observed by Metschnikon' in another species of the genus Teleas, with the single exception of the absence in the present case of any cellu- lar embryonic envelope such as both Ganin and MetschnikofT describe for Teleas and other genera of Pteronialidae. Since the segmentation of the egg was not observed in this case, only negative evidence can be produced to prove that all the resultant cell elements go to form at iirst a single-layered blastos[)here. It is. however, highly probable that such is the case, since at no stage of the blastosphere can any such elements (i. e. endjryonic mem- branes) be found. Since this is the stage in which the embryonic mendiranes (i. e. amnion and serosa) are presumably beneficial to the growing embryo, it must be concluded that all such structures are wanting in this particular case. I hesitate to apply these conclu. sions to any other forms of the I'teromalidae, for the observations of MetschnikolV and Ganin clearly prove that these forms differ greatly among themselves in the particulars of their embryonic development, though bearing very strong resemblances to each other in their older larval and adult states. We have in this form, then, an iasect which has no trace of embryonic membranes such as are found in all other insects. Here also is a case in which no invagination takes place to form the mesoderm as is held to be true for most in.^ects. This is the more significant since there is no excess of yolk matter to hinder the process. The facts obtained from the study of this parasite respecting the origin of the mesoderm should not lead to a misinterpretation of the process. For although the condititms favoring its origin by the typical process of invagination (a blastcsphere filled with lluid) are realized, yet in this particular instance it is to be viewed not as a primitive but rather as a secondary method acquired in ancestors where an accumulation of nutritive yolk substance induced a modification of the primitive process, — a modification which has been retained although the conditions which led to it have ceased to exist. The key to this inter- pretation is to be found in the fact that the eggs of the non-parasitic Ilymenoptera are supplied with an abundance of food material, and in such cases the mesoderm arises in a manner approaching the typical invaginate Ibrm. The loss of nutritive yolk in the eggs of the degraded forms is evidently correlated with their parasitic habits.
The first differentiation of the blastoderm begins as a linear thickening of the embryonic area (germinal band of other insects), and is followed by the formation of a median groove (Primitivfurche) which divides it into lateral ridges (Priraitivwiilste). The mesoderm and endoderm are derived fi-om the ectoderm by a process of cell budding which resembles typical delaraination in that it takes place from all portions of the inner surface of the
' In the figures the outer boundary of the protophasrai mass surrounding the parasite is indicaWd by a line. In some figures the adjacent yolk globules are sketched in.
MEMOIItS HOST. SOC. SAT. HIST. VOL. lU. 34
266
ATERS OX THE DEVELORMENT
blastosplioro. and invaj^ination in so far as it takes place most actively in a region which in other insects is the invaginated tract. It may be said further that the mesodenu and endoderm are at first undifferentiated, since they have the same origin and are to be ilistin- guished from each other only at a much later period. (Compare Metschnikoff and CJanin, loc. cit.)
The elonii-ated embryo is now crcscentic in shape with an anterior, oral or cephalic, end and a posterior, abdominal region. (PI. 24, figs. 2, 8, 9, 13, 14.) The former is the larger Avhile the latter is nuu-h smaller and tapers gradually to a point. The region of greatest thickness lies about one-fourth of the distance from the anterior toward the posterior end of the body. Soon after the embryo assumes its crescentic form it secretes about itself a thin, colorless, transparent cuticula, which (in specimens treated with reagents) projects in front bevond the cell mass into a frontal process, and a little behind this on the ventral side into a decided prominence, which bears at its apex the mouth opening. The cuticula of the free ed"-es of the oral opening is thickened to form four crescentic chitinous mandibles. Poste- riorly the cuticula is extended beyond the body mass to form a long, tapering, more or less curved caudal appendage. The mesenteron at first ends blindly in front as well as behind, but by coalescing with the invagination of the stomodaeum it soon comes to open out through the mouth. The muscular system of the first larva consists of oral, cephalo- thoracic, and abdominal muscles. The oral muscles are four in number arranged in two pairs. Of these the lateral pairs are much the larger. (PI. 24, fig. G.) The shape and size of the muscles vary much in the same larval stage. The oral muscles are tan-shaped and at their smaller ends are inserted in the thickened bases of the mandibles, from which they extend out to their origin in ^e lateral and ventral body walls. A cephalo-thoracic flexor ^ and abdominal segmental mnscles form the greater part of the muscular system of this larva. Some of the abdominal muscles extend into the tail region giving great flexibility to this organ at its junction with the abdomen. The number of body segments occurring in this stage varies in different larvae. The maximum number observed is eight, but the usual number is five. The cuticula is thickest in the head region ; here it is seen in optical section, with a magnifying power of 600 diametei's, as a double-outlined layer, very distinct anteriorly but gradually merging into a single line in the abdominal region. In the equator of each segment the cuticula is produced into numerous, finely pointed, hol- low bristles, the lumen of each of which is at least partly filled with a finely granular pro- toplasm which contains a nucleus situated opposite the mouth of the lumen. On the ventral side of the base of the caudal appendage there are to be seen a varying number of hollow tooth-like projections ^ of the cuticula also filled with a finely granular protoplasm. The caudal appendage ends bluntly, and its terminal fourth is covered by numerous fine bristles which are somewhat restricted to its dorsal surface This appendage, like the teeth at its base and the frontal lobe, is filled in the living animal with a granular protoplasm containing few if any nuclear elements. The hypodermis, which lies immediately under
•There is probably an extensor also, but this latter was spine-like projections of the cuticula resembling the caudal
not observe'!, although motions of the larva were seen which appendage. Tliey arose respectively from the cuticula of the
could only have been executed by the action of such a muscle. dorsum of tlie head, of the thorax, and from tlie ventral side
• One peculiar larva was observed (pi. 24, fig.l2) in which, of the abdomjn just above the base of the caudal appendage, besides the brbtles upon each segment, there were three large
OK OKCANTIirs AND TKLEAS.
207
the outicula wliicli it has secreted, is jit this time very tliick. l»ut as the embryo incresuses in size it becomes proportionately somewhat thinner and diflerentiated into a '• ventral stripe." 8ubse(iuently there is separated from the posterior end of the ventral stripe a mass of cells which comes to He dorsad to the stripe and posterior to the mesenteron, to which latter it is intimately connected. Lying on eitlier side of the mesenteron but connected with its walls are seen two elongated sacs (pi. 24, figs. 9, 11 ) terminating blimlly at both ends, which may be in some way related to the salivary glands of the second larva. The motions of this larva are in the plane deter- mined by the longitudinal and dorso-ventral axes of the body, with the single exception of the lateral pair of mandibles, which move at right angles to this plane. Immediately posterior to the mouth open- ing are seen (pi. 24, fig. 6) two roughened patches of the cuticida which will be seen further developed in the second larva. The larva changes its position in the yolk by movements of the rows of bri.-tles after the manner of fins, by the flexion of the tail, and by bending the entire body. Upon straightening out after having thus flexed itself, it is propelled into new feeding grounds. At this stage the food consists of the yellow fat globules of the yolk. The color- less amoeboid cells and albuminoid masses seem to remain undisturbed by the parasite. In the act of deglutition the whole enteric cavity is thrown into a series of contractions and peristaltic movements, although no muscular elements are to be detected in the wall of the mesenteron.
The second larval stage is characterized by the peculiar form of the body, which strongly resembles the cyclops larva of Ganin ; it is indeed equivalent to this stage in the .scale of development. It is mainly distinguished from the previous stage by the presence of two hooked mandibles and a complicated a])paratus functioning as lower lip. The changes occur- ring in the spindle-shaped larva dm-ing the period of transition into the cyclops form have not been observed ; however, I have not the .slightest doubt that the latter is but the former in a later stage of development. In a series of Oecanthus eggs taken from the same elder stem, eighteen out of twenty-five were infested with the parasite. Several of these contained the three stages that I have described as belonging to one species of Teleas, a greater number enclosed both the cylindrical and the cyclops forms, but by far the majority of the eggs contained two or more cyclops larvae. In those eggs in which the cylindrical larva is found, I have never observed more than one cyclops larva. These facts indicate that the ova of the parasite had been deposited in varying numbers in the eggs of Oecanthus and that of the forms developed from these, .some were retarded in their growth.
In this stage the cuticular secretion is highly differentiated, the complications of its structure increasing with each ecdysis. During the period of transition from the first to the second larval stages, the form of the body undergoes such marked changes that the latter bears but little resemblance to the spindle-shaped larva. The cyclops larva is about 0.5 m.m. in length. PL 24, figs. 19-23, and pi. 25, figs. 1, 7, give one a clearer
FiR. 38. FiR. 39.
Fig. 38. Side view of cau- dal ppiiiC!" sliowinc gnwlcri va- riations in tho number and position of tlio stout basal spines. X 125.
Fig. 39. Two bristles from tho dorsum of the siinio indi- vidual. They appear filled with a granular protoplasm* Osroic acid preparation. X 800.
268 AYERS ON THE DEVELOPMENT
conception of its form tlian any brief description would serve to do. In this stage the cuticula extends over the hirva as an unbroken sheet, except at the mouth opening ; here it is wanting in a circuhir area, the external opening of the stomodaeum. It projects ftn'ward from the forehead to form a sheath for the antennae, at the bases of which it is thin and Uexible, allowing slight movements of the organ. (PI. 25, fig. * 19.) Below the
antennae on the ventral surface the mandibles are formed as scythe-shaped, pointed, tubular projections of the cuticula, which grows gradually thicker and yellowish toward the tips, where it shows the characteristic color of chitin. Here, also, as in the antennae, the cuticula thins out at the base of the organs, allowing great freedom of motion to the man- dibles. Below these the cuticula is thrown into a double-layered fold which varies in its structure with The mandibiennd „n,™f the left side of the body ^he degree of development of the larva. For succes-
of the lana figured in pi. 24, fig. 20. The surfjiccs of give StagCS of this fold, Or Undcr lip, SCe pi. 24, figs. Uic mandibular muscle.s are shown. X about 500. t<t in nri m oa a -ni- r ij
li, ly, 20, 21, 24. As will be seen Irom the.-o figures, the lip is at first a simple projection, later becoming bent up at the tip. Some- times it presents lateral grooves for the reception of the tip of the mandibles, thereby increasing their efficiency in cutting the yolk mass of the host into bits suitable for swal- lowing. The lip sometimes strongly resembles the lower mandible of a hawk or an owl. It may be bifid but its upper surface is always concave. One larva was found in which the mouth was kidney-.shaped and the lip proper extended as a gutter fi-om a point on each side of this opening downwards, and outwards, the edges gradually converging in an up-turned, sharply pointed tip. This fold was only a part of a larger lip-fold extending to, and losing itself in, the lateral boundaries of the body wall posterior to the lip proper. Beneath this was a broad fold which united with the body midway between the primary and the secondary lips. This fold seemed to function as a support to the lip as well as a scoop to aid the larva in feeding. There is a pair of cuticular structures of a problemat- ical nature, ui-xiall}' one on each side of the body between the mandibles and the lower lip, but varying considerably in their relative positions in difierent larvae. (Com- pare pi. 24, figs. 17, 19, 20 ; pi. 25. figs. 1 and 6.) They vary greatly in structure but each usually consists of a cup-like depression in the cuticle in which there are secondary cup-like depressions. The cup may be rendered imperfect by the extension into its area of a narrow band of the smooth cuticula. The secondary cups may present a simple out- line or may be irregular in shape ^nd separated from each other by a band-like margin. These structures assume a more lateral position as the nervous system increases in its devel- opment, and as they lie at all times on either side of the suboesophageal ganglion they may function as sense organs. No direct connection between these structures and the nervous cord could be traced. Posterior to the structures just described there is a thick- ened fold of the cuticula mo.st prominent in the median dorsal line, which gradually lessens until it finally disappears in the lateral walls of the body. This fold forms a boundary line between two distinct regions of the body, the cephalic and the abdominal. It serves to strengthen the cuticular walls of the cephalic region, and like all other cuticular.
OK OI-:C.\XTIIUS ANI» TKI.KAS. 269
structures varies i^reatly in its rt-hitive jiosition with the dfj^rec of tlic (Icvclojuiieiit of the hirva. It forms the border of a cleep groove which indicates the anterior limit of the ahdominal region. From this groove the ahdominal wail gradually swells out into a flask-shaped body, which carries in front of its c(|uat()r a pair of lateral flattened expansions of the cuticula, fdled , with hypodermic cells. These bodies are the fin-pads- On their dorsal surface one finds numerous small dentate papillae, while from their niaigina and outer portions are given off from 1") to .JO long, curved, unjoinled, hollow, colorless Iiristles. These fin-pads are nu)ved in a plane at right angles to the dor.<o-ventral axis of the body by several will developed muscles. The tip of the abdcjiiicn, which is not termi- nal in Jiosition but lies on tiie ventral surface of the body, is continued into a long, hollow, cvliudrical appendage, usually tenninating in a dentate knob (pi. 'Jl, fig. 18), the teeth of which arc on its ventral side. When the larva is (juiet the terminal end of the caudal appendage lies opposite the mouth, and when the larva feeds it serves both to break up the yolk and to shove it into the spoon-.shaped lower lip.
Wiieii the larva is about to enter upon an ecdysis the cell structures become dark from tlie presence of granules in the protoplasm, the liypodermis shrinks away from ..'Ip^a the cuticula, the walls of the nie.senteron shorten and thicken, the muscles ;^«0- lose their striate appearance, the protopla.smic contents of the antennae, nian- FiR. 41 sur- dibles, and caudal appendage recede from their sheaths and together with the tt"hy'p"k'r'- h^'podermic cells of the fin-pads are drawn into the body nia.'is. The cuticula tTiini I'l'irvli'?'' "ow swells and lo.scs its definite shape ami ullimately becomes a thin sac ^'"^' loosely enveloping the larva. The cells of the liypodermis next secrete a
new cuticula and the larva at once assumes its former activity, rupturing the cast ofl cuticula and burying itself again in the yolk matter of its host.
While the spindle-shaped larva is changing into the mandibulate form, the cell elements of the body lose their distinctive characters so entirely that the .slightly differentiated organs are scarcely to be distinguished in the cell nia.ss. As .soon as a cuticula is secreted, however, the relations of the cell groups become distinct and now for the first time the muscular fibres of the abdomen are to be seen. There i.s, then, a histolysis of the cell groups but no cell-fusion or cytolysis. The muscular system of the second larval stage consists of thirteen paired and two median unpaired muscles. The largest muscles of the body are the mandibular adductors, while their corresponding abductors are the smallest ones jires- ent in the body at this time. These lour muscles which almost fill the cavity of the cephalo-tliorax arc pyramidal in tbrm and have their, origin in the dorsal wall of the ceph- alo-thorax and their insertion into the upper and lower rami of the mandible of the right and left sides respectively. When fully extended the mandibles project at right angles from the body, but when completeh- retracted thej- lie in close contact with the body wall, their tips fitting into the lower lip. There are two pairs of dorsal muscles connecting the head and thorax. The more superficial extends lengthwise the body (pi. 24, fig. 22) while the deeper pair extends somewhat obliquely to this axis. The large abductor of the fin extends at right angles to the longitudinal axis of the body, following the dor.sal half of the equator of the abdomen to its origin in the liypodermis of either side. Two other fin muscles extend obliquely from this organ backward toward the median line, in the liypo- dermis of which they take their origin. The insertion of all the fin-muscles is in the
•^70
AYEKS OX TlIK DEVELOPMENT
hvpoilermio colls of tho ]i;ul. In tlio nu'dian dorsal line of the abdomen, in a plane parallel with tho ilorsal lin musolo. is a band-shaped nuisole which serves to flex the abdomen towards tho head. The remaining mnsclos are smaller than those mcnti i i il(A( an without exception are confined to the abdominal region. In pi. 21, fig. 2G, ai'e shown four abdominal muscles which, when viewed from behind, form a rectangular figure about the mesenteron. PI. 25, fig. 10, is a transverse section showing the adductor of the mandible near its posterior margin and its manner of origin and insertion. The striated appearance of tho muscle fibres is shown in pi. 24, fig. 28. PI. 25, fig. 12, illustrates the manner in which the abdominal muscles are inserted into the body wall.
As ha.s been stated, the alimentary tract of the first larva became indistinguishable from the surrounding cell mass as the larva passed into the second stage, but already the stomo- daeum had opened into the mesenteron so that at the beginning of this stage the larva is furnished with as complete an enteric cavity as is present in many insects that are not doirraded by parasitism (c. g. carnivorous larvae of Myrmeleon etc.), and there is a resem- blance between .such larvae and the second larva of Teleas which is even more than super- ficial. The enteric cavity consists of a blind sac in the course of which there are two enlargements, one terminal, the other (pi. 24, figs. 23 and 25), near the suboesopha- geal ganglion and probably near the point of union of the stomodaeum and mesenteron. If this conjecture is correct, this enlai-gement is homologous with the proventriculus of other insects. This second enlai-gement is not always sharply limited. The enteric sac is a cel- lular membrane (pi. 24, figs. 23, 25 ; pi. 25, figs. 1, 7, 8, 17) in which the large, polygonal, thin-walled cells are closely united ; each cell contains a spherical nucleus, central in position, with a varying number of nucleoli, one of which is much larger than the others. The mesenteron or abdominal portion of this enteric cavity is retained in its place by pro- toplasmic filaments which reach out and coalesce with similar processes from the hypodermic and muscle cells, pi. 25, fig. 1. No muscular fibres are to be distinguished in the enteric tract, but contractile motions are sometimes seen, especially in the anterior portion. The oesopha- gus, after passing through the space between the large mandibular muscles and the circum-oesophageal ring of the nervous cord, passes into a depression of the ventral sur- face which is continuous with the furrow in the anterior face of the lower lip. (PI. 25, fig. 19.) Sections through the thoracic and abdominal regions (pi. 25, figs. 10, 11, 13, 14, 17) show that the cells of the mesenteron are closely connected with the hypodermal layer and the ventral stripe, but that later the enteric tract becomes entirely separated and is joined to them only by the protoplasmic filaments. Tlie procto- daeum arises as an invagination in intimate connection with the posterior end of the abdominal nerve plate. The hypodermis, wdiich, like the enteric tract, is a single-layered sheet of cells more or less fused together, lies in close contact with the inner surface of the cuticula and in its primitive condition is a syncytium, the protoplasm of which is finely granular and contains nucleolated nuclei. Subsequently walls appear about all these nuclei thus forming the polygonal cells of the hypodermis. It is probably while in the syn- cytial condition that the cuticula Ls secreted, since tliere is no ti-ace of the outlines of the cells such as would probably appear on the inner surface of the layer if such cell walls existed. The hypodermal cells are o* \bout the same size as the cells of the mesenteron. This layer at its posterior termination opens into the cavity of the caudal appendage so
OF OECANTIIIS AND IKI.PIAS. 271
tliiit the protoplasmic lluids of tlu- l)U(ly cavity can pass freely into tlie Imiu'ii of this appendage. The salivary glands were not detected in any of the living parasites, hut on transverse sections of this stage they are fonnd in various degrees of development. They arise as solid rods of mesodennic elements in which a small hut gradually increasing lumen early makes ita appearance. (PI. '2o, fig. 17.) These rods are derived from the lateral edges of the ventral stripe, and lie one on each side of the incompletely developed nervous cord, which at this time they appro.ximate in size.
At the beginning of this stage the ventral stripe was seen in its primitive state as a hiyer of enlarged hypodermal cells along the median ventral line. These cells, together with the mesodermic elements, .soon form hy a rapid proliferation a thick, ventral cell plate or bed. The derivatives of the hypodermal cells are from this time on to be distinguished from the me.sodermic elements. Tljc hypodermal cord is more and more differentiated, until it becomes sharply defined from the surrounding mesoderm. It exhibits an enlarge- ment at each end, and at one-third of the distance from the cephalic end a less conspicuous swelling, while between this latter and the head end it forms a ring aroun<l the oesojdiagus. The cephalic termination is the primitive brain mass. (PI. 20, figs. '.), I'J ; pi. 24, figs. 23, 25.) The abdominal enlargement consists of the last abdominal ganglion and the se.xual cells, and is in close connection with the proctodaeum. The middle enlargement is the suboesophageal ganglion and lies in the depression formed by the folds of the lower lip, onlv a short distance l)ehind the oesophageal ring. The brain mass consists of a cortical layer of spindle-shaped cells with their long axes arranged in a manner radial to the centre of the mass. The central portion of the brain region in pi. 24, fig. 23, represents a surface view of these elongated cells, which consequently appear round. The central ma.ss is com- posed of small, irregularly disposed, and frequently ill-defined cells. The brain varies much in shape even in individuals of the same degree of development ; it may he oval or quadrangular on side view, and its dorso-ventral axis is usually greater than its longitudi- nal. It is continuous on its ventral face with the nervous cord, which divides soon after leaving the brain to form the oesophageal commissure. The commissural cords unite .soon after passing the oesophagus and enlarge into the suboesojihageal ganglion. (PI. 24, figs. 23, 25; pi. 25, figs. 18, 19.) The latter is circular in transverse section, long oval in longitudinal section. It lies between the cup-shaped cuticular structures, and in the cavity formed between the folds of the lip. From this ganglion the cord extends along the curved outline of the ventral wall of the body and enlarges into a pyriform mass which near its midtUe point is curved upwards around the end of the mesenterou. From the up- curved end of this fold the germs of the sexual organs are budded off as a varying number of cells (2 — 6) imbedded in a homogeneous protoplasm. They appear in sections of hard- ened specimens as though formed endogenously within the substance of the still persisting mother cells. (PI. 25, fig. 11.) In pi. 25, fig. 13, is shown a section of one of the primi- tive sexual masses. The section passes through three cells of similar size. One of these shows within its cell wall two spherical cells, within which is contained all the proto- plasm of the mother cell. These derivative cells have definite cell walls and a distinct nucleus, indicating their origin by endogeneous cell formation. The different shapes of the sexual germs are seen by comparing pi. 24, figs. 21, 23, 25, 26, 30, and pi. 25, figs. 1-5, 11, 13, 16, 18. During this stage they become entirely separated from the nej>
o-o AYKUS OX THE DEVELOPMENT
voiis cord, hilt are oonnectod to the blind end of the mesenteron by protoplasmic filamont^, usually one to each mother cell. The invaguiation of the proctodaeum, the walls of which are intimately connected with this mass, was not very satisfactorily made out. since its lumen can only rarely be obsei'ved (pi. 25, fig. 13), and never with the distinctness shown in Ganin's figures of Platygaster. The size of the nerve cord con- nectinc the posterior enlargement with the suboesophageal ganglion varies much in diQorent individuals, the abdominal portion being sometimes of the same diameter as the latter. The cells forming the cortical layer of the abdominal enlargement possess the same characters as the cells of the corresponding layer of the brain mass. The poste- rior enlargement is usually lobed ; bi- and trilobed forms being of most frequent occurrence. Nothing that could be interpreted as periplieral nerve fibres has as yet been differentiated, but the protoplasmic filaments which throughout the body are stretched between the mesenteron and body wall may possibly serve to transmit the nervous impulses to the muscles and to the cells of the enteric tract. No nuclei could be distinguished in these protoplasmic filaments, so common throughout the body, and their contractile nature was not determined with certaint}'.
This stnge closes the history of the development of the parasite up to date (April 1st). I have not as yet observed the ovate, flattened form which succeeds the cyclops stage in the development of other species of the Pteromalidae, but specimens which were apparently approaching this stage were found in two instances. This was indicated by their greater flat- ness and the proportionate increase in the size of the abdominal over that of the head region. The abdominal region in this stage exhibits no traces of division into segments. The number of ecdyses is unknown. There are at least four, but how many more there may be it is impossible to state.
Explanation of the Plates.
The following letters are used consistently in explaining the figures of Oecanthus and Teleas.
ab. abdomen.
ah.c. abdominal constriction.
ahp. first abdominal appendage.
a.c. amoeboid cells.
ad. corpus adiposum.
alb. albuminoid body.
am. amnion.
an. anus.
ap. append.age.
a.s. anal stylet.
at. antenna.
at.l. antcnnal lobe.
Ji. brain.
b. body wall.
b.c. body cavity.
b.cp. blood corpuscle. b.f. brain fold.
bl. bbistoderm. b.s. blood sinus.
|
c. |
c. |
cuticula. |
|
ca. cap. c.b. |
cavity. c.nudal appendage cell wall. |
|
|
c.c. |
cross commissure. |
|
|
ce. |
cell. |
|
|
ch. |
chorion. |
|
|
cl. |
claw (onychium). |
|
|
cp. |
corj)us luteum. |
|
|
cp.th |
cephalo-thorax. |
|
|
D. |
d. do. |
corpuscle, dorsal. |
|
E. |
e. ec. |
eye. ectoderm. |
|
ef- |
" Endfadcn," tern arium. |
|
|
en. |
endoderm. |
|
|
ep. |
epithelium. |
terminal filament, germ-
e.pff. eye pigment spot.
OF OECANTirUS AND TELEAS.
273
F. / foot. f.c. fat cells. fd. fold.
fg. tl:i<;ellura.
f.k. foruliL-ail.
fjii. fijlsc ineiiibrane.
f.o. fin organ.
fr.nl. free nucleus.
fa. facets.
G. g. ganglion.
g.(i. genital armature.
g.b. germinal band.
g.c. germinal (sexual) cell.
g.ce. ganglionic cell.
g.p. granular protoplasm.
gr. groove.
g.v. germinativc vesicle, egg nucleus.
g£, granular zone.
II. h. head.
h.g. lieacl groove.
ht. heart, dorsal vessel.
hy. hypodermis.
I. 1(7. indifferent protoplasmic substance.
in. median invagiuated part of the nervous system.
K. T<f. head fold (Kopflappen).
L. /. lumen (in Teleas, lii)).
Ih. lobe.
Lc. longitudinal commissure.
l.f. lateral furrow.
l.fd. lateral fold.
lig. ligament.
Ip.f. lip furrow.
M. M. mesoderm.
m. mieropylar apparatus or end.
w*. first maxilla.
tn^. second maxilla.
fn}.p. m* palpus.
m-.p. m--pal)>us.
md. mandible.
mes. mescntcron.
m.f. median furrow.
mo. mouth.
m.p. median partition.
mpg. Malpighian tube.
m.s. median cord of nervous system (Mittel-
strang). mt. mesentery. mu. muscle.
N. n. nerve.
■n.c. nerve cord.
nl. nucleus.
nV-. nucleolus.
nl.f nuclear fibres.
nl.fl nuclear fluid.
nl.m. nuclear membrane.
rd.n. nuclear nodules.
nl.jy. nuclear plate.
nl.s. nuclear substance.
URMOItIS HOST. 60C. HAT. niST. VOL. m.
o.
0. ovariolo or, pi. 18, head cavity. o.c. ovarian or egg chamber.
oe. oesophagus.
oe.c. oesopliageal comniissuro.
oe.in. oeKo])liageal invagination.
01. oj)tic lube. o.n. ocellar nerve. ov. ovunu
ft. polar corpuscle.
p.a, polar aster.
J).C. cheek pad.
pe.v. j»eritoneal vessel or sinus.
p.f. |iriinitive furrow.
ji.fd iiriniitive fold.
jt.fd.d. primitive abdominal fold.
jt.fd.in. j)riMiitive ma.xillary fold.
/)^(/.<. primitive thoracic fold.
pig. jiigrnent bodies.
pr. procloilaeum.
prov. proventriculus.
ps. jiseudopodia; protoplasmic filament*.
R
T.
U. V.
|
pt. pt.e. |
partition. e])ithelial partition. |
|
r. |
rectum. |
|
'•/• |
radiating fibres. |
|
8. |
serosa. |
|
8C. |
scales. |
|
aeg. s.g. s.i. |
segment, s.alivary gland, intercellular space. |
|
sA: |
invagination of ectoderm to form head |
|
skeleton. |
|
|
so.m. |
somatic mesoderm- |
|
sp spa. sp.f. sp.m. |
space, spindle, spindle fibres. s])lanchnic mesoderm. |
|
s.s. |
lateral cords of the nervous system |
|
St. |
(Seitenstriinge). stomodaeum. |
|
sub. |
suboesophageal ganglion. |
T'. y first, second, and third thoracic appen-
jT*. ) dages.
t. tunica propria.
ta. tail.
t.b. tail body.
t.c. thoracic constriction.
t.f. tail fold.
(h. thoiax.
(i. tip of abdomen.
tr. tracheae.
tr.f. transverse furrow.
u.l. upper lip.
V. vacuole. ve. ventral.
vt. vitellariura, chambered part of the ova- riole.
yl. yolk.
yl.m. membrane of yolk sac.
yl.s. yolk sac.
274 AYERS ON THE DEVELOPMENT
S. primitive unpaired organ (motastonuim). ;^. pleural structure (gill-pad).
A. dorsal organ. /i. cup-shaped organ.
PLATE XVIII.
Fiw. 1. The voun<Test observed germinal band of Occanthus uiveus. The serosa is not yet formed. X '-3. (The efl'j is magnified only lo diameters.)
Fis;. 2. Longitudinal optical section (diagrammatic) of fig. 1.
Fi«'. 3. The sierminal band after the appearance of the head fold, which is indicated at this time by the more rapid growth and consequent greater breadth of the lower end of the embryo. X 25.
Fi<T. 4. A vouH'T embryo of Oecanthus after the a]>pearance of the primitive segment folds. X 50.
Fi'T. 5. A more advanced embryo, with t!ic antemial folds distinctly marked off. The free ends of the primitive folds have united across the embryo posterior to the antennal folds. X 50.
Fio'. 6. Deep, or primitively he.ad, end of the egg after the formation of the serosa. X 25.
Fi"^. 7. Upper lip and antenna of a somewhat older embryo. X 100.
Fi^'S. 8 9. Ventral and side views of the embryo with the appendages sprouting out. X 25. In its natural conditions the embryo, having reached this stage of development, remains dormant for six months on account of the cold of winter.
Fit. 10. Ventral view of the tip of the abdomen of the st.age figured in fig. 13. The large cells of the amnion cover part of the embryo. X 50.
Fi". 11. Ventral view of another embryo. Acetic acid carmine preparation, x 50.
Fifs. 12 13. Lateral and ventral views of an embryo more advanced than that shown in figs. 8 and 11, X 5o!
Fi'» H. Camera outline of the head region of the stage represented in fig. 11. Shading diagram- matic. xl25.
Fi"'. 15. Head of an embryo, somewhat older than fig. 8, in which the invagination at the base of the antennae to form the internal skeleton of the head is well advanced. Acetic acid, carmine, glycerine preparation, x 125.
Fig. 16. A portion of the oesophagus near the mouth showing the salivary ducts united into a common tube. X 65.
Fi<T3. 17, 19. Ventral views of two embryos of nearly the same age. . Chromic acid preparations, x 50.
Fig. 18. Side view of another embryo of about this stage, x 65.
Fi''. 20. An embryo with the abdominal flexures straightened out. Chromic acid preparation. X 50.
Fig. 21. The appearance of the embryo in ventral view just before revolution. Sodium chloride preparation. X 50.
Fi». 22. An embryo in which the lobation of the mouth parts has begun. The abdominal region is carved upon itself while the proctodaeum forms another curve, projecting into the yolk. The amnion extends as far as the anal stylets. Osmic acid preparation. X 65.
Fif . 23. Lateral view of the head, maxillary and thoracic regions of another embryo of about tliis stage- Chromic acid preparation. X 75.
Fi". 24. Optical section of an embryo with three folds of the ectoderm projecting into the head cavity These thickenings lie at different depths, respectively 0, 1, 2. X 75.
Fi". 25. Dorsal view of the end of the abdomen of an individual showing the projecting tips of the a. a X 50.
Fig. 26. An oblique dorsal view of the proctodaeum of a younger individual. X 50.
Fig. 27. Ventral view of the abdomen and j)roctodaeum of an embryo. X 75.
Fig. 28. The "gill-pad" structure, -i, highly magnified ; partly diagrammatic. X 225.
Fig. 29. Optical section of the end of the abdomen and proctodaeum of an embryo before revolution. X65.
Fig. 30. The tips of a foot and an antenna, showing the cuticula as a loose sac enclosing the appendage. X 50.
OF OECAKTIIUS AND TELEAS.
PLATE XIX.
Fig. 1. Dorsal view of an embryo showing the relations of the ";^ill-]>aJH," i, to the body. X f>0.
Figs. 2, 3. Lateral and ventral views, resjiectively, of the wauje embryo in titu. X ^W. The enibrjo has almost eomi>leteil its revolution. The abdominal flexures liave dlsapjieared so that tlie ]>roetodaeum now projects into the yolk and lies dorsad to the nervous cord.
Fig. 4. An embryo in which the yolk has all i).issed into the mcscnteron. The remains of the yolk sac (serosa) are seen as a jiiug-like cylinder, continuous with the mesenteron but still jirojeeting beyond tlie region of the body wall. The stoinodaeum and i)roetodaeum have united with the mesenteron. Tlie Mal- pigliian tubes are Biirouling out from the proctodaeum. The "gill-|>ads" have disapiieared ; the thoracic appendages and the mouth parts are confined to the now much narrower ventral area. X ^W-
Fig. 5. An embryo, some time aller revolution, in which the nusoderm plates have coalesced in the median dorsal line. The opening into the yolk sac is nuich reduced. X ^^•
Fig. 6. Frontal view of the lobes oi the bi'ain, which are not yet united. From an embryo in clove oil. X 50.
Fig. 7. Frontal view of the mouth parts (labrum, first and second maxillae, — the mandibles lie beneath the maxillae) after the closure of the dorsal wall. X 65.
P"ig. 8. The mouth parts of another individual near this stage, dissected out to show the lobes of the first and second ma.xillae. X ^^•
Fig. 9. The three thoracic ganglia dissected from an embryo at this stage. Acetic-acid carmine, balsam preparation. X -100. The cross commissures in the lower ganglion are filled iu from another specimen,
Fig 10. Frontal view of the brain and suboesophageal ganglion in situ, showing their connection by the commissural cords. From an embryo treated with osmic acid, picro-carmine, clove oil, balsam. X l-i>.
Fig. 11. Optical section of the germinal ijaiid of Occanthus in the sagittal plane, showing tlie relations of the cells in the free state. X ^60.
Fig. 1*2. The corpus adiposum and i)igmeiit bodies of the right half of one of the abdominal segiaents of the embryo fig. 1. X I'-S-
Fig. 13. The free end of the stomodaeura after its lumen has opened into the mesenteron, to show its structure. The ej)itlielial layer is thrown into six folds, while the muscular layer surrounds this thickest portion by a very thin layer of cells. X "iOO.
Fig. 14. A portion of the antenna of au embryo at\er hatching showing the spines as cuticular out- growths, one to each cell. X 1-5-
Fig. 15. Dorsal aspect of the left anal stylet from the same embryo with its balloon-shaped organ and the hairs. X 65.
Fig. 16. The balloon organ from the above, showing its peduncle. X 100.
Fig. 17. A ventral view of the embryo at the time of revolution, the gill-pad should have been repre- ented as though seen through the body. X 65.
PLATE XX.
Fig. 1. Occanthus. An ovariole dissected in osmic acid, stained in picro-carmine. X 160. Fii's. 2 and 3. Ovarioles of Occanthus prej)ared in sodium chloride, glycerine. X 160. Fig. 4. A follicle of Occanthus from a sodium chloride, picro-carmine, glycerine preparation. X 85. Fig. 5. The upper end of an ovariole of Periplaneta sp. from a dissection in osmic-acetic solution, hard- ened in alcohol ; balsam preparation. X 400. Fig. 6. An ovum from the same. X 800.
Fig. 7-10. Four consecutive stages in the revolution of the embryo. X 15. I. At the time of the fusion and rupture of the serosa and amnion. II. After the head of the embryo has passed through the rupture.
III. The body of the embryo lies curved in the bottom of the egg; the abdominal fle.\ure still persists. The amnion covers only the latter part.
IV. The embryo has completed the revolution, and the serosa has contracted into a thick-walled sac, but has not changed its position. The amnion has turned inside out an<l now forms the dorsal and ]>art of the lateral walls of the embryo. The proctodaeum and stoinodaeum are enclosed between the dorsa
276 AYERS ON THE DEVELOPMENT
and ventral boily-walls. The embryo is now hciitl uppermost ami faces in the opposite direction to what it did before rovoliitiou. It requires about '21 hours with a temperature of 70° F. to accomplish the change.
Fig. 11, Micro]>ylar end of the living egg in its natural condition. X 125-
Fig. 12. Germinative vesicle of Oecanthus in which the nuclear membrane has been ruptured by the dissecting needle. From an acetic acid, glycerine jncitaration. X 5G0.
Fij. 13. Surface view of the follicular cjnthclium of an ovariole of Acheta prepared in silver nitrate. X i'>t!0.
Fisrs. 14-17. Surface views of the follicular epithelium of an ov.ariolc of Oecanthus, from successive follicles, illustrating yolk formation by nuclear degeneration. X 560.
Fig. IS. Segment of a se<!tion of an ovariole of Acheta abbreviata. Prepared in gold chloride, glycerine. X 560.
Fig 19. Nuclei in process of division from the follicular epithelium of Acheta. The ovariole was pre- pared in gold chloride, alcohol, balsam. X 560.
Fig. 20. Follicular epithelium from an ovariole of Acheta abbreviata prepared in gold chloride and glycerine. X 300.
Fig. 21. Ojitical section of the membranes of a fresh egg;0, blastoderm; 1, vitelline membrane; 2, inner-chorion ; 3, outer-chorion. X 400.
Fig. 22. Frontal view of the brain in situ, showing the outgrowing nerves. X 50.
Fig. 23. Lateral view of one of the lobes. From an embryo in clove oil. X 50.
Fig. 24. Optical longitudinal section of the antenna of a young embryo showing the median mcsodermio partition.
Fig. 25. Longitudinal section of the terminal filament, or germarium, of an ovariole of Oecanthus, from an osmic acid dissection. X 600.
Fig. 26. Longitudinal section of the germarium of Oecanthus near its junction with the vitellarium, or follicular portion of the ovariole. X 560.
Fig. 27. Optical section of the smaller part of the vitellarium of Oecanthus, from a hydrochloric-alcohol prep.aration. X 160.
Figs. 28, 29. Two ova of Oecanthus in which the germinative vesicle has come to the surface preparatory to its disappearance. The vesicle lies in contact with the vitelline membrane. Fig. 28 X 30 ; fig. 29 X 25
Fig. 30. A cell from the follicular epithelium of an ovariole of Oecanthus niveus, in which the original nucleus has given rise to three others. X 560.
Fig. 31. A serosa nucleus immediately after division. Acetic-acid carmine. X 560.
Figs. 32 and 34. Serosa cells treated with acetic acid carmine. X 560.
Fig. 33. Four serosa cells of Oecanthus treated with acetic acid carmine. X 600.
Fig. 35. Endodermic or j'olk nucleus in the uninjured egg; the granules were streaming in the direction indicated by the arrows. X 800.
Figs. 36, 37, 38, 42 and 44. Free cell elements from the yolk of an egg of Oecanthus in which the ger- minal band was formed. They are the nuclei of yolk cells. Treated fresh with osmic acid, stained in Beale's carmine, mounted in glycerine.
Fig. 39. Three papillae broken off the micropylar cap. The central lumen tapers to a point near the ex tremity of the papilla. The fine lines radiating from the lumen give it a plumose appearance. X 500.
Fig. 40. Surface view of a ])a2)illa showing a groove on its upper surface. X 600.
Fig. 41. Yolk nucleus. IICI. acohol solution, alum carmine, mounted in balsam. X 560.
Fig. 43. Three albuminoid masses treated while fresh with 0.25 % osmic-acetic acid solution, stained in picro-carmine, mounted in benzole-balsam.
Figs. 45, 46. Lateral and dorsal views of the mandible at the time of hatching. X 65. Fig. 47. Surface view of the eye of Oecanthus soon after hatching. X 125.
Fig. 48. Eight germinative vesicles of Oecanthus and Acheta, one of them from an acetic acid prepara- tion, the others from gold chloride and glycerine pre])aratious, all magnified about 300 diameters.
PLATE XXI.
Figs. 1, 2, 3, 4, 6, 7, 13. Serosa nuclei treated while fresh with osmic acid, stained in Beale's carmine, mounted in glycerine. X 1000.
OF OECANTHUS AND TELE AS. 277
Figs. 5, 11 and 12. Sections of yolk nuclei from osmic-acetic acid prt-parationit, Htained in picro-rarminc, mounted in benzole-bals.iin. X ^00.
Fig. 8. A nucleus from the cells of the follicular eiiithelium of an ovariole of Occantlms. Chromic ai-id preparation. X300.
Fig. 9. Yolk nucleus fresh in clironiic aciil, Heale's carmine. X ^00'.
Fig. 10. Five yolk nuclei from a fresh preparation of an Oecanthus egg.
Figs. 14-17, -0. Nuclei of serosa cells treated while living witli acetic-acid carmine. Fig. 20 shows the cell wall.
Figs. 18, 19, 21, 22. Free cell elements from the yolk of an egg of Occantlius in which the germinal band was formed. They are tlie nuclei of the yolk cells. Fresh in osmic ncid, stained in Beale's camiioe, mounted in glycerine. X ^'^0.
Fig. 23. Section of an unfecundated egg. IICI. alcoliol solution, neutral cannine. X 15.
Fig. 24. Part of a section tlirougli an ovarian follicle of Oecanthus, jirejiared in hydrocliloric alcohol stained in picro-carniine, benzole-balsam. X 5G0.
Fig. 25. Transverse section of the germarium of Oecanthus. X 560.
Figs. 26, 28-30. Sections of an ovariole of Oecanthus j)assing through the germinative vesicle ; fi-om a dissection in sodium chloride, staine(l in picro-carmine, mounted in balsam and benzole. X 500.
Fig. 27. Section of a young germinative vesicle extracted from its follicle. X 500.
Fig. 31. Transverse section of an egg of Oecanthus after the appearance of the blastoderm and yolk cells. X 65. Hydrochloric alcohol, alum carmine.
Fig. 32. Section tlirougli the abdominal region of an embryo after the complete closure of the dorsal wall. The section ]iasses through the ovaries of both sides. X 125.
Fig. 33. Section through the dorsum of an embryo before the closure of the dorsal vessel. The heart is seen as two cavities'in the ascending edge of the mesoblastic plates. X 500.
Fig. 34. Cross section after the appearance of the fully formed dorsal vessel. X 100.
Fig. 35. Section through the dorsum before the union of the two mesoblastic plates.
Fig. 36. Section through the dorsal vessel in the thoracic region. X 250.
Fig. 37. Section of the stomodaeum near the mouth. X 125.
Fig. 38. Mesodermic structures from the body cavity of the same individual from which fig. 41 was taken. These structures may possibly be the hoinologues of the segmental organs of worms. Xl25.
Fig. 39. I'rontal section of the nervous cord in the maxillary and mandibular region, showing the fusion of three pairs of ganglia to form the suboesoph.ageal ganglion, x 125.
Fig. 40. Section of the ventral nerve cord in the abdominal region. X 250.
Fig. 41. Section through the maxillary region of an embryo with a fully formed dorsal vessel. The nervous system is cut across in four places. X 65.
Fig. 42. Section of the egg of Oecanthus with a young blastosphere of Telons in situ. From an oemic- acetic acid, picro-carmine, balsam preparation. X 100.
Figs. 43-46. Nuclei from the follicular epithelial cells of an ovariole of Oecantlius. Osmic and chromic acid, Beale's carmine. X 1000.
Fig. 47. A yolk nucleus exhibiting interesting conditions of nucleolar structure. X 160.
Figs. 48-50. Same as figs. 43-46.
PLATE SXII.
Fig. 1. Longitudinal section of an embryo shortly after revolution. The serosa cells by a process of degeneration set free their large nuclei ; these pass into the mesenteron and the body cavity and there undergo various changes. By an endogenous process each nucleus in the body cavity furnishes from two to three nuclei which, on liberation from the membrane of the mother nucleus, become blood corpuscles. In this stage the sexual organs are seen as a pair of elongated cell masses in connection with the heart X 65.
Fig. 2. One of the nuclei from the fibrous portion of the brain, showing its relations to the fibres, x 560.
Fig. 3. One of the serosa nuclei from the body cavity. X 250.
Figs. 4 and 5. Two stages in the development of the sexual organs. Fig. 4 represents the cell mass before it begins to elongate. Fig. 5 represents the same after taking on the general shape of the future
278 AYERS ON THE DEVELOPMENT
ovary. Within an importcct luraen are seen several cells, liirgcr than their fellows with peculiar bar-shaped nucleoli. These are the germs of the ova. Fig. 4, X 300 ; fig. 5, X 2r)0.
Fig. 6. The relations of the fibres of the longitudinal and cross commissures of one of tlie thoracic seg- ments nt this stage. X 500.
Fig. 7 Three pairs of large granular nuclei from the three thoracic ganglia of fig. 1. X 250.
Fig. 8. Cross-section of an ab loMiiual ganglion showing a triangular remnant of the middle cord. The two Seitenstriinge have not coni])letely united. X 125.
Fig. 9. A portion of the splanchnic mesoblast and its lining endoderm, from the region of the procto- daeum of fig. 1. X 250.
Fig. 10.' Section of a fully formed dorsal vessel. The section is taken from the head region. X 250.
Fi^r- 11. Section through the maxillary region of an embryo with the dorsal wall fully closed. X 125.
Fig. 12. Section of the lieart from the .abdominal region. Two nuclei are seen in the walls of the vessel. These are the nuclei of the two cells which compose the vessel in this section. X 250.
Fig. 13. Section of an embryo after revolution, in the region of the thinl thoracic ai)pendage. The gill organ is cut through at its union with the body wall. The cavities extend the entire breadth of the organ and are irregular both in size and in their course. X 125.
Fig. 14. Section of an embryo p.assing through its gill organ. X 125.
Fig. 15. Section of tiie oesophagus near its termination. X 150.
Fig. 16. Section passing through the commissural cords before their connection with the suboesophageal ganglion. X 250.
Fig. 17. A portion of the outer lobe of tlio right maxilla. X 250.
Figs. 18-22. Successive sections of an embryo before revolution, passing through the proctodacum and through the flexures of the abdomen. Osmic-acetic acid preparation, stained in picro-carmine, mounted in benzole-bals.am. X 50.
Fig. 23, 24. Sections of the same embryo through the first pair of maxillae and the antennae, respec- tively.
Fig. 25. Longitudinal section of an embryo. X 40.
Fig. 26. Section through the abdominal region of this stage. X 125.
Fig. 27. Transverse section of a germinal band of Oecauthus near the age shown in pi. 18, fig. 5.
Fig. 28. Transverse section of the germinal band very soon after the appearance of the mesodermic cells. X 100.
PLATE XXIII.
Fig. 1. Transverse section through the mandibular segment of an embryo after the closure of the dorsal wall, showing the invaginations for the salivary gland and trachea of left side of this segment. X 125.
Fig. 2. Section of another embryo between the mandibles and first maxilla. The section passes through the anterior part of the dorsal " plug " of the mesenteron, which has passed completely within the body at this stage. On either side of the he.art are seen two continuous tubes. X 125.
Fig. 3. Transverse section through the supraoesophageal ganglion. X 125.
Fig. 4. Transverse section of the oesophagus in the maxillary region. X 125.
Fig. 5. Transverse section of the abdomen passing through the proctodaeum at the point of origin of tha three Malpighian tubes. These primitive tubes bifurcate soon after leaving the body of the proctodaeum. X 65.
Fig. 6. An oblique transverse section of the the brain. X 125.
Fig. 7. Amoeboid cells found in the yolk previous to the formation of the blastoderm. Some of these cells go to the surface while others remain in the yolk and form the endoderm and mesoderm. These are taken from fig. 31, ]>\. 21. X 800.
Fig. 8. Transverse section of a germinal band of about the same stage as fig. 3, pi. 19. The amnion is seen on either side of the band as a few small cells closely pressed u])on the ectoderm. X 800.
Figs. 9-12. Sections through the thoracic and abdominal regions of tiie embryo to show the manner of invagination of a median element to form a part of the nervous system. Osmic acid, balsam preparations. Figs. 9 and 11 X 125 ; figs. 10 and 12 X 250.
Fig. 13. Transverse section through the head at the stage represented in pi. 18, fig. 17, passing through the oesophagus and upper lip. Osmic acid preparation. X 225.
OF OECANTIirS AND TKLEAS. 279
V\<^. 14. Several 9pin<lIo-shape<l cctoilerin colls from near V, fig. 13. Uii'ler a low iiower tli»< lar^rc ov;il or spherical nuclvi are easily mistaken for cells. X 660.
Fig. 15. A slightly ol)lii|iu', tninsverMe seetion through the anterior part of tho brain of an individual near the st.ige fiLrured in pi. 19, lig. 5. Osmic acid, jiicro-rarMiine, balsam preparation. X 1125.
Fig. 16. Section through the eyo at this stage, x -50.
Fiifs. 17, 18, 19 and "iO. Nuclei. Fig. 19. iVti endoilertnic nucleus. The others are nuclei from ovarian epithelium of <^)ec:intlius.
Figs. "21, 2'J. Surface view and optical section of a blastospherc of Tele.-w in which the germinal band has made its apjiearance. Shading in tig. '.il diagranunatic. X 1""-
Fig. '23. Optical section of a younger blastosphere. No cells are seen except those composing tho single-layered wall. X 1-5.
F^ig. 24. Optical section of a blastospherc with the primitive fold partly differentiated, if, the head region of the tojcl. J/, :i ])atch of mesoderm cells immediately beneath tho ectodenn. X 1*25.
Fig. 25. An unknown parasite tbund in the egg of Oeoantlius niveus. h, the head end lying in contact Tvith the vitelline membrane. The body wall in the abdominal region was pushed out into three finger-like processes. X 100.
Figs. 26-30. Different views of the same blastosphere in the uninjured egg of Oecanthus. Figs. 27 and 28 are optical sections of the blastosphere in a plane grazing the uj-per surface of the germinal band ; fig. 26. frontal (ventral) view of the germinal band; fig. 27, lateral view; fig. 28, an oltliipic dorsal view. In tig. 29 the posterior termination of the germinal banil is shown. Fig. 30, nearly the same aa fig. 29, but more oblique to the dorso-ventral axis.
Fig. 31. A young blastosphere in its spherical mass of protoplasm. X 125.
Figs. 32, 33. Blastospheres on the surf.ace of which the primitive fold has appeared. The segmentation cavity is partly filled by the mesodermic cells. X 125. In fig. 33 amoeboid cells are shown.
Fig. 34. Ectodermic cells from dit!erent blastospheres. A. treated with osmic-acetic acid solution followed by picro-carmine ; B. a single cell much larger than the others. Acetic acid carmine, glycerine pre]iaratioii ; C. surface view of cells in situ. Beale's carmine, glycerine preparation; D. from an acetic-acid carmine, glycerine preparation. All X -50.
Fig. 35. A section of the blastosphere figured in ]>!. 21, fig. 42. X 800. The thinning is probably caused by reagents.
Fig. 36. Blastosphere collapsed by reagents in a manner resembling a gastrular invagination. X 125.
PLATE XXIV.
Fig. 1. An egg of Oecanthus with the three stages of Teleas in situ. X 30.
Fig. 2. Side view of a well advanced first, or spindle-shaped, larva. There is a thinl prominence between the frontal and mouth promontories. Four of the teeth at the base of the caudal ap])endage are arranged in pairs. There are five incomplete girdles of s])ines. Osmic acid preparation. X 125.
Figs. 3 and 4. Two views of a cylindrical larva near the stage shown in figs. 8 and 9. X 125.
Fig. 5. Cephalic portion of a spindle-shaped larva. The frontal process is seen to be filled with gran- tilar protoplasm ; the mandibles and tlieir muscles are well developed. Acetic acid preparation. X 500.
Fig. 6. Ventral view of the same showing the manner in which the oral muscles radiate from the mouth opening. On either side the body are seen the cuj)-shaped organs. X 500.
Fig. 7. Side view of the cephalic portion of another larva showing the segmental constrictions in the course of the enteric canal of this part. X 125.
Figs. 8 and 9. Side and ventral view of another larva. The mesenteron and stomodaeum have not yet united. Behind the enteric mass of cells is seen the germ of the sexual organs. The ventral band is seen a* a thickening of the hypodermis limited to the middle of the larva. X 125.
Fig. 10. End of the abdomen of another larva, bearing the caudal appendage and seven, short, stout spines. The hypodermic nuclei indicate the termination of the cell elements in this region. The caudal appendage is filled with a finely granular protoplasm and at its tip is covered with bristles. X 800.
Fig. 11. View of the enteric and sexual tract of a larva near the same degree of development as those shown in figs. 3 and 8. X 125.
Fig. 12. A larva with three greatly developed spines. They are placed between the girdles of bristles and are nearly equal in size to the caudal spine. X 65.
280 AYERS ON THE DEVELOPMENT
Fiipi. 13, 14. Side ami ventrnl views of another larva. The frontal process ends in an enlargement. The mosontoron :ui(l stomoilaoum are united. The wall of the blind end of the mesentcrou could not be distinguished in this si>eciinen. X 1-5-
Fig. 15. Side view of the cujvshaped organ of the larv.'i represented in fig. 19. X 200.
Fig. 16. Nuclei in the hypodermic syncytiiini of a larva. X 500.
Fie;. 17. An oblique ventr.il view of tiie mandibles and lower lip of another larva. X 150.
Fig. IS. Lateral view of the end of the caudal appendage. X 250.
Fig. 19. Ventral view of a larva soon afler entering upon the cy clops stage, to show the cuticular structures. X l'-5.
Fig. 20. Lateral view of tlie same, to show the muscular system. X 125.
Fig. 21. Second larva in which the nervous band and germs of the se.xual cells are not fully differen- tiated. The stomodacum and mesenteron are fidly formed but the proctodaeum lias not yet appeared. The muscular system is partially developed. X 125.
Fig. 22. Dors.al view of the s.ime individual, to show the dorsal muscles. X 125.
Fig. 23. Lateral view of the mesenteron and nervous system of another larva. X 150.
Fig. 24. Ventral view of the cuticular structures of the cephalo-thorax. X 125.
Fig. 25. Later.al view of a larva approaching an ecdysis. X 75.
Figs. 26, 27. Dorsal and posterior aspects of the genital cell mass of an individual in the cyclops stage X 60.
Fig. 28. Stri.ated muscle from the b.and-like muscles of the abdomen. X 500.
Fig. 29. Transverse section through the abdominal region. The abdominal appendage is seen in section, lying above the body. The nervous cord shows a distinct lumen and lies imbedded in a mass of hypodermic and mesodermic elements. X 150.
Fig. 30. The germs of the sexual organs from another embryo.
PLA.TE XXV. Figures 1-21 Tele.is. Figures 22-33 Oecanthus.
Fig. 1. Obliquely ventral view of a cyclops larva entering upon an ecdysis. The two swollen cuticular sacs near the fin organs illustrate the manner in which cuticula and hypodermis separate. X 150.
Fig. 2. The mass of nerve and sexual cells lying on the dorsal side of the mesenteron.
Figs. 3 and 4. Side and dorsal views, respectively, of the germs of the sexual organs. In fig. 3 the con- nection with the mesenteron is shown. X 125.
Fig. 5. Side view of the abdominal region of another larva showing the germs of the sexual organs still united to the nei-ve cord. They arc also connected to the mesenteron by the usual protoplasmic filaments X 75.
Fig. 6. Surface view of the cujvshaped structure from the right side of the same. X 250.
Fig. 7. Ventr.al aspect of the larva shown in fig. 1. X 150.
Fig. 8. The cells of the mesenteron seen from above. X 500.
Fig. 9. Lateral view of the larva with the nervous system well developed. X 125.
Figs. 10, 11. Sections of the larva, from osmic acid, picro-carmine, balsam preparations. Fig. 10. Trans- verse section through the mandibular region of the head. The mesenteron is intimately connected with the nerve cord. X 150. Fig. 11. Longitudinal section passing obliquely through the body. The germs of the sexual organs, the abdominal nerve mass and the surface of the mesenteron are seen in this section. X 75.
Figs. 12 - 17. Sections of the cyclops larva, from osmic acid, picro-carmine and balsam preparations.
Fig. 12. A portion of the cuticula of the abdomen showing the manner of origin of the mandibular mus- cles. X 250.
Fig. 13. Longitudinal section nearly parallel to the dorso-ventr.il axis of the body. The nervous cord ia seen ending in a thickened portion which is folded in an S-shaped manner. Lying dorsad of this and behind the mesenteron are seen the germs of the sexual organs. X 75.
Fig. 14. Transverse section through the abdominal region of a larva younger than that represented in fig. 5. X 75.
Fig. 15. Ilypodermal layer of protoplasm containing nuclei. X 500.
Fig. 16. Section of the germ of the sexual cells. X 250.
(iF OKCANIIII S \NI> I KI.KAS. '^81
V'lii. 17. Tr.'iiisviTse section iliroiigli the cfjihuln-ilionix i)o.-t(.'rior to tlie iitnuth u|K-ntii;;. Tin- salivary glariils arc scon nearly cut off from the central l)aiiil «f nicHoljlastic nn<l iiypoderniic elenient-H. Tlie nerve oonl is l)Ut sliiihtly differentiateil. X 2r>0.
Fi;;. l!^- Lateral view of tlie germs of the sexual organs and the inesentcron. x 1^"-
Fig. 19. Lateral view of the nervous system in the ce|.hal<>-thoracie region of tlie same stage, showing tin left half of the oesopliageal commissure. X l^'O.
Fig. 20. Fin orgiin of the same imliviilual. X 5"0.
Fig. -1. Dorsal view of the left half of the ccphalo-thorax of tlic same indiviilual.
Fig.--. Anal stylet of a female Oecanthus showing the balloon-sha|>ed organs on the inner muim.-i mi Us hasal portion. X 1-5.
"'■ '. 23. Tlirec of these cutienlar organs showing their p.irtJ>. X 12<'). . 24. A portion of the vagin.a. <i, the large mucous glands. X 05.
i m. 25. \ portion of the vaginal wall showing its muscles, a', >>', transverse and longitudinal til«i. -. ... the cells ot'tlu' lining e|>ithelinni. Xl25.
Fig. 20. .\u elder stem, the lower part of which is split open to show the relations of the eggs to the •ten). Above are seen the rows of circular openings, which are the mouths of the egg pits. Natural size.
Fig. 27. Section of the same, a, ra]i of wood and hark ghicd over the mouth of the j^it to keep out rain, etc. />, egg jtit uncovered, r, the position of the egg in the pit. X 5.
Fi". 2S. Side view of the cap.
Fig. 2'.>. Theoretical section ot" the first alulominal segment, illustrating the fi>rinatii>n of the gill pad X 211.
Fig. 3'J. Transverse section passing through the extern.al opening of the proclodacum. X ^'O. TIk- genital armature is developed from the edges of the fold, ff. a.
Fig. 31. Lateral view of part of the head and thorax of an embryo just before the closure of the dorsal wall. The i>hig of serosa cells (remnant of yolk sac) j)rojects.
Fig. 32. Camera outline of an embryo within the uninjured ag^r. The tail body is unusually large. X 25
Fig. 33. Surface of the micropylar cap from which the outer cap has been removed. X 25.
Fig. :U Tip of the right half of the ovipositor of Oecanthus. X -""O.
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EMBRYOLOGY OF (JECANTHUS ayers
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IX. Twi) .\i:\v AM) DiVEKSE Types or CAiiunxirEiior.s Mvr.i \i'<)ijs. By Samuel II. Scudder.
Roail April 5, 188>.
VJIARACTFlIJISriCS of a ilistrict typi of carbiiiiL'raus myriapDils wore recently given ill a piipor on tlie Aioliii)olypo(l:i, or gigantic spined inynapj;ls of the coal niea^ures. In collecting the material for t!i;vt me noir .so:n3 other striking for.n-t fell unler notice, which at first were set a-<iile as having no clos^onnection with my studies; but which, with more ample material and careful inspection, proved to be allied, though remarkably distinct. It is the purpose of the present p ipar to bring the^e Strang j forms to the notice of natura- lists. Thev belong to two distinct types, each differing considerably from other known inu'ient myriapods. One of tho-:e types is here noticed for the first time; the other and iiKii'o iriiiiiikable typ ' is tint figured in the Illinois Gaologic.il Reports, to which Messrs. Mt'ck and Wortlieii applied the name of P.ilaeocampa, and of whose aifiuities there has biH'ii luuch doubt and some public discussion.*
Ft)r the opportunity of studying these interesting animals, the writer is entirely indebted to his friends at Morris. 111., Messrs. J. C. Carr, P. A. Armstrong, and F. T. Bliss, who have generously placed at his disposal the material they have, with great pains and a.ssiduitv during a number of years, gathereil in tlie nodules in the .shales of Mazon Creeki in that vicinity.
The first of these new forms, to which the name of Trichiulus may be given, probably belongs to the Archipolypoda. Five specimens of different species have been examined, but they do not togetiier furnish all the details that could be desired, even in those points where most of the Euplioberiae and allied genera are sufficiently clear. They may be de- .'cribcd (pi. 27) as jointed vermiform yiyriapods, tapering considerably from in front back- ward. The segments of the body are unusually short and probably consisted of two ventral plates to every dorsal plate, furnished profusely with rows of papillae, apparently ar- ranged in definite series Ijoth longitudinally and transversely, and bearing long llexiljle hairs which were .sometimes much longer than the width of the body and formed a thick and uni- form flowing mass entirely concealing the bod}-. The body, and especiallj- the hinder half, was capable of being tightly coiled, as in modern lulidae ; more than this can hardly be said. The relation of dorsal and ventral plates is by no means certain and is presumed mainly from certain features which also occur in some obscure but indubitable specimens of Archi- polypoda, and which are there referred with little doubt to a separation of the dorsal and
'For retVioncu to tlii-', set' tlie biblingrapliioal cit.ilions imtler the dcfcription, inyja, of PaLicocninpa anllirax.
MKMOmS !*OST. Snc. NAT. HIST. VOL. III. 37
2S4 f^- II- f^tn'DDKK OX NEW TYPES
ventral liolils. It is also .supportoil I>y a vauuo appearance of what seem to be leg^s on one or two of the speeiniens. and which show two paii's to each dorsal segment. The clu^'c jrcneral resemhlance of inost of the species to the species of Euphoberia is also an argu- ment in favor of the same supposition; and would, perhaps, by itself, be considered sulli- ciont to one studying these forms, were it not for the unexpected discovery of a very distinct type of chilopodiform myriapods next to be considered.
This second type, as we have remarked, has been known to naturalists for some time under the name of Palaeocampa, given to it by Messrs. Meek and Worthen in 18G5, under the supjiosition that it was a caterpillar. The original specimen, figured in 1866, was de- .«troyed by fire a year or two later, but a better specimen enabled these naturalists to give further description of the spines in the same year that I questioned the Icpidopterous nature of the fossil ; and to express the opinion, that, as I had suggested from the figure alone, " it was more probably a worm." I have now received, through the favor of Messrs. Carr and Bliss, three remarkably well preserved specimens of what is undoubtedly the same creature, and which show that the animal combined some most extraordinary features. One of these specimen-s, the discovery of Mr. Bliss, shows the legs distinctly on Ijoth halves of the split nodule in which it occurs, and gives one much fuller information concerning this ancient creature than one could gain from the legless specimens otherwise known.
But for my previous study of the Archipolypoda of Mazon Creek, and the revelation which these ancient types give of the divergence of structure between extinct and mod- ern forms of Myriapoda. it would have been difficult to reach the full conviction that Palaeocampa was a myriapod. It is a caterpillar-like, segmented creature, three or four centimeters long (pi. 20), composed of ten similar and equal segments besides a small head; each of the segments excepting the head bears a single pair of stout, clumsy, suljfusiform, bluntly pointed legs, as long as the width of the body, and apparently composed of several equal joints. Each segment also bears four cylindrical but spreading bunches of very densely packed, stiff, slender, bluntly tipped, rod-like spines a little longer than the legs. The bunches are seated on mammillae and arranged in dorsopleural and lateral rows.
The individual rods have an intricate structure (pi. 26, figs. 1-4); instead of being striate, as supposed by Meek and Worthen in their last examination, they are furnished externally with about eighteen longitudinal, equidistant ridges, about half as high as their distance apart; the edges of these ridges are broken into slight serrations at regular intervals about equal to the distance between neighboring ridges, the highest point of each serration being toward the apex of the spine; the body of the ridge itself appears as if broken at each serration. The intervening space between neighboring ridges is equally divided by two or three exactl}' similar, but miniature ridges, serrated at more frequent intervals. This serration of bath larger and smaller ridges, with the apparent jointing or incision of the ridges to the base at the lowest point of each serration, gives the whole spine a jointed appearance; but a close inspection of the floor of the spine itself between the ridges shows no sign whatever of any break in its perfectly smooth surface. Tlie diameter of the spines is only about one-tenth of a millimeter, and yet it gives room for an ex(|uisitely regular division of its periphery by seventy or more delicate ridges, every fourth one higher than the intervening, and all broken at minute intervals by uniform serrations (pi. 26. fig. 2). The preservation of the.se structures from carboniferous times is only less
()!•" CAKKitNIIKKol S M M;l Al'ol )S. 285
rciiiarkalilf tliiiii tlic occunviice, appurciitly so near tin* uri^^iu of the ty|»i' to wliii-Ii it belong-*, of oriiaiiuMitatiou of such cxcfssivi' (U'li<'acy, liiiish. coinplicatioii ami ri'jrularity. T cannot discover tiiat ilernial apin'Uihijres of such delicute anil specializecl oiyaui/ation
•ur anywliere to-ilay aiuonj^ arthropttils, unless it he when developed as scales, :is ill Lepidoptera, and occasionally in other groups of liexapods ; some chaetopod worms have indeed hairs of curious asymmetrical structure, often vcr^' delicate and somewhat (ipfiialized. hut never, so far as I can learn, to nearly so high a degree as here. The col- lection of tiiese rods into fasci(des is also not a little curious, and is again a feature known now in arthropod-: only in a few in<tances, such as some tufts of hsiirs in lepidoptcrous cater- pillars like Orgyia ; or the pencils of hair-like scales in the nudes of some perfect Lepidop- tera, e. g. at the tip of the aI)ilomeii in lleliconia, iJanais, Agrotis, Leucarctia, etc.; or in the terminal fascicles of l)arhed bristles in the myriapcjdan genus Poly.xenus.'
There is no group »jf animals into wliich such a jointed creature as this could fall except- ing worms, myriapods, or the larvae of h('.\a])od insects. The certainty that this animal possessed a single pair of well developed legs of identical character on every segment of the l)ody behind the first segment or iicad is of itself sullicient evidence to exclude it both from the worms and from the larvae of hexapod insects. No such legs or leg-like struc- tures occur today in worms, ami it would l>e idle to look for them in their ancestors of car- bonifi-rous times. The only approach to such an appearance in hexapod larvae is in the young of tentiireilinous Ilymeuoptera, where, however, a diflerence of great morjihological aigniiicancc is found between the true or thoracic legs and the pro-legs or those attached to the abdomen; a ditrerence based on one of the most es.sential underlying features of their structure as liexapods. No such difference occurs in Palaeocampa, and it is, therefore, impossible to conceive of it as the larva of a hexapod insect of any sort.''
In myriapods only do we find a repetition of legs of exactly similar structure on every or nearly every segment of the body; '■' by this test Palaeocampa is a myriapod ; and now that we have found ancient types of this group, like the Archipolypoda, bearing huge and bristling spines arranged in series along the sides of the body, we need not be at all dis- concerted at discovering this new type, with longitudinal .series of fascicles of stiff rods, al- though we cannot restrain our surpri.se and admiration at their exquisite intricate structure.
Accepting Palaeocampa then as a myriapod, we may next ask what relation it bore to the myriapods of the same period and found in the .same waters, and also to myriapods of to-da\'.
The dilTerences l):'t\veen the stout, j'orked and bristling spines of the Archipolypoda and tlie close-set but spreading bunches of highly organized still' rods of Palaeocanijia appear upon the l)arest statenient. Were it not. however, for the complicated ornamentation of
' Sec Proc. no.ll. Sue. Nat. Hisl., xxit, Gti, fii^s. Amei-ican Journal of Science, llie author supports by no fa<-t.s
- Dr. Packard lias rect-ntly rein.-xriiuil {Proc. .Xmer. /'hit. I'O.vond wliat are implie.l in the above f|iiotatioii. How he
Soc. XXI, 208) : '-It sci-ms to us tliat the larvae of tlie neiiroi)- "'" aecotint for tlie miqueslioiiably close relationship of Pa-
tcroiis Panorpiilae, with their two jointed abdominal prop- lacocainpa, Trichiiilus, and Eiipholjcria does not yet appear, legs, small head and siM<;idarIy l,irf;e spinose spines, arising ' Some smaller groups, formerly, and by some authors still,
in groups from a tubirele or mammilla, come nearer to Pa- considered as belonging to i he niyriapoils, must be excepted
Iaeocanip\ than any myriapod with which scienc: is ac- from this statenient; their relation to Pal.ieocanipa will be
quaiiited." This oi)inioii, expressed since this paper was writ- discussed further on. ten and since Ihc pnlilication of my general results in the
2S6 ^- II- SCrDDER ON NEW TYPES
tlio roils tlionisolvos. tho ilistinrlion botweon the fascicles of Palaeocampa and the spines of Kuplioheria would be hardly greater than that between the latter and the long hairs of Trichiulus ; so that to this I'eature alone we cannot grant so high an importance as to an- other which has already been named: the presence in Palaeocampa of a single pair of legs (and consequently, to judge by analogy, of a single ventral plate) to each segment ; while there are two ventral plates and pairs of legs to each segment in Archipoljq^oda. This is a diflerence of profound significance, which has separated the prevailing types of myriapods down to the present day, lying as it does at the liase of the distinctions between the living chilopods and diplopods. The discovery of this type is of the greater importance because we have liitherto known nothing of any chilopodiform myriapods previous to tertiar}^ times, unless Miinster's dubious Geojjhihis 2)roavits from the Jura possibly be an exception.^
In stuilving the Archipolypoda we necessarily confined our comparisons with modern tvpes to the Diplopoda, because of their common possession of the fundamental feature ■just named ; in the same Avay the comparisons between Palaeocampa and recent forms must be reduced to the conunon features or the radical distinctions which appear in study- iu'f the Chilopoda. Now although the structure of Palaeocampa can be far less perl'ectly known than that of the equally ancient Euphoberia and its allies, enough can be seen to point conclusively to wide and important differences between it and modern Chilopoda.
In Chilopoda, of which the modern scolopendra or centipede is the type, the body is al- ■wavs depressed, formed of many segments, rarely as few as sixteen behind the head, each of which is compound, being formed of two sub-segments, one of them atrophied and carr}-- inir no appendages; both dorsal and ventral plates are coriaceous, of nearly equal width, and possess no armature whatever excepting the simplest huirs, which are occasionally scat- tered over the surface. The larger sub-segment bears a single pair of legs, which are com- posed of five slender, cylindrical, sub-equal joints beyond the coxa, and armed with a single apical claw ; they are attached to the interscutal membi-ane uniting the distinct dorsal .and ventral plates of each segment and are therefore separated by the entire widlii of the Inroad ventral plates. The hindmost legs are transformed to anal stylets, while the first two pair are more profoundly transformed to subsidiary mouth parts, the first becoming palpi and the second stout nippers. The head really composed of eight primitive segments, is appar- ently made up of two, each of which is generally of about the same size as the body seg- ments and as distinctly separated ; the stout biting jaws, composed of the second pair of legs, spring from this second segment of the head, and the palpi or first pair of legs from the hinder part of the fii-st cephalic segment; the anterior part of the same bears the many -join ted simple antennae.
Passing now' to the comparative study of Palaeocampa, we find that its body was in all probability cylindrical, composed of a limited number of segments behind the head, and the head itself, considerably smaller than the body segments, is composed of only a single app.irent segment. The legs of the segment immediataly succeeding it are in every respect like those of the rest of the body, and have nothing whatever to do as auxiliary to the moutli In this point alone W3 hive a distinction as wid3 and incisive as any which separate th' modern Diplopoda and Chilopoda. In the body segments we discover no trace of anythin more than a simple ring without sub-division, but as the specimens indicate a coriaceou.-.
' Hagen considers this a nercMil worm, a suggestion I once adopted, but now find reason to question.
(U ( \i;i:(>\lFEi{ors MVKi.M'ODS. 287
structure like tliat of iiioiliTii riiiln|)uil;i, .iiid no truce of tlie division between the dorsal and ventral plates can be seen in any of tlienj, the separation of the se|^rnents into two sub-segments, as in Chilopoda. one of them greatly atrophied, couhl iiardly be apparent did it exist. But on tiie otiier hand, as we regard tlie seeond sub-segment of (Jhilopoda as atropliied, we should e.vpect to find it fully or partially developeil in thew cinjatures, which of all known ancient typos are certainly the most closely related to tlHim. Yet we find here no sign of anytJiijig more than the simplest possible, uniform, leg-be!rri<ig segments, and of a very limited number. In one feature, however, they are not po simjjle as in Ciii!o[)oda ; for, as stated, each is ]uovideil on each side witii two pairs of maininiilae, suj)port- ing very large l)uncliL's of spreading rods, and tlie rods themselves are scidptiured in a very remarkable way. This distinction between the two types, though more striking and notice- able than any other, is in it.self by no means so important as the others, but may be added to tiie catalogue; a<ul it must have .some weight, from the total al)sence ■ of appemlages of any sort (beyoaid scatti^-red hairs ) from the dorsal plates of Chilopoda. The position of these rows of fa.scicles and of the legs indicates that the ventral plat'cs were only a little narrower thaiithe dorsal, ami pn)l)aMy ol' about the .same extent as in the Archipolvpoda ; in this res^iect they would not dillir to any important degree from modern Chiloj)oda. The legs were diflerent in furm. Imt their poor preservation in the only specimen in which they have been seen prevents auytiiing nujre than the mere statemeoit of the following dillerence : while tJie legs of Chilopoda are invariably horny, slender, atlapted to wide ex- tension and rapid movement; those of Palaeocampa are fleshy, or at best subcoriaceous, very stout arfd coiHcal, certainly incapable of rapid movement, and serving rather as props.
These differences, which underlie every part of the body that is preserved in Palaeocampa, show that while the general accordance of grand features compels us to look upon Palaeocampa as a precursor of the Chilopoda, we must separate it from them in the .same way as we separate the Archipolvpoda from the Diplopoda. For such a group the name of Proto.syngnatha is proposeil, indicating its ancestral relations to the Chilojwds, or Syng- iiMtiia, as they were called by Latreille.
There are, however, two aberrant groups of living animals more or less closely related to myriapods, and placed with them by some authors, with which also we should compare Palaeocampa. The first of these is Peripatus, our knowledge of which has b'icn so much increased of late years, and especially by the researches of Moselev'.
In external appearance Peripatus resembles an annelid, but is furni.shed with a pair of long, jointed antennae, and with numerous fleshy, tapering legs, each armed at tip by a pair of claws; the legs, set wide apart, are obscurely jointed, the joints being perceptible only at the extreme tip and on the apical half of the inner side, above which are the large elongated openings into the nepliridia. The entire body is of a leathery texture with no external sign of segments, or of the separation of the head from the rest of the body, exc^t the appendages : namely, the legs, the nephridia opening on the legs, and the ordinary appendages of the head. The .same is true when the internal structure of the body is ex- amined, for neither in the disposition of the muscles nor of the tracheal apparatus does it appear that one could judge whether a pair of legs representod one or more segments of the body ; even in the nervous system it is only indicated by a small ganglionic swelling next each pair of legs. The tracheae are like extended cutaneous glands, independent of
oi^v; S. H. SCUDDER ON NEW TYPES
one anotlior. and soatteroil over tho body, and tlio li)iiii;itudiiial musolos show no regular seirinontal breaks. Tlii;* weakness oF segmental divisions is nowhere paralleled among hexapods, arachnids or myriapods, and is an indication of very low organization among arthropods generally. The nnmber of legs indicates from 15 to 35 segments in the bodv. according to the species. The first pair, as they are developed in the adult, are func- tionless as legs, and are situated (in the specimens I have examined — a South American species, probably P. Edwardsii), midway between the antennae and second pair of legs, and not onlv outside of, but at some distance from the mouth parts, so that the latter are not furnislied with auxiliary appendages borrowed from a segment behind the first, as in chilopods ; this is further proven by the development of these parts in the two groups. The body is profusely covered above with corrugated papillae, without regular distribution.
From this it will appear that Palaeocarapa differs in many essential features from Peri- patus, and in most at least of these shows a higher organization. The segments are well separated from one another, and the head is distinctly marked. The number of segments is much less, and each bears clusters of appendages of a highl}- specialized character. Al- thouirh no .spiracles are present in the remains we have of Palaeocampa, it is clear that res- piration must have been effected through linearly disposed openings; since the muscular or mechanical requirements for the movement of a completely segmented body (especially if, as in Palaeocampa, the segments bear a heavy armature), forbid the miscellaneous dis- tribution of tracheae, and demand a well-developed system with the same linear arrange- ment which we find in the armature. The best that can be said of the respiratory appara- tus in Peripatus is that the tracheal bundles show a tendency toward "a concentration along two sides of the body, ventral and lateral." The possession, however, in each type, of a single pair of legs to every segment behind the head indicates an affinity which cannot be overlooked, and which is the more interesting since one of the types is very ancient and the other is universally looked upon as an existing survivor of an ancient type. The form of the body and of the fleshy li>gs is also simihir, but these are minor points ; and however close the agreement between these forms, we cannot look upon Palaeocampa, with its undoubtedly well-developed tracheal development, as in any sense the genetic predecessor of Peripatus, for the generally distributed tracheal apertures of the latter could not have developed from a serial disposition, without a degradation of type which, as Moseley points out, many other features combine with this to disprove. It may also be added that while the legs of Palaeocampa are poorly preserved in the only specimen which gives a side view, the presence of nephridial openings, of such an extent and in such a place as in Peripatus, could hardly fail of detection, and they are entirely absent. The presence of these in Peripatus is one of the marks of their inferior organization, or rather of their alliance to an inferior type, the annelids.
The other aberrant group which we must specially notice is Scolopendrella, placed at first among Chilopoda, but recently shown by Ryder and Packard to differ from them in very important feature.s, in some at least of which it agrees with Palaeocampa. The researches of these naturalists, as well as the earlier observations of Mengo, clearly prove that it must be separated frora«the myriapods altogether, and that it is cartainly provided with many points of affinity to the Thy.sanura. Ryder suggests for it an independent place between the Myriapoda and Thysanura under the name Symphyla. Packard, with
OF rAi;i:c»MrKi;()is mvui apods. 2S0
hotter reiHDn. wouM plaoe it witliin tin- 'rii\ sainir.i. uihIit which heml ho woiiM iiho iiicluile tlio Collomlxjhi ami Tliysaniira propor, or ("inura. as ho tonus thoin.
Scolopeinh'olla, as thoso authi)rs point out, tliflbrs from tlie Chilopoila in that tlio appon- dn}!;os of the sogmont holiind that furnishing the mouth-parts proper do not serve as nuxiliarv organs for manihu-ation, l»ut aro developoil. like tliose oftho snccooiling sog- nieiits, as logs, wliilo the month parts rosomlilo tlioso of Thvsanura. and rliffor from tliose ofChilopoda; indoe<l tho wholo lioad is docidcdly thysanuriform ; the logs are provided with a pair of olaws, and tho terminal sogmont l»ears a pair of oauilal stylets with a special function, resides these points the possession of a collo|)hore is distinotivoly thysan\iran, and tho position of the stigmata, hotwoon tho logs, is diflferent from the position they uniformly maintain in Chilopoda, while it only adds to tho great irregularity of plaoe >n:cn in Thvsamua. On tho other h.ind, tho identitvof form in tho tlioracio and alidominal segments, the full dovolopment. upon tho altdoininal si'gmonts, of jointed legs like those of the thoracic segments, and tiie occasional alternation ol leg-hearing and apodal segments in the abilomen, are striking marks of its real allinity to tlie ehilopods. Abdominal appen- daL''es, homologous with legs, hut unjointed, <lo, however, occur in Thysanura to a greater degree than in other hexapoils. so that we can hanlly refuse to admit those polypodous creatures as lowest meinljors of the sub-class of insects proper, although they are the only nun-lioxapoilal typo.
Now the separation uf tiie lioail and it- appendages from those of tho ne.xt succoedin» segment distinguishes Palaeocampa from the ehilopods in the same way as it does Scolo- pendrella; so, too, the segments behind the head in Palaeocampa and ScolopendroUa, alone of all arthropods in which the head is thus clearly .separated, agree in .showing no distinc- tion whatever between what may be looked upon as thoracic and what as abdominal, whotlier in the form of the .segment itself, or in the appendages of the .segments. The.se are certainly fundamental points, but when we have mentioned them we have reached the end of all possible affinities, or points of resemblance, unless we ma}' consider the minute structure of the rods in the fa.scicles of Palaeocampa parallelled by the well-known delicacy of organization of the scales in some Thysanura, though they do not exist in Scolopen- drella. Tiie limited number of abdominal segments might be looked upon as a further point were it not that the number is even less than in Scolopendrella or in the Cinura ; and that the Pauropida among diplopod myriapods have in some instances even a still smaller numl)er. On tlie other hand, the character of the legs, the apparent absence of a double claw at their tip, the jjoculiar armature of the fascicled rods, which forms so striking a feature in Palaeocampa, the want of any caudal stylets, and the complete uniform- ity of the segments of the body unprovided with distinct dorsal scutes, distingui.sh Palaeo- campa not only from Scolopendrella but from all Thysanura whatever; the general form of the body, too, is altogether different from anything occurring there, even its cylindricity being foreign to the Thysanura, excepting in their highest types among the Collembola. It seems, therefore, clear that the points of affinity between Palaeocampa and Scolopendrella, with the single exception of the separation of the head and its appendages from the body, are precisely those in which Scolopendrella is chilopodan, and that the assemblage of fea- tures which our fossil presents are therefore chilopodan rather than thy.sanuran.
Regarding Palaeocampa then as a myriapod, though of a type very distinct from any
290 »• IT- SCUDDER OX NEW TYPES
known, whether living or fossil, we are brought, face to face with two remarkable and somewhat parallel facts : First, that in this ancient myriajyod, as old as any with which we nre acquainted, carrying us back indeed as far as any traces of wingless trachcate arthro- pods have been found, and, therefore, presumably not far from the origin of this form of life upon the earth, ice find dcrmrd appendages of an extraordinarily high organization, more complicated, as we have pointed out, than anything of the sort found in living arthro- pods, excepting the more varied but not more exquisite scales of several orders of hexa- pods ; a form of appendage wdiich it would seem, on any genetic theory of development, must have required a vast time to produce, but which we now seem to find at the very threshold of the apparition of this type of arthropod life.
Second, that at this ear hj period, in marked contrast to what we find in other groups of articulated animals, the divergencies of structure among myriapods was as great as it is to-day. This is the more surprising because we possess only imperfect remains of a few types, and yet from what we already know of the Archipolypoda on the one hand, and of the Protos^-ngnatha on the other, they are found to diOfer quite as mucli as the Diplopoda and Chilopoda, and in jDoints fully as important as those which separate so sharply these great modern groups. Whether they are to be looked upon, one as tlie ancestor of one, the other of the other, of these modern groups, is another question. It would certainly be reasonable to consider the Archipolypoda as the common ancestors of both the Chilo- poda and Diplopoda ; and possibly on the Protosyngnatha as the descendants on one line of a primitive type which, on another line, has retained its integrity up to the present day in Peripatus (and on possibly a third line has reached Scolopendrella) ; while on that which produced Palaeocampa it has not, so far as we know, survived the carboniferous epoch.
With the facts of structure of ancient and modern types now before us, we are compelled, on any genetic theory, either to presume a great acceleration of development in earlier times or to look for the first appearance of myriapods at a vastly remoter epoch than we ' have any reason to do from the slight hints in the rocks themselves — a period so remote as to antedate that of winged insects, which are now known from rocks older than any which have j-ielded remains of myriapods.^ In a memoir on Devonian insects,^ I showed the probability, on developmental grounds, that some of the carboniferous insects, " to- gether with most of those of the Devonian, descended from a common stock in the lower Devonian or Silurian period; and that the union of these with the Palaeodictyoptera (of the carboniferous), was even further removed from us in time." The structural relations of myriapods and hexapods render it probable that the former preceded the latter ; and in complete accordance with this expectation, the structural relations of the oldest fossil myriapods indicate their apparition at a period earlier than that to which the winged insects are hypothetically assigned. This would compel us to consider the earlier type as aquatic, for which we have presumptive evidence in the structure of the Euphoberidae, and renders it all the more surprising that the penetrating researches of the last thirty- t seven years, since the first carboniferous myriapod was discovered, have not yielded the slightest trace of fossil myriapods below the Coal measures.^ This discrepancy between fact and hypothesLs should never be lost sight of, and should stimulate to more searching
' This was written before the pubUcation of Mr. Peach's Ulscov- ^ Aiiniv. Memoirs 15ost. Sou. Nat. Hist., 1880. erj- of myriapods in the Ohl Red Sandstone of Scotland.
OK CAIII'.OMIKIIOI > MVIM AI'ODS. 291
investigation"* piirticiiliirly of tliose iirticnlates of llu- oMiT rocks whose afiliiites have not been satisfaetoriiy settled.
It only remains to give descriptions and refer to illustrations of the speeies of the two groups wiiose general allinities have l)een diseussed.
SuBORDKK AKCilll'OLYFODA. Family K f imi o h i; u i d a e .
Trichiulus iiov. i.'in. (ep\|. tuXot)
Segments from three to four or live times broader than long, covered closely with tolor- ablv large papillae, wiiich arj arranged in definite s^-ries both longitudin dly and trans- versely, and support longfl^'xible hains, whieh togetlier form a sweeping msiss covering the whole body.
Tliese points will serve abundantly to ilistinguisli this genus from the other Archypoly- poda deserilied in my previous paper on the subject. They are derived from the study of all the species describeil below, no one of which, however, presents them all; oidyone ol them shows the sweeping nuine of hair enveloping the whole creature ; the others either have no hair preserved at all, or at most vague appearances of a mat of hair next the integument ; on the other hand the specimen showing tlie hair .so well shows nothing of the papillae which (doubtless) bear them, and which sho.v to perfection in most of the other specimens.
Tiie numl)er of segments appears to vary considerably, from about 20 or more in one spi'cies to 83 or more in another ; the form appears to be nearly the same in all, the body being much larg3r at the front thati at the hinder extremity, and tapering pretty steaddy toward the tail ; in one, however, which is fragmentary, no sign of this change is shown. The head L*nd also tapers, but only just next tlie head itself so far as known, in this respect differing fio)n otlier Archipolypoda. The head itself, too, joins in this rapid diminution entirely, instead, as in most other Archipolypod i. of being considerably larger than the segments just behind it ; its outline, however, is perfectly preserved in only a single speci- men, so that this statement should not be taken as absolute. The various species differ from each other in the form in which the body varies in proportion, in the number and relative proportions of the segaients and in the frequency and arrangement of the papillae or tubercles from wliich the hairs originate.
Trichiulus villosus nov. sp. Pf. 27, fig. 2.
Body composed of more than thirty segments which vary from two to three times as broad as long, being broadest in the stoutest part of the body ; it is broadest from the third to about the tenth segment and then tapers very regular!}^ to less than half the diameter at the hinder extremity ; the anterior extremity of the body in front of the third segment tapers very rapidly and considerably, the head being only a little larger than the tidl — a point seen best in the reverse of the specimen drawn and not appearing on the
MKMOIKS BOST. SOC. SAT. HIST. VOL. Ill 38
292 S. H. SCUDDER ON XEW TYPES
plrtte. TIio whole surface of the body upon both sides, as it lies coiled in an open spiral, is covered with a thick mat of rather fine hairs which appear to bo two or three times longer than the diameter of the body. Two or three pairs of short and slender tapering legs can be seen (not given on the plate) depending from the anterior segments; they are scarcely half as long as the diameter of tlie segments. The length of the fossil if unrolled would be 20 mm. ; its greatest diameter h 2.1 mm. The specimen is from the uodules of Miizou Creek and was obtained by Mr. P. A. Armstrong.
Trichiulus nodulosus, nov. sp. PI. 27, figs. 1, 3.
Two specimens at hand are referred to this species, though each is so fragmentary that the determination is uncertain.
One of them (pi. 27, fig. 1) represents a dozen segments of the entire width of the crea- ture, being apparently only a fragment of tlie larger end ; it does not taper, and the seg- ments are about four times as broad as long, each furnished with two transverse series of equidistant, small, rounded warts, apparently the bases for appendages of some sort ; the series are also equidistant so that the warts are .sprinkled over the surface in a very regu- lar fashion, like a checkerboard, in both longitudinal and transverse rows. Each series on the same segment is separated from t!ie other by a transverse depression a little shallower than the sulcation between the segments. The warts are about 1.25 mm. dis- tant from each other and slightly less than half a millimeter in diameter. The length of the fragment is 29 mm., and its breadth 'J.25 mm. No appendages of any sort are to be seen; but next the margiia in some places are faint signs of delicate hairs, aul tlie discol- oration of the skin in the neighborhood may indicate ^ts previous extent.
The other specimen (pi. 27, fig. 3) is longer, but by the method of preservation and the cleavage of the nodule it on\y shows a portion of the breadth, and neither edge, so that no appendages can be seen, nor any hairs. The same arrangement of warts or tubercles can be seen, rendering it probable that it belongs to the same species as the other. These wartlets are at the same distance apart as in the other specimens, and the series are simi- larly arranged, the sulcations between the segments being slightly deeper than those between the transverse series of a single segment ; but the warUets appear a little sharper or more conical. The length of the fragment is 45 mm. and its extreme breadth 4.5 mm. ; the segments can only be faintly seen over a portion of the fragment, but there were prob- ably about twenty m this piece, which does not seem to reach either extremity. Botii specimens are from Mazon Creek and were obttiined by Mr. P. A. Armstrong, and are in his collection.
Trichiulus ammonitifonnis, nov. sp.
PI. 27, fis- 4.
Although the single .specimen found presents few tangible characters, it differs so much
from the others that it seems worth while to make it public. It is of much greater size
and is coiled into a slightly open spiral, and being preserved on a side view has a cur.sory
resemblance on the stone to a fossil ammonite. If unrolled it would measure about 115
OF CAi;i;(»MiKi{()rs mywiai'ods. 293
nun. in Icnj^th, and its extreme breadtli is 1 } nun. Tin- head en<l is broken badly but enoiij^h is jireserved to show tbat it tapered anteriorly, tlie lar;fest part of the body being probaldy tlie eml of tlie anterior tliird; beyond this the l>ody Uipered j^ently to very ne.ir the tail, but tlu-n diiuinislR-d very rapidly in size, the tip. however, bein;^ rouniled; a little before the rapid diniinuticnj in size the diameter is 'J nun. There seem to have been about thirty-five .segments to the body, about four time.s as broad as long on the average, not very much arched and least so along tin.' upper portion, where, at Iwist in the fossil, the surface is almost completely Hat and shows .scarcely a sign of the tlivisions of the segments. In certain parts of the fo<sil there are indications of minute tubercles as if for the support of hairs, but they are obscure ami woidd not have lieen noticeil but for their occurrence in the preceding .species. There is, however, along the outer edge an exceedingly faint indication of a delicate mat of very fine hair.s, where the surface of the stone, as in T. viilosus, is decidedly darker than elsewhere. This specimen also was found by Mr. P. A. Armstron<r in the nodules of Mazon Creek.
Suborder PROTOSYNGXATIIA.
Palaeozoic myrinpods, with a cylindrical bod}-, the head appendages borne upon a .single segment; each segment behind the head composed of a dor.sal and ventral plate of equal length and. probably, of subequal breadth ; the dorsal at least somewhat Ijroader than the ventral, occupying the greater part of the sides of the body, and supporting .several longi- tudinal rows of clustered needles ; the ventral plates occupying the entire ventral portion, each bearing a pair of widel}' separated, stout, fleshy legs, i. e., one pair to each segment of the boJy behind the head; spiracles probably present in a definite longitudinal row.
Genus PaLAEOC.\MPA (■n-aXoids; HaV-mi )
Pt.daeocam])a, Meek and Worthen, Proc. Acad. Nat. Sc. Philad., ISGo, p. 52 (1865); — lb., Geol. Surv. 111., 2 : 410 (1806).
Desmacanthus, Meek and Worthen, Geol. Surv. 111., .5 : p. 565 (1868).
Head corneous with no armature. Body coriaceous, coarsely shagreened, composed ot
ten segments furnished on each side with two rows, dorsolateral and lateral, of fascicles of
needle-like spines, one to a segment in each row, placed upon tubercles near the front of
the segments ; the fascicles are CAdindrical at base, the needles diverging only a little ;
each needle tapers very slightly, is blunt at tip, and very regularly divided by longitudinal
serrated ridges. Legs stout, subequal, about as long as the width of the body, tapering
and pointed.
Palaeocampa anthrax, Meek and Worthen.
PI. 26.
Palaeocampa anthrax, Meek and \Yorthen, Proc. Acad. Nat. Sc. Philad.. 1865, pp. 52-53, (1865); Palaeont. 111., Vol. 2, pp. 410-411, pi. 32, fig. 3 (1866); — lb., Vol. 3, p. 565 (1868) ; Scudder, Geol. Mag., Vol. 5, p. 218 (1868). Figured also in Packard's Guide to Study of insects, fig. 68 on p. 78.
294 S. H. 8CUDDER ON NEAV TYPES
Four spocimon< of tliis species have been examined, two of them liolong-inii; forniorly to Mr. J. C. CaiT. of Morris, llh, and received for study from him, but now in the collection of Mr. Iv. n. Lacoe. of Pittston. Ponn. ; a third received from Mr. Lacoe and numbered 1851 in his collection ; the fourth obtained by Mr. F. T. Bliss, of Morris, 111., and in my own collection ; all of these are admirably preserved and show both relief and counterpart. Both of Mr. Carr's specimens are preserved from above and have the fascicles spread rciruhirlv upon either side of the body. In one (pi. 26, fig. 7), which has the head end as well a.s the opposite conipletely fringed with spines, the general cursory resemblance of the whole to the caterpillar of an Arctian is very striking. The rods of the fascicles of the first and second body segments and especially of the first are considerably shorter than tho.se of the succeeding .segments, those of the first projecting forward over and concealing the head ; in the same wa}- those of the last segment make a complete fringe around the posterior extremit}' of the body. The fsiscicles are more readily seen on tliis than on the other specimens to emanate from tubercles, which are conical and apparently (here at least) higher than their basal breadth. The fascicles are longer than the width of the body, and their most divergent rods are about at right angles to each other. The length of the body in this specimen is 33 nun. ; or, with the rods, 40.5 mm. ; the width of the body is 5.5 mm. ; or, with the rods, 17 nun. The longest rods are 6.5 nun. long.
The second specimen of Mr. Carr's collection (pi. 26, fig. 6) is about the same size as the last, the body measuring 34 mm. by 5 mm. ; or with the rods 40.5 mm. by 15 mm. The rods in the fascicles are, however, considerably less divergent and trend a little backward giving them a more bunchy appearance; those of opposite .sides of the same fascicle rarely diverge more than 55'' ; the rods themselves appear here to be usually a little longer than in the first specimen though the longest are of the same length, and to be seated on tuber- cles which are stouter and less elevated, but this may be merely an appearance due to the way in which the .specimen is preserved. The i-elation of the rods of the first and second body segments, and of the last segment to the others so far as their size and distribution is concerned, is the .same as in the previous specimen ; but those of the anterior segments are not directed forward, but on the first segment backward and on the second laterally so as to leave the head nearly uncovered. This appears as a rather smalt, transversely oval, rounded mass, about twice as broad as long, and only about half as broad as the body ; neither eyes nor antennae can be made out.
The specimen obtained by Mr. Bliss (pi. 26, fig. 8) is .slightly smaller than thj otiicrs, preserved on a side view, and arcuate instead of straight. If extended, the length of the body would be 33.5 mm. and its height 4.5 mm. ; or, including in the height botli spinu- and legs, 13.5 mm.
The rods in the fascicles are even less divergent than in the last mentioned specimen. rarely exceeding 40'' between opposite rods of the same fascicle (pi. 26, figs. 5, 9). There is also less indication here of any tubercles at the base of the fa.scicles, and those of the first and second segments although .shorter than the others are not noticeably so, and the first are very nearly as long as the second ; the longest .spines are about 6 mm. long. In this side view the head again appears, not separated by any sharp line of demarcation from the segment behind, but considerably'^ smaller than the body, higher than long, rather flattened in front, and with an inferior basal projection of a conical form ; no eyes nor appendages
OF CARIJONIFEItors M VIMA I'oDS. 2\)i>
can be made (nit. TIr- le<^s are almiit as loiii^ as the wiilth ol" tin- IhhIv, ■•tniit. ^-li^^litlv smaller at the immetliate basu than jii<t hi-hind it. ta|tt'rinjr bi'Vimd the middle and with increasing rapidity nearly to the tip. the last joint (apparenth ) hcin^r etjiial ; this is hardly shown in the plate, and does not show on all the lcj.rs in the fossil, the apices of these memhers being exceedingly vague; but in a lew instances it appears to be Soniewlint clearly the case, and a slight appearance of it shows on the leg of the seventh body seg- ment in the plate ; on the reverse of the specimen drawn it appears evi'ii more plainly on the legs of the second, fourth, and fifth seg'nents. This apical joint appears as such simply bv the contour of the leg, l)ut no other joints can be determined in the same way ; indeed, the legs themselves are only pale shiulows, and they are traverseil by numerous darker bands which seem to indicate joints, but thoy are r»ther more numerous than one would ex- pect, and a little irregular, so that little can lie delinitely aHirmed concerning them ; taking them, however, where they appear most regular and best defined and connecting with them the two or tliree transverse rows of miinite granulations, that seem to encircle each joint with some regularity, and it would appear as if there were about five equal j<jints in tlie leg besides the s:naller non-tapering apical joint. The length of the legs appears to be slightly greater in the middle ol the body than at the two extreme erd< ; the midiile legs are 4.5 mm. long (of which the apical joint is 0.7-3 mm. long) and 1.4 mm. broad in the middle, the apical joint being 0.5 inn. broad. No sign of claws can be seen.
The fourth specimen, received from Mr. Cut after the others had been stmlied and figured, differs but .><lighth' from the first two. It exhibit-; the animal expanded in a straight line, but a little on one side so that only the spines of one side .show in full. The spines of the first and second segments are lateral ; but, nevertludes.s, no head is visible, being, perhaps, buried in the stone. The spines, especially in livi Unl ones, are of unusual length, the longest being S.5 mm. long ; they diverge in the fascicles less, rarely cxccLding a divergence of 35" and usually not exceeding 20". The fascicles of the hinder half of the body trend slightly backward, increasingly so toward the tip, but they are almost exactly at right angles to the body on the front half. No legs are visible. The body is 32.5 mm. long, or including the .spines which fringe the posterior end 35 mm. (perhaps more, for the end of the stone is reached) ; the width of the body is 6.5 mm. ; or, incluling the ma.ss of spines (on one side only) 12 mm. ; or, including the longest spines, 14 mm.
These specimens, which agree .so closely in size, are considerably larger than the first specimen found, upon which the description of the species was based by Messrs. Meek and Worthen ; judging by their figure and description, that specimen if extended would mea.s- ure 23 mm. in length ; or, inclusive of the rod.s, 32 mm. ; and 3.5 mm. in breadth ; or, in- cluding the rods, 8.5 mm. To judge from the arcuate position and the absence of rods from the under surface, it probably presented a side view or one partially dorsal ; but the authors sa}- that neither head nor feet can be seen ; the distribution of the rods is some- what like that of our fig. 7, that is they are considerably divergent, but the figure gives no sign of any tubercles to which they are ^attached ; the ''general resemblance of the whole animal is so close that no doubt can exist that it is of the same species as those now figured. The specimen has been lost by a fire.
In a later volume of the Illinois reports the original authors of the species describe another specimen from the same place, only mentioning, hoAvever, the rods, which they
200 !^- II- SrUDDRR ox NEW TYPES
say are much bettor proscrvcd. ixnd which for the first tnno thev discover to have hjiiiri- tiurinal inarUings.
A careful study of the four specimens seen by me show that tliere is no variation in the character of the rods in diflerent indivi(hials beyond what is J'ound on one and the same individual; and these may now have a particular desciiption, which from their remarkable strueture tlu'V well nu'rit.
The rods (pi. '2(). liu;. 1) are straight, rigid, needle-sliaju'd bodies. ^)-C)J) mm. long and about 0.075 nun. in diamelt'r. imperceptibly tapering, so as to be at tij) fully tlnee-quarters as large as at base, and terminating aln'uptly, apparently with a broadly rounded tip. It seems to be composed (jd. 2G, figs. 2, 4) of an inner core, about nineteen-twenlieths (in diameter) of the whole, and a shell upon which very delici;te markings are traced; the .shell readil}- peels from the central core and may thus be nujunted in l)alsam and examined by transmitted light under the microscope (pi. 2G, fig. 3), when the distinctions between the parts may be readily seen.
Two schematic drawings are given to show the minute markings of the shell. PI. 20, fig. 4, represents a diagrammatic view of the cross section of a rod, magnified 1000 diame- ters, and fig. 2 represents an oblique view on the same scale. The rods are thus seen to be longitudinally furnished with about eighteen mainridges, as straight as the rod itself, equidistant from each other, rcuuided at the top and with steepl}' sloping sides so as to be scarcely broader at Ijase than in the middle and of equal l)asal breadth and height; these ridges are divided at subequal distances b}- notches, or rather they are made up of serra- tions, the highest end of the serration next the tip of the spine ; the greatest increment in the height of the serration is in its basal i'ourth, calling the b[ise the end toward the base of the spine ; and the extreme height is about double the least height ; in the same basal fourth occurs the greatest increment in breadth, for each serration increases also in this dimension toward its highest point, so as to be about one-fifth broader at apex than at base. To increase the distinction of the serration, there appears at the base of each to bo a closed joint, separating each one from its neighbors. Although at first these serrations appear to be divided ofl from each other with remarkable regularity, and at a distance apart averaging about .0133 nun., a little observation shows that this is not strict!}- true; and a measurement of nineteen succe.-sive serrations on the same ridge showed the follow- ing series as given in millimeters: .0144, .0135, .0182, .0144, .0135, .0115, .0154, .0115, .0173, .0135, .0135, .0115, .0144, .0135, .0125, .0115, .0077, .0115, .0135 ; another shorter set on another spine gave the following series: .0154, .0115, .0154, .0192, .0135, nudving the average a very little less.
Between every pair of these ridges are generally three, sometimes two, exactly similar but miniature ridges about one-eighth the height of the others, and also cf equal height and width but apparently a little more triangular in cross section ; these likewise are broken up with serrations, apparently resembling the others closely but so minute that the proportions cannot be so closely studied as to be quite sure of this; they certainly diifer in that the serrations are proportionally longer, there being but two or three to each ser- ration of the larger ridges, as shown in pi. 26, fig.. 2. In this drawing, based on instruction given the artist from my studies of numerous fragments, and by his examination of the specimen represented in pi. 26, fig. 3, he has misunderstood a single point, in bringing the
<»F ( .\i;i;i>Mll.i;()i s MVIMArODS. 297
larjrt'r ri<l;-!;t's iicartT to^rcllu'r in .-oiiu- parts of the saiiii- cross section tlian in others, and phieinji; lietween them only two instea<l of unilbrnily three minor ri<lj^es. In all the frag- ments 1 have seen tliere are either two or tliree (almost universally three) minor ridges hetweeii eviry pair of larger ridges on every part of the same fragment. It is possible that in the slight tapering of the spine two larger ridges coming nearer together compel the union of two adjacent minor ridges and reduce the numiier to two instead of three, so that in one portion of a spine one may lind two and in another three miimr ridges between every pair of larger ones ; l)ut this I have not seen, and can only say that while three smaller ridges usually aj)pear in every interspace between adjoining larger ridges, the number is sometimes only two. Otherwise the proportions of these ridges and serrations to each other is very well sliown in lig. "J.
All the specimens limnd camt- from the ironstone nodules of Mazoii Creek, near Morris Illinois.
KxPLAXATIOX OF PlATES.
PLATE XXVI. [All tlic figures represent Palaeocampa aiulirax.]
Fii;. 1. A spine Y- to sliou' Its a|ipe;irance iiniler an ordinary strong lens, showing an a|)parently striated surface. Drawn tiy Katlierine Peirson.
Fig. 2. An oMi'pie view of a fragment of the sarfa.-e of the spine J-Y—, sliowing the serrations of the larger anil smaller rlilges and their relations to each othL.'r; three of the minuter ri Iges should have been shown in every interspace, but in two of them only two arc given. Tai lig^rj is sclicaiatic. Drawn by J. Henry Blake.
Fi.-. 3. A fragment drawn from nature of the shell of a sjiiiie ^j", as seen witli a half-inch objective. Drawn by the same.
Fig. 4. S;;he!uati(- view oS> a cross seotioii of the shell of the spin?, slowing the relations of size and position of the spine, the shell and the two kin Is of ridges, iY^- Dr iwn by S. II. Scud ler.
Fig. 5. One of the clusters of spines of fig. 8, f . Drawn by Katherine Pierson.
Fig. 6. One of Mr. C.irr's specimens, showing the head, above, }• Drawn by the same.
Fig. 7. The other of 3Ir. Carr's sjieciniens, ?. Drawn l)y the same.
Fig. 8. The specimen with legs, found by Mr. Bliss, f . Drawn by the same.
Fig. 9. The same cluster of spines shown in fig. 5, |. Drawn by the same.
PLATE XXTII.
Fig. 1. Trlchiiilus 77odulosus, f. From the collection of Mr. P. A. Armstrong, Xo. 7. Drawn by K:itherine Peirson.
Fig. "2. Trichiulus villosHs, -J. From the same collection, Xo. IS. Drawn by the same. Fig. 3. Trichiulus noJulosus, f. From the same collection, Xo. 52. Drawn by the same. Fig. 4. Tridiiidus ai/intonili/ori/us, |. From the same collection, Xo. 2. Drawn by the same. The remaining figures belong to the next memoir.
X. TiiK SrEciEs OF MYi.Aruis, A Carboxifeiious Gen'us of Cockroacdes.
13 V SamUI;!. II. ScUDDEU.
Read May 21, 1 82.
M
ill YL.VCRIS was first sugj^ested by inc as a name for a genu.s of paleozoic cockroaches in 1S08, but its full (loliuition from other cockroaches was not given until eleven years later in my memoir on paleozoic cockroaches, when five specie-t, two of them new, were fnlly characterized and figured. It is the principal genus of the tribe Mylacridae, the distinct- lively American group of ancient cockroaches, an 1 by the facts known three years ago appeared to be confined to the lower or middle coal measures. Through the indefatiga- ble ellbrts of Mr. R. D. Licoe of Pittston, Penn., whose explorations ol the coal measures of the United States have yielded better results for fossil i nsects than tho.se of any other person, I am enabled in this paper to double the number of .species, besides giving addi tional information concerning an imperfectly known specie.s, nearly all the additional forms coming from the coal measures of Penn-jylvania ; not all, however, as before, from the lower and middle series, but also from tiie upper coal mea.sures, .showing that Mylacris has the same range as Litho;nylacris. Tlie .species of tiie genus may l)e dis- tinguished by the following table.
Ket to the Species or Mvlacris.
1. Extemoiiu'tlian veins siipciior or apical. 2
1. EiteriKinicdian veins inferior or apical. 7
2.', Ext<>monie(lian veins distinctly superior. 3 i. Extcrnoniediaa veins rather apical than su-
jicrior. 5
3. A\w!i. of wing falling in the niiildle line, the costal and inner margins being about equally arcuate. 1. J/, lu-^loiicnsis,
3. Ape.v of wing falling below the nii<ldle line,
the inner margin being much straighter than the costal. 4
4. Costal margin curving inward on the basal
third of the wing. 7. M. anthracophilum. 4. Costal margin bent abruptly inward at ex- treme base of the wing with no previous inward cui-ve. 8. M. priscovolans.
MKMOIKS ROST. SOC. NAT. HIST. \nl.. III.
Externomedian area occu]iying the a]iex of the wing. '2. M. Ileeri.
Externomedian area falling wliolly below the middle line of the wing. G
^lediastin \\ veins comparatively few and distant ; sca])ular vein forked at b: se.
3. M. antiquum.
^Mediastinal veins numerous ; scaindar branches all ernited from a single main branch. 4. Ji/. luclfui/um.
Costal much more curved than inner margin. ^
Costal and inner margin similarly and syra- metr'.cally curveil. 9
Costal margin very strongly curved in the mediastinal area, which s^carcely reaches to tlie middle of the wing. 6. M. carbonum.
300 ^- II- SCUDDER OX THE
S. Costnl margin gently curved in tlio medias- brond at tlic base ns boyoiid.
tinal area, which extends considerably U. J/; Mansficldii.
bevond the middle of the wing. ir 9. Combined mediastinal and scapul ir areas 5. M. pennsylvanicum. much broader near the middle of tbo \vin2r
9. Combined mediastinal and scajmlar areas as than at the base. 10. j\I. via',
1. Mylacris bretonense.
Blattina hretonensis Sciuld., Can. Nat., vii, 271-272, fig. 1. Figured also in Dawson's Acadian Geolog}', Snppl. to 2d ed., p. 55, fig. 5.
Mylacris bretonense Scudd., Mem. Best. Soc. Nat. Hist., iii, 41-42, pi. 5, fig. 1. Sydne>', Cape Breton.
2. Mylacris Heeri.
Blattina Ileeri Scudd., Can. Nat., vii, 272, fig. 2. Figured also in Dawson's Acadian Geology, Suppl. to 2d. ed., p. 55, fig. 6.
Mylacris Ileeri Scudd., Mem. Bost. Soc. Nat. Hist., iii, 43-44, pi. 5, fig. 11. Sidney, Cape Breton.
3. Mylacris antiquum, nov. sp.
Front wing. The inner edge is inipai-rect and a little of tha tip is gone, but the rest of the wing, which is remarkable for its approach to Lithoraylacris, is pretty well preserved. The mediastinal and scapular areas together certainly occupy the Tiiajor part of the wing and the externoinedian area expands but very little apically ; the wing, however, is broad and full and closely approximates M. Heeri. The humeral lobe is full and angular, with the corner well rounded off, the costal margin scarcely convex beyond the base ; the wdiole ■wing was probaldy a trifle more than twice as long as broad. The veins originate from a little below the middle of the base and curve upward at their start until they reach the middle, when they are very nearly straight. The mediastinal area is very large indeed with few and rather distant veins, forking once near the base, reaching the end of the mid- dle third of the wing. The scapular area occupies the rest of the upper half of the wing, the vein itself dividing close to the base, the forks again dividing near togetlier in the basal third of the Aving, with a still further branching of nearly every ramus halfway to the tip, and again of .some near the tip ; these branches are all straight except the lowest near the tip which turn slightly upward, thus throwing all the extremities of the branches above the middle of the tip and giving the scapular-externomedian interspace a .slight sin- uosit}-. The externomedian vein is straight and forks first just before the middle of the wing; each of its branches dichotomizes more or less but without much further divarica- tion, so that the area is more crowded with veins than those above. The internomedian area is tolerably large, notwithstanding the considerable size of the anal area, for it reaches well toward the extremity of the inner margin of the wing, sweeping thither in a some- what sinuous curve with unusually longitudinal veins ; in the single .'specimen the vein ha.*' but three branches, the middle one forked near its origin, the others simple. The anal
SPECIES OF MVI,.\< i:l>. 301
area is very larj^t', the anal furrow lieiii;^ very proiKumced, broadly curved and extemliii}^ far outward in a somewhat unusually lonj^iludinal course nearly to the middle (jfthe wing; the anal veins appear to belong to two sets opposed to eacli other, an upper with inferior, and a lower witli superior branches, all very longitudinal, nearly parallel with the costal margin and nearly all simple ; the upper area is just as longitudinal as the lower and (piite independant of the course of the furrow, leaving a large sub-triangular space near the niost strongly curved portion of the lurrow quite devoid of veins.
The species is a very large one. the largest of the genus yet known ; the fragment of the wing iK'iiig -M mm. long (its probable entire length .37 mm.) and its breadth about 17. r) nun. ; or, t!je breadtii to the length as ai)out 1 : 2.1. Ail the veins are in very dis- tinct relief, with the interspaces deeply sunken between them ; there .seem to be no .surface markings. The specimen is curiously pru^erved. the edge of one-half of the nodule Ihlling longitudinally across the inner margin, following nearly the miil-space be- tween the two sets of anal veins as marked by the light belt in the larger figure we shall hereafter give; all the parts below this, together with the opposite left wing (given in the other figure) lie over the edge on the back side of the stone, the plane of which lies at an angle of about 45^ with that showing the main portion of the right wing, and forms the present surface of the nodule ; the other half of the nodule sliows the counterpart of our larger figure.
Thi.'^ species is, as we have said, most nearly allied to ^[. Ilicrl in the great amount of space occupied by the mediastinal and scapular areas as well as by the course of the anal furrow, and apparently by the peculiarities of the anal veins. It is, however, a very much larger species than it (or any otlijr species of Mylacris), and the peculiar dichotomous division of the .scapular vein .separates it at once from every species known, and it is nearly as peculiar for the longitudinal course and sinuous sweep of the internomeilian veins. In the general positions occupied by the different areas, it resembles J/, hicifufjum, with which it better agrees in size ; but it disagrees with it, not only in the jieculiar division of the scapular vein, but in the less crowded and more regular veins of the mediastinal area, and the more rounded humeral lobe.
The specimen comes from the famous locality of Mazon Creek, and is in the collection of Mr. R. D. Lacoe under the number 203G. Having been received after the plate was en- graved, figures of the species will be given on some future occasion.
4. Mylacris lucifugum nov. .sp. I'l. 27, lig. 8.
Front wing. The l)asal portion, excepting the anal area, is preserved, but at least the apical third is gone. There is a rectangular rounded shoulder of considerable extent, minutely marginate, but without neuration ; the basal, preserved half of the costal mar- gin is straight, but at the extremity of the fragment begins to curve slightly, and this with the direction of the veins makes it probal)le that bej^ond this it was gently arcuate, the tip rounded and the inner margin nearly straight. The mediastinal veins are confused at their base by vegetable remains and may be inaccurately given in the plate, but they apparently occupy the area marked, or more than one-third of the fragment and nearly
302 S. H. SCUDDER OX THE
ono-fourth of tlio wiiiii": thev diverge iVom a point before the base of tlie wing and are very straight and fork somewhat — just how much the preservation does not permit one to say. The scapular vein passes in a very straight course down the middle of tlie wing with a slight obliquity from above downwards in passing distally, but probably terminates at the apex ; it emits a number (4 or 5 are preserved in the fragment) of straight, approximate, so far as we can see simple, branches parallel to the mediastinal veins. The externomedian vein is slightly arcuate, but otherwise parallel to and equi- distant from the scapular, forks before the middle of the wing, each of these branches again forking, but not widel^y ; in the part lost they probabl\- branch more l)ut can hardlv occupy much .space on the border. The internomedian vein is gently and unifonr.ly arcu- ate and probably terminates where the inner margin begins to curve considerably toward the tip ; in the basal half of its course it emits four or five simple, occasionally simply forked branches, more faintly traced than the other veins of the wing and which curve gently in an opposite sense to the main stem. The anal furrow is slight and ftiintly impressed, gently and regularly curved througliout, terminating probably at the middle of the wing; the anal veins are not preserved.
The species is a large one, the fragment being 22 mm. long, while the entire wing can hardly have been less than 3.3 ram. long, and its breadth, which is preserved, is 15 mm., making the breadth to the probable length as 1 : 2.2. The veins are slightl}' elevated and distinct and regular. There appears to be no reticulation or cross venation whatever, and the surface of the shoulder of the wing is particularly smooth.
The species aj^pears to be most nearly allied to JM. Heerl, but it is much larger than it, or, indeed, than any other species of the genus, except the preceding, and its mal furrow is even more longitudinal and less arcuate than in M. Heerl ; it differs also fiom the latter in the much greater number and closer approximation of the mediastinal nervures and in the downward sweep of the externomedian veins, probably causing the area to occupy the margin wholly below the apex of the wing. In the stout square humeral lobe of the wing, in which the veins are obliterated, it seems to be peculiar, as it is also in the regularity of the curve of the anal furroAv.
The single specimen upon which the species is based Avas found by Mr. R. D. Lacoe at Port Griffith Switchback, near Pittston, Penn., and bears the No. 2017 in his collection.
o. Mylacris pennsylvanicum.
PI. 27, fijr. 11.
Mylacris pennsylvcmicum Scudd., Mem. Bost. Soc. Nat. Hist., iii, 44-45, pi. 5, figs. 13-14.
A second specimen of this species enables me to supplant the previous description from an imperfect .specimen by a better ; the present specimen is also imperfect but makes up in part what the other lacks.
Fore-wing. The distal extremity is lost in each, but more of the costal is preserved in the new specimen, while the inner margin is almost completely lost in both ; the form of the wing can nevertheless be judged with probable accuracy ; the course of the veins indicates a .shorter and stouter, as it certainly is a broader wing than in 31. Heeri. The
Sl'KCIKS OF .MVI.A( 1;IS. .-{O^
luiiiicriil IoIk" is jiioiiiiiiciit, its strai^-lit Itjisal side hi-iit at nearly a rijrlit aii^'Ii- witli tin- arcuate rostal v<\<.'v, tlie aj)j!;lt' rouinle-d oil'; tlio costal iiiai'i^iii is coiisirU'rably arcuate, luori' stntujrly at extreme liase and lieyoud tlie niidille than in the inteniie<iiate straij^liter portion wlu-re the arcuatiou is very ^^tuth'; in lliis respect the (ij^,;re previously given i.s sliji^htly inaccurate. The course ol this niar<,'in with the hreadth (d'the wing and the direc- tion of the veins ri'udir it prol)alde that the rest of the wing had the loriu given in the dotted lines in the ligure, in which the apex of the wing tails within the middle line, and slightly changes the form from what was given lieliu-e. ami which we had alreailv noticed as pri>l):il)ly not correct. The \cin< originate from liic miildlc of the wing and curve u little at liie base. The mediastinal area has a liasal width of very nearly half the wing, nntl, separated Iroin the sca])ular Ity a .■^caicely curved line, strikes the costal margin at ahont the end of the second thinl of the wing (in one specimen ])i()liaMy a little le.ss than that, in the other proi)aldy a little more) ; the hasal part of the costal margin is very narrowly and delicately niarginate ; the part of the mediastinal art-a next the humeral angle is not veineil. hut helow it are four or live scarcely curving, long, gently diverging, simple or deeply forked veins ; the middle ones simple (possibly united nearer the base, where they are not sulliciently preserved to see it), the others forked. The .scapular vein is gently and broadly sinuous and probably terminates just above the apex of the wing; in the ba.sal part of its cour.se it runs closely parallel to the costal margin and a little nearer to it than to the inner margin ; in the latter half or more it curves in an opposite sense to the ct)stal margin ; it commences to l)raii(li very near the base, and emits four or five branches, simple or lorkid, rarely compouiiil. long and nearly .straight, having the same direction as the outer mediastinal veins ; in one speciuien the basal, in the other the apical vein is compound, the rest generally sim|»le. The externoniedian vein is somewhat arcuate until it divides, a little Ijcyoud the l)asal third of the wing ; both these branches again divide scaic ly beyond llie mulille oltlic wing, llic uppermost again forking iint long after; probal)ly they fork more, and, as in the central part of the wings, (ill their area with dichotomizing veins whose general direction is nearly longitudinal, with a slight down- ward tendency, but closely approximated, so that on the edge the veins occupy a narrow area mostly below the apex of the wing. The internoniedian runs in a broadly sinuous course parallel to the preceding vein, probably strikes the lower margin where the win" begins rapidly to narrow, and emits four or live. ])erliaps more, simple or ba.sally forked, indistinct, a -cuate branches, which occupy upon the inner margin about as much .'••pace as the scapular upon the costal margin. The anal I'urrow is strongly impressed upon its basal half or more, less so but still distinctly beyond, is composed of a pair of closely appro.xi- mated fine grooves, and is regularly and not very strongly arcuate, terminating on the inner l)order at some distance l)efore the end of the mediastinal area, at just about the midille of the bonier; the anal veins aie numerous and closely crowded, nearly all simple, and all .slightly arcuate.
It is a tolerably largo species, the breadth of the wing being 13.5 mm. ami its length proljablj' 2G nun. ; or, its breadth to its length about as 1:2; the actual length of one frag- ment is 19 mm., of the other 20.75 mm. ; the condition of the first i.s mentioned in the former description of the species; the second specimen is represented both by that drawn and by its reverse; iu the one drawn the veins are iii relief and the figure represents, therefore.
304 !^- "• SCUDDER ON THE
the umlor surface of a riu-lit winjj; (or a cast of the opposite) in wliicli. as in the individual previously described, slight indications of transverse wrinklings may be seen here and there and especially in the scapular area, but there could have been no regular or defi- nite reticulation.
The species differ from J/. Ileer'i, its nearest ally, in the stronger curvature of the anal furrow, and in the greater width of tiie anal area but not in its greater al)breviation, a^ previously stated, the breadth of the area making up for the greater curvature of the furrow; it also differs, as before stated, in the sinuosity of the scapular vein, the more arcuate line of separation between the mediastinal and scapular areas, and the more crowded branches of all the areas but the internomedian ; the wing as a whole is also pro- portionally broader.
The new specimen comes from the same bed as the last, and was sent me liy Mr. R. D. Lacoe of Pittston, in whose collection it bears the number 202-1. It occurs on the same stone as M. carhonum.
0. Mylacris carbonum nov. sp.
1^]. 27, figs. 6, 7, 10.
Fore-wing. The greater part of the wing is preserved, but the apical fourth or fifth ot the tip is missing as well as a patch along the inner margin from the tip to the anal area. From what remains, the wing had probably a form somewhat like that of M. antlira- coj)hUum, but was not quite so tapering, the costal margin being a little, le.ss convex; the inner margin next the anal area was straight. The veins originate from the middle of the wing, but do not curve at the base. The mediastinal area has, therefore, a basal width of half the wing and extends to beyond the anal, or probably to just about the middle of the wing ; in the humeral portion of the area no veins can be made out, but in the opposite h.alf two compound veins can be seen, the first consisting of a pair of simple veins united basally. the second of a pair of forked veins united Ijasally very near the extreme base of the wing; both ofthe.se veins are forked about midway in their course, the outer twice, clo.se together. The scapular vein can only be traced basally to where it begins to curve inward, a little beyond the forked mediastinal vein just described ; it, together with the next vein in close juxtaposition, curves strongly but only for a very short distance, and the curve of the anal furrow would seem to preclude any further continuation of the curve, so that in reaching the base of the wing it must resume its outer course ; beyond this basal curve it is straight and must strike at the apex of the wing, though it cannot be traced throughout; in the fragment it has five equidistant branches, and probably has a couple more before the tip ; the third of these is forked not far from the base, but all the others, so far as .-seen (excepting the first) are simple and .straight, although very long, for the straight main vein runs .sub-parallel to the costal margin scarcely above the middle line of the wing ; the first branch, however, differs from the rest ; it originates where the main vein begins its straight course, and continues the direction of the dedected basal part of the vein, and emits from its apical side three long, straight, equidistant offshoots, the first from its very base, the last half way to the margin. The externomedian runs in a straight line scarcely below the middle of the wing and first divides a little before the middle, and in
Sl'Kl'lKS nl MVI.ACins. liO;',
tlio frai,^ iiciit lias tlirt'C siiiipK' sli;ilitly ciuvfil l)i-;mclif<, tli -ir cnnvi-xitii'-i towanl tin- anal area, and tlu-ir Ijast-s i-onsKk-ralily lurtln-r apart lliau llie scapular hraiirlics. TIk- iiitt-Miio- mt'fliaii runs parallel ami close to the externonieilian vein and its l»asal iuMncli, prol»alily reaching the inner margin more than half-way from the anal furrow to the apex ; it com- mences to divide as soon as there is space for it opposite the iniiMle of the anal Inrrow, the first branch forking, and the second branch originating, next the first branch of the externoinediaii vein ; a third branch springs at a similar distance further on, but more cannot lie seen, 'fhe anal finrow is toler.dily <listinct. curved gently throughout ami bent a little in the midille, teruiinating at ukuc lli;iii oue-tliird of the distance towanl the tip, or about ojipD-ite the (irst divaricitiou ol the externoniedian vein; the anal veins are exceedinglv niuiuTiiii< and crowded, many of lliv-iu forked, some of them doubly, gener- allv near the middle of their course ; those next the anal area are olditerated, but if they retained tlie cli;iracter of the remaining part of the area, about twenty veinlets must have impinged u[)on the outer margin in the anal area ; those lying next the angle of the wing have a sinuous course, changing to a simple gently arcuate curve toward the anal furrow.
This Iraguuut represents a species of tolerably hirge size. t!ie breadth ol" the wing being lo.o nnu., the length of the fragment 23 mm., ami the preserved length of the wing about 27 nun. ; so that the breadth to the length must have been as 1:2. It is the under surface of a right wing, all the veins and the anal furiow being in relief and, with the exception of the anal veins and the internoniedian branches, somewhat prominent. No trace of reticulation or transverse wrinkling can be seen.
Tlu' speciiueu occar.s on a piece of i)lack carbonaceous shale with reed.s al Cannelton, rViiii.. and was sent me by Mr. R. D. Lacoc with the number 2022 a.
After the al)ove descri|)ti()n was prepared two other specimens came into my hands through the indefatigable exertions of the same friend. As they are less perfect than that already described, the poiuts in which they vary from it may best be pointed out by separate description.
The first, No. 2022 b, c, occurs in duplicate on the same stones with No. 2024, M. penmylcanicum, and was found at Cannelton. Penn.. in the same shales as that which yielded the type. It preserves a middle fragment of the wing, with a portion of the costal margin only, and a minute bit of the inner margin ; no part of the wing appears which is not seen in the type, unless it be a little mure ol' the exteruomedian vein. It is a little smaller than that specimen, its width at the end of the basal third of the wing being 11 nun., where in the other specimen it is fully lo mm. In 2022 b, c, all the mediastinal veins are straight and simple as far as they can be seen, .so that they do not divide beyond the base, giving this area a very diiferent appearance from what it has in 2022 a. The scapular vein, although extending on the fragment as for toward the apex as in 2022 a, has only three branches, the outer two simple so far as they can be seen, the basal, how- ever, dividing at its very base into two forked branches, the upper fork of the upper branch again dividing ; this is somewhat different in description from the condition in 2022 a, but is really much the same as if the second offshoot of the first branch were united to the first offshoot and they together arose in the axilla of the first branch. The externome- dian vein also differs somewhat and reminds one rather of the arrangement of that vein
306 S- "• SCUDDER ON THE
in JA peiinst/h'miicum. It commences to <livi(lo at tlio same point, but instead of two or throe simple inferior I)ranelies with a tolerably good expansion it I'oiks narrowly in a longi- tudinal fashion, and each of its forks simultaneously divide in a similar way a little I'urther on. I>elow this the wing is not well preserved, but the veins that do show do not appear to difler from the type.
The second additional specimen, No. 2022 d, comes from a different locality, the Empire Mine at Wilkesbarre. Penn.,anl was found at the horizon of the E. vein on a piece of gray shale filled with remains of ferns, etc. This specimen, excepting in the internomedian area, preserves also no part not found in 2022 a ; it is of the same size as it, measuring fully 13 mm. in width at the same point; the basal half of the costal border (excepting the humeral angle) and a fragment of the inner margin beyond the anal furrow are preserved; the costal margin is represented as perhaps too convex in the figure, where it should cor- respond ver\' closel}- to 2022 a. The veins of the mediastinal area are I)etter preserved than there and resemble their disposition more closely than that of No. 2022 b, c, being compound or two-forked awa}' from the base, while in 2022 b, c. they are all simple ; they diverge from one another more widely than in 2022 a, ami those toward the humeral angle are sunple, distant and incomplete. The scapular vein agrees very closely witli its disposi- tion in 2022 b, c, differing on!}- in having an additional branch in the same space, in which it agrees more closely with 2022 a, and in having the axillary branch simply forked instead of compound. The externomedian vein does not agree with eit'.ier of the other specimen-; ; its main stem runs closely parallel to the scapular and has only one branch, which is emitted in a similar position to that of the first branch in the otiiers; this branch, however, is compound, its upper fork dividing, and the whole area Avhich it appears to occupy, in the lost part of the wing, as broad as in 2022 a. The internomedian area appears to be exactly as in 2022 a, but as a general thing only the terminations, while in 2022 a only the bases, of the veins can be seen ; the fragment of the inner border at their tips is straight. The anal furrow appears to be more gently and regularly curved than in 2022 a, Init the difference is slight. No anal veins are preserved.
The differences between these .specimens, although considerable, do- not seem to be more than individual and strengthen rather than weaken the validity of the other species of the genu.?, and .support the distinctions upon which they have been .separated irom one another.
This species, peculiar for the excessive crowding of the veins in the anal area, falls in its general features between 31. pennsyhanicum and M. anthracojihilum. From the latter it differs in that the veins do not curve downward at the extreme base of the wing, but have a sinuous course, the greatest curve being nearly as far out as the middle of the anal area ; in the simplicity of the scapular veinlets and the composite character of the ffrst branch; and in the crowded condition of the anal veins in contrast to the comparative openness of the neuration elsewhere, nearly all the nervules being long and simple, while in M. anthraco- ph'ilum nearly all are forked about the middle. From M. 'pennsuUanicum, which comes from the same general locality, it differs in its more tapering form, due to a greater con- vexity of the costal margin ; in the stralghter course of the scapular vein, the more gentle sweep of the anal furrow allowing a much narrower space for median veins, which in M. pennsyhanicum first divaricate at the .same point, but here, notwithstanding the narrowness
SPECIES OF .>fvi.Arnis 307
ol" tilt' space, tin- intenioiiifdiaii liist links hftwot'ii tin- lirst ami sccdiid hiaiiclics of tin.' scapular, wliile in M. /niiii.si/h'diiiciiin oiilv opposite tlie base <jI lln' tliinl liiaiicli ; tin- anal veins are also niurli inon- ninnerous in tin- ]irfsent species.
T. Mylacris anthracophiluni
MyUurls aitl/irarojj/iilitin Seudd , in W'nrth.. (i.ol. Snrv. 111., m, .j(;,S-.')7(l. Ults. o. tj. — lb., Mem. Bo.st. Soc. Nat. Ili.st., ill; l-")-17. pi. -j. Ii;:s. G-S. Colchester. 111.
8. Mylacris priscovolans
PI. -JT. li._'. '.'.
Fore-\vin<;. A bit ol'the extreme ti[i and a eonsideralile part oftlie wing ne.\t tlieiinier border is wanting, although the position of the m:irgin itself is indieatt'd by a depressed line upon the stone, showing the form of the wing to have closely resembled that of J/. earbonum. being broadest at the extreme base, narrowing toward the apex with increasing rapidity, so that the inner margin being straight, tlie costal margin is considerably curved ; the tip. though narrow, is broailly roundetl, and lies within the median line of the wing ; the humeral lobe is very square, rounded only at the extreme angle. The mediastinal area is of a very regularly triangular form, one-third the width of the wing at the base, and apically extending considerably beyond the middle of the distal half of the wing ; its three or four veins fork near the base, and extend their long, simple, or branching ra^-s far out to the margin. The scapular vein is rather strongly curved near the base, beyond which it sweeps with a very slight opposite arcuation, sul)parallel to the costal margin to the very tip of the wing; its four or five long and mostly simply and deeply forkeil branches have a completely longitudinal course, and the area forms a triangle of about the .same size and regularity as the mediastinal area, but with an oppo-site disposition. The e.xternomedian vein passes with a curve similar to, but stronger than that of, the .scapular vein, diverging from it, and terminating on the inner margin beyond the middle of the outer half of the wing; but within the extremity of the mediastinal vein, its long, arcuate, simple, or simply forked branches being superior. The internomedian vein is again curvei] in the same .sense as the externomedian and has about four simple or forked arcuate bran^dies. The anal furrow starting from above the middle of the wing is deeply impressed, regularly and con- siderably arcuate, but more strongly curved in its basal than its apical half, and terminates at the middle of the inner margin ; the anal veins are oblique or arcuate, simply forked or compound, .somewhat irregular and hardly more crowded than the internomedian veins.
The species is a large one, the wing measuring 2G.5 mm. in length by 14. G mm. in breadth, the breadth being to the length as 1 : 1.8 ; the continuous part of the fragment is 25 mm. long and 12 mm. broad at the base. The wing is a right one, the under surface (or cast of the upper) having been figured, and the veins are distinctly and sharply impressed ; no sign of cross venation or of any reticulation appears. The wing is peculiar for its excessive breadth at base combined with its square-shaped humeral lobe, which causes it to taper from the very base ; it is nearly allied to M. earbonum and M. anthracophi- luni, differing from both in the peculiarities just noted, as well as in the less produced and
IS
308 S. II. SCUDDER ON THE
more fiillv rounded apox. and tlio oonsidorahly greater extent of the mediastinal area; the veins of the anal area are less crowded and less regular than in M. cnrhonum, and the externomedian branches are superior instead of inferior ; hence it agrees hetter with M. anthracophilum, but the externomedian vein lacks the basal 1)raiich found there and the anal veins are not so regularly disposed ; the much less strongly curved costal margin i dependent upon the basal breadth of the wing, already mentioned.
The specimen figured is numbered 2031 a. in Mr. Licoe's cabinet, and its reverse No. 2031 b. It comes from Cannelton, Penn.
0. Mylaciis Mansfieldii.
Mijlacris Mansfieldii Scudd., Mem. Bost. Soc. Nat. Hist., iii, 47, pi. 5, fig. 15. Cannelton, Penn.
10. Mylacris ovale nov. sp. PI. -27, fi,--. .').
Fore-wing. The anal area and the extreme base of the wing is absent, but the larger part of the wing is entire with perfect margins except an unessential fragment, showing the wing to have been a little more than twice as long as broad, very regularly oval, with similar and symmetrical costal and inner margins and a rounded subacuminate tip. It is peculiar for the basal narrowness of the mediastino-scapular area. The mediastinal area is very .small though reaching beyond the middle of the wing for next the base it is not more than one-fifth the width of the wing and begins to narrow opiiosite the end of the anal furrow; its veins are only two or three in number, simple or forked, very g'utly arcuate and subparallel, the limitation between the mediastinal and scapular areas being arcuate in a sense opposed to that of the anal faiTOW. The scapular vein has a consider- ably arcuate cour.se throughout ; starting so as to be fairly within the upper fourth of the wing, it curves first downward and then upward with a regular sweep which includes two- fifths of the w^ing in the middle, and terminates just above the apex of the wing ; it emits in this specimen four branches, gently arcuate in the same sense, simple, singly or doubly forked, all but one of which are thrown off in the basal third of the wing, not very far apart. The externomedian vein has an arcuate course in the same sense as the preceding, running in the outer half of the wing subparallel to the inner margin ; it commences to divide before the end of the anal area and emits four inferior equidistant branches, the last opposite the end of the mediastinal area, the extreme ones simple, the middle ones simply or doubly forked, all consideraI)ly curved in the same sense as the main vein, at least at their base. The internomedian vein curves again in the same sense, taking no curve toward the inner margin until close to the tip, and reaching the margin fartlier I'roiii the apex of the wing than the .scapular vein, so that the larger part of the externomedian area is below the apex ; it emits half a dozen or more very long, simple, or simply forked veins, all arcuate in the same sense, though more gently ; three of them arising near the ba.se far within the tip of the anal furrow, three other near the middle of the Aving at no very great distance apart, and probably an apical one. The anal furrow is lightly im- pressed, very slightly arcuate and probably terminates before the end of the l)asal third of the wing. No anal veins are preserved.
SPECIKS OF MYLACRIS. 309
Tlie speoics i-; a 1 ir^i' oiu'. tin- iVagiiu'iit mcu^uring lil.j nun. l<»iiir ami \'2 mm. lnuail ; probably the eiitiri' length was not less than 28 nun., ami the breadth to the length lus 1 : 2.3. The wing is a right one, of wliieh the under siuliice is shown in the figure and the iippi r in its le-s eomplete eounter|)art. The veins are distinctly marked, ami HOine- wliat promin -nt on the under surface, exeepting those of the internomeilian area and all the veins in th*; apical fourth of the wing; no cross veiu'* or retieidalion can be discovered.
This sp.'cies ag.ees with .1/. M inxfuld'ti in it'* form and size and in the inferior origin of thee.xternomedian br.inche.s, but it differs decidedly from it, as well as I'rom all other species of the genus, in the sweep of the niediiustinal and .scapular veins, a.s well as in the exceed- ingly restricted area they cover in the basal part of the wing.
The specimen comes fro u Canndton, Penu., and wa-* kindly communicated by .Mr K D. Lacoc, in whose collection it bears the No. 2033.
Explanation of Plate xxvii.
[All the specimens are from the collection of Mr. U. D. Lacoe.] Fi;;. 5. Jfi/fucris ovule, if. No. 2(i33. Drawn with i-aniera luciila by S. II. Seuclder. Fiir. 6. Mi/htcrits curbonuin. f. Xo. :i(l22 h, from Caniielton. Drawn by J. S. Kin^slcy. Fiir. 7. TItti same. f. No. 2022 d, from Wilkesbarre. Drawn by tiie same. Fiir. S. Jli/hicris liici/iiffuni. f. No. 2017. Drawn by the same. Fiij. 9. Mi/hicris pritscovolans. \. No. 2031. Drawn by the same. Fij:. 10. Jfi/liicrl.i car/wmini. ^. No. 2022 a, from Canni-lton. Drawn by the same. Fig. 11. Mijhicris peniisylvaiiicum. \. No. 2024. Drawn by the same.
Tlie other figures belong to the jaucediiig memoir.
■.leni'/ii f. :-
SCUDDKR ON NEW CARBONIFKROUS MYRIAHODS
TStncl>irl>3a>i^
•':;CUDDER ON CARBONIFEROUS MYRIAPODS AND COCKROACHES
XI. Notes ox the Pia;riNr, Fuor;, IIvi.v Pickeringii LeConte. Bv Mauv II. Hinckley.
(I'rofctitcd OotobiT .3, 1883.)
Ilylodes PicTceringii Holbr. N. Amer. Ilorp., vol. iv., p. loo, pi. ?A. Ilylodcs Pickeringii Nichols, Journ. Es.scx Co. Nat. Hist. Soc, No. 2. Pickering's Ilyloden Storer, Report on Rept. Ma,ss., p. 240. Hyla Pickeringii LeConte, Proc. Ac. Piiilutl., vol. vii., p. 429, 1854. Ilylodes Pickeringii DeKay, New York Fauna, p. G9, fij;. 51. Acris Picker- ingii Giintli., Brit. Mus. Cat. Batrachia Salientia, p. 71. liylu Pickeringii Boulenger, Brit. Mus. Cat. 1882, p. 399.
Description.
Adidt. Head moderate in size, as broad as long, about two-fifths length of body for male, a little less for the female. Muzzle somewhat pointed, and projecting beyond mouth opening; canthus rostralis distinct; loreal region somewhat concave; nostrils nearer tip of snout than eye ; pupil horizontal, when partly dilated show.s angle at the base ; tympanum small and indistinct ; tongue heart-shaped, free behind ; teeth in two small rather oblique groups, back of inner opening of nostrils. Male with dark colored vocal sac, outside muscles of throat. Ann longer than tibia, thick in males; fingers free, first short. The hind limb being brought forward the hoel reaches the eye ; tibia a little longer than thigh ; heel and toes a little more than half as long again as the tibia; feet less than half-webbed ; tubercles under hands and I'eet moderate ; two metatarsal tuber- cles, outer small and obscure ; tips of fingers and toes dilated into moderate sized disks. The skin is either smooth or minutely granulate above ; beneath granulate ; a fold acro.S9 the chest. Coloration in variable shades of brown above, dotted with darker and with ir- regular lines not always symmetrical, frequently an x-shaped marking on the back ; a dark brown streak from tip of snout through the eye to about the middle of the .side of body ; generally a dark band or chevron between the eyes ; limbs cross-barred ; beneath dull creamy-white, female sometimes with a few spots of brown or dusky on throat and chest; region of groin often yellow. Iris reddish, especially when frog is excited.
MEMOIRS U03T. SOC. NAT. HIST. VOL. III. 41
312 MAUY ir. IIIXCKLEY, NOTES
AviM-;i>re length of a number of full-grown niiiles 24 mm. ; females a little longer, when fully grown, than males.
Tadpole. Length of head and body about twice the width of the latter. IIea<l l)road, snout large and blunt; eyes prominent; pupil rounded or tending to more or less of an angle at base; nostrils large, nearer the eye than end of snout; distance from one another about equal to their distance from eye. Mouth broad (fig. 2), upper lip curving upward in the middle, edge even or elongated into scallops or points, fringed with deep-brown, horny teeth, as is also the divided fold beneath it and the two folds across the under lip ; the under lip shows variability in the presence or absence of a short space of fringe set in the papillose border of the lip, and when the fringe is present its position and size vary; sometimes it is reduced to one or two teeth attached to about the same number of papillae. The papillae across the border of the under lip are placed either in a single or double I'ow ; if double and the fragment of a fringed fold i>! present, I have found the latter inserted among the papillae of the inner row. Tlie teeth forming the fringe in the mouth are com- posed of a series of teeth placed one above the oiher (fig. 3) ; the base of each tooth is in- verted cup-shaped, the upper edge or rim dentate ; two ^ teeth or a double tooth occasionally appears in the series (fig. 4). The beak is prominent, deep-brown in color ; edge of upper and lower mandible dentate. Spiraculum on the left side, opening nearer the base of tail than end of .snout. The tail measures about twice the length of head and body ; the mem- branous portion of the tail is divided into two pretty equal parts by the muscular portion which runs to a fine point. A suture or band runs the length of abdomen from branchial cavitj- to end of body. Head, body, and tail are traversed by glandulous lines more or le.ss distinct ; those termed " dorso-laterales " by M. F. Lataste (Etude sur le Biscoglossus piciits ; Actes de la Soc. Linn, de Bordeaux, vol. xxxiii, 4 ser. t. iii, p. 313) ai'e most con- stant in presence and disposition. The tadpole leaves the membranous shell of a pale yellow color, dotted with deep-brown on head, body, and tail (fig. 1). During the first few days the brown pigment cells gradually increase, generally leaving intact a narrow space of yel- low from before the eye down each side to the base of the tail ; at the same time a few spots of gold-colored pigment appear on head, body, and tail. By the eighth day numer- ous groups of deep-brown, almost black, pigment cells have spread over the upper surlaces, excepting in some instances the narrow space of yellow, which retains its original color till the golden pigment, which gradually increases on the tadpole, forms here for a while a con- spicuous line, broad and noticeably brilliant, each side the base of the tail ; across the upper edge of this member lines of the same color sometimes occur. With the budding of the legs (third stage of Duges), the gold-colored pigment begins to show a brilliant sheen of green ; that of the iris, however, tends to the reddish hue found later in the fully developed eye of the frog ; as much of the eye as is seen outside the iris, is of a greeni.sh color. The vivid green sheen gives the tadpoles a prevailing tone of that color, excepting on the lower portion of the sides of head and body, where there is a roseate hue ; the dor- sal surface has a bluish gloss. The tail is more or less flecked with brown and black. By
1 M. Van Bambeke. Bull, de 1' Acad. Royale de Bel- so comportent entre cllcs ; la dilatation en entonnoir du
gique, XVI, .347, pi. i et II. Reeherches sur la structure de crochet faisant saillie sur le bord llbre de la 16vre, coiffe le
laboucliechezles tetards des batraciensanoures. " Rien de corps du crochet suivant ; le gaine de celui-ci revolt a son
plus curieux que la manierc dont les dents de chaque serie tour le corps du troisieme appendice, et aiiisi de suite."
0\ TIIK I'KKI'INC mon. 313
the iiiil of ii inaj^nifying glass tlic uppi-r surfucos of the hotly iiiid the tiiil nre seen to he ovcr- 8pre;ul with !i hioken lu-twoik of line, deep hrowii, or hlaek lines. Tiio hram-hi.-il ciivity is more or less pigmented with the colors of the upper surfaees ; the uhdoinen is silvery white. Kiitoriiig the foiirtli stage ol Diigtis, wliieh hegins when tljc anns are thrown out and ends with the resorption of the tail, the greenish sheen gradually disappears and the skin develops the color and texture of the frog. Tadpoles of the same age vary in size, even when grown under tlie same conditions ; when these are favoral)le, however, they measure oO-oj mm. from tip of snout to that of tail, on reaching the limit of their size.
Habits.
//. Picl-crinrjii is the most al)undant of tlie frogs found in Milton, Mass. With /'. si/l- valicd, the wood frog, it is the last species to hecomo silent and retire from tlie surface in autunui, and with that species responds earliest to the mild temperature of the variable New p]ngland spring. The piping is not general, nor heard first at the water. The frogs passing the winter in favorable situations on the land give voice earliest as well as con- tinue it latest, for the notes o^ Pickering U, although most emphatic then, arc not confined to the mating season. In the first mild da^'s when the mercury reaches oO" and 00", days that occur in some .seasons as early as the last part of February, a few tremulous cliirp.s, given as if the frogs were not fully aroused from their winter torpor, come from the sunny, soutlierly slopes of wooded liills wliere the same scattered voices presumably were last heard in the autuiun. In these warm nooks, protected from the north and east winds, snow and ice disappear fust. The wet. llattened, and matted leaves soon become dry and crisp, rustling with every breath of wind that stirs them. With the exception of traces of snow, perhaps on the northerly slopes of the Blue Hills, and the overflow of the meadows, the landscape is scarcely changed from what it was in tlie Indian summer days. The signs of advancing vegetation are hardly perceptible ; there are the same browns and neutral tints, softened by the haze of the south wind, and a like stillness in the wood giving distinctness to any sound. Although Pickeringii may be heard on these days before sylvadca has appeared in the swamps and ponds, observations of many seasons note the latter species invariably collected at the water and egg-laying in the localities both fre- quent, in advance of the former. As sijlvatica gives a note less liable to attract attention, the awakening of those individuals hibernating on land among the dead leaves is not .so promptly known as in the case of Pickeringii. With Ijoth species the time of appearance varies with the temperature of the season.
In 1880 Pickeringii was fii-st heard here February 20, the temperature reaching 52" dur- ing the day ; while in 1883 they were not known to give voice till April 0, when the tem- perature rose to 5S°. In the year included from March 1879 to March 1880 they were heard in Milton in each month of the year, excepting July and January ; but this was ex- ceptional, owing to the unusual temperature of days in December and February wdien the mercury ranged from 40"^ to 64°. I have no record of the frogs piping first in spring at a temperature below 50° ; once called to the surface, however, they give voice at a much lower degree, and, after collecting at the water I have twice heard them, together with
314 MARY 11. HINCKLEY, NOTES
st/h'a(ica, the wood frog, continue giving voice for a while after the mercury had fallen to 30". (Mr. Allen, in his notes on II. Picker iiigii, Proc. Boston Society Natural History, vol. XII. p. 192. notes a similar occurrence at 31°.) Each occasion has followed a sunny day. In one instance the temperature of the air during the day reached 48°; soon after the sun went down it fell to 38^, while the water about the edge of the pond, where the frogs were numerous, was 50-52^ As the air grew chill, light wreaths of vapor arose from the water and were wafted over its surftxce, almost obscuring shore objects for a few feet above the pond's level. Beneath this veil of mist the piping was at first vigorous, but the water grow- ing colder the vapor gradually cleared ; at the same time the " peeps '' were fewer and sounded slow and hoarse, as if given with a shiver, till at length the mercury falling below 30° the two or three frogs which appeared to have continued piping, in a spirit of rivalry as to which could endure the greatest degree of cold, were chilled to silence. Moi-ning found a thin ice about the pond and thick hoar frost on the ground.
In average seasons a few frogs may be heard about the 20th of March, but they are not in full voice here much before the first week in April, about which date they collect in great numbers for egg-laying in the shallow overfiow of swamps, meadows, and ponds, the males appearing in advance, and, as for as my observation goes, in excess always of the females; but even then their concerts are liable to be interrupted by brief periods of snow and freez- ing weather when they disappear till the temperature changes again. The advent of an east wind, to the sweep of which they are exposed, disturbs their piping, while the same and even lower temperature with the wind in any other quarter is endured with apparent indiflerence.
While giving voice the frogs are not moving about in the water, but are partially or wholly out of it, seated along the shallow edge amid dead leaves and grasses or clinging by their sticking disks to the tawny, half-submerged weeds, small bushes, or reeds, where the eye often fails to separate the frog from its surroundings, so perfect is the adaptation of color and form; each curve of body and limb finding counterpart in bent grasses, dead her- bage, and leaves. The frogs will be found of various shades of brown and capable of changes within the limitations of that color ; they do not, however, trust to the security of this color protection with the stolid indifference o? Hyla versicolor, the common tree toad. The male frogs are a little smaller than the females of the same age and often darker in tint. As is known, the latter sex has no external vocal sac and gives no note that I am aware. The vocal sac of the male is largely developed in spring ; it is of a greenish grey color and lies in loose folds outside the muscles of the throat. Inside the mouth are two .slits or orifices, opening into the sac, one on each side near the angle of the jaws. When the frog is about to give voice the whole body is inflated, followed by that of the vocal sac which rounds out into a bubble and does not collapse with each " peep " ; the degree of inflation evidently governs the volume of sound. About sunset 1 have frequently been aided in discovering the frogs by the level rays of the sun striking along the edge of pond or meadow and reflecting from this moist, inflated vocal sac with a glittering light.
Unless the day is overcast, or a warm rain is falling, little is heard from the frogs tiU about four o' clock in the afternoon when their concerts begin, to be continued in mild nights till morning. Considering the size, the volume of sound possible from one frog is surprising. As you approach a locality where they are in full voice the air seems to grow
()\ TiiK i'Ki:i'i.\(; ruoc. :a')
gnuliially 'lenso with this oar-ileafcning, all-pervadinjij sound ; ocpasionally the voice- fall into a rt'^iilar measure of time, hut the efil'ct is u><ually a medley of hhrill sounds, a few voices audible above the others by reason of some peculiarity in key, or lack of smootlinesH in utterance. The piping of each individual is long continued ; the interval between tlieso musical cfTorts appears to depend on the mood of the musician. One does not note the pause of individual voices in the <!;eneral effect, but, however loud and earnest the piping may be, the introduction of any unusual souuil or appe:irance, even (lie low (piiek (light of a bird over the water, is almost sure to give alarm and still them for a while ; the frogs along the edge of the shore commonly settling away out of sight for safety among the dead leaves imder water, while those having a position on the low bushes or reeds merely cling more closely, flattening the body against the object on which they are resting. The inter- val of silence is brief; soon a frog rises and gives a shrill '• peep," which is immediately answered by dozens of voices. The sountls may appear to come from about your feet, but for the reasons given, the chances are against seeing the frogs till some movenu-nt in the water as the}' rise from their hiding places, arrests the eye, which on perceiving one usu- ally discovers more.
Among the enemies that prey on Pickeringil none are more destructive while they are collected at the water than R. halecina, the shad frog ; botli species congregating for egg- laving in the same localities. On one occasion numbers of both frogs had assembh.'d in a small, shallow pool ; the peeping frogs were in commotion, swimming about and by turns climbing any available grass or weed stalk to avoid the near approach of halecina. Sud- denly a gust of wind swept a shower of dead leaves that had remained on the tree all win- ter, from an oak standing near, and scattered them over the water. No sooner were these graceful rafts afloat tliau Plckerlnrju appropriated them as points of safety, nearlv all of them becoming freighted with a little frog. Hither and thither with the eddying breeze they sailed while halecina swam under and about them, the curled and upturned edges of the leaves concealing the little frogs from sight.
Where Pickeringii is numerous, a handful of dead grasses and leaves taken at rau'lom from the shallow water along the shore will usually be found to contain a few eggs attached singly here and there. Mr. F. W. Putnam, in the Proc. of Boston Society Nat- ural History, vol. ix, p. 229. has already described them as follows : '' These eggs were not in a mass or in a string, as is the case with our other frogs and toads, but were isolated, being attached to the plants some distance apart. The tadpoles were hatched in about twelve days, and were very long, coming from the eggs with a more marked tadpole form than is the case with our other species of frogs and toads." To this description I would add that of the color of the egg, which is at first deep brown on the upper surface and cream colored beneath, but in the pi-ocess of development changes to drab; and the tadpole escapes from the outer membranous shell of a pale yellow color with dots of deep brown on the sides of head and body, and measures about 5 mm. in length (pi. 28, fig 1). The eggs are so small that they might easily pass for scattered seeds of the submerged weeds to which they cling tenaciously by means of the viscid substiince surrounding them.
The length of time occupied in the development of the egg varies according to circum- stances ; in the early part of the season they ordinarih^ hatch, as Mr. Putnam has observed, in twelve days ; as the weather grows warmer 1 have known it accomplished in seven. In-
316 IVIAKY II. HINCKLEY, NOTES
stances mis?ht be cited, not only sliowing that the length of time varies according to the teniporature of early spring, but also that eggs laid at the same date may vary somewhat, owing to some difterence in the temperature of the water where they are laid. As the season advances and the weather becomes warmer the eggs of all our frogs and toads de- velop more rapidly; in the summer mouths I have found but a tritling dillerence in time.
The tadpole escapes from the outer membranous shell with eyes and mouth in a rudi- mentary state ; the external gills are often more advanced in development than is usual with the other species of frogs and toads found here ; the nostril pits are conspicuous and the holders, one each side below and back of the mouth, are prominent. The fii'st stage (Duges) is passed and the second entered on during the first week ; that is, the external gills are developed and resorbed and the tadpole assumes the proportions it afterwards retains. The fi'ills on the right side disappear first ; with the resorjjtion of those on the left side, and junction of the thin membrane which has gradually grown downward to the trunk, the branchial cavity and lateral spiraculum are formed. During the first week the mouth is de- veloped so that the deep-brown, horny fringe of teeth at the edge of the lip and folds is defined, and the e3-es so that they have some sense of sight ; the latter are prominent, set widely apart, and relatively large. The head and body are short and broad ; their united length is contained about twice in that of the tail. As soon as the external gills are re- sorbed the tadpoles leave the objects to which they cling by means of the holders, and may be found darting in and out among the dead grasses and herbage along the shallow water. By the tenth day the holders have disappeared. Like the tadpoles of Hyla versicolor, which they so much resemble at this stage, they are extremely quick in movement and, where there is space, do not herd together. Search for food (and for this they mouth against whatever comes in their way, taking animal food eagerly, devouring one another as soon as dead, or even while alive if too disabled to move), escape from enemies, with periods for rest and sleep, appear to be the events of their existence during the larval changes. As soon as the arms are thrown out the tadpoles are in haste to leave the water, climbing the plants, sedge, or graceful panic and manna grasses {Panicum didiotoinum, Gl ycer la jyall Ida) that often choke the shallow water ; the holding power of the dilated tips of fingers and toes enabling them to cling to an object regardless of position. 1 have found them a yard or more from the water before the tail was much resorbed, but for safety they would immediately turn to that element. Tadpoles of Pickeringii ordinarily pass about eight weeks in the larval condition. The same disastrous results that sometimes overtake the larvae of sylvaiica and halecina are shared by Pickeriiuju in the evai)ora- tion of the shallow water of swamps, bogs, meadows, and small ponds created by the spring rains and melted snow and ice. They collect in the pools left where the water has receded, shut in with water enemies, growing thin and maimed, till the water here also evaporates and all peri.sh. It sometimes happens that the oldest tadpoles of si/loaiica and Pick- ering'd are hurried through their transformation under these conditions before it is accom- plished elsewhere, but both tadpoles and young frogs are pale in color and small in size ; the former lacking almost wholly the metallic coloring usually conspicuously brilliant. All trace of the tadpoles, left to perish, is soon gone. This wholesale destruction of life in one direction is Nature's bounty in another. On the soft mud one finds a net-work of footprints made by various birds, and now and then tracks of a skunk which, in his nightly foraging,
ON TIIK rEKIMNc; V\l(U'.. 317
eviiliMitlv IouikI :i fc'iist Iuto. Conspicuous uiiioiit: llic liinl.s' tracks are those of the cniw, whose gait limls expression in the inwiinl-tnrning impress of the toes; and •x-easionally, sunk in the soft uuid.are the hirge. well-ch-lineil tracks of the heron. It is n<jt ran- to find the footprints and horings of tlie wooih-ock here, tlie toe-marks ahnost at ri^ht anj^les, and the soft earth punctured hy the probing of the bird's hnig l)ill for worms. Tliose tadpoles ol' PickerirKjii escaping this fate are constantly l)eing lessened in numlier l)y their enemicH, the newts, water beetles, and the larvae of the beetles and dragon Mies. On two occasions I have seen a spider {Dnhnneiles sexpitnclcilics) run along the surface of the water, smldenly (live, seize, and drag out on land a full-grown tadpole (jf this species ; the spider coming out dry, evidently as much at home in as out of the water.
The young frogs on leaving the water may be found for a short time on and undt'r the growth of herbage that has sprung up about it ; they are exquisite in form and agile in movement. The (juiver of a small leaf and dip of a slender grass l)la<le, a.s the frog leaves the one to spring to the other, frecpiently betray tlieir presence, but their ol»jei;t is evidontlv to seek cool, damp, shaded places. When numerous, they .sound on the dry. dead leaves as thev spring out ol'your way. like the palter of tin; first rain drops in a summer shower.
15y the first week of June, and in some seasons by the third week ul' .May, the period of egg-laying is over, and all tlie adult frogs have become silent and left the water, tlie con- certs gradually diminishing in volume a.s the musicians grow fewer in numbers. I have never heard them give voice in July, and have rarely found the adults in that month. With the muggy days of August piping is resumed, but it is not general as in .spring or sus- tained with such volume and energy; the "peeps" frequently mingle almost unnoticed with the chirp and murmur of birds and insects. At this season I have found the frogs, not only on the ground, and on the ferns, and bushes in the wood, but in the vegetable garden, and on the lilac bushes, apple, pear, and elm trees, evidently in search of insects.
One day I happened on one of these little frogs on the grey limlj of an apple tree ; he was motionless, with the exception of the constantly palpitating throat ; his hands ami feet were compactly folded under him, only their outer edges coming in contact with the sur- face on which he rested ; the same sensitiveness in regard to the disks is shown with the peeping frogs as may be observed with the tree toad ; the eyes were depressed, pupil con- tracted, and the frog seemed to me to be asleep, till suddenly his attention was arrested ; the eyes were raised, the pupil dilated, the narrowed iris glowed ; the hands and feet sought the limb, the toes of the feet twitched nervously, and with startling (|uickness the sure leap was made ; the gauzy wings of some insect, a mosquito I thought, protruding from between the closed lips explained the movement. Although following the direction of the frog's earnest gaze I could not detect the ol)ject which attracted him. There was a pause of a minute or more before the insect was swallowed. Then the frog tucked hands and feet under him and to all appearance became wholly oblivious to everything about him. In common with the other frogs and toads found here, the tongue, as has been often de- scribed, is free behind and fostened down by the front edge to the inner rim of the under jaw ; it is heart-shaped and capable of some distension. When food is taken the free edge is thrown forward and drawn back so instantaneously, that the eye can seldom follow the movement, or perceive wliat has been captured.
31 c; MAFvY II. HINCKLEY, NOTES ON THE PEFriNG FROG..
I have not ofton lioard the piping repeated after dark in the autumn, the nights being gencrallv too cool. The frogs are most active and musical at this season, on those muggy davs when the south wind drives low-flying clouds across the sky; they are evidently in syiupathy with this peculiar warmth and moisture. Above the rush of the wind, as it sweeps through the wood, stripping the dead leaves from the trees, whirling and scatter- in"- them before it like a flock of birds, the shrill voice of this little frog makes itself heard. Guided by their piping I have several times found them clinging to the brown oak leaves fallen from the trees above, and lodged in the top branches of the blueberry and alder bushes growing beneath them ; the frogs, accidently or with intention, choosing a position where, if silent, detection would be almost impossible. As the awakening of Picker'ingii accompanies the first bland days that come with the higher circling sun of approaching spring, so their subdued notes, in harmony with the year grown fodcd and silent, are associ- ated with the mild days that linger latest in the autumn.
The chances of finding the frogs in a torpid state are few, both on account of color and size. Whenever I have seen them among the fallen leaves, it has been the result of acci- dent. I once happened on one in winter under the leaves collected in the deep rut of a cart path in the wood ; the frog was without motion and apparently dead, but the warmth of my hand soon affected him ; the nostrils showed faintly at first the action of air passing through them, the inferior eyelid began to lower, and the frog soon developed an activ- ity that threatened my losing him and seriously interfered with further observation. On reaching home and exposing him to the warmth within doors he soon gave voice with energ}-. The frogs kept in the house in a torpid condition during the winter, whenever exposed to a temperature of 50° would soon come out from under the moss, where they secreted themselves, and pipe, evidently under the impression that spring had come. The young frogs do not reach their growth the year of their birth, although the females lay eggs the following spring.
Explanation of Plate sxviii.
Fig. 1. Ilyla Pickeringii, tadpole, fir.st clay, natural size 5 mm. long.
Fig. 2. Mouth of tadpole, enlarged.
Fig. 3. Single tooth of fringed fold, much enlarged.
Fig. 4. Part of fringed fold, enlarged.
Fig. 5. Adult female.
Fig. 6. Frogs showing vocal sac inflated and collapsed.
B"ig. 7. Adult tnale.
The figures in water show the eggs and tadpoles from time of hatching to the young frog.
/ ■ J ■ * ;.;/'.
HINCKLEY DEVELOPME:
XII I'ai.aeodicttoptera : OR TiiK Akkimtiks and Classification ok Pai.ko/.oic
IIkxai-oda.
Bv Sam IK I. II. Scudder.
Road P'.hnian- IH. 1«M5.
h/XCEFflNG the cockroaches, wliich Conn so largi- a proportion of carboniferous insectj<, most of the known paleozoic hexapods have long been referred to Neuroptera. But the opinion has been gradually gaining ground that (1) the wide divergence of some of them from post-paleozoic as well as from existing forms, and (2) the occasional unexpected proofs of the combination in single individuals of characters now only known to exist separatel}- in insects of distinct ordinal divisions, i.e., the appearance of broadly synthetic or generalized types, required some modification of our earlier notions. The discovery of Eugercon and the discussion of its structural peculiarities by Dohrn, Ilagen, Gerstuecker. Sueileii van VoUeidioven, Packard, Brauer, Goldenberg, etc., did more than any thing t'Ise to suggest ami enforce this opinion.
Dohrn himself in his very earliest paper went so far as to propose to place Eugereon in an ordinal group apart under the name of Dictyoptera. and in the following year to adrl to the sauie order the group of insects then known under the name of Dictyoneura. Ten years later, in changing this ordinal name to Palaeodictyoptera, on account of previous employment of Doiirn's term, Goldenberg also included in it the types described by Dana as Miamia and Hemeristia. and Beneden's Omalia ; Brongniart ha.s of late years employed it in nuicii tlie same sense, liis (july really distinctive addition being that of Gcinitz's Ephe- merites'.
The recent startling discovery l»y Brongniart of insects plainly related in no very dist-mt way to modern Phasmida. — a highly specialized and unique group of Orthoptera, — but yet bearinsx winjrs whose venation compels us to connect them directly with the synchronous type of Dictyoneura.^ and which had heretofore been supposed either neuropterous or to belong to an archaic type some ot whose meml)ers showed distinct hemiptenms characteristics; —
> In liis latest « Tilin<;s Brongniart, inflm nceil no doubt b_v viously accepted by Brongniart, and wlii.-b the recognized
tlie striking combination of neuropterous ami ortlioptirou? laws of nomenclature will not allow us to «cl a.«iae; 2, as a
charaetirs which he difcovered in Protophasma and Titano- distinctive term his fails to cover the synthetic characters of
phasma, has endeavored to supplant this term by Kevror- the entire group (cf. Eugereon); .1, the accepted language
thoptferes. Three distinct objections can be made to this: of nomenclature is Latin and not t rcnch. 1. The group alre.idy h;is a goo<) name which has been pre- * See Proc. Ainer. Acatl., XX, 167-1(3.
320 SAMl r.l. II. SI I'DOKK ON TllK
this disooviTV following close upon my tUMuonstr;itit)u that all paleozoic cockroaches l)olongcd to a type distinct from and taxononiically c(|iiival(>nt to existing Blattaiiae, lends conntenance to a new attempt to discuss the ri'lationship of all .paleozoic hexapods to each other and to later types. The time has plainly coTne for a revision of our general knowl- edge in the light of special discoveries.
Onr ac(|uaintance with paleozoic hexapods is mainly based upon tlic structure of tin' win>rs, and this is greatly simplified by the fact that, as has been ])reviously noted, ditfer- entiation in the structure of the front and hind wings of insects had not in paleozoic times obscured the neural framework of the front wings. It is nevertheless true that the great advances in our knowledge of relationships among paleozoic insects have not come from a studv of the wings, but from the happy and rare discoveries of other p.irts ol" the bodilv structure, as in Eugereon and Protophasma. This Avonld bt' supposed to render any attempt to reduce the entire series to systematic order somewhat hazardous, were it not that, as will appear later, the great body of Ibrms now known can be grouped, by their wing structure, into a few distinct types, whose relation inter se is such as to warrant a belief that they must have been structurally related in the rest of their organization; and that, among the forms so related, one or another has generally preserved sufh frag- ments of the body as enable one to speak with some degree of confidence ; at the saiu • time it will have to be admitted that while w^e are dealing with imperfect remains, any deductions which may be drawn from inferred structure is valuable only a^ it is cumulative.
Brongniart in his latest papers, wdiile, as stated above in a note, unnecessarily and undesirably dropping the name Palaeodictyoptei-a, — a name histoi'ically connected with the greatest advances in our knowledge of the relationship of paleozoic insects, — has also extended its scope, so as to include also all the forms he (and others) had previously placed under Neuroptera and Orthoptera, but, impliedly, leaving the species of Fulgorina still under Hemiptera. There is no reason for this exclusion, and it is probable that it was not intended.
Leaving aside, for a moment, the question of the existence of paleozoic Coleoptera. we submit that the same reasons which would justify the use of the term Palaeodictyoptera for Eugereon alone, as was done in the first instance by Dohrn (for its predecessor Dicty- optera), compel us to include in it the entire series of paleozoic hexapods. It is a name too which is peculiarly appropriate to the insects of the paleozoic epoch as a whole, with their undifferentiated wings. It is as applicable to the ancient ephemerids as to the phasmids or cockroaches, and any definition of it grounded on known characteristics must be based almost wholly upon the structure of the wings, from which the name is derivei! this stnicture is, collectively, so simjile, the similarity between representatives ^of group- whose descendants are afterwards ordinally distinct so striking, that we may be justified in claiming the probability of the homogeneitj^ of other parts of their structure. At all events the known facts of the structure of paleozoic insects, apart from the historic develop- ment of the hexapod type in subsequent epochs, would warrant no ordinal separation between them. In saying this I do not overlook the fact that Eugeieon was probably a sucking, and Protophasma a biting, in.sect, for a physiological distinction is of itself of no value whatsoever : it is tin- und(?rlying structure only that should be considered ; and we
( I.AS>II l( M Kin n| I'.M.Kt •/.( (|( ISsKCl'S. 321
liavL' 111) I'act l)fyt)ml tlie suhsvtjKtut (K-volopiiK'Ht of liitiiij^ types into groups onliiially dis- tinct from sufkiii}; types (a fact parulloled in wing structure), to hIiow tliat from the struc. ture of tile nioutli ])arts Eugereon should he ordinally separated from IVotojihasnia.
Whether the paleozoic relics which have heen referred to Coleoptera should also bo grouped with the I'alaeoilictyoptera is another (|uestion. That c<tleopterifonii insects then existiil is 1 think proiial)le. l)oth from the traces which are reasonaiily referred to borings similar to those made by existing types, and by the present structural relationship of Coleoptera to types whose predecessors are most plainly recognized among jjaleozoic forms, i.e. other lletcrometabola. Troxites — the single relic from the paleozoic referred to Coleoptera — is an obscure object, and may. as IJrongniart has suggested, be the fruit of a plant. It seems to me most probable, all things cousidereil, that Coleoptera sprang IVom .such I'alaeodictyoptera as were wood-borers throughout life, and which in paleozoic times had no greater differentiation of structure between the front and hind wings than e.vist in otlier Palaeodictyopter.i. Such differentiation would be likely to arise from the pre.serva. tiou of fiivored races with such a habit ; while the inlierent proljability that afl the heterometal)olous types had their already diverging stems in paleozoic times, coupled with the entire absence from these rocks of any shards of beetles, which in later rocks are the most readily and frequently preserved of all insect remains, renders the supposition the more acceptable.
If then, Troxites be a fruit, and the above hypothesis account for what are apparently beetle borings in the older deposits, we have left one insect only, Phthaiiocoris, claimed to come from jKileozoic rocks, which shows any considerable sign of such diiferentiation in structure as led to the existing distinction between the front and hind wings of heterome- tal)olous types, as we now know them.
Another reason for the claim here urged, viz.. that all paleozoic in.sects .should be grouped in one order, Palaeodictyoptera, is to be found in the fact that whenever any of the special groups which it include.s, whose distinct affinities to special modern types are easily recognized, are compared with these types, the}' are found to possess chai-acters which distinguish them as a whole from them. My meaning here will be clear l)y reference to my paper oh paleozoic cockroaches ; these insects, though plainly cockroaches or the ancestors of existing cockroaches, are nevertheless structurally distinct from the latter to sueli a degree that it was necessary to recognize them as a separate group, Palaeoblattariae, taxononiicaliy equivalent to the entire modern group Blattariae. The pa.ssage from one gioup to the other took place in early mesozoic times.
The above view of Palaeodictyoptera then reduces itself to simply this : that hexapodous insects were not ordinally differentiated until post-paleozoic time. The example we have given above, however, sufficiently indicates the next step we must take, and that is to di.s- tinguish between groups which the historic development of insects shows were the precursors of types onlinalh" distinct. This it is difficult to do on any other basis than that o( faniili/-con(in>iifi/. It is comparatively easy to see that the Palaeoblattariae were the probaljle ancestors of Blattariae, Protophasmida the precursors of Phasmida, Palephemeri- dae of Ephemeridae, and Hemeristina perhaps of Sialina ; but from wing structure alone, Palaeoblattariae (ancient Orthoptera) are as nearly allied to Palaeopterina (ancient Neurop- tera) as they are to Protophasmida (other ancient Orthoptera). Our clew is through the
y2-2 SAMIKI. II. SClDnKK ON THE
iiiiiior irroups, aiul by tln'ir aid. and almost entiroly by tlieir aid, wo may di^stinguish botwei'ii ortlioptoroid. lU'iimptiM-oid. and hcniipteroid I'alaeodictyoptera.
PALAEODICTYOPTERA.
Hodv more or less elongate. compo.sed of three woll-iUdined regions, head, thorax, and abdomen ; month parts as in modern Hexapoda, variously developed ; antennae filiform, simple ; eyes compound. Thorax three-jointed, subequally developed, each joint bearing A pair of moderately long legs ; the meso- and metathoracic wings closely similar, equally membranous, supported by a framework in which six principal stems are developed, the first of which always forms the costal margin ; the mediastinal is simple or only provided with sujK'rior branches, the scapular and internoinedian simple or compound, the exter. nomedian and anal nearly always compound, their branches almost always inferior ; generally most branches dichotomize ; the membrane is usually more or less reticulate with generally irregular polygonal cells ; stout and well-defined cross veins are rare ; the costal area is generally scant, the anal area generally ample, often very ample, yet not so much from depth as from distal extension ; when at rest the wings appear in all cases to have covered the abdomen as in modern cockroaches, white ants and Sialina; but although there is some indication from their greater breadth that the hind wings were then folded, they were never plaited like a fan as in modern Ortiiopter.i. The abdomen was usually loner and slender, composed of nine or ten joints, the last one sometimes furnished with a pair of articulated appendages.
[Orthopteroid Palaeodictyoptera.]
Palaeoblattariae Scudder.
The points in which the ancient cockroaches differed from existing types has been fully pointed out in a comparatively recent paper,' and need not be repe.ited here. The classi- fication there proposed has been generally accepted and no little addition to oar knovv- ledo-e of ancient types of cockroaches has since been added. A number of 'undescribed forms are in my hands from American deposits, including several new genera, and will be made the .subject of special papers. Recent explorations in Triassic beds of Colorado have thrown new light* on the passage of the Palaeoblattariae to later types and it is announced by Brongniart that he has discovered a cockroach in the middle Silurian. The figures he has given, however (La Nature xiii, 116), though unsatisfactory, would lead us to suppose tlie insect to belong to the neuropteroid Palaeodictyoptera.
Protophasmida Brongniart.
A classification of the members of this group having been recently propo.sed I)y me^ and as I intend to refer to them more fully on another occasion in fully describing and
' Mem. Bosf. So<,-. Kat. HUt., iii, 2.V134. here. Diet, elongata Golii. was place 1 in bolli Breyeria ami
» Amer. Journ. Sc., (3) xxviii, 199-203. Goldenbergia ! It was at first supposed to helong to Broyeria
» Proc. Amer. Acad. Acad. Arts. Sc., xx, 167-173. A and was accidently left tliere after it was discovered tliat its
careless error which crept into this paper may be corrected true place was in Goldenbergia.
CI-ASSIKK ATKiN (»l I'.M.Kn/.oK INsKC I'S. 323
illiistratiii;.' tin- Aiiiciican I'uriii^, it will not ho nocHsarv t<» iMiiarf^i* upon tlii-ni Iiitc It may be added, liowcvt-r, tliat tlii.' Dcvoiiiaii (iL're|»lieiiR'ni tails in tliis group, and that lirouj^niart is pr()l)altly t'onvct in assij^nin<r Arcliat'fiptilus StMidtl. to the vicinity of I)i(r-
I \ iPMLMira.
Archegogryllu- priscus I'l. 2!), l\gn, 2. .'(.
Arc/irf/otjri/ffns priscii.s Sitdd., Proc. Host. Soc. Nat. Hist. xi. 4(12-403.
In ni)\v puMisliing liji:ures of this fossil, I place it among orthopteroid PalaeoMattariae simply ill accordance with my early determination of it, not wishing to speak po.sitively as to the character of so fragmentary an<l uncertain a specimen. The renuiins con.sist of what appears to be a broken leg, and of a iragment of a wing in close contiguity but possibly not at exactly the same level. The wing, as may be .seen by the ligure, shows only a few parallel veins of varying degrees of stoutness, with one, apparently deUiched, crossing several at an acute angle ; no sign of any margin is .seen excepting in the presence above of two or three very distant, delicate, arcuate, oblicjue veins, apparently of the cosUil area. The leg is broken into fragments from which an apparent saltatorial femur and a very irregular tibia can be made out, the general course of each straight, but bent at a slight angle with each other. They are somewhat remarkable, for the femur is smooth, has a m.ilian Hat area bounded by slight ridges, while the tibia is furnished with several promi- nences of large size ; in modern types the prominences when they occur are found only on the femur. There is a slight rounded prominence on the upper surface near the very base of the tibia and another a little beyond the middle; opposite the latter on the u[)per surface, is a deeply cleft elevation, it,s hollow corresponding to the elevation on the upper surface; the basal half of the under surface is occupied by a very broad prominence, of nearly equal height throughout, but slightly depressed in the middle and terminating al>ruptly at either end. The femur is slightly larger than the tibia and more than twice a.s broad. Length of wing fragment 15 mm., width of same 11.5 mm., length of femur 10 mm., greatest breadth of .same 3.1 mm., length of tibia S.5 mm., breadth of same at base 1.5 mm., at tip 1 mm. More has been uncovered since it.s Hrst description.
The specimen w^as obtained by Dr. J. 8. Newberry in the lowest cold beds at Tallmadge, Ohio.
[Neuropteroid Palaeodictyoptera] Palei'IIEMEHIDae bcudder.
This name has just l)een propo.sed by me^ for the ancient Ephemeridae, in which the lower seems to be formed on the same plan as the upper externomedian stem. The ancient types are di.-^tinguishable from their fellows, as the modern are from most of theirs, by the great number of cross veins breaking the interspaces into generally quadran- gular cells larger then the fine irregular reticulation of other paleozoic in.sects. The following insects may be referred here : —
Palephemera antiqua Scudd., Dev. Ins. N. Bruns\v. 7, pi. 1, f. 5, U. 10 ; Devonian, St. John, New Brunswick.
' Eiirlie.'st ningeil inis. Aaier., Cambridge, 1885, p. 4.
•;-)4 SAMIKI. II. SCIDDKK ON I'lll'.
Ej>/u'merHt!i Ruckcrti Geinit/. Jnlnli. f. Miner., 1.^05, 385. pi. 2. 1. 1 ; Lower J)ya^- HeitM<li. Saxony.
Palln(/eiii(( Feistiiuiiitelil Fkitscii. Boitr. Pal. Oesterr.-Ung. ii. [)1. I, f. l-H; Carhonilbrous. Bohemia.
Altliough one can lianlly doubt the po.sition of this insect, the resemblance of the abdominal appendages to those of Dictyoneura Goldenbergi Brongn., as shown in a sketch kindlv sent nie by Brongniart. is very striking.
IloM(iTliETli)AK Scudder.
Though one of the characters upon which this group was originally foundeil lias proved to be fallacious, so as to require an entire revision of the neuration of the single insect upon which it was founded, the name may still be applied to tlie otherwise unnamed group into which 1 have since discovered that it must fall, as I have proposed in a recent publication.'
In this group, which contains a considerable variety of forms, the mediastinal vein ter- minates on the costa at very varying distances from the tip. being .sometimes very brief (Cheliphlebia), at other times very long (Homothetus), almost invariably sending a con- siderable number of short, oblique, usually simple veins to the margin. The scapular vein, which has no inferior branches, generally runs parallel to, but at no great distance from, the mediastinal, and after pa.ssing its limits, which it generally does to a conspicuous degree, continues the emission of branches to the margin now dropped by the mediastinal : this vein .seems invariably to terminate just before the tip of the wing. The externo. median vein is generally the principal branched vein, though there is a curious exception in Didymophleps. It generally begins to branch about or a little before the middle of the wing, and then emits from its main stem at regular intervals from three to six oblique ner- vules, simple or simply forked, and so longitudinal in course that the area rarely infringes far on the inner margin. The internomedian vein is also conspicuou.sly branched, the area generally occupying the larger part of the lower margin, though the anal area not infrequently reaches nearly to the middle of the wing ; its mode of branching is very variable ; generally it closely resembles the preceding vein, sometimes to such a degree as to make all the offshoots appear as branches of one vein, at other times only beginning to part from the .stem after the latter has taken the oblicjue course of the externomediah branches, and then having a different obliquity. The anal area is generally though not always narrow, but often reaches far out toward the middle of the wing, and the vein is abundantly branched.
This family is readily distinguished from the Palaeopterina, to wliich it seems most nearly allied, by the course of the mediastinal vein, which terminates on the costa and not on the scapular vein. The externomedian area is also almost always more extensive, and its veins less longitudinal, by which the internomedian area extends to the end of the lower margin of the wing. It would be hard to .say to what modern family of Neuroptera it was most nearly allied, as its .scapular vein is completely simple, but the general aspect of the neuration leads one to consider it more nearly allied to the neuropterous than the pseudo- neuropterous groups.
' Earliest wiii<:Kl iii.~. Amor., p. o, 6.
( I.ASSIIK AlloN n|- l'.\l.l.(»/(»l( INSI-XTS. 325
I'lje followiiif^ are souk- of tin- lurms faHiii^ Imtc anan^'cd. as far a^ may In-, in tln-ir iialiiral sfi|U<'iK't".
Acridites priscuB
Ai-riiiid's j)risrits AsiHiKE, Nt'iK's .lalirl). Minor., iNtil, Id.Mdl, pi. 1,11;^. 1.
Tliis species is reniarkalde tor the great lengtli of the nieiliastinal vein and its inilforiii distance from the margin, which suggest that it may he a hind wing. Andree referre(| it to Orthoptera. It comes from the Bohemian coal measines at Stradoiiitz.
A fragmetU of a wing, ligured here on pi. "J'.t, lig. *J, seems to come in thi.s vicinity. It is remarkable for the exces.sive length of the mediastinal vein, the longitudinal ohliijuitv of* the hranciies of the same, and the confinement of the branches of the scapular vein to one or two !)rief nervules at the very tip of tlie wing. Tiie e.xternomedian l)ranohes .seem to be almost similarly confined, wliile the internomedian liranches are cnnvded, nearly straight, and simple or apically forked. It also has the ap|)earance of a hind wing. It comes from the carbonifenms beds of Mazon Creek, HI., and was received from .Mr. R. D. fiMcoe, in whose collection it bears the numl)er 2(lo5.
Eucaenus ( »'«■ Kaivos ) ^eii. nov.
Stout bodied, the thoracic segments twice as broad as long, the me.so- and metathorax veiy large; the abdomen ovate, the final segments with a median keel ; front wings very regular, oblong obovate, the costal border uniforndy arcuate, the mediastinal vein .straight, terminating before the apical third of the wing, with numerous straight, simple and regular brandies; scapular vein terminating midway between the end of the mediastinal vein and the tip of the wing, with similar branches- externomedian vein very important with rather distant branches.
Eucaenus ovalis >[>. nov. I'l. 2:i. (i-r. 4.
The fore-wi]igs are very regularly rounded, a little more than three times a,s long as broad, the tip situated rather below the middle, only a little above the termination of the middle externomedian branch ; externomedian branches about five in number, taking a course about parallel to the apical third of the costal margin, very distant compared to the mediastinal branches, ahvays forkeil. sometimes doubly ; anal veins more oblique, numerous and parallel. The prothorax has a slight median ridge, and the flat fore femora are minutely, distantly and rather coarsely granulate. Length of body (excepting the missing head) 22 mm., breadth of abdomen 7 mm., length of front wings 22 mm., their probable breadtli 7 mm.
A single specimen is known from Mazon Creek and bears, in the collection of Mr. R. D. Lacoe. the number 2(l4!l.
Q'erapompUS dfiipa . iroinrds) ".roil. IIOV.
IJody slender, elongated, the meso- and metathorax tolerably stout, but the prothorax at
^.JC, S.VMIKI. II. SCrDDKH ON THE
least as loiiiT :>s Itrnad. Front wings obovnte, the costal margin sligiitly less arcuate in the middle than at either extremity, the mediastinal vein subparallel to the costa and termina- ting near the apieal third of the wing, with rather distant simple branches ; scapular vein terminatint"- near the tip, with longer and usnally forked but otherwise similar branches. Externomedian vein very import^uit with numerous, very long, generally forked, curvin- iiranches. subparallel to the outer half of the costal l)order.
Gerapompus blattinoides $i>. nov. I'l. 29. tig. i.
'riie general aspect of the closed wings is that of a cockroach. The prothorax is sub- cordiform. not unlike that of some Carabidae, with a blunt suljcentral boss; the parts in front are obscure. The hind leg is rather long, the femur much stouter than the shorter tibia, the tarsi obscure but nearly as long as the tibia. Wings slightly produced at the apex but well rounded, less than three tinies as long as broad. Scapular vein first forking some way beyond the middle of the wing, at or beyond the last fork of the mediastinal vein, and then at once curving downward to approach the margin less rapidly. Length of prothorax 3.0 nun., hind tibia 4 mm., breadth of hind femur 1.") mm., length of front wing 20 mm., breadth of same 7.5 mm.
The carboniferous beds of Mazon Creek ; discovered b}" Mr. F. T. Bliss.
Gerapompus extensus sp. nov. PI. 29. figs. 5. h.
The prothorax is quadrate, the mesothorax of the same width in front as the prothorax but widening posteriorly ; the head apparently a little smaller than the prothorax. Foi^ wings tapering apically but rounded at the tip, less than three times the length of their median width, the costal margin less arcuate than in the preceding species. Scapnlar vein nearly straight, first branched near the middle of the wing, some distance before the final forking of the mediastinal vein, and unaccompanied by any change in the direction of the stem. Hind wings, very similar to the front wings in size and shape but with the branches ol' the externomedian vein much more transversely oblique and curving in the opposite .^ense, their open side being toward the tip of the wing. Length of prothorax 3 mm.. breadth of same 3 mm., length of front wings 30 mm., median width of same 11 mm.
M:r/<.ii Trf-ek. Mr. R. D. Lacoe, No. 2011).
Anthracothremma ( a'^pol- 9p<'|i|ia ) g,.ii. ikiv.
Body stout, apparently depressed, the thoracic segments several times broader than lonu tapering anteriorly to a subtriangular head and more gradually behind along the alniu- parallel-sided abdomen, broader at tip than the head. Wings elongated, with nearl\ straight costal margin, extending far beyond the abdomen ; the mediastinal vein extend- over about two-thirds of the wing ; the scapular vein rather strongly arcuate, and reachini: very near to the tip ; the externomedian vein closely parallel to the latter, commencing to branch before the middle of the wing and emitting many long, parallel, simple or siinplv forked, straight or gently curving, longitudinally o})iique branches; internomcdian brandic- similar.
CLASSIMC A HON oi' I'AI.I.u/olC INSKCTS. 327
Anthracothremma robusta. -\<. imv. I'l. .'to. ^\^f. i. .1. 6.
The surface of llie Ijudv in llie s|HHiiiu.'ii illiistnited in fiir- •'» iw nut well enough pre- served to show much texture, but the head ajjpears to liave a median suture and to tjiper rajjidlv to a rounded front in ailvance of the hiteral eyes. The prothorax, although very short and transverse, taj)ers rapidly in front ; the mesothorax is a little larger and longer than the metathorax, which does not exceed the ahdominal .segments in length. The front wings are three and a (jiiarter times longer than hroad, with the costa very straight excepting at the extremities ; the stiffness of the wing, however, is relieved by the arcuation of the principal veins; the branches of the mediastinal vein are simple, obli(|ue, ii little curved, not crowded ; those of the scapular vein are few in numljer, lie wholly beyond the iiH'diastinul and are rather vague ; those of the externomedian vein are nearly straight, on one wing about half of them forked at varying distances along the stem, on the other wing in the single specimen at hand most of them simple, and one transferred from the main 8tera to a forking branch ; they are equidistant and not closely crowded. Legs stout and flattened. Length of body 30 mm., of head 3.2o mm., of prothorax l.o mm., of entire thorax (i.'io mm., of abdomen 1!J mm., breadtli of head 4 mm., of thorax 10 mm., of last gegment of abdomen 5 mm., length of front wings 28 mm., In-cadth of same 8. Go mm.
Mazon Creek, 111. Carboniferous. Collection of Mr. R. D. Lacoe, No. 2048.
Another specimen (figs. 1, 5) is better preserved in some parts, showing the texture of tlie body to have been uniformly and delicately granulose. The borders of the head are imperfect so that the drawing may here be incorrect. The tip of one of the wings is better preserved so that the Ibrm can ])C better determined. Nothing additional can be gained from the neuration. It comes from tlie same locality and bears in .Mr. Lacoe's collection the number 20o2.
G-enopteryx (-(('vos, irrcpug) gen. nov.
Wings obovate, with more or less arched costa, and somewhat produced apex ; medias- tinal vein of variable length, the .scapular extending to or nearly to the tip, connected to the veins on either side of it by transverse or oblique cro,ss- veins ; externomediiin vein very important, coiiuuencing to branch con.siderably before the middle of the wing and by several longitudinally oblique mostly forked vein.s, closely connected by feebler cross veins, feeding the apex of the wing ; internomedian vein also important with .'several similar veins, the outermost of wliicii runs in close proximity to the ba.sal externomedian branch from its very origin, so that at first .sight both extemomcdian and internomedian branches appear to .spring from a common vein.
Genopteryx constricta. sii. nov. I'l. 29. fig. 11-
A single broken wing is preserved with part of another, probably of the same side. It conforms best to the generic characters laid down above in the similar appearance of the externomedian and internomedian branches, which are all less longitudinally disposed than in G. lithanthraca. Another marked distinction from that species is in the comparative nnrrowuess of the area of the wing above the scapular vein, due partly to the less strongly
30v; SAMUEL H. SCUDDER ON THE
convex oostal luurgin, and in the much greater length of the mediastinal vein, which in G. lithantliraca scarcely extends be^yond the middle third of the wing, while here it does not stop mnch short of the tip. Probable length of wing 30 mm., its breadth, 8.25 mm. Carboniferous beds of Mazon Creek (Mr. R. D. Lacoe No. 2046).
Genopteryx lithanthraca.
Gryllacris lithanthraca Gold., Palaeontogr., iv, 24-27, pi. 4, figs. 1, 2. Carboniferous deposits of Fischback and Rushutte near Saarbriickcn, Germany.
Cheliphlebia (xn^n- <t>^.t'ptov) g^>n. nov.
A large coarse-winged group, with tolerably slender form, indicated by the jiosition of the wings in repose and marks on the stone too vague to be ^ve\l represented. The wings are elongated with sub-parallel borders, have a scarcely arcuate costal margin and variable tip, and ci'oss veins, unless exceedingly feeble, entirely absent. The mediastinal vein is short, terminating before the middle of the wing. The scapular vein being distant from the margin, though tolerably straight and supplying many oblique branches to the same, reminds one of the species last mentioned. The externomedian veins are few, distant, simple or compound, and terminate mostly on the apical margin ; while the internoraedian vein extends far towards the extremity of the lower margin parallel to the e.xternome- dian branches, and feeds all that margin with transversely oblique, curving branches. This feature, most conspicuous in the first of the species, has suggested the generic name.
Cheliphlebia carbonaria. sp. nov. PI. 30. fig. 8.
The wing is about three times as long as broad, uniform in breadth over most of its extent, with a very broadly rounded tip. The middle third of the lower margin is almost per- fectly straight, giving a stiff appearance to the w'ing, which seems to be largest beyond the middle ; the veins are very pronounced. The mediastinal branches ai'e very different from those of the rest of the wing, being feeble, crowded and arbore.scent. The internomedian brunches, which are distant, are pretty strongly curved, their convexities toward the tip of the wing, and especially curved when, toward the margin, they fork in a claw-like fashion. The anal veins are few in number and more longitudinal than tlie internomedian branches. Length of wing, probably, -38 mm., breadth 13 nun.
Carboniferous nodules of Mazon Creek, ill. (Mr. R. D. Lacoe, No. 2034.)
Cheliphlebia elongata, »p- nov. I'l. ■2'.K lig.- 7.
The wing is probably about three and a half times longer than broad, broadest in the middle, and beyond that regularly tapering to a prolonged and probably somewhat pointed tip; the veins are obscure. The mediastinal branches seem to be few, distant and simple. The externomedian branches differ considerably on the two front wings, being of the usual type on one side, but more or les.s arbore.scant on tha othj;', the subordinate branches fork- ing more than tiie more important ones. The internomedian branches, which are not distant, are rather gently curved, with their convexities away from the apex of the wing.
CI.ASSinC AllDN (»!•• I'AI.KO/.OIC INSKCTS. 329
Len;^'tli of I'nifjjmcnt ol" wing 2"> imn.. piohnlilr (•(unplctc leiij^tli liS imii.. hri'iidth 7.7'» iiiiii. CailKJiiil'crous bods of Miizoii Cn-rk, 111. (Mi-. \j. M. L'iiil).icli).
Tlie specimoii fijfurcd on pi. 30, fitr. 7, also bolonj^s to this family, but too little of tlu' neuration is preserved to enable one trt speak with any confidence of its exact position. It would seem probable that it should fall here. The inject is exposed on a side view and the wind's overlap so as to confuse the neuration at the costal border, but the mediastinal anil .scapular veins arc plainly simple and the former ends on the eosta and ha.s few or no branches. The body was elongated and the wings probably al)out ."?•> mm. long. It comes from Mazon Creek. Illinois, ami bears the number 201.S in the collection of Mr. H. D. Liicoe.
Genentomum ( yiVoc, iVro|iov ) roii. iii>v.
The wings in this group are largo and elongated with coar.se neuration and abundant, somewhat feeble cross veins. The front is more ovate than the hind wing, the costal margin being more arched, the tip apparently more pointed and the anal area more exci.sed. The mediastinal vein is long, at least two-thirds the length ol' the wing, and sends abundant though not crowded branches to the costal margin. Tiie .scapular vein lie.s very close to it and emits no branches until beyond it, when it sends off a few more oljlique ones and itself extends to the tip. The externomedian vein is separated by an unusual interval from the scapular and emits several stout forked branches, which cover the apical and the extreme outer part of the inferior border. The internomedian vein is forked once or twice only in the front wing, the l)ranches appearing similar to tho.se of the preceding vein ; while in the hind wing it bears many shorter and mucli more oblitpu; inferior bninches.
Oenentomum validum. sp. nov. PI. .'50, ficrs. 2, 3.
The only parts preserved in the single specimen known arc the greater portions of two wings, a front and a hind wing, widely separated from each other but in the same nodule. In the front wing the greater part of the costal margin, including all of the mediastinal vein and its branches, is destroyed, unless as is probable the first vein shown is the extremity of this vein ; in the hind wing the branches of this vein are oblique, increasingly longi- tudinal away from the base, and often forked and sinuous. In the front wing the exter- nomedian vein is separated from the scapular by a space about eciual to the interspaces between its branches before they fork, and is connected with it by distant transverse cross veins, breaking the interspace up into subquadrate cells; in the hind wing, the course of tlie vein is not so straight, it is rather more widely separated from the scapular vein and, besides the transverse veius, the interspace is traversed by a supplementary, longitudinal, binding vein in the middle of the wing nearly a fourth the length of the latter; the branches of the externomedian vein are more frequently and extensively forked in the front than in the hind wing but do not differ much. The internomedian vein is soon forked in the front wings and both branches again dichotomize to a considerable extent, while in the hind wing half a dozen simple arcuate branches, their concavities toward
330 SAMUKL H. .SCIDDKK ON IHK
tho !i[H'.\ of tlio wing, part troiu tho umlor side ol" the single stem. The aiml area is broailer ami the veins more numerous in the hind than in the front wings, but in both they are tolerably simple and take the eourse of the externomedian branches ; near the base thov are separated by a broad space from the internomedian branches, a space which is occupied in both wings by a number of longitudinal arcuate wrinkles or independent cross veins, difficult fully to understand. The front wing is broadest about the middle ; the hind wing, notwithstanding its basal expansion, in the middle of the outer half.
It mav be added that on the same stone (reversed of course on its counterpart) the scapular vein of the front wing is depressed, and the externomedian and internomedian veins with all their branches raised ; while in the hind wing, the mediastinal vein, the exter- nomedian vein and its branches, and the branches (only) of the internomedian vein arc depressed, while the scapular, the supplementary binding vein and the main internomedian are elevated ; showing that on this stone (the one drawn) we see the two wings of one side, one of them upside down. Length of wings 45 ram., breadth 14 mm.
Carboniferous deposits of Mazon Creek. From the collection of Mr. R. D. Lacoe, No. 2047.
Didymophleps (SC5u|j,os. <t>X£'v|i) tjen. nov.
This is one of the most anomalous genera of this family, all the veins and branches above the internomedian being longitudinal and nearly parallel to each other and the straight costal margin ; the externomedian vein is twice forked not fiir from the base of the wing, and all the branches run in the same general direction ; so does the internome- dian vein, which is exceptionally developed, and emits a considerable number of rather distant, parallel, oblique, rarely forked, nearly vstraight branches.
Didymophleps contnsa. PI. 29, lig. 6.
Ttrmes contusus Scudd., Proc. Bost. Soc. Nat. Hist., xix, 300-301.
The body is crushed past all recognition, and fragments of legs lying between the wings only show that they were slender. The wings, also, are only partially preserved, their bases being destroyed with the crushing of the body and their tips by extending beyond the edge of the nodule in which they are enclosed ; more than half of each wing remains, however, comprising some of the more important parts. All the veins from the marginal to the internomedian inclusive, as far as they are traceable on the stone, are nearly straight and parallel ; the upper three are also simple, and the scapular area is considerably and uniformly depressed ; the externomedian vein is forked near the base of the wing and the space included between the forks, as well as the externomedian area, is traversed by feeble. inequidistant, straight or oblique cross veins. The internomedian vein traverses the middl' of the wing, or runs scarcely above it, anil emits from its lower border a large number <; oblique veins, which run, often with a slightly irregular course, to the margin of the wing ; in the fragment there are eight such veins on one wing and six on the other and more imperfect wing, in both cases about equidistant, l>ut more regular and straighter on the left than on the right wing , in both also one of the secondary veins, and one only- arising shortly before the middle of the wing, is forked — on the left side close to its origin. on the right side near the middle of its coarse. Both borders are perfectly preserved on
( I.ASSIFK ATION OF I'AI.KD/.OIC INSKCTS. 331
tlie ri{j;ht wing, sshowing it tu ho Id iiiiii. lnnad ; tlie Iciijrtli of (lie lurj^cr IVagiiu-iit is l!0 nun., and the probaMe k-ngtli of t lie win;^ alioul ;;'* mm.
Coal mea.sniL'.-< of Vermilion Co. Illinois, obtained and .sent to me iiy Mr. Wm. (Inrley.
HomothetuB Sctnlilii.
The chuiacters of this genus having l>een misapprehended by me in my detailed paper on the -DevDnian Insects of New Hriinswiek," 1 have given a revision ol' them in a recent paper on "The Earliest Winged Insects of America." The genus is remarkable f(ir the length of the mediastinal vein, which is scarcely shorter than the scapular, for tiie absence of ol)li(jue branches of the same, for the al)S(»lute simplicity of the scapular vein, and for the small importance of the externomedian vein, wliich has duly a few ol>li<iue generally simple brandies occupying the a]ie\ of the wiiiLT-
Homothetus fossilis.
lI())H()thi:tits fossil ii SciDD., Dev. In.s. New Bruusu., 17, pi. 1. ligs. 1-2. Earlier P'T'-r- ences may be found in the synonomy there given. Devonian beds uf St. John. N. 1>.
Mixotermes Sicizel.
Tliis genus, considered by Sterzel, not without some reason, as one of the Termitidae, seems to find its place here. Pi-obably the mediastinal vein will be found to reach the mar- gin not far beyond the middle of the wing, where the scapular vein, otherwise simple, first begins to send short branches to the border. The structure of the e.xtcrnomedian vein precisely accords with this family. What Sterzel considers the lower branch of the exter- nomedian is probably the internomedian vein, while at least the lower of the veins con- sidered by him as internomedian should be considered as anal.
Mixotenues lugauensis.
Mh-otermes luyauensis Sterzel, Ber. naturw. Gesellscli. Cliemn., vii, 273-276, pi., fig. 3-5. Carboniferous deposits of Lugau. Germany.
Omalia Coeni.-V:m Ren.
Probably this form belongs here but the original needs a new study, as its curious venation is plainh- impossible and no sufficient description has ever been given.
Omalia macroptera.
Omalia macroptera Coem.-Vax Bex., Bull. Acad. roy. Belg., (2), xxiii, iv, 384-401, pi. Carboniferous deposits of Sars Longchamps, Belgium.
Palaeopterika Scudder.
Wings obovate, several times longer than broad, the mediastinal vein of front pair ter- tiiinating, usually not far from the middle of the wing, by running into the scapular vein.
332 SAMUEL H. SCIDDEK ON THE
Tho soajuilar vein throws o{\' an inferior branch before tlie niifldle of the wing, jrenerally close to the base, and runs past the extremity of the mediastinal without being affected by it ; it usually reaches nearl}' the tip of the wing, but in some cases does not extend beyond the midille ; the inferior branch is forked a few times, the branches, very longitudinal, rarelv occupying more than the upper half of the tip of the wing. The externomedian vein is very unimportant, often simple, occasionally divided at the base into two stems, each of which may fork once or twice, and in one abnormal type assuming an importance equal to the main branch of the scapular vein. The internomedian vein nearly always extends so far a-s to occupy with its branches the whole of the lower margin; the main vein is some- times strongly sinuous, and the branches are nearly always more oblique than in the llomothetidae, more numerous and arising somewhat continuously from the base out- ward. The anal vein is provided with many closely crowded, generally longitudinal branches, the area never reaching beyond tlie middle of the wing.
This account of the structure of the wing differs from that formerly given by me (Mem. Bost. Soc. Nat. Hist., i. 189) in some slight particulars only, due to the discovery of addi- tional types.
The group differs conspicuously from the Homothetidae in the termination of the medias- tinal vein, which impinges upon the scapular vein and not upon the margin of the wing. The relative importance of the externomedian and internomedian areas is reversed, and the contrast between the course of the branches in the two areas generally more marked here than in the Homothetidae. The importance of the internomedian area prevents the anal from encroaching beyond the middle of the wing. It differs from the Xenoneuridae principally in the structure of the lower part of the wing, in the complete independence of the externomedian vein, and in the conspicuous branching of the internomedian. The ter- mination of the mediastinal vein separates it from the Hemeristina, as does the less im- portance of the scapular and e.xternomedian areas. Apart from the termination of the mediastinal vein, the relation of the neuration to existing neuropterous flimilies is much the same as in the Homothetidae. In this respect, however, it more closely re.sembles the Sialina and Perlina. From these it is .separated by the decided deficiency of the scapular branch, whose offshoots rarely fall below the middle of the apex of the wing; by the unim- portance also of the externomedian vein, which is usually simple; by the far greater extent and importance of the internomedian area, which may bo considered the remarkable part of its structure, reaching out far toward the tip of the wing, and with tlie anal area occuping nearly half of the wing.
Gerstaecker has in various places claimed that their neuration would place the Palaeo- pterina in the Perlina, but nowhere specifies the reasons for this belief The more perfect presentation of the family characteristics, which we are now able to give, shows that his claim is unfounded ; indeed, the single point in which a special resemblance can be traced is in the distal union of the mediastinal and scapular veins, by the impinging of the former on the latter in the apical half of the wing; a feature which these two families share in common with- the Embidina, Raphidiidae, etc. The externomedian vein, for example, is either simple or divided almost at the base in the Palaeopterina, while in the Perlina it runs undivided pa.st the middle of the wing, separating two great fields, the one above devoid of cross vein.s, the one below cut, at least in one sex, by numerous prominent cross veins.
CI.ASSIKK Al l(».\ (II I'Al.r.dZOK INSICCTS. 383
and to<j;etlKT f(niiiiii<r ii vcrv ilistiiict iuid cliaiai'tfristic feature having no Hort of coun- terpart in Palai'ojiterina.
Most of tlie genera agree in the structure of the internoinedian vein; but in one (Stre- phocladus) it is reniarkable for tlirowing off its oflslioota from its superior, and not inferior, side; wliile another type (Aethophlehia), which we have phiced at the end of the series, is very remarkable throughout, thougli it would seem to fall in this place.
Miamia Bronsoni Diiiisi.
Miaviid Bi-<»iKoiii Dana. Anier. .Jourii. Sc, (2), xxxvu, 34-35, fig. (1864). .Mazon Creek, Morris. (Jrundy Co.. III.
Propteticus ( wput, in-nTiKo's > gen. nov.
Body apparently flattened, of moderate si/.e. the thorax very broad but narrowing in front of the wings, the reduction falling on the me.^othorax, the prothrjrax and head being narrow and prolonged. Abdomen aj)parently similarly slender. Mouth parts formed of a spreading tuft of organs extended in front of the head and in the same plane. Legs obscure l)ut apparently rather long and slender, and increasing in size in pa.ssing back- ward. Wings large, full, oval, of nearly equal breadth excepting at extremities, at rest considerably overlapping the abdomen ; the scapular vein prominently elevated, widely distant from the margin in the basal half of the wing, gradually approaching it in the dis- tal half where the mediastinal vein soon falls into it, and terminating in the margin just before the tip ; it has a single inferior brunch arising near the base, which divides beyond the middle into two apically forked or simple branches. The externomedian vein divides at base into two long curved branches either simple or apically forked, which, with the branches of the scapular, occupy the whole of the apex of the wing. The internomedian and internal veins occupy nearly half of the wing, the former the outer and probal)ly larger portion, with nearly straight, oblicjue. rather distant, simple veins. Straight or curved cross veins are scattered over the whole wing.
Like Miamia, this genus has a remarkable aspect from the narrowness of the head and prothorax as compared with the rest of the body. The me.sothorax is broader than long and narrows rapidly, so as to be less than half as broad in front as behind, while the head and prothorax, each longer than broad, are paiallel sided. Since the mouth-parts project for- ward in the same plane, the prolongation of the parts in front of the liase of the wings is exce.ssive, being considerably more than half as long as the body behind the front base of the wings, and perhaps as great as the extension of the abdomen l>ehind the posterior base of the hind wings. The wings are ample and apparently folded upon the back as in mod- ern Sialina. The hind wings appear to have been of the same general shape or a little broader, but without any special fulness of the anal area ; this point, however, is very obscure from the imperfection of the Ibssil.
The genus differs Irom Miamia in the even greater slenderne.«s of the head and protho- rax, the anterior prolongation and tapering of the mesothorax, the larger anal appendages, and particularly in the neuration of the wings; viz., in the wider marginal field in advance of the scnjnilar veins of the front wings, the arcuate course of the same vein, the much
334 SAMi Ki, 11. scrnoKH ox the
oarlior oriiiin of its inforior l)r;iiu'li. and tho much wider space between it and tlie main vein (Hied with stout, aivuate bianehes.
Propteticus infernus. sp. nov. IM. ,11, fitrs. 3, 4.
Head snhquadrate, rounded l)eliind and apparently a little broader tlian in front, nearly lialfas long again as broad, very slightly arolied above, the ej'es and antennae not appearing on the stone ; the mouth-parts are nearly us long as the head itself, but do not admit of any clear separation of the parts; apjiarently, however, they consist of three pairs of very .<iniilar. single-jointed, moderately stout blades.
Prothorax similar in shape to the head, but a little larger, snbquadrate with rounded an- gles, and apparently no broader behind than in front, transversely arched like the head, with a slight median carina obliterated in the centre. The head could apparently be partly with- drawn beneath it. since it seems to have been preserved in that condition, as the illustrations show, the front margin of the prothorax appearing to cut the head in halves in fig. 4, where it best appears ; while in fig. 3 the hinder edge of the liead is seen embraced at the sides by the edges of the prothorax, as is seen better still upon the stone. The front legs appar- ently are indicated by the scars ou either side of the stone, especially by that on the left side of fig. 4 and its reverse, where a tibial joint appears to be marked. The legs are shown b}' this to have been rather short and very slender ; toward the base of the de- tached scar of the right leg, in fig. 4, is seen the end of a slender femur, which appears even slenderer in the reverse (left side of) fig. 3.
The mesothorax is of a very stfange form when taken in connection with the prothorax ; it is half as broad again as long, and the wings are attached next the hinder margin, while the parts in front taper, as has been said, to the size of the prothorax, which is considerabl}^ less than half the posterior width of the mesothorax ; the front margin is roundly excised as If forming a socket for the movement of the prothorax, and the taper- ing sides are gently convex ; the surface does not appear, as in the parts in front, to be regularly arched, but to be furnished with coarse bosses, especially in the medial portions. Its legs are shown only on one side, and that very obscurely, indicating a length about the same as that of the front pair. ^
The dimensions of the metathorax can onh' be judged b}' the size of the legs and wings, the hind wings being ampler than the front pair, and the hind legs longer, .so far as can be told from the scars, than either of the others ; it can hardly be narrower than the meso- thorax, and in all probability was of the same width ; its legs, or rather the fracture-soars indicating where they were, are preserved on both sides of the body, and a basal fragment of that of the right side (in fig. 4) is actually preserved, showing again that they were very slender, compressed, and of considerable length, or much longer than either of the other pairs.
The indications of the abdomen are very vague, but .show it to have l>een .^lender, nearly as broad at tip as the prothorax, and provided with a pair of rather slender, tapering, pointed anal appendages about as long as the mouth-parts.
Front wings broad, more than three times as long as broad, oblong oval, the middle half or more equal or very nearly equal, the apex very regular!}' rounded ; costal margin a lit-
?«;v-^
CLASSIFICATION OF PAI.F.OZOIC INSF.CTS.
335
Ue shouldert'd nciir tin- Inise. Maririiiiil vein honli-n-d on the |in».\iiii:il IimIC of tlii' win;^ 1)V
very narrow and tajjorinj^ ineml)raiR', so tliat it doe-* not form tlie actual inar^rin until
jeyond the middle of the \vini;s. Meiliastinal vein parallel to it, iinpin;;in^ on the seapulir
llittle before tlie end of the uiidille third of the winj^, and runnin;^ nearer the inaririnal than
,he scapular vein, i^capular vein j^ently arcuate, ru'ininj^ in the proxinnd half of the wiu;^
na straight course parallel to the marginal vein, then hending slightly npwanl to meet
he top of the mediastinal, and in the apical third (tithe wing curving gradually downward,
I little less rapidly than the marginal .'•o as to unite with that not far before the extreme
ip (which is broken olT) ; very far toward the base of the wing (near the middle of the
lasal fourth) the inferior oflshoot originate^, and runs completely parallel to the marginal
ij'ein until it forks, at or ju<t beyond the tin of the mediastinal vein ; each of its lbrk.s
ignin subdivides in the left wing, at no great distance from the border, the upper one
jiore di.stant from it than the lower; but in the right wing the upper fork is simple, and
he lower as in the opposite wing. The externo'.nedian vein forks near the base, ne.\t
lie origin of the scapular branch, and its branches pass in a broad curve to the tip of the
liner margin, the lower one simple, the upper lorked apically, the fork being deeper on the
, light wing than on the left, where, in this feature, it st uuls midway between the two forks
If the scapular branch. The internomedian vein is a little oljscure except in the apical por-
« on, where the veins originate a very little earlier on the left wing thin on the right; it
flarts from the neighbcrhood of the other veins next the forking of the preceding vein, and
lasses first in a straight line to just about the centre of the wing, when it sends a straight
Iblique branch to the middle of the apical half of the lower margin ; it then takes a course ib-parallel to the costal margin, very soon emits another similar branch, and finally forks Dposite the tip of the mediastinal vein ; whether it also emits some branches nearer the ise is uncertain, but it is prob.ible that either there is a single one thrown ofT clo.-e to the 'ise, parallel to those beyond : or that all the nervules within the first distinct branch jilong to the anal vein ; these last nervules are obscure, but appear to repeat the course jid separation of the internomedian veins.
' Hind wings shaped as the fore wings, but more ample, extending at rest, like the forc- ings, biyond the tip of the abdomen, which reaches about the middle of the distal half. : ttle of the neuration can be made out. but the apical half of the scapular vein appears to 1 the .same as in the front wing. The internomedian vein is strongly curved before it Irks in a sense opposed to the general course of the curving veins; it first branches a lit- tf before the middle of the wing, and in sending out its three or more branches (a little 1 arer the base than in the front wing) it turns parallel to the costal margin, and its lanchos part at a much wider angle and pursue a much more transversely oblique course Un in the front wing. The anal area is probably not any fuller than in the front wing, f • the hind wing of the right side shows by its apical margin, beneath the front wing of the 1 t side (a margin not shown in the figure), that if there were any fulness to its anal area i should appear beyond the costal margin of the left front wing. Length of body, from extremity of head (exclusive of mouth parts) to tip of body (.vclusive of anal cerci), o4.o nun., of mouth-parts, 2.5 mm., of head, 3.25 mm., of pro- t)rax. 5 mm., of mesothorax, 5.75 mm., of ana! cerci, 2.5 mm., of front wing, 31 mm., t?adth of head, 2.25 mm., of prothorax, 3 mm., of mesothorax, 9 mm., of front wing, 1 mm.
•Ill
'.'.V
I • i I < I i •
• I • I I • •
ill III
< I 1^1 III
• • • III
1 I • I III "III I I I I I I
III 1 f I III
III '.If J I f I f f I I f f III I f I f f f I I f i 10 11 I I i I 1 1 f •
*'.'.^^rW
r
334
SA:\H"KI. II. SCl'DDEH OX THK
• I
till • I I
till;
.• • • I I I I I I
I • • I •
• • lilt
earlier origin of its inferior l)ranoIi, and the much wider space between it and the main vein (iUed with stout, arcuate branches.
Propteticus infernus. sp. nov. PI. .Tl, fijrs. .*?, 4.
Head subquadrate. roinided lieliind and apparently a little broader than in front, nearly half as long again as broad, very slightly arched above, the e3'es and antennae not appearing on the stone ; the mouth-parts are uearl}^ as long as the head itself, but do not admit o) any clear separation of the parts; apparently, however, they consist of tliree pairs of very similar, single-jointed, moderatelj' stout blades.
Prothorax similar in shape to the head, but a little larger, subquadrate with rounded an- gles, and apparently no broader behind than in front, transversely arched like the head, witi: a slight median carina obliterated in the centre. The head could apparently be partly with drawn beneath it, since it seems to have been preserved in that condition, as the illustrations show, the front margin of the prothorax appearing to cut the head in halves in fig. 4, when it best appears ; while in fig. 3 the hinder edge of the head is seen embraced at the sides b^ the edges of the prothorax, as is seen better still upon the stone. The front legs appar- ently are indicated by the scars on either side of the stone, especially by that on the lef side of fig. 4 and its reverse, where a tibial joint appears to be marked. The legs anj shown by this to have been rather short and very slender ; toward the base of the de tached scar of the right leg, in fig. 4, is seen the end of a slender femur, which appears evei slenderer in the reverse (left side of) fig. 3.
The raesothorax is of a very stpange form when taken in connection with the prothorax it is half as broad again as long, and the wings are attached next the hinder margin' while the parts in front taper, as has been said, to the size of the prothorax, which i considerably less than haff the jjosterior width of the mesothorax ; the front margin i roundly excised as if forming a socket for the movement of the prothorax, and the taper ing sides are gently convex ; the surface does not appear, as in the parts in front, to b regularly arched, but to be furnished with coarse bosses, especially in the medial portion? Its legs are shown only on one side, and that very obscurely, indicating a length abou \ the same as that of the front pair. ^
The dimensions of the metathorax can only be judged by the size of the legs and wing,-, the hind wings being ampler than the front pair, and the hind legs longer, so fiir as can b , told from the scars, than either of the others ; it can hai-dly be narrower than the mes( '' thorax, and in all probability was of the same width ; its legs, or rather the fracture-scai | indicating where the}' were, are preserved on both sides of the bod}', and a basal fragmer | of that of the right side (in fig. 4) is actually preserved, showing again that they were ver | .slender, compres-sed, and of considerable length, or much longer than either of the othc| pairs.
The indications of the abdomen are very vague, but show it to have been slender, ne.ul a.s broad at tip as the prothorax, and provided with a pair of rather slender, taperiuj ■ pointed anal appendages about as long as the mouth-parts. I
Front wings broad, more than three times as long as broad, oblong oval, the middle ha | or more equal or very nearly equal, the apex very regularly rounded ; costal margin a li
CLAS.SIFICATK)N OF PALEOZOIC INSECTS. 335
tie slioiiMi'ivd iiciir the fmse. Marginal vein honlcicil on tlu' iiinximal liall" of llic win;; l)y a very narrow and tapcrin^f nirinlirani', so tliat it tloes not lorni tlio at'tiial niar;;in until beyond the middle of the win;;s. Mediastinal vein parallel to it, iin|tiii;;in;r on tlie scapular a little before tlie end of the middle third of the winj;, and runnin;; nearer the mar^rinal than the scapular vein. Scapular vein j^ently arcuate, ruMniii;f in the pro.xinud half of the winj^ ilia straii^dit course parallel to the mar^^inal vein, then bendin;; slightly upward to meet the top ol the mediastinal, and in the apical third of the win,:,Murvin;; ^rradually downward, u little less ra|)idly tlian the marginal so as to unite with that not far l)efort' the extreme tip (which is l)rokeii off); very far toward the base of the wing (near tin- middle of the basal fourth) the inferior oflishoot originates, and runs couipletely parallel to the marginal vein until it forks, nt or just beyond the tip of the mediastinal vein ; each of its forks again .subdivides in the lelt wing, at no great distance from the border, the up|)er one more distant from it than the lower ; I)Ut in the light wing the upper fork is simple, and the lower as in the opposite w iug. The externoniedian vein forks near the base, iie.\t the origin of the scapular branch, and its branches pass in a broad curve to the tip of the inner margin, the lower one .simple, the upper forked apically, the fork being deeper on the right wing than on the left, where, in this feature, it st;nds midway between the two forks of the scapular branch. The internomedian vein is a little obscure e.\(X'pt in the apical por- tion, where the veins- originate a very little earlier on the left wing th m on tlie right ; it parts from the neiglil)crliood of the other veins next the forking of the preceding vein, and pas.ses first in a straight line to just about the centre of the wing, when it sends a straight oblique branch to the middle of the apical half of the lower margin ; it then fakes a course 8ub-paraliel to the costal margin, very soon emits another similar branch, and finally forks opposite the tip of the mediastinal vein ; Avhether it also emits some branches nearer the ba.se is uncertain, but it is prob.;ble that either there is a single one thrown olT clo>e to the ba.se, parallel to those bejond : or that all the ncrvule.s within the first distinct luancli belong to the anal vein ; these last nervules are obscure, but appear to repeat the course and separation of the internomedian veins.
Hind wings shaped as the fore wings, but more ample, extending at rest, like the fore- wings, beyond the tip of the abdomen, which reaches about the middle of the distal half. Little of the neuiation can be made out. but the apical half of the scapular vein appears to be the .same as in the front wing. The internomedian vein is strongl}' curved before it forks in a sense opposed to the general course of the curving veins; it first branches a lit- tle before the middle of the wing, and in sending out its three or more branJics (a little nearer the l)ase than in the front wing) it turns parallel to the costal margin, and its branches part at a much wider angle and pursue a much more transversely oblique course than in the front wing. The anal area is probabh' not anj- fuller than in the front wing, for the hind wing of the right side shows by its apical margin, beneath the front wing of the left side (a margin not shown in the figure), that if there were any fulness to its anal area it should appear beyond the costal margin of the left front wing.
Length of body, from extremity of head (exclusive of mouth parts) to tip of body (exclusive of anal cerci), o4.o mm., of mouth-parts, 2.5 mm., of head, 3.25 mm., of pro- thorax. 5 mm., of mesothorax, 0.75 mm., of anal cerci, 2.5 mm., of front wing, 31 mm., breadth of head, 2.25 mm., of prothorax, 3 mm., of mesothorax, 9 mm., of front wing, 10 mm
3S6 SAMUEL II. SCL'DDEI? ON THE
This specinieii is one of tlio most l)Oiiutiriilly prcsorvcd of llio fossil insects in nod- ules wliirh 1 have seen. It was sent nie for study by Dr. Jasper C. Winslow of Danville, HI., to whom it belongs, and was found b}^ him on Little Vermilion River, about lour miles above Georgetown. Vermilion Co., 11!.. in a carboniferous deposit. It is referi'ed to as a species oi' Miamia in the Geology of Illinois, vol. iv. ]). 253, where the relation of the deposit to the region is explained. Tlie drawing by Mr. Blake is a very perfect represen- tation of its appearance.
Dieconeura (Siii'ku, vtvpov) st'n- nov.
The wings of this genus arc long and slender, largest beyond the middle. The iiiedias- tin:il vein strikes the scapular vein considerably beyond the mitldle of the wing, wliilc the main branch of the latter, bearing two or more simple or forked branches, which (ill the whole apex of the w'ing, arises in the middle of tho basal half of the wing. Tiie externome lian vein is simple. The internoinodian vein is very long, reaching nearly to the extremity of the lower margin, and sending at equal distances a number of simple oblique branches to the border. The anal vein with it> branche> occupies the basal third of the lower margin.
The simple externoniedian vein, combined with the importance of the internomedian, are the striking features of this genus.
Dieconexu'a arcuata sp. uov. PI. 30, fig. 4.
The scapular branch begins to fork be3ond the middle of the wing, ;ind is connected near here by an oblique cro.ss vein to the externoniedian vein, which is at (irst straight and divides equally the broad space in the middle of the wing between the scapular branch and the internomedian vein, but afterwards curves downward following the course of the extremity of the internomedian vein. The latter is strongly sinuous, taking at first a nearly straight course as if it would terminate at about the middle of its aclu il area, then curving upward into close proximity to the base of the fir.st offshoot of the scapular branch, and then turning to its former course, but arcuate; tlie main steni is bordered throughout by a dusky band intensifying its otherwise striking character. The abdomen is long and slender, the joints of nearly equal length and breadth. Length of thorax and abilomen 21) mm., of front wing 3U mm., width of same, 7.25 mm.
Carboniferous beds of Mazon Creek, 111. Mr. R. D. Lacoe, No. 21)4.3.
Dieconeura rigida sj). nov. I'l. 29, fig. 10.
All the veins are remarkably straight and stiff. The mediastinal strikes t'le scapidar vein at an acute angle without bending down to it. The scapular branch has few and di.«tant branches (two only are seen), the first arising far before the middle of the wing and forking near the origin of the second branch below the union of the mediastinal with tlie scapular vein. The externomedian vein is perfectly straight, filling the equ d space between the internomedian vein and the scapular system. The internomedian vein is slightly bent near the middle of the wing and its simply oblique branches are slightly
( I. assii-icaTion of rAi.i-.oznir insects. 337
iircujito. 'I lie wiiiL' i^ tin' oiilv pint pirservctl iiml is vcr\ iiiiin'ilrcf, .showing' only ilic middle of the win;;. Tho Iciijtli ol" the frai^ineiit i-< II mm.; |)i-o!)il)ly tlic whole length of" the winjr "iis 2il mm., the brejidth (i mm.
From tile intercomgloaieriite iieds of I'ittston, I'enii. Mr. K. I). Liroe, N(j. liOlli.
Strephocladus (<rT<'4>ui. kXcLSos) »;i'm. no v.
The win;.^ is lo:i.;, sleuler iiii 1 n -urly equal t!iro;i<^!ioat. The me lia-diiuil vein throws off distant and lon>^itudinally ohliciue, more or le.*<s arciiite or sinuoU'i liranehes to the margin in the basal lialJ of the wing; in the apic il Ii;df. in common with the mediastinal, IVecinent, straight and tranversely (jbli»|ue branches. The scapular branch ari-es shortly !)eiore the middle of the wing and sen 's several simple longitudinal branches to the upper hall'of the apex ; it is connected clo^e to the base to the otherwise simple externomedian vein. The iMternomt'd'an vein is the mo>t remarkable and char.icteristic ; instead of following the co..r e ul' tiie exteino'.nedian vein and emitting inferior oflT-ihoat-', it runs to the middle of the lowei border of t'le w!ug an 1 enit; fro.u its .su;)jr'.or surface a nuiu')er of nearly straight simple or forked oflVhoots parallel to the externo;nedian vein, to which the upper- most is united by a few ba<al cross veins. The anal veins are numerous and arcuate.
Strephocladus subtilis
Pelrohla/fiiin sithfilLs IvLiVKit. Palaeontogr., xxix. 2-')i. pi. 35, fig. 1. The peculiarity of the internoiuedian vein wrongly led Kliver to consider this a cock- roach, since IVtroblattina presents a similar feature. CarbonitLTous deposits of Schitrweiler, Germany.
Aethophlebia (irieTis, 4>\t>|/) gen- nov.
\ verv remarkable and anomalous genus, particularly in the structure of the intcrno- median vein. an<l in the existence of an adventitious vein made up largely of a branch of the internoniedian, and running across the externomedian vein into the main branch of the scapular vein in such a way as to appear a baseward continuation of it. The medias- tinal vein strikes the scapular a little beyond, and the main scapular branch i.s thrown off a little before, the middle of the wing ; the latter is at first parallel to the costil margin until, just below the tip of the mediastinal, it meets the adventitiou.s vein, when it takes the upward course of tiie latter until it is in near proximity to the main vein ; it emits three or four longitudinal, slightly declivent, parallel branches. The externomedian vein is coalesced with the internoniedian at the base, then takes a straight, horizontal cour.se to the adventitious vein, where it forks into two simple In-anches parallel to the .scapular off- shoots, the base of the fork forming part of the adventitious vein. The internoiuedian vein runs in a .slightly tortuous course toward the middle of the lower margin of the wing and beyond its middle sends out obliquely upward the main branch which forms the adventi- tious vein, and from the lower surface of the branch and the outer surface of the main steiu aii.se frequent straight and mostly simple branches like the scapular oilshoots.
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3S6
SAMUEL H. SCrDDER ON THE
This spccinuMi is one of the most beautifully preserved of the fossil insects in nod- ules wliieh I have seen. It was sent nie for study by Dr. Jasper C. Winslow of Danville, 111., to whom it belongs, and was found b}' him on Little Vermilion Rivei*, about four miles above Georgetown. Vermilion Co.. 111., in a carboniferous deposit. It is referred to as a species of Miamia in the Geology of Illinois, vol. iv. p. 253, where the relation of the deposit to the region is explained. The drawing Ijy Mr. Blake is a very perfect represen- tation of its appearance.
Dieconeura (SiiiKu, vcvpov) gen- "ov.
The wings of this genus are long and slender, largest beyond the midtlle. The medias- tinal vein strikes the scapular vein coii-;idorably beyon.l thj middle of the wing, while the main branch of the latter, bearing two or more simple or forked branches, which fdl the whole apex of the wing, arises in the middle of tho basal half of the wing. Tlie externome lian vein is simple. The internomedian vein is v.-ry long, reaching ne.irly to the extremity of the lower margin, and sending at equal distances a number of simple oblique branches to the border. The anal vein with its branche- occupies the basal third of the lower margin.
The simple e.xternomedlan vein, combined with the importance of the internomedian, are the striking features of this scenus.
mi
Dieconeui'a ai'cuata sp. nov. PI. 30, fig. 4.
The scapular branch begins to fork beyond the middle of the wing, iuid is connected near here by an oblique cross vein to the externomedian vein, which is at first straight and divides equally the broad space in the middle of the wing between the scapular branch and the internomedian vein, but afterwards curves downward following the course of the extremity of the internomedian vein. The latter is strongly sinuous, taking at first a nearly straight course as if it would terminate at about the middle of its aclu d area, then curving upward into close proximity to the base of the first oITshoot of the scapular branch, and then turning to its former course, but arcuate; the main stem is bordered throughout by a dusky band intensifying its otherwise striking character. The abdomen is long and slender, the joints of nearly equal length and breadth. L -ngth of thorax and abdomen 29 mm., of front wing .3U mm., width of same, 7.25 mm.
Carboniferous beds of Mazon Creek, 111. Mr. R. D. Lacoe, No. 204.3.
Dieconeura rigida f-\i.
PI. 29. fi-:. 10.
All the veins are remarkably straight and stiff. The mediastinal strikes the scapular vein at an acute angle without bending down to it. The scapular branch has few and distant branches (two only are seen), the first arising far before the middle of the wing and forking near the origin of the second branch below the union of the mediastinal with the scapular vein. The exteruoaiodian vein is perfectly straight, filling tlie equd .space between the internomedian vein and the .scapular system. Tlie iuternoinedian vein is slightly bent near the middle of the wing and its simply obli(iue branches are slightly
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CLASSlFir.vTlON OF I'Al.KOZniC INSFXTS.
337
arcMiiite. Tlu- winir i^ the oiilv part preserved ami is verv imperfect, sliowiii;^ only the middle of the win;^. The len^rth of the frai>;!nerit is 11 imn.; proljiljly the whole length of the winjr was 2ll nun., the breadth G nun.
From the intercomglomerate beds of I'itt>ton, IVnn. Mr. K. I). I/hih', No. 2012.
Strephocladus i<r-r<4M.>. xXaSot) \iv\\. nuv.
Tiie wiii^ is loi^. sl-uler an 1 nearly eiiuil t'lro ij^ho;it. The melia^tinal vein throws off distant and longitudinally oblique, more or less arcu ite or sinnou-; l>ranehes to the margin in the basal liaU" of the wing; in the apic il h:df. in common with the mediastinal, frerpient. straight and tranversely oblique branches. The .scapular l)raneh ari-es shortly l)efore the niii'dle of the wing and sen 's several simple longitudinal i)ranche.s to the U])per half of the apex ; it is connected elo-e to the base to the otherwise simple externomedian vein. The internoniedian vein is the ino?t re:narkalde and e'.iar.icteristic ; instead of following the coi;r-e of tlie e\te:no:nedian vein and emitting inferior ofTdioats, it runs to the middle of tlie lowei border of t!ie w'ug anl e.niti fro.ii its su;)jr'.oi- surface a number of nearly straight simple or forked offshoots parallel to the externoaiedlan vein, to which the upper- most is united by a few basal cross veins. The anal veins are numerous and arcuate.
Strephocladus subtilis.
Pelrohlaittna suhtiUs Kliver, Palaeont(3gr., xxix, 254, pi. 35, fig. 1. The peculiarity of the internomedian vein wrongly led Kliver to consider this a cock- roach, since Petroblattina presents a similar feature. Carboniferous deposit.s of Schiffweiler, Germany.
It
Aethophlebia ( ai;eiis, 4)X€\|/) gen. nov.
A very remarkable and anomalous genus, particularly in the structure of the interno- niediim vein, and in the existence of an adventitious vein made up largely of a branch of the internoniedian, and running acro.ss the externomedian vein into the main branch of the scapular vein in such a way as to appear a ba-eward continuation of it. The medias- tinal vein strikes the scapular a little beyond, and the main .-capular branch is thrown off a little before, the middle of the wing ; the latter is at first parallel to the cost<tl margin until, just below the tip of the mediastinal, it meets the adventitiou.^ vein, when it takes the upwai'd coiir.se of the latter until it is in near proximity to the main vein ; it emits three or four longitudinal, .slightly declivent, parallel branches. The externomedian vein is coalesced with the internomedian at the base, then takes a straight, horizontal cour.se to the adventitious vein, where it forks into two simple branches parallel to the scapular off- shoots, the base of the fork forming part of the adventitious vein. The internomedian vein runs in a slightly tortuous cour.se toward the middle of the lower margin of the wing and beyond its middle sends out obliquely upward the main branch which forms the adventi- tious vein, and from the lower surface of the branch and the outer surface of the main stem arise frequent straight and mostly simple branches like the scapular off.shoots.
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338 SAMrKL II. SCUDDER ON THE
Aethophlebia singularis sp. nov. PI. 31, fig. 9.
The single ."spocinien i.^ a nearlj* perfect wing, broade.st in the middle, witli the tip lost Avhere it extended beyond the nodule. The straight mediastinal vein is at considerable distance from the nearh' straight costal margin and connected with it by straight, trans- versely oblique, mostly simple veins whicli become more crowded toward the extremity, and whore they arise from the .scapular vein, whicli is sinnoa-5 and beyond the tip of the mediastinal approaches the margin. Tiie interspace between these two veins is traversed by straight, transverse veins, but the other main interspaces are crossed by oblique and generally' straight but sometimes arcuate and aiwaA's simple cross veins ; the offshoots from the .scapular branch and adventitiou-i vein are parallel to each other and equidistant, con- nected by straiglit. transverse veins in places (and probably everywhere), making quadrate cells in these narrower interspaces. The large triangular space between the middle portion of the externomedian vein (here straight and parallel to the costal border) and the interno- median and adventitious vein is broken by a sinuous, longitudinal vein parting from the externomedian, below which the cross veins are oblique, above, transverse. The anal veins are obscure, excepting the two outer principal ones which are close together, distant from, and sub-parallel to, the internoniedian vein. The lower margin is gently convex. Length of fragment, .31 nmi., probable length of the wing, 38 mm., breadth, 12 mm.
Carboniferous deposits of Mazon Creek, R. D. Lacoe, No. 2037.
Xenoneuridae Scudder.
The characteristics of this family have already been given by me in my paper on Devo- nian Insects.' It agrees best with the family just reviewed, in that the mediastinal vein impinges upon the scapular, and that the latter bears a principal branch with offshoots feeding the tip of the wing. But the externomedian vein is peculiar in being amalga- mated for a considerable distance with the scapular, and then forking considerably and occupying the outer half of the lower margin; while the inuL-r half is equally divided between the internomedian vein with its basally divided, simple branches, and the anal vein crowded against the border.
Xenoneura antiquomm.
Xenoneura antiqiiorum Scudd., Dev. Ins. New Brunsw., 24-29, pi. 1, figs. 5-7. Earlier references will be found there. Devonian beds of St. John, N. B.
Hemeristina Scudder.
Wings elongate, the mediastinal vein simple, terminating on the costal margin beyond, generally far beyond, the middle of the wing. The scapular vein throws off an inferior
> Aniiiv. MfiT). Bost. .Soc Xat. Hist., 1880.
(•I,ASS11-|('AT1()N OF I'AI.KOZOIC INSKCTS. 339
branch wliicli arises ht'lore, j^i'iicrally far hcrun'. tin- middle of the winj;. ami nms siih-|)ar- allel to the iiiaiii stern; IVoin tliis hninch arise a varial»le nnnil)er Dfohlicinely lon^^itrnhnal, simple, or forked olVshoots, whieh generally oceupy the whole of the apex of the wing, and sometimes infringe a little npon the lower margin. The externomedian vein generally extends nearly to the middle of the wing before branching, and then forks more or less nbnndantly, showing considerable variation in this respect, the nervnles sometimes oc- enpying tiie larger part of the outt'r half of the inner margin, sometimes reduced to a sin- gle branch or two. The internomedian vein reseml)Ies the preceding, althougli it branches from the the base and is generally more important than the externomedian vein where the latter is poorly developed, though .sometimes it is simple. The anal veins generally occupy the basal fourth of the inner margin, with a series of simple, or simply forked, sub-paral- lel branches, generally arising close to the base of the main stem.
This group has been twice described and named by me — once in 18G0' under the name of Ilemeristina, when only a single and rather aberrant form was known to me ; and again in 1880^ under the name of Cronicosialina, when discussing the allinities of one of the Devonian forms. It now appears that not only these, but the series of wings discussed by me in a paper on English paleozoic insects (excepting one, Archaeoptilus, shown to belong in quite anotiier place) should be brought together from possessing one important charac- ter in common, characteristic of the neuratiou of most plannipennians to-day, — the exis- tence of a main scapular branch from which a considerable number of inferior offshoots arise and occupy the entire tip of the wing, or even more than that. In modern planni- pennian Neuroptera it is usually more important than here, and the modern groups to which this series of forms bears most resemblance — the series allied to Sialis — difler in that the nuMliastinal vein impinges on the scapular and not on the costal margin. The ancient group can, indeed, oidy be looked upon as a generalized plannipennian type, as we have already pointed out in our discussion of the British forms [loc. ci(.).
Other ancient groups, indeed, the Palaeopterina and Xenoneuridae, agree with it in the possession of a single, main scapular branch from which offshoots arise ; but in each of these the offshoots are few in number and importance as compared to what is found in the Hemeristina ; from them it further differs in the point of termination of the mcdinstinal vein, and the usually far greater importance of the scapular branch ; while from the Palae- opterina it may also be distinguished by the minor importance of the internomedian vein, and from the Xenonfeuridae by the more abundant neuration. Gerstaecker has referred Hemeristina positively to the Ephemeridae with which it has no more in common than have the other families here characterized, whose mediastinal vein terminates on the costa.
Lithomantis Woodwanl.
Prothorax with large, dilated, and rounded lateral lobes. Mediastinal vein of front wings running in very close proximity to the border, but forther from it in the middle than at the base of the wing. Internomedian area extensive, occupying the middle third of the lower margin, and fully as importMut as the externomedian area.
' Mem. Bost. Soc. Nat. Hist., i. 190. ' Mem. Bost. Soc. Nat. Ilisf.. tti. 213.
^ Devon. Ins. New Brunsw.
340 SA^MUEL II. SCUDDER ON THE
Lithomantis ceirbonaria.
Lithomanliii carhonarlus Woodw., Quart. Jouni. Geol. Soc. Lond., xxxii, GO-04, pi. 9, fig. 1.
Carboniferous deposits of Scotland.
Lithosialis Scuflder.
Wing'' only known. Mediastinal vein of front wings moderately distant from the margin, gradually approaoliing it all the way from the base ; internomedian area unimportant, and far less extensive than the externomedian.
Lithosialis Brongniarti.
LifhosiaVis Brongniarti Scudd., Mem. Bo.st. Soc. Nat. Hist., iii, 223. Carboniferous deposits of Coalbrookdale, England. See the reference above for earlier sjnonjmy.
Lithosialis bohemica.
Lithosialis bohemica Scudd., Proc. Best. Soc. Nat. Hist., xxi, 167. GnjUacris bohemica Novak, Jahrb. geol. Reichs., xxx, 69-74, pi. 2, figs. 1-2. Coal measures of Stradouitz, Bohemia.
Lithosialis carbonaria.
Acridites carbonariiis Germ., Munst., Beitr. zur Petref, v., 92-94, pi. 13, fig. 5; — Ib., Yerst. Steink. Wettin, 87, pi. 31, fig. 10.
1 place this species here from the close general rese.nblance of the ncuration to that of the two preceding species. To do so, however, it is necessary to suppose an error in the figures given by Germar in miking the meliastinal vein arise as a superior offshoot of the scapular; but as this correction seems necessary to any understanding of its neuration, it is not a violent supposition. Germar in his later work presumed it to be the hind wing of his Blattina didyma, but it does not at all agree with the neuration of the hind wings of any paleozoic cockroaches. *
Carboniferous beds of Wettin, Germany.
Brodia priscotincta.
Brodia priscotincta Scudd., Mem. Bost. Soc. Nat. Hist, iii, 215-217, pi. 17, figs. 3-7- —1b., Geol. mag., (2) viii, 293-295, 300, fig. Carboniferous deposits at Tipton, England.
PachytylopsiS DcBoiie,
There has been .some dispute about the position of this genus, but I think there can he no doubt that its place is here. Through the kindness of Mr. DeBorre 1 have been able. to examine not only the excellent iieliotype he has puidishcd, but a cast from the fossil, by
CLASSIKICATIOX OF TALKOZOIC INf^F.CTS. 341
wliicli it is evident tliat wliilc tlie w iiij.' lia-i iiuicli the j;eiier.il I'driii :iiiil proiiorlioiis ol" a nioileni Paeliytylus it-* ueuiatioii i'* altoj^etlier (lini>rent. Tin; iiiediastiiial vein ends in tlie niarjijin a little l)eyond the iniiMle of the wing. Th • strong and prominent gently arcuate scapular terminates at the upper tip; from it is thrown od" hefore the middle of tlie basal half of the wing a simple branch parallel to it-elf, which supports numerous, parallel, oblique lu-an-hes, the innermost of whi<-ii strikes the middle of tiie outer half of the lower border. The externomedian and iiiternomedian olldioots. similar and parallel to those of the scapular branch, are comparatively in-iigiiilicant and divide about equally between them the space between the scapular and anal veins, which latter .strikes the lower margin below the origin of the first ofishout of tlie scapular braiK h. An additional proof of its position here is the presence of a long longitudinal cross-vein uniting the ba.se of the main scapular branch with the externomedian branch, as in Brodia.
Pachjrtylopsis Fersenairei. PI. ."51, fij;. 7.
P(icJii/f>/I< pais Perniiiairii I)i:I!oi;;;r.. Am. Poc. Fnt. B -Ig. xviii. o-G. ul. 5, lig. 1 ; — GiAUi), Bull. Sc. Hist. Litt. Nord, vii, 121-122. — VanV.olxem, Co.upted Head. Soc. Ent. Belg. (2) XXIV, 20-26.
Carboniferous beds of Mens, Belgium.
Lithentomum ScikIcUm-.
Tliis genus differs from idl the otliers placed in this group in the presence of only a single olT-lioot of the scapular br.inch ; and althoug'i tliis point \^ uncertain from the imperfect nature of the single fragment, it seems improbable from what is preserved that more can find a place. It agrees, however, in all other fe.itures witli the family and seems to find its place here.
Lithentomum Harttii.
Lithentomum Harttii Scudd., Dev. Iii<. New Br.. 22 24. pi. 1. fig. .3, where earlier refer- ences are fidly given; — Hagex, Bull. Mus. Coiiip. Zool., viii, 278; Scudd., Earl. Winged Ins. Amer., 4, pi. fig. 2-3.
Devonian beds of St John, New Brunswick.
* Chrestotes Scudder.
The termination of the mediastinal vein in the border and not in the scapular shows that this insect cannot be referred to the Palaeopterina as formerly supposed by me. Its place seems to be here in the neighborhood of llemeristia. though it differs widely from that in the character of the scapular branch, and is peculiar for the deep impression of the principal anal vein.
Chrestotes lapidea. PI. 31, fig. 2.
Chrestotes lapidea Scudd., Geol. Surv. 111., iii, 567, fig. 2.
In the figure formerly given the engraver obscured the venation by numerous lines parallel to the veins. The one now given is from a sketch taken by myself at that time. Carboniferous l)eds of Mazon Cr.. Mnrri*. Illinois.
34'2 SAMUEL H. SCUDDER ON THE
Hemeristia occidentalis.
Eemerisiia occidentaUs Dana, Amer. Journ. Sc, (2) xxxvii, 35, fig. 2 ; — Scudd., Anier. .Tourn. Sc, (2) xl, 269-271; — Ib., Mem. Bost. Soc. Nat. Hist., i, 191-192, pi. 6, figs. 1, 3; — Ir.. GgoI. Mag., V, 217-218.
Same deposits.
Apparent!}^ allied to this, but too imperfect to warrant confidence in a definite state- ment, is an insect (pi. 31, fig. 8) from the same deposits, received from Mr. R. D. Lacoe wider the number 2050. It certainly differs from the preceding in the development .and structure and curving disposition of what appear to be the internomedian vein; but the outer half of the wing being lost, no scapular branch can be seen, although one would look for it in the portion preserved. The course of what appear to be the extcrnomedian oflfshoots — at least as seen on the left side — lead one to suppose that such a branch (or branches) must exist, and the general appearance of the insect is that of this fiunily. The head is transverse, well rounded and strongly convex, and obscure parts in front of it take on a triangular form.
Gerarina fam. nov.
Wings -variable in form but usually not so elongate as in the other types, and sometimes remarkably short in proportion to their width. The mediastinal vein is simple, runs close to and terminates in the margin, usually far toward the tip of the wing, and sends numerous oblique ofishoots to the margin. The scapular is generally the most important vein in the wing, running parallel to the mediastinal, and emitting several or many longi- tudinally oblique branches, most of them generally in the outer half of its course; these branches may be perfectly simple, the outermost forked a little, or all more or less forked, and then liable to appear arborescent; even when most numerous they rarely occupy more or much more than the tip of the wing, on account of their longitudinality and their lack of tendency to spread. The extcrnomedian vein is generally less, often far less, impor- tant than the scapular, and has two or 'more branches, the offshoots running parallel to those of the preceding vein, which they resemble so as to be indistinguishable from them when their origin is concealed; the innermost branch never strikes the margin in the basal half of the wing. In one curious type (Megathentomum) this seems to be the most important vein in the wing, and all its branches fell on the broad apical margin. The in. ternomedian vein is generally reduced to a simple vein, or to a lesser imitation of the extcrnomedian vein. The anal area generally extends to or beyond the middle of the lower margin of the wing, and seems usually to be filled with more or less o])lique and more or less frequent nervules running to the margin.
This family differs from all the preceeding in that the scapular vein has a considerable number of offshoots depending from the main vein itself and not from a simple principal branch. Nor is there any modern type to which it can be compared. A considerable pro- portion of the forms are now for the first time described, and all are American, excepting one which is very closely allied to an American form, falling into the same genus, which is in many respect** widely different from tlie other types.
CLASSll-ICArtON or l'A[,K()/()|C INSK,CT8. 343
Polyernus iwoX«. <pi«i| y,.|i. nov.
15i)(ly apparently of inoileratt.' stoutness, the win^s large and nitlier broail, well nmnili-d. Meiliastinal vein at a toleralile ilistanee iVoni tlie IVont niari^in, to whioli it. semis many curv- ing branches, and extending nearly to the tip of the wing. Scapular vein with three or lour distiint, inequiilistant. but very longitiidinal, and therefore closely crowded, ramose branches, the lowermost falling but little below the tip of the wing. E.vtcrnoniedian nu- merously branched but less ramose, of about ecjual importance with the preceding. Inter- nomedian with numerous inferior, mostly* simple liranche.-!, occupying the muldle half of the lower nuirgin. Anal veins similar.
Polyernas complaaatus. sp. nov. I'l. .V2. figs. .s. n.
fhe protliorax forms a .sort of depressed .shield like that of a cockroach, anil is toleraldy well preserved, showing that it was sultquadrangular, narrowing anteriorly, with well rounded front and rounded posterior angles, a little broader than long, the posterior margin convex ; the whole surface was rugo.se, but especially over a large, subcentral but poste- rior, .subcircular boss, the cast of which .shows a depression filled with coarse, low granules. The wings are very large and long, evidently extending far beyond the tip of the abiloinen, and overlapping, in the single example known, so that it is ditticult to separate them, or to distingui-<h certainly to whicii wing each belongs. From a careful study, however, it would appear that the mediastinal extends nearl}' or quite to the tip of tlie wing (which is lost) ; that the scapular throws off three long and sliglitly curving, forked, or multiple forked, offshoots ; and the externomedian three or four more oblique, but not more curv- ing, simple, or simply forked, branches. Length of prothorax, 7 mm., breadth of. .same, 9 mm., breadth of mesothorax, 'J.o mm., length of fragment of wing, 36 mm., probable length of wing. 46 mm., apparent breadth of the same, 12 to 14 mm.
Mazon Creek. 111. Received from Mr. R. D. Lacoe, No. 205S.
Polyernus laminarum. sp. nov. PI .31. fig. 1.
The four overlapping wings are alone preserved, the base lost and the whole somewhat obscure ; the tips of all arc roinidly pointed. The mediastinal vein is much farther re- moved from the margin in the hind than in the front wing, and shorter ; in the front wing it reaches only the rapidly declivent portion of the margin before the tip ; the branches both of the scapular and externomedian veins have a strong, but graceful, downward sweep in the apicid third of the wing ; and the two ba.sal offshoots of the former are forked just on a line (slightly oblique) with the singly forking externomedian branches, and just before the commencement of the downward curve of the nervules ; the outer branches of the scapular vein are very ramose, in rather strong contrast to the simple forking of the exter- nomedian branches. Length of fragment 50 mm., breadth of same 30 mm., probal)le length of wing 6j mm., its probable breadth 23 mm.
A single specimen and its reverse, No.s. 2012, 2013. were received from Mr. R. D. Lacoe. They are from a thin shale interleaved in the conglomerate near Pittston, Fenn. (No. xii of Rogers Survey of Penn.), and very near its base, there being bnt six or eight feet of coarse pebbly rock between this shale and the " red siiales " beneath:
544 SAMUEL H. SCUDDER ON THfi
Gerarus cy'pttpo's) i;en. nov.
Body slender and elongated, the prothorax rapidly nan-owing in front, so that the head is probably narrow and elongated. Wings correspondingly slender, well rounded, but with tips not produced. Mediastinal vein at a considerable distance from the front margin, united to it by many arcuate cross veins, and extending a variable distance toward the tip, but alwa3-s to some distance beyond the middle. Scapular vein with a considerable num- ber of longitudinal, more or less oblique, simple or forked offshoots, making it by far the most important vein in the wing, the internomedian and anal veins apparently dividing the remaining space about equally between them.
Qeranis vetus, sp. nov. PI. 31, fig. 6.
The mesothorax appears to be broader than long, the prothorax rounded subtriangular, and in front of it a linear prolongation more than three times as long as broad, which may be the head, or a prolongation of the prothorax ; in front of this the stone shows a black- ish discoloration. The wings are broadly rounded at the apex. The mediastinal vein ex- tends nearly or quite to the tip ; the scapular vein, arcuate and separating itself gradually from the former, again sweeps toward it past the middle of the wing, and throws off a large number of mostly sunple, parallel, oblique branches, the earliest of which must strike the lower margin not far from the middle of the hind margin ; transverse cross veins are to be seen throughout in the minor interspaces. Length of whole preserved portion 71 mm., of head (?) 11 mm., breadth of same, 3 mm., breadth of mesothorax 10 mm., length of wings. 52 mm., breadth across the partly opened wings 2.3 mm., breadth of wmg 19 mm.
Mazon Creek, 111. Received from Mr. J. W. Pike and now in the collection of Mr. R, D. Lacoe under the number 2054.
A much smaller but very imperfect fossil, figured on pi. 32, fig. 3, appears to belong in this neighborhood, but to be distinct from anything known. Nearly all the numerous ner- vxiles of the scapular and lower veins are straight, simply and early forked, parallel and oblique. A future find may enable us to place it more exactly. The length of the frag- ment is 30 mm., the probable length of the wing about 40 mm., and its probable breadth about 15 mm. It comes from Mazon Creek and bears the number 2016 in the cabinet of Mr. R. D. Lacoe, to whom 1 am indebted for the opportunity of seeing it.
G-erarus mazoniis. up. nov. PI. 32, fig. 7.
The body Is much elongated, but is very imperfectly preserved, patches only or obscure indications of it appearing at various places. There seems to be a transversely rounded granulated prothorax, in advance of which is a longitudinally ovate head, shaped like that of Eugereon, and in advance of that the base of a tube-like prolongation, which is almo.st immediately broken at the end of the nodule in which it is embedded, and is half as broad as the head. The abdomen is slender and the wings long and .slender with scarcely pro- duced rounded tips. The neuration is imperfectly preserved, and in some parts it is ditli-
ci.AssiiK Alios or i'Ai.i:o/.oi( iNsKcrs, 34;-,
cult to determiru' whether certain veins heioiij^ tu the upper or iimler wings, hut it would appear as if the mediastinal vein were shorter than usual, not reaching the middle ol" the outer half of the wing, and that the scapular vein had four or five forking and curving branches, which occupied nearly one half the area of the wing. The neuration would appear to bring the species in this group, and I have accordingly placed it here, but with reserve. Length of body from front of heatl (excl. appendages) to tip of abdomen lo mm., of head o.omni., breadth of same '2 mm., apparent breadth of j)rothorax G mm., apparent length of .same 4.-'') nun.. ])r()l)iii)le length of wing 111 ituii., breadth of same I'J mm., width of abdomen 3.") mm.
Mazon Creek. HI. Found by .Mr F. T. HIiss and now in my collection.
IVrhajis in this vicinity comes another moderately .slender species (pi. 32, fig. 5) which is very imperfectly preserved. Very little of the wing structure can be made out, but the general arrangement seems to be much as in Gerarus and to be most nearly allied to what is found in the preceding .species. The wings are about 20 mm. long. It comes from Mazon Creek, where it was obtained by Mr. F. T. Rliss.
G^eranls Danae. I'l. M. fig. 5.
Miamia Danae Scudd.. (Jeol. Surv. 111., lu, oOG, fig. 1.
This species differs from the others placed here by the longitudinal dispcsition of the veins, which have little obliquity in them. Tiie mediastinal vein extends nearly to the tip ; the ajjical .scapular branch is compound, but the others simple ; a few cro.ss veins may be seen. It is the .smallest species in this genus. The body is very vague but shows enough to prove that it was much elongated. The thorax looks as if it had a median furrow. The wings were apparently about 25 mm. long ; their breadth is 8 mm.
Carboniferous deposits of Mazon Creek. Illinois.
Adiphlebia {»■-■ 8is. 4>X€p«)v) gen. nov.
Body rather stout, of subequal breadth throughout the thorax and basal two-thirds of the abdomen, the latter tapering apically, and the obscure parts in front of the prothorax tri- angular and about as long as one of the thoracic joints. Wings rather broad, well rounded, with straight costa. All the nervules arising from the main stems in the ba.sal third of the wing and extending without any forking, sub-parallel, scarcely divergent, straight and lon- gitudinal throughout the wing, giving it a very unusual appearance.
Adiphlebia Lacoana. f^p. nov. PI. 32, fig. c,.
The mediastinal vein runs to the declivent portion of the costal margin, the .scapular in close proximity to it, throwing off three branches only, close together at the root of the wing, which run parallel to each other unbroken to the tip, where they do not fall below tbv.' middle. It is impossible to tell to which veins all the subsequent similarly simple ner- vules belong, as they al.-^o part from one another and their main veins at the very root of the wing. Length of hody 31 mm., of abdomen 17 mm., breadth of body 5.25 mm., length of wing 25 mm., its width 9 mm.
Miizon Creek. 111. K. D. Lacoe. No. 2057.
346 SA^MUEL II. SCUDDKR OX TIIK
Megathentomum SciuUI( r.
This gemis h;is eortiiin relations to tlio preceding, since most of the branches, which are apieally Ibrnicd, must, in most instances, to judge of their direction by the only fragments which are known, have originally parted from the main stem very near the base. The branches are, however, very few iu number, and the wing remarkably broad, rounded and large, the main scapular vein branching onl}^ near the tip, and the vein there bent upward as if it were a superior branch and the first branch the main vein. Two species are known, one Irom this country and one from Germany.
Megathentomum pustulatum. I'l. 32, figs. 1, 9. 10.
Megathentomum pustulatum Scudd., Proc. Bost. Soc. Nat. Hist., xi, 401-402 ; Is., Geol. Surv. 111.. Ill, 570, fig. 7.
The original specunen (fig. 1) is the best that has been found, so far as 1 know, but sev- eral others have been discovered, one of which is figured here. The wing was exceedingly broad, indeed, probably more than half as broad as long. It was broadest beyond the mid- dle and subtriangular in shape, though the outer margin was fully rounded. The medias- tinal vein was long, terminating shortly before the declivent termination of the straight costa, and emitting several very oblique and nearly straight branches to it. The scapular vein, parallel to the latter, first branches near the tip of the latter, sending out one or two simple or forked branches which support the upper tip of the wing. The externoraedian vein occupies the middle third of the wing, and occupies the largest area, dividing into three branches near the base of the wing, each of which forks singly and rather widely near the border, and at varying distances from it. The internomedian vein divides more than once and supports the lower outer angle of the wing.
In this specimen there are six larger, round or squarish, discolored spots, the surfaces irregularly elevated or blistered ; four of them form a bent row in the middle of the outer half of the wing, the upper three spots being nearly straight and the lower one turned inward at a little more than a right angle ; the uppermost spot occurs in the scapulai'-exter- nomedian interspace; the others follow in succeeding interspaces. The two other large spots are found in the same interspace with the upper two of this inner row and are situ- ated about half way between them and the border. There are also many smaller spots, often deeper in tint and not elevated, which appear to be les-s regularly distributed ; they are usually round but sometimes oval or transversely elongated ; there are three at equal dis- tances from one another in the lower interspaces formed by ihe branches of the .scapular vein, another occurs just within and above the inner of tlie-^e three, and one in the angle of the last branch of the scapular vein; there are' two between the forks of each of the upper branches of the externoinedian vein, and one near the margin between these two forks ; two larger and elongated spots occur in the same interspace with the lowest of the larger spots, at equal distances on either side of it, and the outer close to the margin of the winu : three equidistant ones are seen in the fork of the upper internomedian branch, one ncir the middle of the hind border, and finally two faint one-; iu the middle of the wing situated beneath .and against the upper branches of the externoinedian vein.
CI-ASSIKICA ri<)\ OK l'\l,i:< >/.()!( INsKcrs. ;;.J7
In the otiior frajnnent |i!irti<tiliirly studii'd ( (i<f. lOl llicrt' aiv two large spots, as befurc, in tlu- scapuliir-eNtiTiiDiiU'tliaii iiitt'i's|»ai'C', hut tlit-y aro more widely separated ; a single large one in the interspace beneath, situated mid-way between the two ; but one of inter- mediate size, though apparently belonging t<i the laiger series, in the same int»'rspaee nearly iiall"wav between the inner an<l the margin. The smaller spots are distributed in a very irregular and evidently uuMuingless way ; they are less Irecjuent than in the first s|)eeimen Ibuml, but on the other hand there is a third series of mere dots, to the numl)er of twenty or more, scattered about the apical ])art of the wing in the scapular area aiul just above it, below the apical branch of the nu'(liastinal vein. A ])oint unnoticed in the pre- vious specimen, and perhaps from its preservation not discernible, is the fine but pro- nounced serration of the entire costal nuirgin (fig. 9). which is armed with a close-set series of conical dentations, two or three times longer than broa<l, and separated l)V about their own wi<ltli from each other ; they are about O.oo nun. long.
The wing in both specimens is of a dark l)rown color, the spots bhicki.sh brown, and the interspaces broken by a Hue weak tracery of delicate irregular veins, having a general transverse disposition.
The smaller fragment is o7 mm. long and 'l'-\.') mm. l)r()iul ; the larger ;")■") mm. hjng and 4t) mm. broad, the latter lieing the breadth of tiic wing, the length of which was not far from SO mm. The smaller fragment appears to belong to an even larger wing.
The original specimen was sent to me by Prof A. U. Worthen, through Mr. L. Les- quereux, and came from Mazon Creek, 111. The smaller came from the same place and was sent me for study by Mr. Lacoe, in whose collection it bears the number 2025.
Meganthentomum forzaosum.
Acridites formostim Gold., Fauna Saraep. Foss., ii, 18-20, pi. 2, fig. 18.
Megathentomitm formomm Scudd., Proc. Bost. Soc. Nat. Hist., xviii, 359.
This species differs from the preceding in the absence of spots and dots, and in having a more rounded and less triangular form and a more abundant branching, the externo- median vein having four principal offshoots and thirteen ultimate veinlets again.st scarcely more than half that number in the American form. Both have the same weak reticula- tion and are of about the same size.
Fischbach, Germany.
[Hemipteroid Palaeodictyoptera.]
A Eugereon Bockingi. Eugereon Bockingi Dohrn, Palaeontogr., xiii, 333-340, pi. 41. Permian deposits of Birkenfeld, Germany.
B Pulgorina Ebersi. Fidgora Ehersi Dohrn, Paleontogr., xvi, 131-133, pi. 8, fig. 2. FuJgorina Ebersi Gold., Faun. Saraep. Foss., ii, 28-30, 51, pi. 1, figs. 16-17. Carboniferous deposits of Saarbriicken, Germany.
348 SAMUKI. 11. SCrDDKU ON TIIK
Fulg. hhachensis Gold, nnd P. Klteveri Cold, are probably hind wings of Palaeoblatta- riae. I niav remark that Goldenbcrg left behind him a drawing, now in m}' possession, in which he tried to restore the latter so as to make it fit the wing of a Gerablattina. Macro- phlebunn Holleheni Gold, seems to me also most probably the hind wing of a cockroach, and the supposed separation line between a basal and distal area (coriuui and membrane) an accidental circiunstance.
C
The two forms conceded above to belong in this section of Palaeodictyoptera seem to Ibreshadow the homopterous rather than the heteropterous division of hemipterous insects. The reverse is the case with the interesting species next to be described.
Fhthanocoris occidentalis {4>9avio, ko>s) gen. et spec. iiov. PI. ;12, tig. l.
Phthanocoris occidentalis Scudd., Proc. IJost. Soc. Nat. Hist., xx, 58-59.
A perfect front wing of moderately large size, nowhere very broad, and less than three times as long as broad. The corium occupies rather more than three quarters of the wing, separated from the membrane by an oblique sinuous line running from a point on the lower margin about three-fifths the distance from the base, and reaching the costal mai'gin only a little before the tip. Beyond tiie basal fourtli the costal margin is very regularly and gently arched. The inner margin is strongly rounded next the base, beyond that to the end of the corium straight, with a scai'cely perceptible turn outward where it strikes it; beyond this forming with the apical margin a regularly convex curve, the ape.x; of the wing falling in the middle of the upper two-thirds and the greatest breadth of the wing being twice its width near the base. All the principal veins are stout and prominent, but especially is this the case with the mediastinal and scapular. The marginal vein forms the costal border. The mediastinal is simple and follows the curve of the mai'gin, 'constantly and very gradually approaching it and finally blending imperceptibly into it just before the extremity of the corium, or in the middle of the downward slope of the margin. The scapular vein is the stoutest and most prominent in the wing ; it originates scarcely above the middle of the base (the mediastinal midway between it and the margin), and runs par- allel to the mediastinal until it divides, a little beyond the basal third of the wing ; its infe- rior branch here recovers the straight course of the extreme base of the vein and retains it to the extremity of the corium, scarcely turning upward at the end and gradually losing its prominence ; while the upper branch or main vein curves upward, very gradually and very slightly approaching the mediastinal vein until it reaches the upper limit of its con- vexity, and then runs parallel to it, terminating in the margin at the extremity of the corium. The externomedian vein originates just below the middle of the base of the wing and runs in a straight course down the middle of the wing to the end of the corium ; it is the least promiment vein in the wing but occupies most space, filling the area below it with somewhat approximate, parallel, straight, oblique veins, most or all of which originate from a principal branch which runs parallel and near to the main vein. The internomedian vein, or sutura clavi, runs from the base of the last vein to the inner extremity of the corium a little beyond the end of the middle third of the wing in a straight line, curving very slightly
cLAssiricA ri()\ (»F rM.Kozoic insix-is. 349
townnl tlie inar<riii at the I'Xticiiiity ot" its course. Tliu anal vein, starting from the sani<; point, rims paralk-l to the inner niurgin tlirouirlutiit its Imsul curve and as far IVom it as the mediastinal Irom the marginal, and after that runs in a straight line to the tip of the sutura clavi. or almost exactly ])arallel to the inner margin. The margin ol" the memhrane is fiile<l from a cjuarter to a third its hreadth with crowded, parallel, .-traight veinlets, which apj)ear to arise vaguely from irregularly arlioresc-ent interlaced veins origiuiiting from the nuu'gin of the corium. at suhequidistant intervals, which are ahout eijual to those between the ohlique hranches of the interitomediMii vein. The siu'face of the clavus and corium lias a minutely wrinkled appearance, not shown in the figure, formed of faint, crowded, transverse lines ; the.<e are most distinct upon the clavus; the surface is of a pale brown cohu", a little irides- cent excepting where along some of the veins it appears to be covered with a clay brown film. The length of the wing is l').7"i mm., and its greatest breadth 5.70 mm. ; a minute fragment of the tip is all that is not preserved.
it was found in the upper coal mea.sures of Kansas City, Mo., in a small nodule in the blue and bituminuous shales, forming layer 95 of the general section given bv liroadhead in Pumpelly's Geological Re|iort. II. SS-'.ty (187-)). and was received for examination from Mr. H. L). Lacoe under the number 2<i;)(l.
The discovery of this fossil in carboniferous beds is a very remarkable one, for up to its discovery not only was nohemipteron known from rocks earlier than the tertiary in Amer- ica, but no heteropterous liemipteron liail been rouinl anywhere in paleozoic formations. Yet the structure of the wing shows it to be distinctively heteropterous. The separation of the corium and membrane and the flifferential character of their structure is as clearly marked, apparently, as in existing types; the corium. it is true, is usually large in pro[)or- tion to the membrane, and the clavus is very narrow; moreover while unquestionably divided into areas as in modern Heteroptera, their characters are very different. The su- tura clavi for instance, instead of arising far toward the costal margin above the middle of the base of the wing, originates as in most ancient insects consideiably below it ; and the clavus, instead of being a broad field of a quadrangular shape (the opposing suturae clavi often forming a secondary triangular projection similar to the scutellum), is a narrow, elon- gated, triangular field of very slight importance and scarcely affecting the shape of the wing, especially as the sutura clavi terminates not before but at the extremity of the corium. Then the membrane, as stated, is very small, somewhat as in Zaitha, and indeed there is no group of Heteroptera to which it can be so well compared as to the aquatic rcduvioid subfamily Belostomidae. one of the lowest groups of Heteroptera, though it certainly cannot be brought within the limits of any existing family. Another striking feature is the basal width of the margino-mediastinal, and mediastino-scapular interspaces, a feature almost or quite unknown in Heteroptera though not so uncommon in tlie Homo- ptera. We .see, therefore, in the structure of this wing inherent signs of its antiquity — of its alliance to the earliest types of Homoptera and of less degree of divergence from other ancient types. No signs whatever of any approach to an, embolium or cuiieus are present, showing that in this as in other respects diflerentiation of the wing had not proceeded very far. Still tlie actual differentiation into the three grander areas is an indisputable fact which is very surprising; and adds another to the many startling instances already known, where a deep seated dif!ference of structure has appeared abruptly so far as any evidence in w;ng structure or discovery in the rocks can iioiiit out.
;j-,() sAMrKi. n. scrnnKU on tiih
A few ispooies which have been mentioned, figured or described as coining from paleozoic rocks have not been introduced above and may here be briefly referred to : —
Euephemerites j^rhnordialis Scudd. (Proc. Bost. Soc. Nat. Hist., xix, 248-249), is no in- sect at all, but the half of a leaf of Cyclopteris.
Tlje three species which 1 described briefly and figured poorly in the Geol. Surv. 11!.. vol. III. under the troneric name of E])homeritcs (wrongly printed Euphemerites) are also prob- ably plants.
LibeUula carhonaria Scudd. (Can. Nat., (2) viii, 88-89, fig.), as- a recent examination .shows, is more probably the abdomen of an Arachnid, one of the Anthracomarti.
Termitid'nnn amissimi Gold. (Faun. Saraep. Foss., ii, 17, pi. 1, fig. 6), is too fragmen- tar)' to be of any value, and it would be impossible to determine its position,
Termiiidhnn rugosum Gold. (Ibid. pi. 1, fig. 14). which Dohrn first described as perhaps the remains of an orthopteron (Palaeontogr., xvi, 134, pi. 8, fig. 4). shows no vein attach- ments, and is, therefore, of very uncertain position.
Corydaloides Scudderi Brongn., (Bull. Seances Soc. Ent. France, 1885, p. xiii) has not vet been figured and the description of it is only provisional, so that its precise position cannot be discussed at present. A photograph Mr. Brongniart has kindly sent me shows that it is an interesting insect.
I venture to add the figure of an obscure fossil (pi. 32, fig. 2) showing most of the veins of the two overlapping wings, but generally without their attachments, so that their rela- tion to each other cannot be determined ; it is impossible to say until further material is at hand where it belongs. It was found by Mr. R. D. Lacoe near Pittston, Penn., in coal C of the Boston Mine and bears the number 2029 in his collection.
A species to which I had given the MS. name of Termes longitudlnalls (see Lacoe's list of paleozoic insects, p. 15) is omitted here, because from an accidental circumstance it could not be obtained for reexamination before the plates went to the engraver. It is not a Termes and will be considered on a future occasion.
Explanation of the Plate."?. Plate xxix.
Fig. 1. Gerapompus hlaltinoides,\, Mazon Creek, 111. Drawn b^' J. H. BLake. Fig. 2. ArchegogryUus priscus, leg, f , Talmadge, Ohio. Drawn b}' S. H. Scudder. Fig. 3. ArchegogryUus priscus, vi'xng, ■t,^., Talmadge, Ohio. Drawn by J. II. Emerton, Fig. 4. Eucaenus ovalis, f , Mazon Creek, 111. Drawn by Katlierino Peirson. Fig. .5. Oerapomjms extensu.t, |-, Mazon Creek, 111. Drawn by Katheriue Peirson. Fig. 6. Didym&phleps contusa, ■}■, Vermilion Co., 111. Drawn by J. S. Kingslej-. Fig. 7. Clieliphlehia elongata, f , Mazon Creek, 111. Drawn by Katherine Peirson. Fig. 8. Gerapompus extensus, f , Mazon Creek, 111. Drawn by Katherine Peirson. Fig. 9. No. 205.5. See p. 325, f , Mazon Creek, 111. Drawn bj' S. F. Denton. Fig. 10. Dieconeura rigida, f , Pittston, Penn. Drawn by J. S. Kingsley. Fig. 11. Genopteryx amstricta, ^, Mazon Creek, 111. Drawn by Katherine Peirson,
fLASSII'lCAllON (II' I'AI.KdZdIC INSKCTS. afjl
I'l.ATK XXX.
Fig. I. Anthracotliremma rultu.Hla, No. 20,')2, <f, Mn/.oii frock, III. Diiiwn liy Katlicrinr IVirHon. Fig. 2. GeneiUomum iHiliiliim, front wing, 'j, Ma/.on Crcok, III. Driuvn by Kiitliuriiic IVirson. Fig. 3. Geni'iilomiim vulidiim, hind wing, j, .Mazoii Cri'ek, 111. Drawn l>y Kiitliurinf IVirHon. Fig. 1. Diei-oneitra arruala, f, Mazon Crook, 111. Drawn by Kathorino l'oir»on. Fig. ."). Anthnicothremma robuntn. No. 2()')2, f . .Mazon Crook, 111. Drawn by Katliorinc I'oirson. Fig. (j. Aitthracothremina rohii.stii. No. "JO-IK, f. Ma/.on Crook, 111. Drawn by Katlioriuo I'oirson. Fig. 7. No. 2018. Seep. ."529, ^. JInzou Crook, 111. Drawn l>y Katliorino I'oirson. l'"ig. H. Clieliphlebia rarboiKirin, f, Msiznn Crook, 111. Drawn by Kallioriiu' I'oirHon.
PlaTK XXXI.
Fig. 1. Poh/ernus hnninurum, \, Pittston, Ponn. Drawn by .1. II. Emerton.
Fig. 2. ChnMdtea lapidea, |, Mazon Creok, 111. Drawn by S. II. .Soudder.
Fig. ."?. PropMicus iiiferiiti.i. anlovior extroniity, rovcrso of lig. 4, x- I'ittlf Vorniilion Hivor, III. Drawn
by .1. II. HIakc. Fig. -1. I'roplclirus Infeniux, rover.se of lig. ."?, f. Little Vermilion River, 111. Drawn by .1. II. Hiako. Fig. .'). Gfnirus Dunae, \, Mazon Creok, 111. Drawn by .S. II. Scudder. F'ig. 6. Gemriis veins, a little enlarged, Mazon Creek, 111. Drawn by S. II. S<-udder. F\g. 7. Piwhi/tylopsis Pvysimtirei, f, Mons, Uolgiuni. Drawn by S. II. Scudder from the lioiiotypo piib-
lisheil by DeBorre. Fig. 8. No. 20.iO. See p. 342, ■{. .Ma/.on CrorU, 111. Drawn by Kalherine Peirson. Fig. y. Aethoplilehia ,s«»;/H/f/n'.s, f. .Ma/.i>n Creek. 111. Drawn by Katliorine Peirson.
Plate xxxir.
Fig. 1. Meijatlientomum pttslulatum, \. Mazon Creek. 111. Drawn by S. H. Scudder.
Fig. 2. No. 2029. See p. 350, f , Pittston, Penn. Drawn by J. S. Kingsley.
Fig. 3. No. 2016. See p. 344, f, Mazon Creek, 111. Drawn by Katherine Peirson.
Fig. 4. Phthanocoris ocridentalis, J, Kansas City, Mo. Drawn by J. H. Blake.
Fig. 0. See p. 34.5, ^, Mazon Creek, 111. Drawn by J. S. Kingsley.
Fig. G. Adiphlehia Lacoana, 2, Mazon Creok, 111. Drawn by S. F. Denton.
Fig. 7. Gero.rus mazontix, ^, Mazon Creek, 111. Drawn by J. S. Kingsley.
Fig. 8. Polyerniis coinplaiialus, reverse of fig. 11, f, Mazon Creek, 111. Drawn by .S. F. Denton.
Fig. 9. Merjathentomum pustulatum, showing the serration of the costal margin of fig. 10 near tip, Y".
Mazon Creek, 111. Drawn by J. S. Kingsley. Fig. 10. Megatlient07num pustulatum, \, Mazon Creek, 111. Drawn by .J. .S. Kingsley. Fig. 1 1. Polyernus complanatas, f , reverse of fig. 8, Mazon Creek. III. Drawn by S. F. Doutou.
XIII. WlXGED IXSKCTS FROM A PALEONTOLOGICAL I'OINT Ol-- \'lK\V, OK TIIK (lE()\A>r,l(:AL
History of Insects. By Samuel II. Scuddeh.
Read .April 1, 1«M.-|.
J. HE division of liexapod in.sects into orders has undergone no very striking cliangen since the time of Linne and Fabricius, the founders of entomological science ; new ele- naents, indeed, have entered into their definitions, but the main divisions introiluced by these pioneers have, on the whole, stood the test of time and increasing knowledge in a somewhat remarkable way. Unquestionably this is due in large measure to a somewhat unusually sharp delimitation of most of the main groups, recognized even by the least observant, who, if given a thousand chance insects from his own neighborhood, would be pretty sure to separate from one another the wasps, the moths, the flies, tlie beetles, etc., or at least most of them. There are, of course, a few forms (few, compared to the ma.ss) which would prove disturbing elements, and there are .some concerning which the best informed are not wholly agreed. There are also some groups about whose ta.xonomic value there is still disagreement, such as whether the Heteroptera and Homoptera should be looked upon as orders or as primary divisions of the order Hemiptera ; others con- cerning which there is some dispute whether they should be separated as orders, or as mere families of one of the long established orders, instances of which may be found in the Westwoodian orders of Aphaniptera and Euplexoptera; still others, not regarded as di.s- tinct orders, concerning whose nearest affiliation there is or has been question — as in the case of the so-called Pseudoneuroptera. This is in effect only to say that here, as in other great zoological divisions, there are aberrant groups, and the main groups them- selves are unequally delimited.
The attempts, however, to group the orders into larger divisions still suljordiuate to the grand liexapod type have resulted in very diverse presentations, according as one or another set of organs, or other peculiarities, were deemed of prevailing weight. The two which have found the most adherents have been that which separated the mandibulate from the haustellate insects, and that which divided them from each other according as their metamorphosis is complete or incomplete. To the first, the objection naturally arises that it places the Hemiptera beside the Hymenoptera, Lepidoptera and Diptera, rather than with the Coleoptera and Orthoptera, to which by all other points in their bodily structure and by their metamorphoses they are certainly far more closely allied. To the
3r,4 SAMIEI. H. SCUDDER ON THE
latter, that we find very varied forms of metamorphosis within the limits of a single order, so that it would require a dismemberment of the orders to uphold the distinction in a loirioal form.
In the attempts alluded to above, naturalists have simply selected, as it were, combina- tions of acknowledged ordinal peculiarities in order to form and distinguish their super- ordinal divisions, and have failed to search deeper into the general structure for more fundamental characteristics. Packard, however, has done this, and by employing the terms Met^ibola of Leach, in a modified sense, and Heterometabola, has brought the H^Tnenoptera. Lepidoptera and Diptera under the former, and the other orders under the latter. In a paper published six years ago on the Early Types of Insects, I gave my adhe- sion to this view, and strengthened it, as I believe, by some additional characteristics drawn from the regional divisions of the trunk. In the Metabola, the thorax, supporting the orscans of aerial locomotion — a primary feature of the Hexapoda as a whole — is very highly organized and compact, well diilerentiated from both head and abdomen, the prothorax very small; the body is generally cylindrical ; the mouth parts prolonged into a beak of some sort, and the mandibles rarely opposed at tip ; the front wings are membranous and laro-er, orenerally very much larger, than the hind pair ; the larva is cylindrical and in no way resembles the adult, and the pupa is inactive. In the Heterometabola. on the other hand, the prothorax is large, and the joints of the thorax are less compacted, as a rule, than in the Metabola, or, if compacted, generally massively soldered to the abdomen; the body is usually flattened ; the mouth parts are generall}' not prolonged into a beak, and the tips of the mandibles are generally opposed ; the front wings are generally more or less coriaceous or with very numerous and thickened veins, and generally smaller than the hind wings ; the larva is usually depressed, often resembles the adult in form (except- ing, of course, in the wings), and the pupa may be active or inactive.
The exceptions, in special points, to the above general statements, are not few, especiall}' amonfT the less homogeneous Heterometabola, but if any superordinal division of Hexapoda is to be looked for, it would seem to be on the lines here indicated. The points which are especially disturbing are the opposition of the mandibles in the Hymenoptera, and the appearance of many metabolous characteristics among the Neuroptera properly speaking, a group which is, nevertheless, as a whole, admittedly related most nearly to other hetero- metabolous orders.
That the Metabola should rank, as a whole, higher than the Heterometabola, can scarcely be disputed ; the regional division of the body, the structure of the wings for fiigh*, and especially for strong and directed flight, the complication of the mouth parts, and the universally complete metamorphosis and quiescent pupal state, — are fundamental features, in which the hexapodal type is carried, as a whole, to its highest development. And 3-et, as we shall see, there are some features in which its members have held to fundamental characteristics of paleozoic hexapods more firmly than have most of the heterometabolous groups.
This brings us fairly to the main object of this paper. What were the relations of the ancient to the modern types of winged insects ? In what succession did the two super- ordinal divisions of insects appear, and at what period the different orders as we now recognize them? What light, in short, can paleontology throw upon the origin and suc- cession of insects ?
CKdI.OfiK Al. IIIslOKV (tF INSKCTS. 355
III iittciii|itiii;i some years ago, in ii iinpi-r already referred (o. to aii<\i<'r this question in a liioad way, I stated that all the orders ot" Ileteroiiietahola, and none of Metahola, hinl been found in paleozoic deposits. 'I'o-<lay 1 shall have to iiiodily this proposition. N<tt only have luiiiieroiis discoveries been made in paleozoic deposits within the past six years, hut those already known have been subjecteil to more rij^orous study and wider comparisons, wiiich have considerably enlarged our knowledge. Protophasma had then only just been discovered, an insect which has done more than any other, excepting Eugereon. to throw light on the fundamental characteristics of the early world ol' insects; and even imw Brongiiiait has published liut five or six examples of the treasures of I'ommentry, a place which has already yielded remains exceeding in numbers those of all tin- rest of the world put together. Nor must we leave out of sight his discovery of a winged insect iu the Silurian.
While our kimwledge of paleozoic in.sects is thus shown to be clearly still in it< infancy, it may appear hazardous to attemj)t to formulati' statements ot a iuoad ami sweeping character concerning the ap])earance of the primary groups of insects in paleozoic times, especially if I am already compelled witliin six years to modiiy such assertions then made. Yet when 1 ])oint out the nature of this modilication, made after a special study of every known paleozoic form, it will appear less hazardous.
The modilication I would introduce is to this effect: That while we may recognize in the paleozoic rocks insects which were plainly precursors of existing Heterometabola, viz.: Orthoptera, Neuroptera (both Xeuroptera projier and Pseudoneuroptera). IIenii|)tera (both Ilomoptera and Ileteroptera), and perhaps Coleoptera — and no Metaliola whatever — a statement almost identical with that previously made, we may yet not call these ()rtho])tera, Neuroptera. etc., since ordinal J'cffh/rcx ir ere not then differentiated; but all paleozoic insects belonged to a single order which, enlarging its scope as outlined liy (loldenberg, we may call Palaeodictyoptera; in other words, the paleozoic insect was a generalized Hexapod, or more particularly a generalized Ileterometabolon. Ordinal differentiation had not begun in ])aleozoic times.
It will be asked, were there then no cockroaches in paleozoic times? I answer, yes; cockroaches but no Orthoptera; Palaeobhittariae, not Blattariae ; that is, Palaeodictyo- pteia, not Orthoptera. Mayflies; but they were Palephemeridae, not E])hemeridae — again, not Neuroptera but Palaeodictyoptera. Walking sticks; but no Phasniida — only Protophas- tnida, another group of Palaeodictyoptera.
The grounds for this view are as follows: 1. No group of paleozoic insects has yet been studied carefully — and it is important to observe that, though our knowledge of them is of necessity fragmentary, yet the more perfectly they are known the clearer is this true — no group, I say, has been carefully studied which does not show, between it and the modern group which it most resembles, differences so great that it must be separated from that group as a whole, as one of equal taxonomic rank, as in the case of the three related groups last mentioned.
2. That the different larger groups of paleozoic times, of which we now know nine or ten, were more closely related to one another, at least in the structure of their wings (which is the only point of general structure yet open for comparison), than any one of them is to that modern group to which it is most allied, and of which it was with little
356 SAMUEL H. SCUDDER ON THE
doubt the precursor or ancestral type. Thus the Palaeoblattiiriae are more nearly allied in the ground structure of their wings to certain neuropteroid Palaeodictyoptera of paleozoic times than to the modern Blattariae ; and yet we can so completely trace in mesozoic times the transition from the Palaeoblattariae to the Blattariae, that no reasonable doubt can exist as to their descent, the one from the other.
3. The ordinal distinction which is now found in the wing structure of modern insects did not exist in paleozoic insects, but a common simple t^pe of neuratiou which barely admitted of family division.
It will appear from this that, by a sort of principle of fomily. continuity, we may recog- nize in the paleozoic insects a tendency toward a differentiation in ordinal characters, suffi- cient to enable us in an ex ^Jos< /ac/o fiishion to distinguish between orthoptcroid, neu- ropteroid, etc. Palaeodictyoptera.
In speaking above of the different orders of Heterometabola which were foreshadowed in ancient times, I included the Coleoptera with a limitation, for the followmg reasons : Troxites, the only supposed paleozoic beetle which has not been shown to be an arachnid, is a very obscui-e object, and is very likely, as Brongniart has suggested, to be merely some fruit. But there have been found wood borings of different kinds which so nearly resemble similar excavations made now by Coleoptera that it is natural, though of course not necessary, to attribute these to them. Yet if Coleoptera, with front wings differentiated as those of to-day existed then, it would be rather anomalous, since all the paleozoic insects we know excepting one, Phthanocoris, which foreshadowed the heteropterous Hemiptera, had fore wings as completely membranous as the hind wings.
It seems to me probable, therefore, though there are no farther gi-ounds for it than those ju.st given, coupled with the present relationship of the Coleoptera to other Iletei-ometabola, that Coleoptera sprang from such Palaeodictyoptera as were wood-borers throughout the greater part of their life, and which at first showed no greater distinction between the front and hind wings than existed generally in other Palaeodictyoptera ; but afterward those races were preserved in which the thickening of the membrane of the upper wings the better protected the insects while in their burrows for the marriage flight in open air. Their habits would render their preservation in the rocks less frequent, and tliis special differentiation would be likely to proceed rapidly, and to be retained even by those which lost the wood boring habit; — a habit, by the way, likely to have existed with some insects living in the va.st carboniferous forests.
Of the metamorpho.ses of the paleozoic insects we know absolutely nothing, for no lar- val or pupal form has yet been found, nor even any apterou-i insect' which might, by any po.ssibility be looked upon as such. The preparatory stages of existing Heterometabola ; the fact that from every form of evidence the more " complete " metamorphosis must have been derived from the less complete; and the generally admitted proposition of Brauer and others that metamorphosis, that is, radical change of form after birth, 's a secondary adaptive feature ; — these all lead us to conclude that the only significant change in the paleozoic Palaeodictyopteron after leaving the egg was the acquirement of wings ; and that the acquirement of wings was the lever which natural selection handled to procure the present varied forms of metamorphosis in insects.
' Polyzosterites of Goldenberg is looked upon as a crustacean.
CKOI.OCIC.M. IIISTOKV (t|- INSIXTS. 357
A curious and somewhat uiiexpocted fact is CoiiikI in tlic |)resent universal prevalence of membranous front winj^s in all the orders of Metabida. similar to what is fouml in the direct paleozoic ancestors of Ileterometabola; while most existinj^ Heterometjdjola, thouj^h lower in general oriranization than the Mctabola, have passed beyoml this feature of uniformity to one of greater (lillerentiation. tiie front wings being more or less coriaceou'^, while the hind wings are still nuMnl)ran()iis. This, t(»gether with the direct rela'ion of some paleozoic insects to later types, would lead us to believe that we are to look at the neuropteroid Palaeodictjoptera as the ancestors not only of later Neuroptera but also of all Metabola, and would account in a measure for the somewhat cIo>e relationship of the Pliryganiflae and lower Lepifloptera.'
Allusion has been made to Brongniart's discovery of an insect's wing in the middle Silurian — a long way removed from the upper Devonian, which had hitherto been their lowest known horizon. But though he quickly published a rude figure of his fossil, it is insufficient for critical purposes, and it would probaljjy be hard to obtain from a single discovery the clew we need as to the ancestry of the Palaeodictyoptera. We may safely conclude, however, that the winged Falaeoilictyoptera came in as early as the middle Silurian and that up to the close of the paleozoic epoch their divergent stems were still admissible into one general order.
Now when we look at the insects of later formations, we find types of every one of the existing orders of insects — speaking of these orders in their broadest sense, as we have everywhere done in this essay — we find (.-very one fully developed in the Jurassic period.
In the Orthoptera we find as good a proof as anywhere, since cockroaches are the only insects found in any numbers in the very lowest mesozoic rocks. Their presence in the Triads and its significance will be alluded to later. In the Jurassic rocks nearly forty species are known, of which about one-third are in the lower Jurassic, and nearly all are true Blattariae. So too in the Liassic rocks we recognize all the families of saltatorial Orthoptera and the Forliculariae, so that the Orthoptera may be considered as well established early in mesozoic times. Unlortunately no Pliasmida have yet been recovered.
Only one or two Neuroptera have Ijeen recognized in the Trias, but in the Lias we have a considerable number, including Megaloptera, Sialina, Panorpidae, Phryganidae, Ephe- meridae, Termitma and Odonata, showing that the differentiation into the non-existing families was apjjarently complete early in mesozoic times, and that forms of nearly' all recognized families were abundant in the middle and later Oolite.
The two orders just mentioned are almost the only ones that have yet been recognized in the scanty fauna of the Trias, but the moment we reach the lower Jurassic rocks we find traces of nearly all the others; thus several families both of Homoptera, and of Heter- optera are found in Liassic rocks, including such diverse^ types as the Coreidae, Belosto- midae, Cicadina and Cicadellina, while Fulgorina and Aphidina are added in the Oolite.
The (Joleoptera, of which we found only indefinite traces in paleozoic rocks, have been found in the Trias (^Chrysoinelites), and the adjacent Rhaetic has disclosed forms as differ- ent as llydrophilites, Buprestites and Curculionites, while the Lias already claims some one hundred and twenty-five species referred to as many as seventeen distinct families.
• In this connoction it woiiM be woll to call atlenlidii to "svntlietic tvpe." See Bost. Journ. Xiit. Hist., vii, 590. one of Dr. A. S. P;ickiird's early papers on Neuroptera as a
358 SCUDDEH OX THE GEOLOGICAL HISTORY OF INSECTS.
AVlion we come to the metabolou'^ orders we find a scantier representation, but in the more Hunted sense necessarily attendant upon this foct nearly the same things are true. Three or four spacies of Diptera, referred to Chironomidae, Tipulidae, and Asilidae, are found as low down as the Lias, about as many more in the middle Oolite, and some fifteen or twenty in the upper Oolite, of several different fiimilies, mostly Nemocera. Of Lepi- doptera. the remains of which are exceedingly scanty even in the tertiaries, we know of two unqnestionalde Sphingidae in the middle Oolite, and the mines of a tineid moth in the Cretaceou-^. While of Hymenoptera we have eight or ten mesozoic species, the oldest of which is an undoubted ant from the Lias, next a wood wasp and four or five very obscure remains from the middle Oolite of Solenhofen, two ants again from the upper Oolite (Purbecks), and the eggs of one of the Tenthredinidae from the Cretaceous.
We find then that the entire change from the generalized hexapod to the ordinally specialized hexapod was made in the interval between the close of the paleozoic period and the middle, we may say, of the mesozoic. These significant changes were ushered in with the dawn of the mesozoic period, and the Triassic rocks become naturally (together with the Silurian) the most important, the expectant, ground of the student of palentomology. Hitherto for fifty years t!;e Carboniferous period has claimed this interest as its birthright.
The Silurian period has furnished only a single insect, just discovered and already .alluded to. The Triassic has four or five representatives in tlie Old World, while a new locality recently made known in Colorado has yielded a considerable number of specimens of about twenty species, mostly still unpublished. Most of these are cockroaches, and they illustrate and enforce the conclusion we have reached in an interesting way. One of them, the Euro- pean Legnophora of Heer, shows for the first time in the history of cockroaches* a thickening of the front wings, rendering the veins nearly obsolete, a characteristic of Blattariae (not always very striking) but never found in Palaeoblattariae. A similar ap])earance is to be seen in a few of the American cockroaches of the Trias, and in addition to this they are divided between Blattariae and Palaeoblattariae, and the passage from one to the other is traceable. The two exist side by side, but some of the Blattariae have the front wings equally membranous.
It would then appear that the geological history of winged insects, so far as we know from present indications, may be summed up in a very few words. Appearing in the Silurian period, insects continued throughout paleozoic times as a generalized form of Heterometabola which for convenience we have called Palaeodictyoptera, and which had the front wings as well as the hind wings membranous. On the advent of mesozoic times a great diflerentiation took place, and befin-e its middle all of the orders, both of Hetero- metabola and of Metabola, were fully developed in all their essential features as they exist to-day, the more highly organized Metabola at first in feeble numbers, but to-day and even in Tertiary times as the prevailing types. The Metabola have from the first retained the membranous character of the front wings, while in most of the Heterometa- bola, which were more closely and directly connected with paleozoic types, the front wings were, even in mesozoic times, more or less completely differentiated from the hind wings, as a sort of protective covering to the latter, and these became the principal organs of flight.
* Etoblattina iiisignis Goldenb., sp., may, perhaps, be an preservation, as the liind wings share fiillv the same cluirac- exception, but the apparent thickening maybe due to poor teristic. Is it possibly a " pupal " form?
-I. Hist Vol III
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SCUDDER ON R\LEOZOIC INSECTS
T.SiBcIavrSSoc.lilh Pinia
XIY. The LiFi:-lIisToitY of tiif. HvdhomkdusvK : A Discussiox or the Ohigin of the Medus.t;, and of the
SiGNIFICAN-CK OF MeTAGEXESIS.
By W. K. BnooKS, Johns Hopkins University, Baltimore, Md.
(Keiul Oc-t. 7, 1885.)
^tlOST recent "writers u]ion the origin of the sexual Medusa' Avliich are set free from communities of sessile hydroids, and upon the relation hetween them and the hydroids, agree in the opinion that the sessile community is the ]M-imitive form from which the medusas have been derived, and that the medusai have originated through the gradual specialization of the reproductive members of a polymorjjhie hydroid-cormus.
This opinion is generally, but not universally, accepted for Bohm (9) has given his reasons for believing that the medusae have arisen from floating, rather than fixed hydroids ; and Glaus has advanced the opinion that the medusa is older than the pol}'- niorphic hydroid-cormus, that the hydra is simply a medusa-larva, and that the alter- nation of g'cnerations has originated through the power to multiply asexually which this larva possesses ; and that the alternation of generations is therefore a secondary modifi- cation of a life-history Avhich was originally simple and direct.
Neither of these Avriters refers to the life-history of the Karcomedustc and Tracho- medusne, and the pui'pose of the present i)apcr is to show that the metamorphosis of these medusie furnishes direct disproof of the polvmorphism-hypothesis, and completely establishes the explanation advanced by Bohm and Glaus, through evidence which neither of these authors discusses.
I may also be allowed to state that I was led, several years ago, by the study of the development of the Trachomedusaj and Narcomedusa*, to the conclusions which are here given, before I was aware that Bohm and Glaus had also ari'ived at the same view of the relation between the medusa and the hydra. As this is my first opportunity to publish the illustrations which are necessary for demonstrating the'correctness of this conclusion, I now select, from notes which I have made on the Medusae of Beaufort during the past six years at the Marine Laboratory of the Johns Ilophins University, those observations which are best adapted for illustrating my view of the oi-igin and significance of alternation of generations or metagenesis in the Ilydromedusa. This paper therefore contains an account of the life-history of a Narcomedusa, Cunocantha
1 (359)
3(50 "^V. K. BROOKS ON THE LIFE-ITISTORY
octonaria; a Trachomcdiisa, Liriope scutigera; an Anlhomedusa, Turritopsis nutncula ; and a Lcptomedusa, Eutima mira. I give delailod accounts of these four life-histories, as I believe that in each case I have enough new facts to warrant their publication as purely descriptive worlc, independently of their usefulness as illustrations.
I take this opiwrtunity to express ni}' indebtedness to Messrs. A. Iloen & Co. of 'jj Baltimore ; who, prompted by their interest in the advancement of science, have warmly * seconded my eiforts to obtain satisfoctoiy photo-lithographs from pen drawings, and| have permitted me to draw at will upon their technical knowledge, and upon the! resources of their establishment.
The four species Avhich I have selected are among the most abundant and character- istic meduscB of our southern coast, and as no figures of the adult Cunocantha octonaria, | or Liriope scutigera have ever been published, and as nothing whatever has ever been I known of the life-history of Turritopsis or Eutima, I have made use of the opportu- 5 nities which have been afforded by a lesidence of several summers on our southern coast to obtain a thorough knowledge of these common species.
In a recent paper (1), A. Agassiz says that "IlaeckeFs work shows how much pro- gress could be made in our knowledge of Acalephs by selecting a few properly placed . stations where Medusse could be studied advantageously," and I hope that this paper will| also serve to exhibit the value of such stations. *
The four species which I have studied have all been accurately described by McCrady l (48), but as my dail}- familiarity with them for several seasons has enabled me to add? many new points, and to correct the few errors which occur in his writings, it seems | best to preface my accoi;nt of the development by a brief revision of the systematic! zoology of each species. This is the more necessary as an unfortunate accident de-^ stroyed nearly the whole edition of McCrady's papers soon after they were printed, and they are now almost unattainable by the student ; and while his descriptions are very graphic, later writers have often given his specific names to other Medusas than those ' which he studied.
Section I. The Narcomedusae.
Plates 43, 44.
Although Cnuina and its allies have, in times past, been regarded as Discophora; rather than Hydromedusje, chiefly on the account of the fact that the gelatinous substance of the bell is lobed, and also on account of the very striking resemblance between a Cunina and an Ephyra, I think that naturalists are now almost universally disposed to agre^ that these resemblances are superficial and that the Cuninas and -^ginas are true veilei Medusae. The establishment of a correct view of their atEnities is due in great jiart to' the careful study of their anatomical structure, which Haeckel was led to undeitakc on account of his remarkable hypothesis that they are genetically related to the Geryonidae, and that the two forms are stages in the same life-cycle ; and we can well atford to over- look this error since its fortiinate result has been a clearer insight into the aflinities of^ the most instructive of all the Hydromedusae. His conclusions regarding their relation-* ship to the Craspedota? are so generally received that it is unnecessary to discuss the sub-^
OF Till-: iiYi)i;().Mi:i)i\s.i:. ;{(;i
jict, nor do I l)t>rK'\i' tliat any one (loiil)ts ihc |ir()|)rii'ty ol' cstahli.Nljiii;^- I'oi- tlicst' funiis a (lisiiiict Older of Ilyilroiiu'diisH-. Ciiiiiiia tlicn is a ri'in'csnitalivt! oi" Ilaeckcrs I'oiiilli oidiT of IlydioiiU'diisji?, the Xaivoiiu-diisa', or veiled medusa! with free teutaeidar aii- ililory organs, with oiulodermal otolith cells on the hell niai'gin ; uith ocelli usually ah- xiit, and the tentacles inserted on the dorsal sui'face of the unibrella, and connected hv peronia with the free edge, which is thus divided into a number of lobes. Radial canals absent, or present as flat i-adial stomach ])oclicts, in the sid>umbi-al walls of which the i'ei)roductive elements are developed. Cii'cular canal obliterated or converted into a series of festoon canals, whicli fringe the edges of the lobes. U'lie numi>ei- of radial oigans is very variable, seldom four, usually eight, and often as many as thii1y-two. A'llum tliin and wide. Ontogeny, so far as observed, a metamoi-phosis, with metagen- esis in a few excei)tional forms. Cunina belongs to the first of llaeckel's four families, the Cunanthidcc, or Narcomedusa^ with liroad, radial stomach-pockets, which are united lo the circular canal by double jjoronial canals; with ot0})orpa2 or ciliated centripetal -tripes, and with nettle cells at the bases of the auditory tentacles. Our si>ecies, Cunina /o?jan'a, McCrady, belongs to Haeckel's genus Cunocantha, which includes species with only eight tentacles, while the true Cuninas have more than eight ; and these eight tentacles arc inseilcd into the ends of the eight stomach jjockets, while Cunoctina, which also has eight tentacles, has them inserted into deep notches which divide each pocket into two.
Cunocantlia octonaria, llaeclcel.
rhites 43 and 44.
Cunina octonaria, McCrady, LS.j". Gymnophthalmata of Charleston Ilarljor, p. 109,
pi. 12, fig. 4: (young specimen), Foveolia octonaria, A. Agassiz, 1865. N. A. Acalephie, p. 57. Cunocantha octonaria, Haeckel, 1879. Das System der Medusen, p. 316.
Species-Diagnosis. Umbrella lens-shai)ed, more than twice as wide as high. The eight lobes semicircular, and cibout two-thirds as long as radius of central portion of imibrella. Stomach pendent, reaching nearly to level of veil, with a wide base and a small circular contractile mouth. Stomach pockets a little wider at distal than at proximal ends, with reproductive elements developed over the whole sub-umbral sur- face, two-thirds as long as the radius of central portion of umbrella. The tips of the eight equal tentacles project only a little beyond the bell margin. Three auditoiy ten- tacles on each of the eight lobes, the central one largest.
Color. Stomach pockets and tentacles golden brown.
Size. Diameter 12 mm. Height, 5 mm.
Ontogeny. Metamorphosis together with asexual multiplication of the larva^, Avhich are parasitic in the bell cavit}' of Turiitopsis.
Habitat. Charleston, S. C, McCrady; Beaufort, N. C, Brooks; Hampton Roads, Tirginia, Brooks.
While the larvae are said by McCrady to be quite common at Charleston, he found no mature specimens, and only one which had the adult characteristics. He fig-
3G2 ^\ ■ '^- nrvOOKs ON tiik lii-i:-iiistory
urcs this spciimen iifhis PI. 12, fig. -4, and this figure is copied as fig. 3 of PI. 44, of this paper. Tlie figures of the adult wliieli arc here given, PI. 44, figs. 4 and 5, are the only ones w hich have ever been published. Adult specimens arc quite common at Beaufort during September and October, but I have found very few during the last weeks of August, or earliei*, nor do the specimens of Turritopsis which are captuied early in August contain the larvjv, although these arei^resent in about one-third of the specimens which arc captured after the Cuniuas make their appearance.
By actually rearing the larvfe and medusje, I have verified McCrady's conjecture that the parasitic form found in the bell of Turritopsis is the young of this species; and Avliile there was no reason to doubt this conclusion, the extremely great interest of the subject, and the ver^^ perplexing character of most of our information regarding the parasitic Cuniuas, rendered this direct proof very desirable.
One other species of Cunina, C discoides, Fewkes (21), is a very rare visitor at Beaufort, and I have found only a single immature specimen, Avhich was captured out- side the bar on Sept. 2, 1882.
The LifE-IIiSTOKY of Cuxocaxtha octoxaijta.
The NarcomedusjE are unquestionably the most primitive of the Ilydromedusfe, and we might therefore expect their ontogenetic development to throw light upon the more complicated life-histories of the other members of the group, and I shall try to show that this actually is the case, and that the sei-ies of species which have been carefully studied does present us with the successive steps through which mctamor})hosis has become converted into metagenesis or alternation of generations. Our species furnishes one very important Hnk in this chain, and as I have been able to verify all the jwints in McCrady's classic, but almost inaccessible paper, and to add many new ones, I shall give as complete an account as possible of the metamorphosis, nsing ni}- own material as well as McCrady's description.
The life-history is illustrated by Plates 43 and 44. Figs. 2 and 5 of PI. 43, and figs. 3 and G of PI. 44, are copied from McCrady, while the others are original drawings from nature.
McCrady gives (49, ]). 10) the following account of the discover}^ of the larvae. "In. the early part of July, I found the first full-grown specimens of Turritopsis. Among them was one somewhat larger, perhaps, than the rest, which I took Avith the bell in- verted. When placed under the microscope, conceive my astonishment to find, clinging to the bell and sides of the proboscis, numerous little animals of singular aspect, each of W'hich appeared to be sustaining his hold by a foiir-lcgged pedestal, and to be writh- ing about in the w'ater a long appendage, the meaning of Avhich I could not understand.
* * * It was not until the loth of August, that I again encountered the same ])henomenon, in a smaller size of Turritopsis, of which quite a number were taken. I found the cavity of the bell around the proboscis again occupied by these larvas" (see PI. 44, fig. G, which is copied from McCrady's PI. o, fig. 28), "but besides these formerly obsei-ved, were others, which were gradually becoming Medusa?, and still others which had assumed the Medusa-form already, and, lastly, to complete my satisfaction, I saw them, after expulsion from their foi'mer abode, swimming about fieely in the water,
OF Till-; llVI)i;().Mi;i)l s.i:. .IC;;
uilli tile' ili\ tlimical ooiitiactioiis of Mt-diisa". It was (|iiiti' ]il:iiii Iroiii this, tluit t-x- ])ulsi(»ii had taken platv, Init still I had not srcii liu; ('XpilUd aiiiiiials until sohr' tinic altiT the occnncnct', and it was not until a later date, Sept. ISth, that I had an «»i)p(»r- tunity of (»hsoivin^ the condition of the laiva al tin- time of expulsion. From this I learned that shortly after assuming- inde|)enilenee the larva chan;^es the Medusa-fonn, under whieh it is first freed, for another which is more persistent."
Although ISIcCrady believed, at the time his first jiaper was written, that the larvje wi-rt- the young of Tnrritopsis, he discovered that (heir position inside the hell is not their jirimitive one, and the youngest larv;e whieh he found, and of whieh he givef? the following description, were on the bell-margin among the tentacles. He says of this Stage, "It was proboscidian and apparently unj)rovided with tentacles. * * * It was clinging to the tentaculiferous border of the jiai-ents' disk, by means of the extrem- ity of its own prol)Oscis. This circumstance also was i)eculiar, since in no other instance have I seen the larva to use the proboscis as even a means of temporary adherence lor the jmrpose of locomotion. Its position, also, at the border of the disk, is woi'thy of especial notice, for the habitual position of the tentacuhUcd larva, is on the sides of the ])i-oboscis of the parent, or clinging to the inner surface of the njjper part of the swim- bell, and in no other instance have I been able to satisfy myself that there was any adhesion to the tentaculiferous border. Just Avithin the cavity, and almost on the border of the veil, it clung Avith such tenacity that, notwithstanding the poAverlul contractions of the parent, by which it would be thrown, now within and now without the opening of the swim-bell, its hold was never lost. Yet it appeared to be in contracted con- dition from tlie constant irritation to wliich,by its position, it was subjected. From the same cause I was pi-evented from making anything but an outline." This rough outline seems to show that this larva was like, oi- perhaps a little younger than, the one shown in PI. 43, fig. 1.
This also Avas found on the Ijcll-margin, and consisted of a body Avith two .short stout tentacles, ending in rounded batteries of lasso cells, and a very long proboscis Avith a very small mouth. The digestive cavity, c, is lined by large ciliated endoderm cells,/', and the moutli may be closed until it is almost invisible, or it may be Avidely opened. The ectoderm, AA'hich contains scattered lasso cells and S])ots of broAvn ])ig- mcnt, is thin everyAvhere, except at the tips of the tentacles and at the aboral end, be- tween the bases of the tentacles, where it forms a thickened pad, g.
When detached it swims or glides slowly through the Avater, and as floating particles are driven aAvay from the surface, there can be no doubt that the ectoderm is covered Avilh small cilia, although I Avas not able to see them. McCrady says that his specimens had no mouth or tentacles, but his figures sIioaa^ that the larva Avas essentially like the one Avhich I have draAvn, although the tentacles may possibly have been a little shorter.
The Acry close similarity betAveen this larva and the larva of Polyxeiua Avhich Metschnikoff has studied (51), renders it probable that the a^'^ in this case also gives rise to a ciliated ])lanula Avhich floats in the water, and acquires a stomach and a mouth, and that tAVO opposite tentacles are then dcA'eloped, either just Ijefore or just after it fixes itself to the Turritopsis. The rhizopod-like stage, Avhich Metschnikoff (.52) has de- scribed in the pai-asitic Cunina-larA'a AA'hich is found on Carmarina, is probably absent in
3G4: '^^ • 1^- linOOKS ON THE LIFE-IIISTORY
our speoios. and the plamila undoubtcMlly becomes ilirectly converted into the larva shinvii ill liy. ].
TUo larva next makes its Avay into the bell cavity where it fastens itself by the tips of the tentacles, as shown in PI. 44, tig. 6. Its proboscis now becomes enormously lengthened, as shown in PI. 44, fig. 1, and its enlarged tip is inserted into the mouth of the Turritopsis, while two new tentacles are developed between the first two, and soon become equal to them in length, and the aboral end of the body becomes a little elon- gated, between the bases of the tentacles, as shown in fig. 1.
The interesting fact that the larva shown in PI. 44, fig. 1, is a true hydra, dilfering from the aetinula larva of Tubularia only in the length of its proboscis and the small number of tentacles, has been almost completely overlooked by all recent writers, al- though it did not escape McCrady's attention. lie says in his second paper, in his diagnosis of the genus Cunina (48, ]^. lOS), "Larva a free hydra, like the free stage of the Tubularia," and on p. 12 of his first paper (49), "The I'eseuiblancc of these beings to the free young hydra of Tubularia was unmistakable." Yery soon after the larva fastens itself by its tentacles, and either before or soon after the two secondary tentacles are developed, it begins to multiply asexually by budding from the aboral process between the bases of the tentacles, and thus forms little communities, like the one shown in PI. 43, fig. 2. which is copied from McCrad}', who calls attention on \^. 21, to the obvious fact that this method of budding from an area which is aboral to the tentacles is directly comparable with what occurs in the fixed hydroids, Avhen this part of the bod}^ becomes the stem or root. On p. 14, he states his belief that no more than two buds are ever developed at one time, but this is an error, as communities like the one shown in fig. 3, consisting of six or seven larvje, are frequently met wnth. This figure will also serve to illustrate the changes through which the larva passes during its development and conversion into the medusa. The young buds have, at first, no tentacles and no mouth, but the proboscis soon lengthens, the mouth appears at its tip, and two opposite tentacles grow out from its base, and are soon followed by two more, alternating with, and at first shorter than the primary tentacles. A rim or flange now grows out from the wall of the body, and in the zone which is occupied by the bases of the tentacles. This zone which is to become the umbrella of the mcdnsa occuj^es the same position as the inter-tentacular web of such hydroids as the Campanopsis- larva of Eutima, although, unlike the inter-tentacular Aveb, it is composed of both layei's of the body wall, and contains a circular diverticulum from the digestive cavity. Four more tentacles now make their appearance, alternating with the first four, and the cir- cular rim becomes notched or infolded opposite the base of each tentacle, or more .strictly the free edge between the tentacles grows faster than it does elsewhere, and thus converts the rim into eight marginal lobes, each of which contains a pocket or diver- ticulum from the central digestive cavity. The tentacles are at first on the rim, in the notches between the lobes, but they very soon begin their migration towards the aboral pole of the body. It is important to note that the lobes are at first directly comparable to the marginal lobes of an Ephyra, inasmuch as their free edges are cntirel}' separated from each other. As the tentacles retreat however, and the notches deepen, the cndo- derm alone is infolded, thus leaving the bottom of each notch spanned over by a double
OF Tin: llYDHOMKDUSiE. ;5(m
lavcr of c'etixliMiii, tlie radial string; of tin- adult. .V si-iisory tcntacli-. witli a siiij|;lL' otolith now <;io\v.s out fiom tin- tip oi" lacli loln', ami tin- live td^i-s ol" the liiljos bend down towards the mouth, thus Ibrming a shallow ciicular sulj-uniiji-ella around the base of the proboscis, and at tliis stage the hirva detaches itself and escapes into the water as a medusa, fig. 4, with an enormously long proboscis, a shallow sub-unibrelln, four long and four short tentacles, and alternating with the tentacles, eight marginal lobes, each of which ends in an auditory tentacle, and contains a spacious diverticulum from the central stomach. I have not been able to study the manner in which this cavity becomes converted into the ''festoon-canal," but this is probably formed by the growth of an area of adhesion in the centre of each lobe, between the sul)-umbral and the e.\- umbral endoderm. The pockets of the young medusic shown in PI. 43, fig. 1, must not be compared with those of the adult Cunina which arc of much later origin. After the medusa is set free the umbrella grows very rapidly, while the i)rr)l)oseis remains without change, so that the animal .soon assumes the form shown in PI. 4;}, fig. '>, which is an aboral view, copied from MeCrady. The lateral pockets of the digestive cavity have now disappeared and the central digestive cavity is nearly circular, but it soon becomes folded in at its edge, between the bases of the tentacles, as shown in PI. 44, fig. 2, in which figure the right half is an oral, and the left an aboral view. The eight intcr-tentacular notches on the free edge of the stomach now deepen rapidly as shown in fig. 3 (copied from McCrady), and thus give rise to the eight stomach pockets of the adult, while a thickening on the oral surface around the circumference of the stomach marks the rudimentary leproductive organs, which soon spread over the whole oral surface of the pockets. The long proboscis of the larva .soon disappears, so that the stomach becomes a flat pouch with a contractile mouth in its centre, but in the adult the oral wall of the .stomach again becomes drawn downwards to form a pendent pro- boscis.
The life-history of Cunocantha ocfonaria may now be briefly summarized as follows: The larva is a ciliated swimming organism, with a mouth, a long proboscis and two opposite tentacles. It soon develops two more tentacles, loses its cilia, and becomes a hydra with a greatly developed proboscis and with its aboral extremity reduced to a small prominence, from which other hydras are budded. There is no sessile stage, but the locomotor hydra makes its Avay into the bell of a Turritopsis, where it fastens itself by its tentacles, and lives as a parasite. It then becomes directly converted into a medusa by the outgrowth of an umbrella around its tentacular zone, and escaping into the water begins its medusan life. Before it becomes a medusa it produces other larvjv by budding, and all these become medusa?. The state of our knowledge of the development of other Xarcomedusai, especially of Polyxenia and ^Eginopsis, indicates that the parasitic habit of the larvae is not primitive but recently acquired, and the ten- dency to multiply asexually has probably been also secondarily acquired by the larva as an ada])tation to its parasitic life. In the case of our Cunocantha all the larva? become mcdusie, and there is therefore no true alternation of generations, but in the case of the Cunina studied by Uljanin (<30), and aftei'wards by Metschnikofl", the adaptation to a parasitic habit is much more perfect, and the larva which h.atchcs fi-om the v<^^ and
3GG "\V. K. BUOOKS ON TIIK LIFK-IIISTORY
gain?: access to tlio Cannarina, iicvei- becomes converted into a pci'fect medusa, but remains as a degraded nurse, from whicb other larva are budded, and as Uljanin points out, Ave have in this case a true alternation of generations.
Tm: Evolution' of ouk Knowledge of the Life-History of the Narcomedus.e. The growth of our knowledge of the I^arcomodusa' forms one of the most remark- able chapters in the history of zoology, and I shall review it at some length, in order to exhibit the life-historj' of our American Cunina odonaria in its true relations, and also to show by what slight increments our knowledge has grown. The life of an ani- mal which passes part of its time inside the body of another as a parasite, and then, assuming quite a dilferent form swims at large in the water, presents a very perplexing puzzle, Avhich becomes still more confusing Avhen, as in the Narcomedus;T:>, some species are parasitic and others are not. Each observation then becomes impoilaut, and I shall refer to man}' papers which contain very small additions to our positive knowledge, the present state of Avhich may be summarized as follows:
1. Some of the Narcomedusse develop directly from the cg^, without asexual multi- plication.
2. In other species the ciliated larva becomes a parasite upon the body of a totally diilcrent medusa, gaining access to the siib-umbrella of Turritopsis, or to the digestive cavity of a Geryonid. It there multiplies asexually; producing, by budding from an aboral stolon, other larvae Avhich are at first hydras. These hydra larvaj become con- verted into medusjTc by direct metamorphosis.
3. Similar Cunina larvie are foi'ind in the stomachs of many species of Cunina. In some cases the larvas become converted into Cuninas Avith the specific characteristics of the adult Avhich carries them, but in other cases they differ in the number of tentacles and sense organs, and in other particulars. The youngest of these larvre are free and ciliated, while the older ones are attached and produce buds from an aboral stolon.
4. Xo one has shown, by careful examination, that any adult Cunina produces buds from its stomach or from any other part of its bodv, and there is every reason for b© lieving that the Cunina larva; found in their stomachs are parasites, like those founl in Turritopsis and in Geryonids, and that a Cunina larva, found in the stomach of an adult Cunina, does not necessarily belong to the same species with the adult.
So f[\r as I am awai'C Krohn was the first to observe a Cunina larva. In a papeif Avhich Avas published in 1861 (41), he says that he found at Messina, in 1843, grea^ luimbers of tentaculated larva?, fastened hj their aboral surfaces to the protruded gas^ rostyle of a Geryonid, Geryonia j)rohoscidalis. He gives fcAV details, and appears tiE> regard the laiwaj as the asexual progeny of the Geryonia.
In 18.51, Johannes IMiiUer (71) caiDtured at the surface of the ocean at Marseill great numbers of small ciliated larvjc, and a series of older stages Avhich Avere suflicientl complete to satisfy him that the larva is the young of a A^ery simply organized Naro medusa, JEglnopsis {Sohnundella) mcditerranea.
As the youngest larvrc are ciliated, he believed that they are newly-hatched egj embryos, and as each one of them becomes converted into a medusa, he suggests th
I
OK TIIK IIYDliOMKDUS.'E. 'MVJ
-.^i^inopsis will i>rol):\l)]y lio found to (U'vclo)) directly IVoiii the *"^<^ without :dt('i-ii:itioii; a prophecy whicdi was vcrilit'd twciity-Uve yi-ars lati-r by MetschnikolV (ol).
The youngest larva which Mullor lijji^iires, I'l. xi, fig'. 1, is a hydra essentially like the one shown in our I'l. A'.i, iv^. 1. The position of the tentaeles is diU'ereiit, hut he says in the text, that they are often carried as they are shown in oni" li^^fure.
In the autumn of the iollowing year, IH.l'J, thr^e yonu<j^ naturalists, Ge^jfenhaur, Kol- liker and II. MuJler, met at Messina to spend a few mouths iu zoolo<^ical research at the seashore, and their fruitful harvest furnishes one with the eai'liest evidences of the value of marine zoolog-ical stations.
Kolliker, who studied the lower invertebrates, m:ide many interesting observations on the medusiP, one of the most impDrtaut being the discovery of young Cuninas in the stomach of an old one, which he names Enrij.^toind ruhujlnosimi {Cmiinu ruhlyinosa, Haeck.).
The oldest larvjij are so similar to anothei- Cuuina which he found at the same place, and named St('nof)Ui<k'r comphni'ifns, that he decided that they were the young of this species. Pie says nothing about budding from the stomach, and adopts the view, which is nndoul)tedly coiTect, that they had gained access to the stomach from outside, al- though he sa[)poscs that they had been swallowed b}'^ the Eurystoma as food.
In 18.34, Gegenbaur (24) fonnd small bild-like bodies, each with four tentacles, at- tached to the walls of the stomach of a Cuuina, which he named Cinima jn'oUfera, since he supposed, from the fact that the larvae became adults of the same species, that they are produced by l)udding.
The observations which come next in histoi-ieal order (18.36) are by an American naturalist, McCrady (48, 49), and they will always remain a monument to the accu- racy of this sharp-sighted observer, for they give for the fii'st time a pretty complete history of the life of a Cunina, which is accurately illustrated and vividly described. McCrady's ])apers are very different from the brief notices which have been referred to above, and they are by far the most important which have ever a])peared ujjon the subject. They not only serve to throw a flood of light upon the significance of earlier observations, but they also contain a record of facts which should have prevented the confusion which later writers have introduced. Unfortunately the edition of his paper was almost completely destroyed before it was distributed, and reference to it is now nearly impossible, and although proper credit is now given to the author, a desire to place the facts which it contains within the reach of all was as strong an inducement to the preparation of this paper as my desire to publish my own additions to the subject. I have illustrated some stages which he did not obtain, and my figures exhibit many points which are not shown in his much smaller ones, but I have also copied a few of his orig- inal figures, and I have embodied all the leading points of his paper, the chief results of which are as follows:
1. The young Cunina octonaria is a parasite inside the bell of a Ilydromcdusa, Turritopsis,
2. The larva is a hydra.
3. It multiplies asexually by budding from an aboral stolon, and gives rise to other larvae like itself.
3t)S ^V• K- BROOKS ON THE LIFE-HISTORY
4. Each larva finally becoinos metamorphosed into a moJusa, and there is no alter- nation of g;enerations.
MeCrady's papers were i)ul)lished in ISoG and 1857, and at abont the same time (1856) lAHK'kart (-47) iignred and described a Cnnina larva nnder the name Pyxldlam truncatum (PI. 11, fig. 7), bnt he gives no account of its history.
In 18G0, Keferstein and Ehlers (7^ repeated Gegenbaur's observations upon a Cn- nina which they call ^-Egineta gemmife?-a, but which is probably the same as j-TJgineta {Cnnina) proUfera, Gcgenb. They Avcre ignorant of McCrady's work, and believed with (xcgenbaur that tlie larva? aie formed as buds from the wall of the stomach.
In 1801, Krohu published the observation above referred to, made in 1843, to the effect that peculiar bud-like bodies are sometimes found on the gastrostyle of Geryonids, and the same volume of the Archiv f. Natnrgeschichte contained a paper by Fritz Midler (56), in which he says that, in 18G0, he found on the gastrostyle of a Brazilian Geryonid, Liriope cafherinensis, a group of medusa-buds, each of which became metamorphosed into a young Cunina closely resembling an adult Brazilian Cunina which he names Cnnina KolUTceri. In the same paper he says that in 1859 he found in the stomachs of male specimens of the Cunina, young ciliated larvte which became young Cuninas, differing from C. KolUkeri, in the number of tentacles. He holds that the larvae found in the stomach of the adult Cunina are asexual buds from the Avails of the stomach, while he believes that those found in the stomach of the Geryonid have been swallowed as food.
In 1865, Xoschin published a paper (57), in which he states that he has found on the gastrostyle of Geryonia {Carmarina) hastata, bud-like larvae which became medusre which he identifies as young specimens of Kcferstein and Ehlers' Cunina discoidalis. He regards this as a case of alternation of generations, and advances the astonishing h3'pothesis that the Geryonid, a Trachomednsa, and Cunina, a IS'arcomedusa, belong to the same cycle, and that the buds which become Cuninas are produced by the Carmarina.
In the same year ITaeckel published a brief preliminary abstract and two fully illus- trated papers (29, 30), in which he describes the same fiicts, and advances, independently^ the same astonishing hypothesis, but the mistake is the more remarkable in this case since Ilaeckel had himself traced the metamorphosis of Carmarina from a very young and small larval medusa, which, as he correctly conjectures, is an egg-embryo (30 d). If we believe that the Cunina buds are also produced by the Carmarina, we are com- pelled to believe that this medusa has two methods of reprodnction, producing Geryo- nids like itself from eggs, and producing Cuninas from internal buds. Haeckel boldly accepts this hypothesis (30 a, p. ISi), and says on p. 293, "I do not doubt that what I have here described as a remarkable exception will in time l)e found to be a widely dis- tributed occurrence, at least among the lower medusae, especially the ^ginidie. Allo- triogenesis or alloeogenesis, as this form of reprodnction may be called, is very essentially different from all forms of alternation of generations." Haeckel's papers are beautifnlly illustrated, and his figures show that although the proboscis of his larva is shorter than that of Cunina ocionaria, and the number of buds which are produced very much greater, there is, in all other res[)ccts the closest resemblance to the American larva as described by McCrady, with whose work Ilaeckel was not acquainted.
OF Tin; IIYDKO.MKDI S.K. IWJ
< )i\ till' wlioli" Ilaccki'l's cn-or was a r.niniiati' diic lor sciciici', \'nv it It-il liiin to inakc .1 very thoroiii^li CDinpai-alivc study ol" tlif atliill (Jci-youid and ( 'iiiiiiia, and this coui- parisoii resulted In his two valual»Ie and hrautii'ully illustrated papeis ('M), and showed conclusively that the Cuniuas are veiled niedusa-, not very <lilVerent in struclurc Iroin the Gi'ryouida', through whieh they are related to the ordinary Ilydroineilnsa'. The Cuninas and their allies liad ]ii('viousIy heen rej^aided as Aeraspeda. hut Ilaediel's re- sults, wiiicli arc now ahiiost imiviisally accepted, form a valiiahle addition to positive seience, although they were based np(Mi this strange hypothesis.
The next paper in historical order contains no new observations, and is simply an attempt 1)V Allnnn (0) to b:'iug Ilaecdcers hypothesis into harmony \vith oin- knowledge of other hydroids. lie accepts without rpiestiou Ilaeekers opinion that a (ii-ryonid may give rise to Cuninas hy huiMing, and he sees nothing n.'markal)le in such an occurrence. On p. 4G9, he says "While the observations of Ilaecdcel, however, can scarcely be too highly estimated for the light they throw ui)ou the relation between the Geryonid:e and ^ginida\ it appears to me that he (/reafl;j ooerrates the difference between the genetic phenomena which arc here presented and those already well known among the Ily- droida." lie then gives a series of diagrams by the aid of Avhich he attempts to show that tlu' production of medus;e by budding from the wall of the stomach of a me- dusa of a totally distinct order, which also rejjroduces itself normally by eggs, is no more than the analogy of Hydractinia would lead us to expect. lie makes no reference to McCrady's paper, with which he does not seem to be acquamted. It is rather strange to find that while he accepts without question the statement that a Geryonid may pro- duce Cuninas by budding, he is half disposed to believe that the Cunina buds found in Cnninas by Gegenbaur, Keferstein and Fritz MuUer, arc to be regarded as "suggesting parasitism rather than gemmation" (p. 474).
Metschnikoff's papers (30 a, b, and c), which come next in historical order (1874), are, with the exception of McCrady's papers, the most important ones which have ap- peared, for he gives for the first time a complete life-history of two Cuninas, yEf/ineta (^Solmonefa) flarescens, and yEr/inojisis {Solmtmdella) mediterranea. lie proves, by rearing these medusic from the og^, the correctness of the pr(i{)hecy Johannes Muller made twenty-live years before, that, in these two species at least, there is no alternation of generations, no sessile hydi-a-stage, and no asexual multiplication. In a third paper (30 a), he shows, as Fol had done a few months before, that Geryonia (Cannarina) hasfata also develops directly from the cg'^ without alternation or budding. In a third paper (30 c), he gives an illustrated account of the development of the Cunina larvte which are found in the stomach of Cunina, and although he calls attention to the close similarity between the youngest of these larv:e and those which he reared from the eggs of ^'Egineta and ^^inopsis, and although the youngest larvtc were found swimming in the stomach, not fastened to its Avails, he regards them as buds from the wall of the stomach. His account shows that the history of the larva is very much like that of the one which McCrady studied; that the larva is a hydra; that it multiplies by budding from an aboral stolon, and that the hydra-larvji? which are thus produced change into medusiE by metamorphosis. He does not refer to McCrady, but it seems strange that he was not led to question the origin of the larv:e l)y budding from the stomach, by
370 ■\^'- K- BKOOKS OX THE LIFK-IIISTORY
his kuowleilgc of the fact that Fritz IMi'illcr and Ilaeekel had observed similar prohfer- ating- Cunina larviv in the stomachs of Geryonids.
In 1870, Uljanin (GO, 01) proved that there is no genetic connection between the Ger^'onid and the Cunina hirvie found in its stomach, but that they gain entrance from outside and then multiply asexually, and that they are sometimes found on the inside of the bell, as well as in the stomach. He does not refer to McCrady, whose papers ■were published twenty years before, but he shows that the histoi-y of the parasitic lai'vae found in Carmarina is essentially like that of the one which McCrady had found in Turritopsis.
There is one interesting difference, howevei', for in his species the original larva never becomes a medusa, but permanently retains its larval nature, budding off numerous larva? which become inedusje. He calls attention to the fact that this is a true alter- nation of generations, the egg-larvae being the first, and the larvJB which aie budded from it the second generation.
This discover}-, and his verification of McCrady's discovery that the larva? are parasites, entitle his paper to an honorable position, but I cannot believe that his account of the minute structure and of the mode of development of the larva is cori-ect, as it conflicts with all our knowledge of the subject. He says that the tentacles are developed on the edge of the mouth, that the buds are formed at the oral end, that the digestive cavity is formed by a peculiar infolding and si)littiug of the endoderm, and he figures the embryo as a two-layered gastrula, with an aboral mouth which has nothing to do ■with the definitive mouth of the larva; and as this account cannot be reconciled with our general knowledge of the subject, or with the cai-eful observations which Metschnikoff made (o2) several years later, I am compelled to believe that he has failed to interpret his observations correctly.
In the same year, 1875, Schulze shoAved (i"8) that there is no organic connection between the Geryonid and the larvfc found on its gastrostyle, and he thcrefoi'e decides that the Cunina embryo originates outside the Geryonid, and after fastening itself to its gastrostyle, gives rise to new larvj* by budding, as Uljanin also shows to be the case.
In December, 1881, Metschnikoff published an illustrated paper (52), in which he traced the embryology of the pai-asitic larva found in Carmai-ina, showing that the group of medusa-buds is foi-med by budding from the aboral surface of a ciliated egg-embryo, which gains access to the digestive cavity and there multiplies asexually. In this species, Cunocantlia parasitica, Haeck., the egg-embryo, which in all probability corresponds to the mother hud of Cunina rJiododadyla and to the larva shown in our figure 1, is very much degraded. It fastens itself to its host by means of pseudopodia which^ue thrown out at the oral end from a very peculiar large cell, which fills its digestive tract. It develops tentacles, but never acquires an umbrella or a proboscis, and soon begins to produce medusa-buds from an aboral stolon.
As Uljanin has shown, it does not become conveited into a medusa, but is simply a nurse for the production of medusa-buds. This species therefore presents an example of a true alternation of generations, since the embryo which hatches from the egg re- mains as a larva and never becomes a medusa, although it gives rise to buds which do become medusae.
OF TIIK HYlJKO.MKUUSiE. 371
III many respects MetschnlkofF's observations upon the striietuiv of the e;n^<jf-oinhiyo are in conllict with Uljanin's account; l)nt as it is impossible to reconcile the statements of thj latter writer with oar gjajral kii )wle.l^e of tliJ subje -t, I tiiink we m:iy safely conchule that MetschnikolFs account is the more trustworllu'.
Both authors ag-ree that the egg-embryo of the species which occurs in the stomach of Carra:irina is deg'raclocl and has no umbrella, while Metsshnikolf shows that the proboscis also is absent.
The next paper in historical ortlcr is a short one wliich Fewkes published in 1884: (19). He gives a brief account, with one figure, of Cunina larvie which he found at Villafranca, attached to the gastrostyle of Carmarina, and he verities Uljanin's state- ment that the larvae are sometimes found on other parts of the medusa. lie has ob- served them on the mnbrella.
The youngest larva which he fouml was attached to the tip of the gastrostyle. It was solitary and he regards it as an egg-eml)ryo destined to develop a stolon and to give rise to medusa-buds. He states that it was furnished with a long' proboscis and a di- minutive bell, and was almost identical with the youngest larva figured by McCrady, which, however, has a short probiscis and no boll, and it is impossible to reconcile his account with the observations by Uljanin and Metschnikoff, which show that the nurse is, in the si)ecies which they found in Carmarina, greatly degraded and has nei- ther proboscis nor umbrella. His description is inaccurate, or else his species is a new one; and if the latter is the case it is to be hoped that his drawings and a more minute description will soon be published.
Fewkes attempts to show that there is a morphological similarit}- between a Siphono- phore and the clusters of Cunina buds whicli are found in Carmarina. In support of this view he states that " these clusters or colonies of 3oung Cuniuje, as is well known, ultimately dissolve their connection with the stolon and swim away as fi'ce medusai." If he means by this sentence that the clusters or colonies swim away, the phenomenon is neither " well known" nor supported by a single published observation. If he means simply that each madusa-bud is detached from the stolon and becomes a free medusa, there is little resemblance to a Siphonophore; nor does our knowledge of the subject furnish any basis for his statement, p. 305, that the stolon whicli carries the buds is a modified proboscis.
He says " Cunina has become degenerated by its parasitism or commensalism so that the proboscis with yonng budding from it alone remains. Its bell has gone, the mouth opening is no longer functional, and the proboscis, which has elongated into a stolon attached to the body of a host, is closelj^ crowded with the young;" but Metsc-hni- koflPs account of this particular form, shows that hero, as in all other Cuninas which have been studied, the stolon arises from the aboral surface and has nothing to do with the proboscis.
This paper completes the long list of observations upon this interesting subject, and it may now be Avell to summarize the history of research regarding the parasi- tism of Cunina.
1. In ^gineta.and ^ginopsis the e^g gives rise to the ciliated plamila, Avhich ac- quires a mouth, a short proboscis and tentacles, and thus becomes a free h^-dra or actinula, which is directly metamorphosed into a medusa.
372 "^V. K. BROOKS ON THE LIFE-IIISTOR\'
single larva ami this beoomes converted into a single adult. There is no asexual multi- plieation. no parasitism and no alternation of generations.
2. In Ctmina octoiiaria, the hydra embryo, while still eiliated like a planula, but furnished with a mouth and two tentacles, gains access to the bell of a Hydi'omedusa, Turritopsis, where it lives as a parasite, and produces other larvtB, like itself, by bud- ding. The first larva, like all the others, becomes a medusa, so that we have budding and parasitism, but no alternation.
3. The Cunina larva, which inhabits Geryonids, is essentially similar, but the first larva or egg-embrj'o does not become a medusa, so that we have alternation as well as budding and parasitism.
4. As no one has proved that the Cunina larv;e found in Cuninas do not pass in from outside, and as their history is like that of the species above noticed, there is every rea- son for believing that they also are parasites.
Section II. The Trachomedusse.
Plates 41,42.
Lii-iope is a representative of the tbii-d of the four orders into which Ilaeckel divides the HydromedustB; the Tntchomedusai, or veiled medusje, with auditory tentacles, which are either free on the bell margin or inclosed in auditory vesicles, with endodermal otolith- cells. Ocelli on tentacular bases usually absent. Reproductive organs on the course of the radial canals, which are four, six or eight in number, often with blind centripetal ca- nals between them. Veil, thin and wide. Ontogeny, as far as it is known, hypogenesis or direct development without alternation, but usually with metamorphosis.
It is a representative of his fourth family or the Geryonidm: Trachomeduste with four or six radial canals, with Ijroad, leaf-Hke reproductive organs; along proboscis, eight or twelve peronia, and closed auditory vesicles, which lie on the axial sides of the peroniain the gelatinous substance of the umbrella-margin; and to the first subfamily, the Liriopidse, or Gerj^onidai Avith four radial canals, four reproductive organs and eight; auditory vesicles. He divides the subfamily into two genera: Lii-antha with eight/ ])ermanent tentacles in the adult; and Liriope, with only four; and he places our species- in the first genus.
Haeckel has undertaken the veiy. perplexing and laborious task of introducing order and system into the confused mass of fragmentary observations which have been printed regarding the Geryonidae, and as his Avritings upon the subject introduce order where all had been confusion, and as he himself is more familiar than any other natui-alist with the species and genera of the fiimily, I hesitate to depart in any particular from his sys- tem: but inasmuch as s\nicm\ens, oi owY Liriope scutigera are sometimes found with four, five, six or seven tentacles, as well as specimens with the unusual number eight, I cannot believe that his two genera Liriantha and Liriope are natural, and I therefore retain the generic name Liriope for our species. Fewkes' statement (Acalephs from the Tortugas, Bull. Mus. Comp. Zool., ix, No. 1, p. 279) that Ilaeckel bases his two genera
OV TIIK IIYDHOMEDUS^E. 373
upon the ])i-osonco or absence of Itliml cenlii|)(tal canals is inaciiiiatc, as a ri-ffrence to Ilacckel will show.
The lar^o H'j:ui'e at the top of PI. 42, whifli is a pliotolithoj^raph of a pen drawin;^ made IVoin natiiii-, is the only ligiirc of Lin'opa scufi(/i;i(i which has cvci- hi'en piihlished.
Liriope scutigera, .yrCiKthj.
Liriope srnfiiiira, ^IcCrady, 1S."7; Ci yinno|)lithMhiiata oC Charleston Ilaihor, p. 1()0. Liriope scntigira, L. Agassi/, 18(!2; Contriinitions iv, p. :5()."J. Liriopn scati(jer(i, Brooks, 18813; Studies, 11, p. 47.'). Liriantha scutiyera, Ilaeckel, 1879; ^ledusen, p. 287. Xanthea scutigera, Ilaeckel, 18G4; Geryonidcn, p. 24.
Species-Diagnosis. Umbrella, when relaxed in swimming or floating, about half as high as wide: but sub-spherieal or almost cubical when violently conti-acted. C«astric peduncle conical, thick, about as long as diameter of umbrella, gi-adually diminishing in size from the base to the proximal end, where it terminates in a pointed, tongue-like process, which may be protruded from the mouth, which is quadrate, without lips. lie- productive organs nearly square with rounded corners, extending from near circular tube to top of sub-umbrella, and nearly meeting along the inter-radii. Four perradial flexible, contractile hollow tentacles, three or four times as long as the diameter of the umbrella, and four short stiff interradial tentacles, which are absent in a few exceptional adults. Eight sensory vesicles, one at the base of each interradial tentacle, and one a short distance from the base of each perradial tentacle.
Color. By transmitted light, the tip of the proboscis is purple; by reflected light it is green and the ovaries red.
Size. About one-third of an inch in diameter.
Habitat. Abundant all through the summer in Ilamjitoii Hoads, A'irgiuia; at Beau- fort, T^orth Carolina, and at Charleston, South Carolina. It is one of the most charac- teristic medusiti of our southern coast.
Ontogeny. Ilypogenesis Avith metamoi-jihosis.
Ilaeckel's diagnosis of the species, which is abstracted from ISIcCrady's account, is in the main correct, but it contains several statements which are not strictly accurate, such as the statement that the umbrella is nearly spherical, that there is no tongue-like pi-ocess and that the reproductive organs are i-ound. The species is distinguished from Fritz MuWer^s Liriope catherinensis (Arch. f. Naturges. xxv,p. 310, pi. 11) bythe fact that the reproductive organs are nearly square, instead of being elliptical, and bythe fact that they reach nearly to the circular tulje, while Midler's figures show quite an interval between them and the circular tube. The primary radial tentacles of the young also lack the terminal flagellum or. hook which is shown iuMulIer's figures.
Haeckel has shown that Agassiz's Liriope scutigera (N. A. Acalephs, p. 60, fig. 87) is quite diflerent from McCrady species, and this is also true of Fewkes' Liriope scutigera, (Studies of tlie jelly-fishes of Narragansett Bay, Bull. Mus. Comp. Zool., viir, 8, p. 126, PI. 6, figs. 7, 10,11, 1881). There is a lack of agreement between the text and the
374 W. K. BROOKS ON THE LIFE-HISTORY
?
fis^ui'es of Fewlvcs'' jiaper, as lie says thoi-e arc only four otocysts, Avhile his figure show# foixr on one-half of the umbrella, but neither the text nor the figures correctly represent L. scutigera, McCrady.
Special Description. McCracl3''s description of this species is so very vivid and minute, that, although he gives no figures, there is not the least difficulty in identifying the species, thousands of specimens of which maybe procured at any point between Charleston and the Chesapeake Bay. His account of the habits of the animal is so graphic that I quote it: " This species is evidently gregarious, great numbers being found together in nearly every instance when I have found it at all. It is bold and i-apid in its movements and very rapacious. I have seen one of this species, so extremely diaphanous as to make the im- pression of nothing but a set of outlines, seize upon a small fish fully thrice as large as itself, and securing itself by spreading out its lips upon it, making them act as suckers, and then entangling about the poor animal its four long tentaculie, hang on in this man- ner despite the violent struggles of the fish which, alarmed, swam violently about the jar, until at last apparently from sheer exhaustion, it was evident he was dying. At last changing color, the fish turned over on his side and expired." McCrady speaks of the great size and circular form of the reproductive organs, but their shape may be more exactly described as square with rounded corners. He gives the following very accu- rate account of their general appearance. "They are four in number, and are so large that they very nearly touch each other laterally, and stretch very nearly from top to'bot- tom of the disk-cavity, thus occupying almost the whole inner surface of the bell. "When viewed from above their unyielding structure gives the disk a quadrate outline, and viewed in profile they appear as largo, circular shields especially when at the death of the animal they assume a marked white coloration." The quadrate outline, however, is only apparent, except when the violent contraction of a freshl}^ caught or a dj'iiig speci- men causes the substance of the umbrella to conform to the shape of the distended ovai-ies. McCrady's account of the sense organs is somcAvhat misleading, owing to the fiict that it is founded, in part, upon an examination of immature specimens. He saj^s "the concre- tionary capsules are of two sorts, a small round vesicle containing a concretionary corpuscle at each of the shorter and complex tentacnla, and at each of the longer and simple ten- tacula, a double ca\isn\e consisting of two cysts, one above the other, and connected by an intermediate (tubular?) thread, ajiparently a continuation of the membrane of the cysts." This second cyst, with its connecting thread, is really the degenerated primary radial ten- tacle of the young medusa. It must not be confused with the interradial club-shaped structure described and figured by Fewkes (PI. vi, figs. 7 and 11.)
f
The Embryology and Metamorphosis of Liriope scutigera, McCrady, and t^
LlFE-HlSTORY of THE GeRYONID^. J|
Since the publication, in 1856, of Leuckart's observation on the metamorphosis of Gery- onia exigua (47) naturalists have been aware that the young Geryonid is quite differ-
I
OF Tin; IIVDUOMKDLSiE, ;}7.-;
ent fntin tli;- ailiill, ami lliat, (lining- il-; yoiitli, it iiiuU'rji^oc's a eoiiiiilicate'd uu'lainor- phosis.
It is f^fiHM-aily stall-dill tlu- mDimi^n-aplis as well as in tin- text l)i»(iks that altliouj;!) the youiiir ineilusa is unlike tiic ad nit, there are no true larval staj?os, since the i^<r<r i^ives rise directly to a inedii<a, which heeonies nietaniorphosed, thronj^h a series of ehan^rt'-'^. ii'to the adnlt.
This is. as I shall show, an erroneous interpretation ol'the facts, for the published ac- counts, when rii^htly interpreted, show that the larva actually passes, like olln-r hydronie- c1us:T5, throui^-h a plaiiula stage and a hydra sta<ife, althoujz^h natnralists have been misled by th J fact that the hydra-larva is locomotive, and as it does not multiply asexnallv the fact that it is a true hydra has ln-eii entirely overlooked; and, so far as 1 am aware, not a sin- gle naturalist has noticed the existence of a hydra stag-e.
M)st wi-iters in fact have been so firmly im|)ressed with the belief that medusa- have originated from sessile hydroid communities, that they have not only overlooked this stage in the development of the Geryonid:u, but they have expressly stated that it has disappeared. Thus Balfour states (65, p. 153) that The Ti-achomedus.-e are * * * "prob- ably derived from gono])hores in which the trophosome disajipeared from the develop- mental cycle," and Ilaeckel says (31) of the development of the Trachomedusae: "This form of ontogenesis is to be regarded as a secondary or cenogenetic ])rocess, which has originated from the primitive metagcnetic mode of development through the loss of the polyp generation." See also Leudenfeld (4G, p. 448).
So far as I am aware, Bohm is the only writer who has recognized the possibility of any other explanation, and he dismisses the subject very briefly and makes no reference to the Trachomedustxj, although he does not believe that alternation of generations is ])rim- itive, and suggests (9, p. 158) that "Lucernaria, the Ctenophora, the free Siphonojjhora (^andjiossibly some Of the medusce without a polyp-generation?) may be the direct descend- ants,of a free ancestral form without the uitervention of a sessile stage."
The total absence of anything like alternation of generations gives especial importance to the occurrence of a hydra stage in the life-history of the Geryonida-, and furnishes a key for the interpretation of the more complicated life-histories of other Ilydromedusa?, proving, as I think, the correctness of the view so briefly hinted by Bohm; and I therefore give in PI. 41 figures of various stages in the life of TAriope scutigera. The develop- ment of tliis species has never been described, although we have in Fol's paper on the embryology of Geryonia fungiformi.^ (22) and those by Metschnikoff (51, 52) on Gery- onia fungiformis, Geryonia hastata and Liriope enryhia, a very complete history of closely allied species.
Ray Lankester has stated in a recent pajjer that Fol, in his well known and valuable monograph "has completely failed to give even an approximately correct account of them atter" and that Metschuikoft"s description is "erroneous" (45). As my own ob- servations on our American Liriope agree in every essential jiarticular with the accounts by Fol and Metschnikoft' it seems proper (o give, in detail, my verification of the excel- lent researches which are thus swccpingly condemned.
I have been able to add a few poii\ts, such as the origin of the mouth, and of the radial
3
37(5 W. K. BROOKS ON THE LIFE-HISTORY
c:innls.liii( my ol)>;ervntioiis show that the development of our Liriopeis, in all essentials, like that of the European Geryonichr.
Oiii speeies appears to be very regular in its breeding habits, and speeiniens capturec at all hours of the day laid their eggs at about 8 r*. m., the eggs passing out of the mouth. Fol says that when he kept female specimens of Oeryonia fungiformis bj themselves they did not lay their eggs, but that as soon as a mature male was placed) with them and discharged the contents of his reproductive organs into the water, the females at once deposited their eggs (22).
This was not the case with our species, for when I placed a single female by itself it discharged its eggs promptly at the proper hour. In two or thi-ee cases these eggs were not fertilized and soon died, without exhibiting any evidence of vitality, but in othes cases the eggs laid by an isolated female developed normally. Schulze has shown, how- ever, that hermaphrodite Geryonida^ sometimes occur, and these females may possibly have been hermaphrodites; Ijut the occurrence or absence of fertilization makes no dif- ference in the time of oviposition. ,
The eggs develop very rapidly and at six o'clock the next morning the embiyos aref in the stage shown in PI. 9, fig. 3, so that it is necessary to keep them under observa-' tion all night in order to study the early stages. The segmentation of the egg and the formation of the ciliated embryo have been correctly and very minutely de- scribed by Fol (22) and by Metschnikoflf; and, as is well known, the origin of the germ-layers is very peculiar and without any exact parallel. The transparent spherical egg, which consists of a peripheral layer of granular jirotoplasm, and a central less granular portion, in which the protoplasm is finely reticulated, undei-goes total regular segmentation, and gives rise to a spherical embryo, composed of a single layer of larger cells, arranged around a small central segmentation cavity.
Each of these cells consists of an internal transparent reticulated portion, and an outer more granular portion, PI. 41, fig. 1, a + h. Soon the outer granular portion, fig. 1, a, separates from the transparent j^ortion h, leaving this as an independent endoderm cell inside the layer of ectoderm, Avhich is formed from the outer granular ends of the blas- toderm cells. This division of each blastoderm cell, into a central endodermal cell, and an outer ectodermal one, does not take place in all i)arts of the c^g at the same time, and eggs may easily be found in the stage which is shown in fig. 1, where two distinct layers are present on one side onl3^ The central cavity, the segmentation cav- ity, persists, and ultimately becomes converted into the chymiferous tubes, and the stomach of the adult medusa. Before the delamination of the blastoderm cells is com- pleted, the ectoderm cells begin to multiply by division, and the ectoderm cells of the young embryo are therefore more numerous than the endoderm cells, which divide more slowly. At the end of the process of delamination, the embryo, fig. 2, consists of a continuous hollow spherical layer or shell of granular and slightly flattened ectoderm cells, fig. 2 a, and within this, and in contact with its inner surface, a second concen- tric hollow sphere, c, of large transi)arent rounded endoderm cells, with reticulated protoplasm, surrounding a small central digestive cavity, d. The gelatinous sul)stance of the umbrella now begins to apjjcar between the ectodermal shell and the endodermal one, thus stretching and flattening the ectoderm cells, which continue to increase in nnni-
OF TlIK IIYDIKI.MKDUS-K. 377
bcr and soon form a very tliiii layer ol" pavi'nu'iit i-pitlu'liiini, li;^'. '.), upon tlic outer sin*- face of tlio gelatinous umbrella, />.
According to Fol, the gelatinous sul)staiice is not homogeneous, hntis marked hy line striations, which radiate through it in all directions from the surfaces of the endcKlerm cells. The latter also increase in number, and become ilattened as at c, in lig. '.], while the digestive cavity, fig. 3 rf, becomes con-espondingly enlai'ged. 'J'he endoderm (tils ])reserve their reticulated structure, which is visible until after the tentacles of the me- dusa appear. "When the gelatinous substance lirst appears, and for some time after, it i- uiiirornily thick a ud aim )st perfectly sphorical, and theendodermal shell is also spherical, ( iincentric with tlu outer surface, and S3parated fro.n the ectoderm at all points; but it > )on a[)proaches, and finally touches the ectoderm, at a point which is to become the oial pole of the medusa, and which is below in fig. 3. The gelatinous substance, which lies between the two layers, is absorbed at the oral pole during this process, and I'ol makes the very satisfactory conjecture, that the force which pushes the endodermal u' to one side of the spherical embryo is produced by the more rapid seci-etion of the
latinous substance at the aboral than at the oral pole. The embryo now changes its shape a little, and becomes slightly flattened at the ends of the principal or oral-aboral axis, and the cells of both laja'rs become tliickened aroinid the oral ])ole, to form an oral area or peristome, a', c'. At this period the embryo rises from the bottom and floats in the water, apparently at rest. Under the microscope, howevei-, it is eas\' to see tliat it does not simi)ly float, but swims aljout witli a very slow unifoiin motion, and al- thongli I was not able to see any cilia, small floating particles were thrown away as if by the action of cilia, which are undoubtedly jjresent ii[)on ])art if not the whole of the ec- tiiderm. Fol states (22, page 482) that, at this stage in the development of the very uuich larger embryo of Gerijoniafungiformis. scattered cilia make their appeai'ance over the whole ectoderm, and cilia are visible upon the oral area of our sjDecies at a later stage, as shown at c, in figs. 4 and 5.
The spherical larva, with its two concentric layers of cells separated from each other by a gelatinous umbrella, without a mouth or any other passage into its spacious diges- tive cavity, and swimming b}^ means of ectodermal cilia, is at first sight very dilfei-ent from the embryos of other medus;e; but its peculiar appearance is due to the very early formation of tlie gelatinous substance of the umbrella. If this were absent or if it made its ap[)earance at a later stage, the embryo would be a ciliated, mouthless, two-layered planula, almost exactly like an ordiuai'v i)lanula, after the endoderm and digestive cavity have made their appearance, but before the mouth has been formed. The Geryonidje accordingly pass through a planula stage, directly comparable with the same stage in other hydroids, but complicated by the accelerated development of the digestive cavity and the gelatinous umbrella.
The origin of the endoderm, at a very early stage of segmentation, b}' the simulta- neous delaminatiou of the inner ends of all the blastoderm cells is clearly amodificaticm of what occurs in ordinary hydroid planuUe, although the segmentation cavity persists as the digestive cavity, and the endoderm never forms a solid mass, as it certainly does in the planulje of Hydractinia and Tubularia. In Eutima however the segmentation cav- ity persists as it docs in Liriope, and this is no doubt true also of other hydroids.
;578 ^^'- 1^ 15UOOKS OX 'IMIK LIFK-IIISTOKY
The twii natunilists wlio iirst (lesciibcd the (leveh)pment of the Gervonidie, Fritz Miiller (oo) ami llaeckel (.">()) i)ul)lishecl their accounts at a time when enil)ryological knowledge was much less advanced than it is to-day and when compai'atively little was known of the histological structure and significance of the hydroid larva. They both fell into tlie error of regarding the central capsule of cells as the sub-umbrella, and believed that the digestive cavity, and its endodermal walls originated at a much later period; but our l)resent comparative knowledge of the eml)ry()l()gy of other organisms would now lead us, even in the absence of any record of its later history, to regai'd the central cells as an endoderm, for (he hypothesis that they are the ectoderm of the sub-umbrella im]ilies that the Geryonoid embryo is fuudamcutall3^ different from all other known hydroid embryos.
At the present day the fact that the central cells of an ordinary planula become the cells of the digestive cavity is, in itself, an evidence that the central cells of the Liriope ^ embryo are their homologue and equivalent, and the later history of the embryo fully ^ bears out this view of their nature, and puts out of question the acceptance of Fritz ' Mailer's and Haeckel's interpretation.
The next change which takes place, the formation of the mouth, is shown in figs. 4 and 5. The cells of the oral area or peristome become ciliated and a depi'cssion appears in the centre of the outer or ectodermal area, and a similar internal one is found in the endoderm, as shown at e in fig. 4. These two depressions soon meet, and breaki through to form the mouth, fig. 5, c, the edges of which become ciliated. Food isj noAV sw^ept into the digestive cavity, although little growth takes place until the larva' is much older. If the gelatinous substance at the stage shown in fig. 5 were absent, the larva would be identical in structure with a typical gastrula ; but it is qiiite clear, from the account of its origin which I have given, that it is essentially dilier- ent from the invaginate gastrulfe of oi-dinary metazoa, and that the mouth is not ar orifice of invagination, but a j'ounger structure than the digestive cavicy. At this an the following stages there is a noteworthy difference between our spfcies and thos which wei-e studied by Fol and INfetschnikoff. In our species the endodermal cap- sule, fig. 5, c and fig. 7, which is now a stomach, retains its rounded outline, and ultl mately becomes elongated along the principal axis, fig. 7, d. INIetschnikoft' says that, in Geryonia hastata, it becomes flattened so that its aboral wall is almost in contact Avith its oral (52, PI. 11, figs. 10, 11 and 14), while in Oeryonia fungiformis, accord ing to Fol, the aboral side becomes pushed down into the oral half, so that it forms a double cup, with a very thin cup-shaped cavity. The absence of this flattening, in the American Liriope, shows that it has no important morphological significance.
The tentacles,/', now begin to grow out around the edge of the peristome, as shown in an oral view in fig. 6, and, in an oblique view in fig. 5. Two of them probably appear before the others, and in the stage shown in fig. 6, there are three: two, which are probably primary, opposite each other; and a third, 90° from these. A fourth soon appears opposite the thii-d, and Fritz Midler's figures show that they are the primary radial tentacles, figs. 9, 10 and 11 /, of the medusa. They are solid, and consist of a layer of ectoderm, continuous at the base of the tentacle with the ectoderm of the edge of the peristome, and a solid endodermal axis, which may, in our species, b* clearly seen
OF Tin; IIVDKOMHDUS.E. 379
to I)C coiitimioiH willi the t'lidoiU'i'inal |>i)i-|i()ii ol" (lie cilijc of tlic i)i'i-i>;toint'. Fol says, (22, page 484) that he found it dilliciilt to trace, in his hii-jj:ei-enil)rv<)s, any visible erjntiiiu- itv between the emloilerni eells of the tentacK-s and the wall ol" the stomach, but in our species there is no snch dilllculty. The en<lodernial oii;:;in of the axial <(lls of ilic tiu- tacles of hydroids and nu'dusa- is such a lirndy estal)lished lad, that the i)rescnce of tentacles at this stage is, in itself, a proof that the digestive cavity is present, and would in the present condition of embryological science compel us to regard the central struct- ure as an endoderm rather than an ectodermal sub-umbiella. The tentacles, fig. 8, f 11 iw ra])idly elongate and their tips become eidarged and crowded with lasso-cells. Fritz Midler, Ilaeckel, Fol and Metsehnikoft' figure at tliis stage pecidiar hook-like ap- pendages which project beyond the enlarged tips of the tentacles, but I have not ob- served anything of the sort in our species.
The larva shown in fig. 8 is a veiy interesting one, for it is in all essential points a hydra with a gelatinous deposit between the ectoderra and the endodeiin. It has a month, a peristome, and solid tentacles, but no bell cavity; and if the thick unil)rella were absent, and the endoderm and ectoderm in contact, it Avould be almost exactly like the floating, solitary actinula of Tul)ulaiia. It swims through the water, and its ecto- derm is probably ciliated, and I think that comparison will convince any one that the hydra-like stage is actually represented in the life-history of the Geryonidte; and that the Actinula, the Gcryonid larva, and the Polyxenia larva shown in Mctschnikoff's PI. 3, fig. 11 (.>1) are modifications of the same type, a free, solitary, swimming hydra with solid tentacles. It is well known that the solid tentacles of the Geryonida- arc transitory larval organs, and that the persistent radial tentacles of the adult, PI. 42, fig. 1, are hollow, Hke those of ordinary Anthomedusa? and Leptomednsa\ This difference is in perfect harmony with the view that the larval tentacles arc hydra tentacles, while those which jiersist are medusa tentacles.
According to Fol, who has given a very careful account of the changes which now follow, from the study of an embryo which is much larger than ours, and, therefore, more convenient for study, the periphei-y of the mouth area now thickens to form a circular rim, from which the ectoderm of the tentacles is derived; while the i-im itself becomes the free edge of the umbrella, and gives rise on its inner side to a circular fold of ectoderm, which becomes the veil. The ectoderm cells of the peristome, between the rim and the mouth, become the epithelium of the sub-umbrella, which meets the en- doderm around the mouth, where the line of demarcation between the two layers can be clearly seen.
Metschnikoif' s account is like Fol's in all essentials, as he also says that the periphery of the mouth area becomes the free edge of the umbrella, and gives rise to the tentacles and velum, while the area between the velum and the mouth becomes the epithelium of the sub-umbrella; but Laukester states (45) that there is a " substantial disagreement" between Metschnikotf's statement (.52, page 20), that "Der Centraltheil der Scheibe stulpt sich dagagen weiter in's Innere ein, um die aussere Bedeckung der SchirmhOhle darzustellen," and Fol's account. The two authors studied different genera, and we should not expect to find an exact agreement in every point, but I fail to discern any reason for questioning either of them, and certainly do not perceive any difference re-
3j;0 '^^- 1^- liliOOKS ox THE LIl'E-IIISTOUY'
awarding any significant points. Lankester's claim, that the two accounts conflict with eadi other, seems to be the result oF his desire to show that neither of them is correct, but that his own very different explanation of the process is the true one; and I, there- fore, quote the words of Fol's account, for comparison with the statement which I have quoted from Metschnikoff.
He sa>'s (22, p. 4S5), "Der anfangs fast kugelige Sehirm breitet sich mehr nach unten uud aussen aus, und nimmt bald cine wirklich schirmformige Gestalt an. Der Rand des Schirmes nimmt der Randwulst ein, welcher sich schnell ausdehnt und zugleieh relative verdiinnt.
Der Magen tritt dabei verhaltnissmassig immer mehr in die Ilohe, so dass er in den Grund ciuer, anfangs seichten, trichterformigen, spater tiefen, glockenformigen Hohle zu liegen kommt. Letztere ist die wachsende Schirmhohle. Ein Epithel kleidet ihre Wande aus, welches direct von der oralen Ectodermscheibe a])stammt. Am Mundrande sieht m;ui immer noch die Grenze zwichen Ento- und Ectoderm, welche ihrer verschie- denen Besehaffenheit wegen noch unterscheidbar siud."
For all morphological purposes it is a matter of no consequence whether the bell cavity is formed by a pushing in at its centre, or by the growth of its edges, or in botl ways, and it is easy to understand that closely allied species may differ in this respecl This difference upon a minor detail is therefore no reason for doubting the accuracy either Fol's or Metschuikoft's account.
The youngest medusa which I obtained in the open water is shown in PI. 41, fig. 9 It is peculiarly interesting on account of the simple structure of its digestive cavity, aa it presents a very early stage in the formation of the chymiferous tubes, the origin which has never been traced.
It is true that Haeckel gives an account of the origin of these structures, and says that they are formed by differentiation of the epithelium of the sub-umbrella; but Ave now know that the sub-umbrella is lined by ectoderm, no one would, at the prese; time, believe, without very conclusive evidence, that endodermal structures originate this way, although, at the time Haeckel's paper was published, such an error was not unnatural.
Haeckel says (30 i, p. 136) : " The gastrovascular system is differentiated fro: the cells which cover the velum and line the cavity of the bell as a sulj-umbrella. Thii differentiation takes place in such a way that, on the bell margin, at the junction of t velum and the sub-umbrella, a broad sti-ip of larger and thicker-walled cells comes specialized as the embryonic circular tube. At the same time two similar stripi crossing each other in the middle of the arch of the sub-umbrella, and joining the base# of two opposite tentacles, are differentiated from the general surface of the sub-umi, brella.-' !
"These are the four i-adial canals, which, like the circular canal, are at first so wid4 that only four small four-sided areas of the sub-umbrella remain free and coverea, with the smaller, flatter and thin-walled epithelial cells." {
According to Ka}' Lankester (4.5) Haeckel alone has given a correct account of th# origin of the sub-umljrella; Init I doubt whetlicr any other embryologist would at the present day credit the statement that the endodermal chymiferous tubes are formed from
OF TlIK IIYDKOMKDUS^E. 381
the cpitlielium <>l" (Iio siil)-iinil)ivll;i, ;iIllioiii;li siidi :i statciiiciit was not, twenty years ago, intrinsically iniprobahk'.
My own ()l)servatii)ns show that iracckcl really oltsei-ved the oriu:in of the ehymifei-ous tubes, altli()n<;"li ho failed to discover that they are Ibrmed by the diireiciiliation ol" the- walls of the digestive cavit}', instead of those of the sub-unibrelhi.
At the stage shown in fig. D, tiie oial layei- of endoderni has been pnsluMl in. by tlui formation of the snb-umbrella, until it is neai-jy in contact witli the aboral wall, and I he digestive cavity is thus reduced to a thin dome which is concentric with the snb- uinhi-ella and extends to the bell mai'gin. At four jjoints on the four inter-i-adii .Mid near the bell margin, the two layers of endoderni have come into contact with each ilher and fused to form four shield-shaped areas of adhesion, lig. 9, i. The stomach thus divided, by the four areas of adhesion, into first, a spacious axial chamber or
iinach proper, which reaches more than half-way down the bell; second, four short, wide, radial canals, I; and third, four short arcs of the circular tid)e, m, which unite the distal ends of the radial tul)es with each other.
Ill older medusic I have traced the gradual extension of the four areas of adhesion, ligs. 10 and 11, i, i, until four narrow, sharply defined radial canals, I, and a circular canal, m, ai"C produced, and I think there can be no doubt that, in a younger medusa than the one shown in fig. 9, the areas of adliesion would be still smaller, and that, in a still younger medusa they would be entirely absent, while the stomach would extend to the bell margin as a continuous cavity without interruption.
While I have not found a larva in this condition, a reference to Fritz Midler's (55) and Haeckel's papers (30) will show that both these authors have seen and cor- rectly figured this stage of development. The larva shown in Ilaeckel's PI. 4, fig. 35, is like our fig. 9, except that the areas of adhesion have not yet appeared, and the four quadrate, interradial areas, of wliich Ilaeckel speaks on p. 13G, are, beyond doubt, the areas of adhesion.
Although both Fritz Mfdler and Ilaeckel were led astray in their interpretations, I believe that their figures correctly represent the larvie, but this is not true of the figures which have been given by other authors.
Drawings which are touched up at home, from sketches made at the seashore, are very apt to become conventionalized, and I cannot help believing that the sharply de- fined radial canals which are shown hy Leuckart (47) and Fewkes (68, pi. 7, fig. 2) in young Geryonids at about the same age as onr fig. 9, were introduced into the drawings upon theoretical grounds, rather than from observation. This is certainly the case with Gegenbaur's figure (25) for he represents the canals as interradial.
It is interesting to note that the endoderm cells do not completely disappear in the areas of adhesion, even in the adult. The Hertwigs give (69, PI, 4) two sections, figs. 2 and 9, through the bell margin of Carmarina hastata, and in each section they show a double layer of endodei-m cells, >■', t', in contact with each other, running up toward the axis of the bell from the oral side of the cii-cular tul)e, with the epithelium of which they are continuous, although the cavity of the tube does not extend betAveen them.
3S2 ^^- K. BROOKS ON THE LIFE HISTORY
The observations here given show the correetness of Balfour's conjecture (65, p, l.'>0) that " while the exact mode of formation of the gastrovascular canals of Geryoni has never been worked out, the presence in the adult of hypoblastic lamellae, and th mode of formation in medusa-buds, justify us in believing, with the Hertwigs, thai they are the remnants of a once continuous gastric cavity."
The metamorjihosis of the }■ oung medusa has been well described by Fritz Muller ana Haeckel. The bell gradually becomes flattened, as shown in fig. 11 and in PI. 42, an^ the gastrostyle gradually grows down fi-oni the apex of the sub-umbrella, carrying witli it the stomach and the oral ends of the radial canals, until, in the adult, the mouth an« stomach are far below the level of the veil. At various stages in its life the medussf has three sets of tentacles, four in each, or twelve in all. Of these, one set is radial and larval, soon disappearing with the growth of the medusa. The second set, figs^ 9 and 10, Ji, next appear, and in some species persist throughout life, while they arJ absent in the sexually mature medusje of other species. They are interradial. Tha third set, fig. 10, (/, fig. 11, g. are radial; and are the long tentacles of the adulf- medusa.
The primary radial tentacles, figs. 9, 10, 11, are larval organs. They are the first to make their appearance and they are present in very young meduste. They are solid^, consisting of a central axis of very large cartilage-like endoderm cells, and a surface laj'cr of ectoderm which is thickened at the tip of the tentacle, to form a knob or bulb, which is crowded with lasso-cells.
"When these tentacles first appear in the larva they are situated at the edge of the peristome, and when this becomes pushed in, to form the sub-umbrella, the tentacles spring from the edge of the umbrella, just outside the velum, and their endoderm is continuous with that of the circular edge of the digestive cavity; but as the raedusi grow, they are carried out on to the outer surface of the umbrella, some distance froi its edge, as shown in fig. 9. A string of degenerated endoderm cells persists for som<S time between the base of the tentacle and the circular tube, and thus marks out the line along which the tentacle has migrated. There is also an ectodermal ridgei " Schirmspang," on the surface of the umbrella, running from its free edge to the base of the tentacle. These tentacles drop off" before the medusa attains to its full size^ and they are entirely absent in the adult.
The four primary' interradial tentacles are the next to appear, figs. 9, 10, 11, h. The also are solid, but. they arc distinguished from the primary radials by the fact that tl ectoderm of the axial side is thickened to form a number of ridges or incomplete rin each of which is filled with large, oval lasso-cells. The stiff interradials are usually^ carried turned up against the outer surface of the umbrella, with thin rings of lassos- cells facing outwards. They are, at first, situated on the bell margin, but they migrate like the primary radials, and in the adult they are separated from the bell margin by an interval which is somewhat greater than the diameter of the circular tube, wiA which a row of degenerated endoderm cells coiniects the base of each tentacle, antt there is also an ectodermal ridge or ^' Mantelspang" with large lasso-cells running from the axial surface of the b:isc of the tentacle to the bell mar":in. Accordins; to Haeckel
OF Till". IIVDUOMKDl'S.K. 3S3
the Gcryonida' arc dividfil \\\\(i two jj^n-.U <i;r()ii|)-;: one i^roiip inclmrmLC lliosc fipucics in which the iiitc-n-adi-.il tentacles are retaincvl Ity the adiiU. and tli" ulhcr inchidin;^ thDsi- in which they disap|)ear Ijelbre maturity is reached.
In our species, h )\vever, tiiere is no invarial)le rule. Most adults retain all four ol" them; but individuals with only three, two, one, or witii none at all are .sometimes Ibuiid. It is possil^le, and in fact probable, that this is true of other species also, and that tiie presence or absence of these tentacles cannot be used as a dia;^nostic characteristic.
The third set of tentacles, the secondary radials, are always present in the adult. They appear as small buds, fig. 9, r/, in the young medusa, and grow throughout life. They are very elastic and niay be stretched out to four or five times the diameter of the bell, and they are seldom contracted to less than twice this diameter. They are hollow and theii" lasso-cells are arranged in prominent rings along the whole length of the ten- tacle.
Summary of tfie Developmext of LiitroPE.
The following features in the life-history of Lirio[)e arc especially impDilant as a basis for comparison with other hydromedusa- in the attempt to trace the origin of alterna- tion.
1. Each ogg gives rise to no more than one adult medusa, and there is no alternation of generations or asexual process of multiplication.
2. The segmentation cavity persists as the digestive cavity, and the embryo is not a solid mass of cells at any stage of its develojiment.
3. The process of delamination which results in the formation of the two germ lay- ers takes place rapidly over the whole of the spherical blastoderm.
'4. The metamorphosis is gradual and is not divided into well-marked stages separated from each other by sudden changes; but it maybe divided into a planula period, a hydra period and a medusa period, although certain characteristics of the medusa appear during the planula and hydra pci'iods, and certain characteristics of the hydra are re- tained after the medusa period is reached.
5. During the planula period the sphencal embryo consists of a ciliated ectoderm, and a capacious digestive cavity which has no opening to the exterior and is bounded by a single spherical lawyer of endoderm cells concentric with the ectoderm, but sepa- rated from it by the gelatinous uml^rella which is at first spherical and of uniform thick- ness.
6. The jjlanula is converted into a hydra by the union of the ectoderm and endo- derm at the oral pole, where the two layers become perforated to form the mouth, around which the ectoderm cells become differentiated into a sharply' defined oral area or peri- stome, on the peripheiy of which four solid In'dra-teutacles are developed. The h3Tli-a is free, does not multiply asexually and has a gelatinous innbrella. If this were absent it would be very similar to the actinula of Tubularia.
7. As the hydra becomes converted into the medusa the peristome becomes pushed inwards to form the sub-umbrella, at the top of which the mouth is situated ; while the digestive cavity becomes converted into a dome with its edge at the bell margin. The ex-umbral and sub-umbral layei's of endoderm are thus brought close together and they
:k<i
\V. K. r.KOOKS ON THE LIFE III STOliY
now unito wiili vM-h otlu-r over lour intiM-nulinl aiva-^ of adhesion wliioli increase in size ami convoii tlie peripheral jiortion of the dijieslive cavity into a circular tube and four radial tnln's.
8. The vt'il is formed around the periphery of the peristome. The solid radial hydra- tentacles disappear and the solid interradial tentacles and the hollow radial medusa-ten- tacles are di'vcloped. The larval tentacles do not disajijicar until all the characteristics of the in.vlu-sa are actiuired, so that there is a period, before maturity is reached, when the aninrd is both a hydra and a medusa.
9. During the hydra period there arc no marginal sense organs.
LlTKKATriMC OF THE DrOVKLOrMRXT OF THE CxEUVONID.K.
In 1S.")(» lA'Uckarl jtointcd out (47) the fact that the yoiuig Gcryonid medusa is cjuitc tlilVcrent from the adult, and that its growth is accompanied by mctamori)liosis; and in }^')~ (iegenbaur iigured and described (25, p. 247, PI. 8, fig. 12) a young Gcryonid under the name EunjUopsis anisoslyla. Fritz MttUer's minute and amply illustrated account iA' Liriope catherinensis, published in 1859 (55), is the first in which the absence of an alternation of generations is established. lie gives an account of the metamorpho- sis of the medusa, and shows that the young endu'yo is a double spherule of cells, and that the central capsule has, at fii'st, no opening; and he also figuies an older embryo with a mouth, but without tentacles, although he supposed that the cintral cavity was the sub-umbrella, that the mouth was the opening of the umbrella, that the peristome was the veil, and that the endiryo has, at this stage, no mouth or digestive tract. In his classic monf)gi-a|)h. ])ublished in 18GG, Ilaeckel gives beautifully illustrated figures of the metaujorphosis of (ilosfiocodon eunjhea, (30 h) and Carmarina hasfdta (30(Z) ; but he falls into Fiitz Midler's error regarding the endu-yo, and describes the cudoderm as the sul»-uml>i-ella, stating that the digestive tract and chymiferous tiibes are formed, at a la- ter stage, by the differentiation or specialization of the sub-mnbral ectoderm. In 1873 Fol (22) reared Carmarina funf/ifonnis from the egg, and gave a complete account of it.s development, illustrated by beautiful figures, showing that the central cavity is the digestive cavity and that its endodi'rmal cells arise by delamination from the blastoderm, that the mouth a]i]icars later, ar^d that the tctcdcim aicund it becomes the sub-mnbial epithelium, arouiul the edges of which the veil and tentacles are developed. Metschni- kotf states (52) that his observations (51) are a year earlier than Fol's, but as FoPs i)aper app«'ared Xov. 18, 1873, while Metschnikoffs was not pidilished untU Jan., 1884, the di.«eover>- belongs to Fol, although Metschnikoff's observations, which wci-e made at Villafranca in 1870, agree with Fol's in all essential particulars.
Kowalevsky's Russian i)a])er, which a]j])eaix'd in the same year, 1874, gives a totally •lifferenf account of the early stages, as observed in Carmarina hastata. According to MetsehnikofTs statement (52) and Leuckart's abstract in the Arch. f. ^N^atui-geschichte, Kowalevsky observed theoriginof the central capsule by delamination, Imt decides that its cells become conv<'i-tcd into the gelatinous substance of the umbrella, and ha\ e nothing to do with the digestive tract, which originates by invagination at a later period.
We therefore have three iri-ccoucilal»le statements as to the fate of the central capsule ,
OF riiK in Diio.MKDrsyK. 385
iiiiil till' iiii;;iM (il'tlir ciiili mIciiii. I IjhcIvcI iiikI I'lil /. .M iillcr mi v tliat llic cciiti;!! i-;i|iMilc l)((iiiiics the siil)-iiml)itll.i. I'loiii llic walls (if \\ liicli tin- ili^csiivf Iracl is siil»>i'<nitiillv Iniiiud ; Fill a 11(1 .Mclsrliiiikoll" IntM thai I lie ciiilral (a|isiilf is thi' tli;;fsli\ c cavity, and llial I lie siiii-iiiiilii-clla is an (•clodiiinai >l iiicl lire id' lati-r ori^iii ; while Ki)\val»'vsky claims that the cciilial capsule is iicilhiT ciiiIikUiiii imr siih-nnilntlla, Iml llial it Iticaks ddwnanl hccoincs the ^•elatiimus suhstance ol'the l)i-ll.
In the siimiiier of ISSli 1 studied the enihrynjo^y of Lirloju si-iitit/i r(i in (»rdiTti> decide hetweeii these eonllii 1 iiij;' \ieus, and (|iiickly satislied niyseir<il' the correctness of the aeeoiiiil^ (if I'ol and Melxhiiikull'.
While 1 was cii<;a;;'ed in lhi> work 1 leceixcd .Mel>(liiiikoil"> la>t |ia|iri- (;VJ) ilatcd Dec. 30, 1881, <;"iviiij;' an aeeoiml oC liis renew id >tiid\ al Naples o|" ihe emhryolojxy ni' rjirii>j)e eiiri//H'(i,lli\i-i\n-\, and CaniiiiriiKt f'iiiii/if'ar/iii.-<, Ilaeekel, ic-iiltiiii;' in iheeoni- pletc vcrilication of the account which lie |tiil)lishi'd in 1871.
The next paper in historical or<U'r. "< )ii \<inn^- Slaves oi' Linmocodiuin and («cry<j- nia." hy I\ay Lankester (4.^). is a veiy imw worthy example nj' "deduclive hiolo^y ;" lor wliiii' the title wouhl lead us to expect new(ili-er\ at ioiis on the yoiiii;;,' stuj^cs of the ( ieryonid;c, the i)a|)i'r contains nothini;- to show that theaiithoi- has ever seen a (»ery- onid. either yonii<;- or adult, and his statement ( l-J) that the ti-ntades of tlic Trachome- diisM' ai-e solid would hardly be made I)v any one who had examined an adult (ii-ryonid; nor lor liial matter WKuld anyone who is ramiliar w ith Kucopi' venture the statement, that the Leptoinedusa' all have hollow tentacles. In this connection see ilaniann (32) and the Ilertwi^i's (()!». p. 72).
It i^ true that the paper does contain dia;^rainiiiatic ii^-uri's, ])a<^-e 200, to illustrate the devilopment of the Tracliomedus;e, hut they are purely iina<;inary an<l unlike auythin<^ which has ever been observed, for the author has undertaken tlu' very danj^crous task of constructin*;' embryolojiy upon general gronnd rather than from ob.servation.
As his theoretical views bring him into confliet with the careful observations of Fol and ^Metschnikolf, he attempts to show that there is a "substantial disagreement" between their accounts, and he does not hesitate to assert that '"Fol has completely failed to give evt'U an approximately correct account of the matter," whiU- >U'tscliiiikoirs acccmnt i.s "erroneous."
The same author had pultli-hed, a lew months before, an account of an iiiterotiiiL;' me- dusa which was found in vei-y great luniiliers.at \arious stages of grow tii. in a lank in w hich tropical watei- plants were eultivati'd in I-]ngland. The medusa, Limnocodinm,is remarka- ble in many respi-ets, as it is very ditlercnt from all the known species, and has, so far as we know, no close allies. liay Lankester I'egards it as a Trachonudusa, although Allman, who described it on the same day in another place (70), considers it a Lei)tomedusa.
In his second paper (45) Ray Lankester gives figures of young medusfe -which were found in the water with the adults, all of which were males, and althotigh the young are similar in all respects to the medusa-lnids of hydroids, and (piite unlike an}-- medusa- embryo which has ever been reared from tlu' vg<!;, he I'cgards them as egg-end)ryos, and constructs upon them a new view of the embryology of the Trachoinedusje, although he did not rear them from tlii' I'gg. and gives no reason for believing that they are egg-em-
..^^,. W . K. liKOOKS ON THE LIl-M-'.-HISTORY
i>r\.>v/\-\cfi<t liis iipin'mii llwil tlu- iidiill is ;i 'l'r:icluniU'(liis:u and imisl thrrclorr dcvi'lop «li'iv«tlv IVoin lilt" i'<i>;\ wilhoul llir iiili rvinlion <)l":i livdra-stage.
Thi' luimluT of spi'c'u's of 'I'raclioiiu'diisu' wliic'li liavi' hvvn roavod Iroin tlio I'gg is so small, and llu-si-aiT all so dillori-nt Irom Linnux-odinni, that tlio argmncnt from analogy alVonls viM-v sc-antv gi'ounds lor ivjrcling all the i)nblislK'd observations, and as a inat- ti-r of fact, wi' may well donht wlu'tlu-r Linmoeodiuni is a Traehomednsa at all, as none of his rfas«)ns are eonehisive. 'i'lu' yonnger ones are exactly like niednsa-bnds, -with a closed sulvnmbivlla. a month and a niannbrinm which have no functional importance, and foiir radial canals which appear before the o])ening of the sub-nnibrella. In all these respects they airree with mednsa-bnds and dilfer from all egg-embryos which have ever been described. There is. therefore, good irason Ibr believing that they are bnds, which are detached from n fixed hvdra, and this view fnrnishes an explanation of the fact, so |)uzzling to Lankester, that among thonsands of specimens no females were fonnd. In animals hatched from ♦'•"••s, we shonld certainly expect to find both sexes, and when thousands of embryos oc- cur, rij)c females nuist be present, but a fixed hydroid comnuinity gives rise to medusfe of onlv one sex; and the occni-rcnce in the tank, year after year; of thonsands of male nicdusie. at all stages of gi-owth, without any females, is just what we shonld cx])ect if llu-v are all the progeny- of a single hydi'oid conummity, which has been accidentally in- troduced into the tank, and there gives rise to medusa} by budding. The author does n<it hesitate to resort to hypothetical explanations, and he attempts to explain the ab- sence of females (42) by the hypothesis that the females may be fixed while the males are free.
This may prove to be the case, but there is not a single fact in the history of the lly- dromedusa' to give it the least support except his faihuv to find females and the frag- mentary account of the life-histoiy of Limnocodium is therefore an extremely narrow base ujMin which to construct the embryology of the Trachomedusfe in opposition to the ob- f^ervations of Fol and ^Ictschnikod'.
Section III. The Anthomedusse.
Plate 37.
Turritopsis is a craspedote or veiled medusa belonging to Ilaec-kers order Axtiiome- DUS.E or veiled medusa' without marginal vesicles or otoliths, with ocelli on the bases of the tentacles, with the repi-oductive oi'gans in the walls of the digesti^ e cavity, and with (in most cases) four radiating tubes. The AnthomedusaMjriginate, by alternation, from Tubularian Ilydroids.
In the order Anthomedusa-, 'J'uriitopsis'is a representation of Ilaeckel's Family Tiau- iDiE, or Anthomedusie with (bur brcjad oial lips, fmir wide radiating canals, simple un- branched tentacles, four separate i-eproductive organs in the walls of the stomach, and h b.longs to Ilaeckefs Sub-Family Vandjeidje, or Tiaridse Avith eight or more tenta-
/i- a number of allied medusa? weie unknown when ]\IcCrady's original diagnosis of the genus Tun-itopsis was ]»ublished (4:S,p. 25) his characteristics of the genus include
(IF TIIK llYDKOMKUrS-K. 387
(•('il;iiii |t(iiiil> wliicli ;iit' now kiiKWii t<> lie .-.Iwiit'd 1)V nilui- piuia, .iinl iilli(i> wliicli nil- only of s|K'(ilic iiii|ioi'taiu-i-. Ilaccki-rs »liji;;iiosis (;51, j). (»()) is liaxd in pail upon an irroni'ons iiiti'r|tn'tation of .Mc( 'lady's acconnt of oiir s|H-»-it's, and I tlurtlore ^ivt- a new statcMunt of the distinctix c cliarartiTistics ol'tlic ;;i'nus.
Cn'nus-I)ia;;nosis. 'I'iaiid with nnnuTous (i-ntaclt's in a sin^^li- row, and a sin<;lr oc«-l- iu> on the inniT or axial side* <»f tin- l)nll) of racli. .Vo ;x':i'^ti'i<' |»i'<lnn<l»' Ironi the ;^i'lat- inoussul)stanft'of tlic unibivUa, from wliicli tin- di^^'c^tivc cavity is snspciulcd 1)V acarti- lago-likc mass, made up of the j^^ivatly eidar;j;^ed cndoderm cells of the radiatin;^ tuhes. No mesenteries. Four t<imple perradial reproductive organs in the walls of the ili;4'es- tive cavity, separated by deep furrows with smooth surlaccs. ( )i;d lip- (Vin;rcd with >lalkcd bimchcs of lasso-ccUs.
The stalk which suspends the dij^i'slivc cavity of Tinritopsis from the centre of the sub-umbrella is not a <j:felatinous prolongation from the umbrella, but a peculiar struct- ure, made up of the greatly enlarged endodenn cells of the radiating tubes, whieii. in the adult, are ])eudent from the sub-umbrella, as in Ilaeekers figures of C'allitiara ( :{, I'l. .'!) but so greatly thickened as to form a solid cartilage-like mass, through which the four small channt-ls pass down to the digestive cavity, into which the choi'da-cells also extend.
McCratly's tigures and minute descrijition of this structure are so very clear that there should be no room for mistake, lie says (48, page 3) "The stomach surrounded by the ovaries oecupiesthe lower half (of the jjeduucle), but above is a mass of verij larije cells filled with a clear substance like that in the upper part of the disk in Oceania. 'J'his porti(m is traversed by the four ascending chymiferous tubes, around which the large cells are arranged with much regularity, and which, on i-eaching the nuiscular disk, arch over it to descend through its substance as vertical tubes."' On p. 5, he says, " Jii-turn- ing now to the vertical tubes, we find that before entering the tissues of the bell, they traverse the clear portion of the proboscis. Here they do not preserve the even, some- what flattened form which the}* have in the disk, but assume a rather irregular outline. This a})pears to be due to the circumstance that the canal occupies the somewhat irreg- ular cavity left between the juxtaposed ends of the large cells composing the transparent part of the proboscis. How these cells are arranged radiately is slK)wn in a diagi-annnatic cross-section at fig. 7. .\ small quath-angular space is left lietween the four masses thus formed, which is, probably, tilled with the same clear substance which fills the cells. The tissue so formed is not confined to the tubes, though it has there its greatest development; it spreads also downward over the several lobes, but in this portion the cells ai-e very much smaller. .Vrouuil the tubes the cells are of a somewhat pyramidal form, their bases turned outwards, the apices inwards, to meet the chymiferous canal."
Keferstein (36, p. 20) correctl}' describes the peduncle of his Oceania poli/cirrha, which is a true Turritopsis, as "made up of large transparent cells Avhich look like a network;" but Haeckel (31 , j). (JO) misled, no doubt, by the close resemblance between Turritopsis and Callitiara, lias described the struct ui'e as an ordinary gelatinous gastric stalk, although it is, in reality, a very dilferent structure from the peduncle of Eutima or that ftf the Gcryonida'.
McCrady failed to discover that the cells are nothing more than the greatly thickened walls of the radiating tube-, but in other particulars his account is very accurate, al-
388
\V. K. nUOOKS ON THE LIFE-HISTORY
thon<'li Fowkos st.-itos (21. pajiv 15o) uikUm \\\v luiidiiit;- Tarriiopsis nutricola, in his tK'sn-iption ol" a modusa wliich he wrong:!}' supposes to l)e a Tun-itopsis, that McCrady's «leMTip(ion is "[uite faulty," and that there is iiothin*;- which eorresponds to liis "long dfseriptitm «tf what he calls a cellular u])per portion of the ])roboscis."
lUMi-ihutiou of the Genm. So far as our j)resent knowled<>e goes, the gx-nus is dis- tributed as follows: Messina, Mediterranean (Kolliker, (iegenhaur, Keferstein, Ehlers, Haeckel); St. A'aast. Normandy (Keferstein); Australia ( Teron & LeSueuer ) ; Charleston, South Carolina, U. S. (^Nk-Crady) ; Beaufort, Xorth Carolina (Brooks); ll;nnpton Koads. \'a. ( Hrooks) ; Xaushon, liuzzard's Bay (A. Agassiz.)
Turritopsis nutricula, McGmdy.
Turrilopsis nutricula. ^IcCrady, 1S.")(3. Description of Oceania (Turritojysi)<) nutricula,
nov. spec, and the enihryological history ol" a singular medusoid larva found in the
cavity of its bell. Plates 4 & 5.
McCrady, 1857. Gyuino])hthahuata of Charleston Harbor, page 127, Plate 8.
L. Agassiz, 18().'). Contributions iv, p. 347.
Haeckel. 1879. Systeui der ^Nledusen, p. (JG.
Hrnoks, 1883. Studies Biol. Lab., 11, p. 4G5. Oceania nutricula, McCrady, 185G. Desci-iption, etc. Mudeeria multiteniaculata, Fewkes, 1881. Bull. Mus. Conip. Zool., viii, 8, page 149^
PI. 3, figs. 7, 8, 9. Modeeria nulricola, Fewkes, 1882, Bull. ]\rus. Conij). Zool., ix, 8, page 295.
Species-Diagnosis. Umbrella nearly flat on top. In profile view the upper third is nearly rectangular, while the outline slopes ontwards in lower two-thirds. Diameter o| umbi-ella about three-fourths of height. The large proboscis nearly fills the upper portioi of the sub-umbrella. The uj^per wider than the lower half, cubical, and made up of foi masses of endoderm cells, perforated by the channels of the i-adiating tubes. Digestivi ca\ity, making about half total length of ])roboscis, cubical, ending below in four simple large lips, fi-iuged with stalked bunches of lasso-cells, and nearly reaching level of velum, o^ s«»metimcs reaching below it. Four very large ovoidal ivpi-oductive organs, separated fron each other by deep intei-radial furroAvs, rounded below but di\ided above into two lobe^ Avhich run up for a short distance on sides of radiating tubes.
One hundred or more tentacles, placed close togetlu?r around bell-margin, and consist ing of an enlarged imlb, a long slender contractile shaft, and a slight teruiinal clavat^ enlargement. Tentacles capable of extension to three or foui- times diameter ol" uud)rell^ and with a single ocellus on axial side of basal bulb.
Color. Umbi-ella transparent-reddish brown; rei)i-oductive organs, ri'ddisli orange^ interradial fun-ows, deep lake; lips frosted, base and tip of tentacles red, shaft a ver faint purple.
Size. About G mm. wide, and 8 nun. high.
Ontogeny. Larva a Ijranching tulndarian hydroid, with a fusifoi-m body, and three ir regular rows of short fiUiform tentacles. It is a member of AVeismann's ienus Dendn
OF Tin: IIVDKOMKDrSyK. 389
cliivn. Mini it is so vi-iv siniil.ir to lii> 1). /)ii/iriiii\ :i- \i> ii-ihIii- il inoli.iMi' that llii- also is tilt' larva of a 'riiiiil<»|>sis. Stilus jroiii S iiiiii. to I'J iiiiii. lii;;li. llMlraiitlis, palf yc'llowisii ivd. .Mt'diisa-hiids orijiiiiali'oii stem at hast-ol' livilraiitli. Voiin;^- iiii'(lusa lias eight tentacli-s, a small j^i'latinoiis |ic'(liiiitU". and no cillnlar |K-(|iinclc. Month oC yoniij^ mi'diisa sim|»l('. WIiiiii of" yoiini;" with lour radial and I'oiir intcrradial liciiiisphiiifal
]tolK-llC.-.
Ilahitat. ( "iiarK>ton, S. { ". (M(( 'la.lv ) : IJiaiiCort. N. ('. (Hrook-.); Ilain|itoiiKoad-«, \a. ( Hi-ooks) ; Nanshon, linzzard's IJav (A. Aj;assiz).
Kcniarks. 'i'ht' di'scription and fignivs whic-h have b^'cn fjivcii hv A. Aj^assi/, (2. ]). 1(57. tius. 2G9-270), and whiih are referred !«> h\ Ilaeekel (Ml, p. ().">) as j^ivin;,' all we know of the inetainorphosis of the inednsa. do not represent a Turritopsis at all, hnt a (piite ditfeiiiit inednsa.
Fewki's's Modeeria muJtitentaculatn ('1\. p. !-!!•. I'l. o. iiji:s. 7. 8 and !») isa true Turri- topsis and so far as 1 ean jnd<i-e from tlie fij^nre. wliieh is copied from a sketc-h made l»v A. Ajiassiz of a single specimen wliieh he fonnd in 18(55 near Xaiislion in linz/ard's Hav, an immatiire specimen of (mr southern T. mdricula.
This seems to he tlie only recorded instance of its occurrence north of the ( "liesapeake Bay, where it is very rare. Yerrill states ((52, page 454) in his "List of species taken at the surface of the water on the sontheru coast of Xew England" that it was found there at night Iroin July to September, but as he refers on i)age 734, to A. Agassiz's descrip- tion and figures, which ai"e noticed above, I infer, in the absence of all description, that the medusa which he found was the one which A. Agassiz figures, and not a Turritopsis.
Fewkes (21 , p. 153 ) describes and figures a inednsa which he calls Turritopsis n ufricola, but which he was able to reconcile with ^IcCrady's figures and description, only on the supposition that they are quite faulty. In a later paper (20, p. 2D1) he corrects this er- ror, projiosing a ncAv name for his Turritopsis, and stating, incidentally, that his Modee- ria muU'dentaculata is probably the same as MeCrady's Turritopsis nut ricida; an opinion which is undoubtedly correct. He says, however, that ''as the generic name Modeeria is older than Turritopsis. and as they seem to have been apjilied to similar jelly fishes, Mc- Crady's medusa may later be known as Modeeria iintricnla;" but as Forbes, who estab- lished the genus Modeeria, states (23) that it includes only medusjc with four tentacles, there seems to be no good reason why it should supplant !McCrady's name ^br medusfe with more than a hundred tentacles.
^pecicd Description. ^[cCrady gives the following vivid and accurate description of the general appearance and habits of this interesting medusa, which may be readily rec- ognized by its reddish brown color, its square outline and its rapid zigzag movements. " Turritoj)sis nut ricida is a lively animal swimming gaily about, near the surface of the water, with very regular rh)i:hmical pulsations. * * * Its motion in swimming is peculiar; though it does not shoot forward so far at every stroke as Sarsia, yet each throb of the disk gives it a considerable impetus. Now if we examine a Thaumantias, Geryonia; or Turris while swimming, we see it jiropelled by many successive j)ulsations in a straight line, corresponding to the vertical axis of the animal, but this is not the case in Turritop- sis. Tlie pulsations here are slow, measured, j)owerl'ul, each a|)[>earing to have a more
390
A\ . K. HKOOKS ON THE LIFK-IIISTORY
siHTiitl »U-siiru in it. than tho (>l\-roiH':itc'(l pulsntions oi" 'I'liiuunanlias, and each, instead of di-ivinir tlic animal dirertly forward toward tlu" point whitlior its Avholc course tends, Hii.|M-is it in a direction erossiny- that line dia<;-onallv, like the course of a ship in tacking «ir traverse sailinji". It is t luis ])roi)ened first to oiie side of its course, and then to t he other; itsa<-lnal track heing- a zi-t/a-j;. * * * This is the motion of Tnrritopsis when i)er- ft»rniinir a lonir journey, hut he may be oiteu seeu s])()rting- al)ont the surface, taking a few sidelouiT leaps like those described, and then, with the mouth of the bell downwards, expanditig himself to the utmost, all his tentacula, which in progression Avere tightly curled up. now gradually disentangling and stretching themselves to their greatest length, turned upwards or hori/outally, while the motionless parachute slowly sinks to the bot- tom (See PI. 37, tigs. / and K) . However, the tentacula thus extended seem to be keenly alive to every i)assing i)article, and every noAV and then, one or two or more of them \m\\ be seen to contract with great i-ajjidity, as if they had come in contact with sonu'- tliing to be seized or avoided. At this time the Tnrritopsis has sjjread all his snares, and lusti-ntacula radiating (m all sides.form a circle probably equally efticaci(ms with the spider's wt-b. ludi'cd 1 have ioinid snudl Crustacea, their principal food, frequently dead or dy- ing in the end»race of these tentacula, or rather simply hanging to them by invisible attachments, illustrating in another instance the deadly- properties of these wonderful tluvatl-cells. ^Vlter, however, the Turrito])sis has been sinldng I'or some time (he may even allow himself to touch the bottom of the jar), he suddenly draws in, more or less, all liis teutacuhe. and beats up again toward the surface in the same old zigzag way, now and then running along for a little distaiu-e in a horizontal direction, but genei-ally going quite up to the surface, and then expanding himself, mouth downwards, again to sink slowly towards the bottom. The animal may continue fishing in tliis way a Avholc morning."
A.S it is a hardy species it thrives perfectly in an aquarium, Avhere its active movement ^ and the graceful curling and unfolding of its long hair-like tentacles, as well as its briglil color, render it verA' attractive. A specimen ma}^, if su])i)lied with proper food, be kept all smumcr. l)ut it is very voracious, and T have seen a small specimen kill and finally swallow a Sagitta more than half an inch l<mg, the Sagitta l)eing bent like a bow in thi middle aiul distending the whole body of the Tnrritopsis.
At Beaufort a few specimens may be found throughout the whole summer, but it is nut very abundant inside the inlet until the end of August, although we frequently obtained great nmnbers outside in Juiu- and July. "^Mien the south wind, which blows almost con- stantly during these months, c(mies to an end, near the endof August, Tnrritopsis make- its api)earance inside the harbor, and with the continuance of calm Aveather, it become- more and more abundant, and through .Sejjtember aiul October hundreds of specimen- of all ages and sizes may be captured nearly every day. I infer from this, that the li\- dra lives in deep water offshore, and that the proper home of the medusa is in the open fK-ean. Indeed, Ave have taken them at the bottom outside with the traAvl, at times Avlicn the Avater was so rough that none Avere found at the surface or inside the iidet. 1 ha\x found only a single colony of the hydroid, and this was obtained inside the harboi-.
OF TIIK IIYDROMEDUS.K. .{'.H
Description of the Lciiva. Jii a pirviuiis |)a|»cr ( Id. \\. V^7^) I ^^avc a lnii I' accoimt ol' tlic hydra and yt)iiii<:; im'tlu«ia, wliicli I am now aide to >ii|i|»lcmfii( with ilhistratioiis and additional notes. Althoiij^ii I made many attempts to icar tlir younj^ from thi* e^Xj;, I succeeded only once, and the phinida is sliown in I'l. I'J, lijj^. 2. It is very ()pa(|ue, and as I obtained very few, I did not sacrillee any ol'them J'or examination, and learned very little of the minute structure. In a livin<; planula it is easy to make out, at tlu; posterior end, an ectodermal invauination, which looks very nnich like the month of an inva;^inat<! <;;astrula, hut this resemhiani-c is misU-adin^j;, lor the careful study of a similar structure in the planula of Eutima shows that the invagination has no connection with the di^^^es- tive cavity, hut is an ectodenual gland for the attachment of the planula. My few |)lan- uhe of Turritopsis attached themselves in the anji^le at the bottom of the a(piarinni, where examination was impossible, and I was not al)lc to dis|)lace them without destroying them. Finally, I broke the glass, and was fortunately able to secure, among tlu- frag- iniiits, one specimen which was uninjured, and this I have lignrctl in I'l. ili, (ig. .'{. 'I'he ligure shows that the jjlanula does not become convei-ted into a hydranlh but forms a root, a, from which the tir.st hydranth, /i, is formed as a bud. This has as yet no mouth nor tentacles, but its oral end is enlarged and tilled with lasso-cells.
The only colony of the hydra which I obtained was .scraped from the jiilcs ol" t he steam- boat wharf at Morehcad City, seven or eight feet below low tide mark. The ti|»s of two of its branches are shown at //, in 1*1. 37. It lived for two weeks in the house, and set free great numbers of hai-dy nicdusic wliich were reared until tlicy had acijuiivd the c-har- acteristics of the genus.
The upright stems of the hydi'a, from 8 mm. to 12 mm. high, boi'c large tci-minal hy- drauths, as well as smaller ones which were scattered iiTcgularly along the stem on short stalks. The long fusiform body of the hydranth carries from eighteen to twenty thick, short, filiform tentacles, which are arranged in three ormore indefinite whorls. The medusa- buds, jB, i?, originate around the stem just below" the hydrauths, and they are themselves car- ried on short stems. The perisarc is not annulated, and it forms a loose cylindrical sheath around the main stem, and the short branches which carry the lateral hydrauths and the young medusa?, while the latter are closely invested by a miu-h thinner and more trans- l^arent ca])sule of jjcrisarc. The sheath on the stems is thick and crusted with foreign matter. It terminates abruptly by a shai-p collar just behjw each hydranth. The young hydranths and the medusae are budded oft* above the collar, but they soon become en- tirely sheathed in perisarc by the groAvth of the stem. The pale yellowish-red hydranths, arc very similar to those of Tubularia (Allman) and the hydroid is so similar to Dendro- clava Dohrnii recently described by AVeismaiui, that the\- undoubtedly belong in the same genus.
Metamor pilosis of the Medusa. The little medusa remains attached to the stem, as shown in PI. 37, C, for some time after the rupture of its capsule of perisai-c. At this time it is nearly spherical and covered with large conspicnons ectoderm cells. Its eight short tentacles are thro^vn backrwai-ds in contact with the outci- surface of the bell, and their tips are hooked or bent upon themselves in a very characteristic manner, which is
•Y)2 W. K. SHOCKS ON THE JJFK-IIISTORY
.■.howii in till- liuurc. This jjosiliou oC tlie ti'iitaclr iindiTs tlic bull) :it llic Icisc, witli its »K-»'Ilus. viTV promiiu-nl.
Tlu' nuHliisa wlu-n sot I'lvi'. IM. 37, iigs. D mikI 7i', has t'iglil kMitaclcs, a lliin •••lol)!!!!!!- Ik'IK ;uul a slmrt simple proboscis. AVlu'ii tln' aiiiinal is in active motion tlie tiMitju-k's aiv rontracted. bent into hooks and thrown baek against the umbrella, as shown in fig. I), and at eac-h pulsation the bell is lengthened and emarginated during eon- traetion. imt when relaxed it is nearly glolndai'. Fig. Z> shows a young inedusa in the shape whieh it assumes Avliile swiunning, at each period of contraction, wliik' R sliows a medusa of the same age Hoating in a relaxed conditicm. When at rest the height of the unibirlla is al)out equal to its diameter, and the shape is that of a s^jherical segment al- most v(\un\ to a sphere. The tentacles are capable of extension to a length equal to about twice the diameter of the bell, and when the animal is at rest they are stretched out almost hori/ontally. and the distal half is bent downward a little at an obtuse angle near the middle of the tentacle. The lour interradial tentacles, when tlms extended, lie nearly in the j)lane of the velum, while the fom- jjcnadial tentacles are carried a little lower. This ])eculiar bending and alternation of the tentacles, which is very characteristic, is well shown in tig. JE, which, like all the other fignres, is a careful study from life. Many liydroids cai-rv their tentacles bent so as to form two cycles, and the resemblance to them which the yonng Turritopsis exhibits, seems to be an embryonic characteristic, for I have failed to observe anything of the sort in older medusae. The tips of the extended tentacles are slightly clavate, each w ith a spot of dark orange pigment. The length of tlie proboscis of the young medusa is about two-thirds the height of the umbrella, and its upjier and loAver ends are smaller than the middle. The month of the medusa, whei^ it is set free, and foi- several days afterwards, is simple and circular, and the endoderm of the oral end of the proboscis is thin ; bnt, just below the aboral constriction, it becomes ver}- thick and cartilage-like, and the thickened area arches ontinto the sub-nmbi-al sur- faces of the radiating tul)es, as shown in fig. 7.
This thickening of the endodermal cells of the aboral end of the stomach is character- istic of the genus Turritopsis; and in a specimen a week old, fig. H, the whole nppe* half of the proboscis is made np of four great masses of very large, cartilage-like end©? denn cells, which meet n])on the central axis and run out for a short distance into the radiating tubes, which ])enetrate the masses of cells (m their way to the stomach, the cav- ity of which lies below the cartilaginous peduncle. The singular structure which is thvSt fonned is quite unlike anything which occui's in any other genus. It has been describe* by varioas authors as an ordinaiy gelatinous peduncle or gastrostyle, but it is not at aS the same as the gelatinous projection from the substance of the mnbrella wliich, in many mcdusjc, hangs down in the centre of the bell.
As the medusa grows the proximal ends of the i-adiating tubes are drawni down into the cavity of the umbrella, as sho^ra in fig. IT, until in specimens two Aveeks old stomach is suspended some distance below the sub-umbrella by a transparent mass large cells meeting in the central axis, and perforated by the four tubes. In the adl figs. Z ./, K, this body almost entirely fills the upper half of the cavity of the bell.
In a medusa a week old, fig. //, the foui- (jral lobes or lips have made liuii- ai)pcar-
OK TlIK llVDKOMKUUS.i:. 393
aiHT, and ai-i' lriii'4\'il l)y thi' .stalknl l)iiiii-lii-> of laric.- |ii-<niiliii'iil la^^n-cclls wliidi liavi- lu'cii tli'scrihi'd in the atlull hy McC'iady and nllu'is.
At ahout this tinii' trat-i-s of tlu- iv|iri)dni-tivi' oi-.ifan-i made tlitir a|i|)carancf in llu- walls oCtlu' i)i'()l)i)scis at tlu' lower cndsol'llu' niassi-s of L-ndodcrnuH-lls. Tlif tentacles, af tlie sla^j^e shown in Ih^. H, are still earrii-d in two eyeles: tin- interradials liein;^ hi-^lier than the [jerradials. There are only eiji^ht, and no more were developed in the niednsa; which I ri'ared I'roni the hydra, althongh I captnred many specimens in the same state, and al all the lollowinij^ stajj^es up to maturity.
In specimens from one to two weeks old the lower surlace of the very wide vehiin, fig. G, is pushed out to form eight hemis[)herieal pouches; four of them radial and four intcrradial, in the planes of the eight tentacles. They j)roject sf) much that they are rjuite easily seen in a profile view, and I have represented them in fig. II. May they not be homologous with the pouches, which, in the ocellate medusa) become closed and con- verted into the marginal vesicles?
The adidt medusa is shown in figs. /, t7and K. "When it is swimming u]) from the bottom the tentacles are carried tightly cui-led up close to the edge of the bell. AVhen it reaches the surface they are suddenly extended on all sides, shown in fig. K. They are nearly straight, but their tips are a little bent and sometimes coiled. This attitude is preserved only for a few seconds and the medusa at once begins to sink towards the bottom, while the tentacles coil n[) at their tips and assume the position shown in fig. I. The bell also becomes flattened and nearly hemispherical, and before the animal reaches the bottom of the aquarium it usually assumes the appearance which is shown in fig. J. As it uears the bottom it suddenly draws in its tentacles and rises to the surface, and again extends them, as shown in fig. K.
The plate, which has been photo-lithographed from sketches and studies Avhich were made from the living animals, may, I believe, be relied upon as a faithful ])ictare of the life-history of Turritopsis, and I trust that this accuracy, which is often lacking in draw- ings which are carefully finished at home, may compensate for the roughness and lack of transparency which are unavoidable in a pen-and-ink sketch. The figures of the adult medusfc, /, J, K, are much less magnified than the others, which arc all drawn to the same scale.
Eutima. Plates 38, 39, 40.
I have selected Eutima as an illustration of the life-history of the second of the four orders, into which Haeckel divides the Craspedota or veiled medusaa. This order, the Leptomedus^, includes the Craspedota which are set free as buds from an asexual Campanularian nurse and which have the reproductive organs on the radial canals. Ocelli on the bases of the tentacles are usually absent, and marginal vesicles are almost imi- versally present, and are developed along the veil at its junction with the umljrella, and contain ectodermal otolith cells.
Haeckel divides the order into four families, in the third of which, the Eucopid^, or Leptomedusa3 with marginal vesicles and four simple unbranched radial canals, Eutima is placed, being included in the third of Ilaeckers sub-families, the EuTiMiDiE or Eucopidai Avith eight adradial marginal vesicles, and with the stomach at the end of a proboscis or peduncle.
:vM
W. K. HROOKS ON THE LIFE-IIISTOEY
The sevondvn spocics wliicli aiv cMiiiiiK'nikHl In- ITacckt'l arc anaiigcd by liim in eiirht •'•onora. livo of whii-h arc iu>\v, ami the eight gcnora are tlividcd into two groups: the SAriiKNin.K. or Eutiniidtc with four reproductive organs, and the Octorciud.e or those with eight; but as the reproductive organs are sometimes four and sometimes eight in 1 wo (»f our species, we cannot regard this division as a natural one. llaeckel's genera dilVor in the nuinl>ei- of reproductive organs, the presence or absence of marginal cirri, and the numln-r of tentacles, but as all of these characteristics are either variable or sub- ject to change during growth, it is possible that a more complete knowledge of the life- histories of species which have been described from single specimens will compel us to make a very considerable reduction in the number of genera.
llaeckel's personal familiarity with the meduste undoubtedly exceeds that of any other writer, and all students must bear testimony to the great value of the laborious researches into the perplexing literature of the subject, the results of which he has given us in his "Svstem der Medusen." My own studies have taught me the value of this w^ork, and I hesitate to jM-opose any change in llaeckel's classification; but his arrangement of the species of Eutimidie is not even available as an artificial key, for his genus Eutima is cliai-acterized by the i)resence of only four reproductive organs and numerous marginal cirri, while all my specimens of Eutima mira, a species which he places in this genus, had eight reproductive organs, and Avhile nearly all of them had marginal cirri a few had none. His genus Octorchandra is characterized by eight reproductive organs and numer- ous cirri ; but McCrady says that our Eutima variabilis ( Octorchandra variabilis, Haeckel) sometimes has only four reproductive organs, and my specimens had no marginal cirri.
The genus Eutima, as originally established by McCrady, is equivalent to Haeckel's family Eutimid:c, and as all the species are very closely related to each other, while several of them are as 3Tt vei-y imperfectly known, it does not seem pi-acticable to divide them into a number of genera at present.
Genus-Diagnosis. Eucopidic with eight adi-adial marginal vesicles, and with the stom-, ach at the tip of a gelatinous peduncle from the apex of the umbrella. Keproductive^ organs linear in the course of the four radiating tubes, which themselves extend down" the peduncle to the stomach.
Remarks. The reproductive organs are often disposed in two masses on each radiat- ing tube, one on the sub-umbrella and one on the peduncle, as shown in PI. 3!>, but McCrady states that some specimens bear them only on the peduncle, some only on^ the sub-umbrella and some in both positions, and I have found specimens of Eutimtk mira in which ova were scattered along the whole course of the tube, from near the bell margin to the base of the stomach, although as a rule they are divided into two sharply defined regions separated from each other by an area where the canal bears no ova^ This area is often longer on one of the tubes than it is on the other, and the two ovariei in one quadi-ant are sometimes confluent, while those in the other quadrants are distiuci "We must therefore agree with McCrady that, far from furnishing a basis for a divisi into genera, the number of reproductive organs cannot even be used to separate species that they may be double or single, and that Avhen single they may be placed either onl the peduncle or on the sub-umbrella, or they may sti'ctch over both regions without inter-' ruption, and that all their variations may occur in one and the same species. In th^
f
I
OK TIIK llYDHOMKDL'SvE. 395
two spocii's wliitli liave hccn traced to lliiir Iivdia st:i<i^e, this is a C'aiiiiiaiidjtfciiK, or a Campamilaria-likt' hydroid willioiit a calyx.
Eutima mira, McCmtUj.
E utlma mi'ra, ^McCrad}', 1857. Gyiiiii()iptlialina(a (jf Charleston llaihor, p. SS. PI. 2,
fijjs. 8 and 0.
L. Agassiz, 1802. CoiiUilmtions, iv. p. .'JG3.
A. Ajrassiz, 1865. X. A. Acalcpluv, p. IIG.
Ilacckcl, 1879. System dcr Mcdiiscn, p. 101.
Brooks, Studies liiol. Lab. 1882. p. Species-Diagnosis. Umbrella, when contracted in swimming, neaily hemispherical, about two-thirds as high as wide. Proboscis slender, slightly enlarged at base, four or five times as long as the diameter of the bell. Stomach of greater diameter than the pe- duncle at its junction with the stomach, about three times as long as wide, quadrate in cross section, and less than half as long as the heiglit of the bill. Edges of the mouth folded to form four everted radial lijjs, separated from each other by four interradial inverted folds. Reproductive organs linear, sometimes extending from near the edge of the bell nearly to the base of the stomach, sometimes divided into a sub-umbral and a l)eduncular portion, either of which may be present alone. Four tentacles, with enlarged hollow bulbs, six or seven times as long as diameter of bell, sometimes with ])asal cirri, sometimes without. Numerous marginal tubercles, Avith or without cirri. Marginal ves- icles with one large medium otolith and two or three pairs of smaller ones. Bases of tentacles covered by hood-like gelatinous projections from the umbrella.
Color. Almost perfectly transparent, endoderm of tentacular bulbs yellowish i-ed. Size. Umbrella 12 or 13 mm. in diameter and about 8 mm. high. Habitat. Charleston, S. C, McCrady; Beaufort, N. C, Brooks. Remarks. This is a very active and graceful species and the specimens which I l^ept in aquaria were seldom at rest. "When swimming the tentacles and proboscis are usually extended to their full length, as shown in PI. 39, fig. 2, but when the animal is floating at rest or sinking to the bottom, the tentacles are swept into graceful folds by the resistance of the watei', as shown in tig. 7. As the animal rises rapidly from the bottom the tentacles are thrown into undulations by the flapping of the bell. AVhen contracted in swimming, the outline of the mnbiella is nearly hemi- spherical, but when at rest it is slightly emarginated, as shown in McCrady's figure. In an oral or an aboral view, the outline of the umbrella is not circular but produced to form four roimded, radial projections or hoods over the bases of the tentacles. The en- larged bulbs at the bases of the tentacles taper rapidly into the slender, hollow shafts, which may be extended to seven times the diameter of the bell, and are never com- pletely retracted but lie around the medusa in loose, irregular coils when it lies at rest on the bottom. In nearly all the specimens which I examined, the radial canals anasto- mose with each other through an irregular plexus of canals around the base of the peduncle, as shown in PI. 39, fig. 3. Some specimens have coiled accessory tentacles on each side of the bulb of each radial, but these as Avell as the marginal cirii are often absent.
.^,^ W. K. lUiOOKS ON THE LIFE-HISTORY
The species is very ahiuulant at Bcauloil in August and September, and it is usually found in ci^nipany with Liriope smtigera, to which it bears a close superiieial resem- blrtnco which may possibly be tluc to miuiicry. This resemblauce led Esclischoltz to associate these and allied medusaj with the Geryonidas and it is expressed by the name Gcrvonopsidie proposed by Agassiz for the Eutimidte, Eirenidaj and related medusje.
Ontogeny. I have reared the hydroid from the egg laid by the medusa. It is a Campanojisis very similar to the one from which Clans obtained the young medusro of Odorchis (Etdima) GegenhaurL It has a prominent, rounded manubrium, a single circ- let of ten tentacles, arranged in two alternating series, and an elongated cylindrical body, which is not covered by the pcrisarc which invests the unannulatcd stem, PL 38, iig. 10.
Eutima variabilis, McCrady. V\. 39, lig. 1 ; PI. 40.
Euiima rariahilis, ;^[cCrady, 1857. Gymnoi)htlialmata of Charleston Harbor, p. 88. L. Agassiz, 18G2. Contributions IV, p. 30)3. A. Agassiz, 1805. ]S^. A. Acalei^ha?, p. 116. Odorchandra variabilis, Haeckel, 1877. Prodrom. System Med., ISTr. 211.
Haeckel, 1879. System der Meduscn, p. 199. Eutima sj).. Brooks, Studies Biol. Lab. 1882.
Species-Diagnosis. Umbrella thick, flattened, more than three times as wide as high Peduncle about equal in length to radius of bell, and less than twice as long as its height. Stomach short, quadrate, much folded, and i)rolonged into four pointed, crenu- lated lips. Sixteen tentacles of equal length, with three or four marginal thickenings between adjacent tentacles. Eight marginal bodies with ten or twelve otoliths in each ; the medium one largest and the others in pairs. Each marginal vesicle lies close to radial sides of bulb of tentacle next radial tentacle. Reproductive organs usually divided into a sul)-umbral and a peduncular i)ortion ; the latter absent in the young. 2so marginal cirri or accessory tentacles.
Color. Umbrella and peduncle transparent and colorless. Stomach and endoderm of tentacular bulbs intense green by reflected light. Endoderm of tentacular bulbs bright pink, and ectoderm sky-blue by transmitted light. Ectoderm of tentacular bulbs colorless b}' reflected light.
Size. Diameter of bell about 30 mm. Height about 7 mm.
Habitat. Charleston, S. C, McCrady ; Beaufort, N. C, Brooks. It is a rare species at Beaufort and most of the specimens which I obtained were captured outside in August and September.
Ontogeny. Although I obtained I'ipe eggs on several occasions they were not fer- tilized and we have no direct knowledge of the ontogeny, although there is no i-eason , U) suppose that the hydra is different from that of OdorcMs (^Eutima) Oegeribauri anc Eutima mira.
Remarks. McCrady's specimens had only twelve tentacles, while all the mature specimens which I obtained had sixteen, but as the Beaufort specimens agree with hisl description in all other respects, their identity can hardly be doubted. The tentaclesj
OF Tin: iiYDKOMKDUs.i':. 397
Were all (if (([iial liiiutli. and wt-rc anan;;((l as in tliis <lia;^i-aiii, wlii-iv R stamis for a i-adial Iciitac-k' and O for a marj^inal vi-s'k-Ii-.
li T T T i: T I' 1' li
O () () ()
If tile middle ti-nlack' (if cadi (jnadrant i> llif youn^^cst (tiie, tliu .sta;jfu whicli is sIkjwii in PI. 40 must be i)rcct'dcd by a stage with only twelve tentacles. This plate, which is a photographic coi)y of a jien sketch made from the living medusa, is the (Mily figure Avhicli has ever been jjuldislied of this beautiful species.
The tentacles of tlie adult have wi-ll-niarked bulbs; their long, slender shafts are usually extended to four or live times the diameter of the bell, and are never completely nil-acted, but when shortened they are thrown into zigzag folds.
On Aug. 7, lv?80, I obtained a single specimen of a Eutima with a thick, ilaltened umbrella, and four long, slender tentacles. It is shown in PI. HiJ, fig. 1. Jt was 8 nun. in diameter and although it dillers in many respects IVom the adult Eutima virid/i- ilis, it shows so many points of resemblance that it is, in all pi'obai)ility, the four-tent a- cled stage of this species. The bell is very ilat, about four times as wide ashigh, thick in the middle, and gradually becoming thin at the edges. The peduncle is longer than the diameter of the bell, while the stomach is very short and only a little longer than Avide. Veil very narrow. The four tentacles have bulbs, Avhich are covered by hood- like outgrowths from the umbrella, and their long, slender shafts are capable of very limited contraction; and, when extended to four times the diameter of the bell, are throAvn into zigzag folds. The four ovaries are long, narrow and continuous, and they run from near the circular tube up into base of peduncle and down this for a short dis- tance. There are no accessory tentacles on the tentacular bulbs, but between each pair of tentacles, there are nine or ten marginal enlargements, some of which have ciri-i. The lips are simple folds, and there are eight marginal vesicles, each with from three to nine otoliths.
It is possible that Agassiz's Eutima pyramidalis may be the yonng of this species, al- though he states that the bell is hemispherical, which is certainly not the case with any of the specimens Avhich I ha\'e seen.
A. Agassiz's Eutima limpida (2) and Fewkos's Eutima f/racilis (20) are, beyond ques- tion, distinct from the species Ibund at Beaufort, so that avc have, on our coast, four species of the genus.
Eutima mira, Avith a hemispherical bell, and a very long proboscis, Avith folded lips, and Avith four tentacles; Eutima ^•ar^a&^7^s Avith sixteen long tentacles, a short proboscis and a flattened bell; Eutima limpida Avith short tentacles Avithout bulljs, and Avith sim- })le lips; Eutima f/racilis Avith a flattened bell, four tentacles Avith bulbs, large cirri, acces- sory tentacles and a globular stomach. The latter species, Avhich is so far knoAvn fi-om only a single specimen, is very similar to Keferstein's Siphonorhynckus insignis (3G) with Avhich it may prove to be identical.
In June, 1879, I obtained at Beaufort several young specimens, about .5 mm. in diameter, of a yonng Eutima Avhich agrees Avith A. Agassiz's description of Eutima
308
W. K. BROOKS ON THE LIFE-IHSTORY
limpitlii in so nnny respects that I am inelhiod to regard it as the young of that species. It is shown in PI. 30, figs. 4, 5 ami (5. It has a llitteu^d, em irgiuated hsll, sim;)le lips and short tcntack^s without hulhs, and with accessory spiral tentacles. Spscimens were also found at the same stage of growth in Aug., 1870 and Aug., 1880.
The Embryology and Metamorphosis of the EtJTiMrD.i:.
In 1881 Claus called attention to the fact that ahnost nothing is known regarding the lifo-historv of Eutinia or any of its nearest allies, and that the only observations upon the development of any of the Gerynopsida" are those of A. Agassiz (2, p. 115, figs. 171 and 172) who has reared the plannla of Tlma formnsa from the Q.^g and has given a very brief description and a single figure of the hydra, although he did not observe the production of medusa-buds and says nothing about the very young stages of the ine«lusa.
Excc]>t for Clans' paper, which will be noticed presently, the only addition to our knowledge of the subject is a very brief account by Merejkowsky (50) of the young embryo of Irene. In the spring of 1880, Claus (66) found a number of small hydroid communities in an aquarium, in which specimens of Odorchis Gegenbauri, Irene pel- hicida and yEquora ForsTcalia had been placed some time before. From these hydroids he obtained a number of young medusre, which, however, he did not succeed in rearing; but, as he was al)le to collect in the open water series of young medusj^ of each of the three species, he showed that those which he obtained from the hydroid were essentially dilTerent from young specimens of Irene and ^Equora, while they were sufficiently like the youngest specimens of Octorchis which he obtained in the open ocean, to render it verv probable that the hydroid belongs to this species, although the gap between the two is sufficiently great to render further information desirable. In the absence of any ob- servations which connect the hydroid with its parent or the medusa-buds with adult medusne, it is possilile that the hydroid may not have been reared from the eggs of any one of the three species which were placed in the aquarium, as eggs or planulaj may have been introduced with the water. Clans' observations render it very probable that the hydroid is the larva of Octorchis, but they do not prove it beyond question, and I have been able to complete the story by actually rearing from the eggs of our Eutima mira, under constant observation, a h^'droid which is so similar to the one Avhich Claus figures, as to show beyond doubt that his conclusion is correct. Octorchis is a Eu- tima according to IMcCrady's definition of the genus, and the species which I studied is verj' closely related to the one which Claus observed. As I have observed the seg- mentation of the egg, the swimming life of the planula, its attachment and the origin of the hydroid, while Claus has described the medusa-buds and the metamorphosis of the medusa, the two accounts give a very complete life-history of the Eutimida?.
The fertilized eggs of Eutima may be obtained by placing a few mature specimens in a small aquarium or a shalloAv dish of sea water. They usually lay their eggs the first night after they are captured, and if the species is very abundant, the water will often contain enough spermatozoa to fertilize them, even when only one specimen is used; but the result is much more certain if several specimens ai'c placed in the same dish, for
OF Tin: IIVDUOMKDUS.E. 399
many of the vj;'^< fail to (Icvclo]) if no inak's an- pivscnt. Kutinia is very rcj^iilar in its brooding habits, ami wliilu my spoiinicns were captured at all lioiirs in the (biy. nearly all the egjjs were laid between the honrs of 7.:30 and S.30 i'. m.
The tendency to lay eg<?s at a fixed lionr of the day seems to be <inite prevalent among marine animals, and a knowledge of this is of the greatest importance to natu- ralists, since a failure to procure the fertilized eggs of an animal may oilcn be due to tlie fact that it has not been collected or ol)sei'ved at the proper hour. The ])he- nonienon has received very little attention and I therefore give a few illustrations wliich have recently atti'acted my attention. Clans in 1882 (11) and Merejkowsky in 1883 (oO) have shown that the young stages of ^quora and Obelia are found only in the morning, and Merejkowsky says that the successive steps in the formation of the |)lanula of Obelia follow each other with such regularity that each stage is met with only at a definite hour in the morning. This author attributes the regularity to the direct infiu- ence of light, but he gives no jiroof of this and observations which have been made at Beaufort, under my direction, during the jjast three or four years, show that the perio- dicity is not due to any external influence, but that it is a specific characteristic deter- mined within the organism. Wilson found at Beaufort that the eggs of Renilla, an Aleyonarian, which lives in the sand below low-tide mark, are always laid at or about G A. M. He observed only a single instance of spawning at 5.30 and it was never ob- served later than 7 A. m. The regularity is entirely independent of temperature, for the spawning hour was the same on cold and on warm days, although the rate at which the embiyo develops docs vary with the temperature. He says that the eggs of Leptogoi'gia are laid with the same regularity, although in this case the hour is 4 A. M. (G7).
AVhile Merejkowsky says that the eggs of Obelia are laid early in the morning, I find that several allied Beaufort raedusse spawn at night. Thus Entima, Eirene, Turritop- sis and Liriope discharge most of their eggs about 8 p. m., although captive specimens drop a few eggs irregularly at all hours. As one hydromedusa lays its eggs early in the morning, while other species lay them in the evening, the regulating influence can hardly be the supply of light.
AVhile studying the development of a pelagic crustacean, Lucifer, I found that sexual union took place Avith great regularity, between G and 8 p. m.; while the eggs wei'c laid between 8 and 10 p.m., so that the early stages can be studied only between 10 p. m. and 7 A. yi.
Dr. II. H. Donaldson has observed at Beaufort that actinia^ of various genera are fully expanded only between the hours of 5 and 6 p. m. This is true of these animals in their natural homes, as well as in aquaria; and expenments showed that specimens which were kept in darkness expanded as promptly at the proper hour as those which were exposed to direct sunlight.
Among the animals which are here enumerated, some live at the surface, as Eutiina and Obelia; some, such as the actinias, live near low-tide mark; some, Renilla for ex- ample, live in deeper water; and some, like Lucifer, arc vigorous sw^immers, while some, like Geryouia, are fixed. Wilson's observations show that the periodicity is not due
4(.X) "^^■- !<• BROOKS ON THE LIFE HISTORY
t«) teni|)oratuiv. wliile Donaldson's cxi)eiimcnts show that it is not the effoct of light. Thori' is no I'vitU'nco to show that it is due in any way to the direct inflnence of sur- roundinjr I'ondilions, and I think we mnst Ixdiov-o that it has been established in eaeh s|K'c-ii's bv natnral selection on aceonnt of some advantage to the animals which exhibit it.
Tlie fact that the hour for discharging the reproductive elements is, in so many species, a definite one, often in the night-time, shows the importance of marine observa- tories where the naturalist may keep his specimens under his eye at all hours of the day and night; for, as midnight collecting is usually impracticable, the early stages of many animals cannot be procured without facilities of this sort.
Tiie eggs of Eutlmn mlra develop rapidly, and the swimming ])lauida stage is reached early in the morning after the eggs are laid.
Segmentation is total, but as shown in Pi. 38, fig. 1, it is not perfectly regular. A capacious segmentation cavity, fig. 8, a, soon makes its appearance, and the cells which are a little lai-ger at one pole than they are at the other arrange themselves in a single laver, //, and continuing to subdivide soon become nearl}' uniform in size as shown in fig. 3. The embryo now becomes ciliated and, rising from the bottom, assumes the wcll- kni>wn pear-shaped outline of the hydroid planula, fig. 4, with a spacious segmentation cavity, surrounded by a single layer of ciliated cells, i, which are much thicker at ^the small end of the pear than over the rest of the body. While the blastodei'm consists of only one layer of cells, the planula increases considerably in size, and appears to have some method of nourishing itself.
According to Mei-ejkowsky (yO) the central cavity of the planula of Obelia com- municates with the exterior through a great number of minute pores which are situated between the blastoderm cells. He says the i)ores are large enough to permit small in- fusoiia to pass through them into the centi-al cavity where he has seen small animals swim- ming actively. lie believes that these small organisms serve as food, and, although I have not been able to discover the pores in Eutima, I have satisfied myself that the plan- ula does obtain food in some Avay and increases in size.
The endoderm cells soon begin to make their appearance at the small or posterior end of the cavit}' and are set free, as shown at c, in fig. 4. They soon arrange themselves in a continuous layer or endoderm over the whole inner surface as shown at c, in fig. 6. According to Merejkowsky, they ai'c not formed by the transverse division or delamina- tion of the blastoderm cells, but by migration, in the manner which has been described b}' Schultze, Metschnikotf and others in the sponge planula. In a preliminaiy paper on the life-history of Eutima (11) I have stated that they are formed by delamiuation, but as I made no attempt to watch the changes of a single cell, I did not actually wit- ness the process of division and it is possible that they are not foi-med in this way but by migration. The formation of the endoderm cells goes on rapidly and the planula soon appears to become a solid mass of cells, fig. 5, but careful examination will show that a small central digestive cavity, fig. 5, g, persists in the axis of the embryo, although it is rendered almost invisible in the living planula by the increasing capacity of the endoderm cells, which are appaiently distended, so that they almost meet in the centre. In a specimen which has been killed with osmic acid and stained with picro-
OF TIIK IIYI>l{().Mi:i)l>>.i:. 1(11
carmine, they aiv flatter than they are in tlie livin;;: animal, and it is easy to see that they are arranged in a single layer to form the walls of tlu' digestive eavity. Fig. 0 i« a stained specimen of the same age as the one shown in fig. '}. In a surface view, c, the rounded ectoderm cells are seen and hy focussing a little deeper, the polygonal ontline.>i of the granular en(h)derm cells, c, come into view, while still rleeper focussing shows an empty space, //, the stomach, aruuml the edges of which the single layer of endoderm cells is seen in sectional view.
There can, of course, he no douht that in most hydmids, the plannia is at first solid, and that the digestive cavity does not make its appearance until some time alter the cells are specialized into an ectotU-rm and an endoderm, and I think that the persistence of the segmentation cavity of Kutima as th:' digestive cavity and thi' ahsL-nct; of a solid stage must h;- regarded as a scconchiry modification of the ancestral history, altiiough it is not impossihie that the manner in which the endoderm and digestive cavity arc formed in the Geryonichii (sec below) maylje the primitive one and the solid stage a secondary phenomenon.
The fact that a solid stage occurs in so many hydroids, in the .Vcraspeda (xrc Kowa- Kvsky. 40) and in the ,\nth<»zoa (sei- Wilson, ()7), as well as in the sponges, would seem however to indicate that tiic early appearance ol" tlic digestive cavity in Kulinia and in till' (Jeryoiiida' is nol primitive hiU secondary.
I shall not enter upon tin- discussion o|" the relation of the enihryology of the Ilvdro- medusa' to the gastrula theory, further than to point out that not a single hydi'oid gas- trula has been observed; but that, in every species which has been studied, the digestive cavity has at first no opening to the exterioi-. and that the mouth is formed very nuicii later than the stomach. Most writei's believe, it is true, that the planula is a modified gastrula. and that its digestive cavity was originally invaginated from the exterior, but this is purely a de(hictive inference from the analogy of other animals. Thus ( "laus ( 14) describes the origin of tlu' endoderm and digestive cavity of vEipiora and Mei-ejkowsky that of ()i)i'lia (oO) as like that of lOutima. but both these writers state their opinion that the planula has oiiginated through a modilication of a primitive invaginate gastrula. Bohm says (p. 1.33) that it is natural to derive the Ilydromedusa' and .sponges from an ancestral gastrula, since in no other r/roup is descent from this form so certain.
Xo one can qnestion the resemblance between an athdt hydroid or spcmge, and the gas- trula stage of the ordinary mctazoa, and there is every reason for belii'ving that the ahnost universal occurrence of this larval stage indicates that the co'Iomatous metazoa are the descendants of an ancestral form which was essentially like the existing caden- terates and that these themselves are the divergent modifications of a common type, the gastrula or two-layered metazoon, with stomach and mouth; but it is rpiite conceivable that the cadenteiates themselves may be the descendants of a form with a stomach, but without a mouth, and that tiie planula stage may be the ontogenetic representative of this just as the gastrula stage is the ontogenetic representative of the adult coelenterate. Most writers have started however with the assumption that, as the hydroids must be the descendants of a gastrula, the plamda must be a modified gastrula ; and one writer (32) has, with the greatest simplicity, given us the cliain of reasoning which has led him to supply a missing gastrula stage in the life of the In^droids. Ilamann says in Ills section
H,., AV. K. liKOOKS ON TllK LI FK-IIISTOUY
tin "St-^iiU'iitiitioii .-iinl lln' roi-iiialioii of tlu' ( J;istriil;i" tliiit lu' was iiuluci-d to study the suliji-i-t h\ liis hvVwi' thai a plaiuila staiiv did not exist and that the published aceouiits wfiv wnni". He says, however, that in liis studies of the embryos of 'rul)uhuia, Agkio- i)henin and several PIunudand;v\ wliich were entered upon in this frame of mind, he was unable totintl anything- like the formation of a gastrula by invagination; that the paper bv Ciamieian. in which the invaginate gastrula of Tubularia is figured, is a eonglomera- lion of tiTors, and that in all the forms whieh he himself has studied, the embryo be- conu-s a plamda like that Avhieh Sehultze had described for Cordylo])hora ; but while his anjH'al to naluri' leads him to these facts he says, "I hold that while the hydroid planula does in iact originate by dclamination, without a segmentation cavity, nevertheless the planula is just as truly a gastrula as it would be il" it originated by ei^ibole or in any other manner." and that Halfonr's view that the plamda stage of development represents a free swiiimiing ancestral Ibrm in the history of the Cadenterata, in which the mouth and the digestive cavity were absent, is untenal)le.
If we believe that the gastrula stage of tlie higher metazoa is the representative of an ancestral form like the adult hydroid, we certainly should not expect to find a gas- trula stage in the embryology of the hydroids themselves; and the analogy of the ani- mals above the hydroids is no reason for sujjposing that the planula is a modified gastrula if we believe that these forms are the descendants of an ancestral form which was itself a divergent branch from the coelenterate stem. The planula stage is certaiidy dominant among the sjjonges, and the so-called gasti'ula is here beyond doubt a secondary larva. Kowalevsky has shown that the embryo of Lucernaria is a planula (40) and Fol states (22) that his examination ol" the embryos of Pelagia has shown the need for a renewed examination of the alleged gastrula stage, while Wilson (G7) shows that the Itenilla em- bryo is ceiiainly not a gastrula, and as there is not a single observation of a gastrula in the Ilydronudusa', we may, so far as this gnmj) is concerned, contimie to speak of the larva as a planula.
Ilamanu says that since we have a idanula in some hydroids, and instead of this, an actinula in others, we are compelled to believe that the life-history of the lower Coelen- terates is consideiably modified and does not give us the pi-imitive condition of things; but his «)wn observations show that the actinula of Tubularia is not the ecpiivalent of the planula of (jthei- hydroids, Init that it is preceded by a planula stage, although this is n<it free but contained within the medusa-bud, and not lieing locomotor has no cilia.
Mcrejkowsky, who has given us a minute account of the planula of Obelia (50), says that he found a few embryos of Irene, in what seemed to liun to be an invaginate gas- trula stage, but he made no minute stiidy of them and did not rear them. Irene is very chisely related toEutima, and it is interesting to note that, in Eutima, after the endoderm and the digestive cavity are f»)rmed, and before the ajjpearance of the mouth, there is an ectodermal invagination which is possibly what he has seen in Irene, although the study of the late stages shows that it is not a mouth, but an ectodermal adhesive gland. At the stage whieh is shown in fig. 6, there is a mouth-like aperture/ at the small or pos- terior end of the planula, and in the living animal it is easy to see that this is formed by an invagination from the surface. In a specimen which has been killed with osmic acid and stained with picro-cannine, fig. 5, it is still more consjjicuous, and is seen to be a
OF nil; ilYDKOMKDUSJE. 403
■Bpacious cm ity, /". (ipfiiiii^ tu tin- cxlriior and Minoiimlcd l>\ a .«.iii^lc lavcr of iii\ a;:^!- nated cells, wliicli arc coiiliiiiioiis annind llu' t(l;;t' nf the (irilic-c witli the cihated cells i»|" the surl'ace ol" the hody. As this iii\ a;4iiialii>ii is very cuiispicuous while it is dillicidt to trace out the structure of the more opaijue eudoderni, tiie plaiiula hears, at first si;;ht, a wry stiikint; reseuihlance to an iuvajj^inatc f>;^astrula like that of the lOchiuodenns; hut umri' ( aiilMl e\an)iiiation shows that the digestive cavity, //, is ah'cady present, and sur- rounded l)y a continuous wall ol' endoderni cells, i\ <\ and that tlu- eudoderiu as well as the ectoderm is intoldctl. and that the invagination (hn-s not conununieate with tiie di;;e.s- tivo cavity, and takes no part whatever in its formation. At a soniewiiat later sta^c, fii^. 11, the eiidoderm becomes drawn away Ironi the invagination, leaving thi.s as an ev- clusivcly eetodennal structure.
I have observed a similar invagination at the small end of the planula «il' Turriiop>.is, I'l. 42, figs. 2 and ."}, although the planula of this species is so opacpie that the study of its internal structure is very dillicidt. The fact that thi' invagination is present in an .Vnlho- nu'dusa and a Leptomedusa gives a reason for helicviug tiiat it occurs in other species as well and that future research may show that it is not at all ninisual. At first, the orifice is terminal, as siiown in tigs. ;1i and (5, and the invagination lies on the axis of the larva, but
I one lip or edge of tlu' opening soon grows faster than the other and thus pushes the pouch on oiu' side, fig. 11,/', which may be called ventral, since it is the surface by which the planula becomes attached; but, before attachment takes place, the whole structure is evaginated as shown in tig. 7, so that only a slight notch, f, remains to mark its jjosi- tion. Lasso-cells now begin to appear at the small end of the planula, the cilia are hjst, and a delicate layer of transparent cement is thrown oil' from the ventral surface of the Miiall end of the planula, as shown at u in tig.8.
This soon hardens, and, entangling foreign |)articles, becomes the perisare. AVheii first attached, and for a short time after, the larva retains the shape which it had dui'ing the swinuning stage, but it soon elongates, as shown in tig. 9, and becomes the sessile, creep-
j ing root, Avhich idtimately produces a community of hydroids. For some time, its pos- terior end, figs. 9 and 10, h, is marked by a flattened pad of ectoderm cells, separated by a constriction from the ectoderm of the general surface of the body. 'I'his jiad is the area which was invaginnted during the swimming stage. The root has no mouth nor other opening to the exterioi-, and there is for some time no trace of the future hydi-anth ; but a bud, fig. 9, soon grows out from the free end of the root and, developing a circlet of tentacles and a mouth, becomes the first hydranth, fig. 10. A second bud now grows out from the root on the i)roximal side or l)ase of the first and this is soon followed l)y a third and so on. As the first hydranth is formed, like all the others, by bu<lding from the root, the growth of the hydranth from the planula is rather a process of metagenesis than metamorphosis and this is not the only species of which this is true. The ])lamda of Turritopsis, PI. 42, figs. 2 and 8, also becomes a root from Avhich the hydras bud, and I have observed the same thing in Hydractinia, where it has been frequently described ; first by Wright (G4) I believe. Merejkowsky shows that the hydranth of Obelia originates in the same Avay; that the planula becomes a star-shaped root from which the first hydranth grows out as a bud. and many other cases are recoi-ded. In sonK> forms the planula I)e-
.^j^ W. K. lUlOOKS ON THE LIFE-IIISTOKY
conu's tlim-tlv coiivorti'a into a siniilr In dra. as in 'ru1)ulai-ia. wIumv thciv is no niota- •nMiesis. hut in inanv otluT forms tluTc is c-iM-tninly a triir alternation iK'twrcn tlu" plaunla stJiiro niul tho Intlra stajxo.
Tlu- din'ct fonvorsion of the c-iliated, mouthless planula into the tentaculated stonia- t<nis hvilra will, without douht, he reeog^uized as the primitive life-history; and the alter- nation «>l" irenei-ations bi'tween the ])lanula, or the root into which it becomes converted, and the hvilras formed from it by budding, will, I think, be universally accepted as a secondary niodilicat ion. I shall <>:ive, in the last section of this paper, my reasons for be- lievin" that the altifnation of generations betAveen the hydra and the medusa is not primi- tive but secondary, and that originally a tentaculated hydra-like larva became directly metamorphosed into a single medusa; and tlie fact that an alternation of generations be- tween tlu- planula and the hydra has been secondai'ily established in llydractinia, Eu- tima and Obelia certainly shows that this view is not without the support of analogy.
The oldest hvdrantlis of Eutima which I reared from the egg were like the large one in fi"-. 10. They had ten tentacles, live long ones alternating with five short ones, w'ith their bases united by an intertentacular web, ^•, in the centre of which there is a rounded luini>itlu'rical maiudM-ium, ending in a simple circidar mouth, without oral tentacles.
Although the livdroid is Campanularia-like, the perisarc is not annulated and is con- tined to the root and stems and does n(jt extend over the bodies of the hydranths, which therefore belong to Clans" genus Campanopsis (66) from which he has reared a medusa which is very closely related to Eutima, and which belongs to the same genus as origi- nallv established by McCrady. The metamorphosis of the young medusa has been well described bv Clans for his species and there is no I'eason to suppose that ours is essen- tially dilVerent.
In the species which he studied, Odorchis Gegenhauri, the medusa-buds originate on the l)odv of the hydranth,on short jjedicels, and they are inclosed in mantles or capsules which are cellular and without a covering of j^erisarc. When set free, the bell of the medusa is deep, the height being somewhat greater than the radius. There is no ped- uncle, and the stomach, which is less than half as long as the depth of the sub-umbrella, ends in a simple mouth without lips. There are two opposite radial tentacles, the rudi- ments of two others, numerous solid marginal cirri, and eight adradial marginal vesicles, each with a single ocellus. Clans did not succeed in keeping the medusaj alive, but he traced in a series of captured specimens the gradual inci'ease in the number of tentacles, the growth of the ])eduncle and lips and the development of the reproductive organs, the peduncular |)ortions of which appear earlier than the sub-mnbral portions.
TllK OniGIX OF AlTEUNATION of GeXERATIONS IX THE llYDROMUDUS-li:.
In the experimental sciences, the investigator seeks for the simplest manifestations of the natural hnv which he wishes to study, and divests it, as far as possible, of all second- art^ complications. In the natural sciences Avhere experiment is usually impossible, the phenomena nnist be studied as they pi-esent themselves in nature; and the dilHculties
OF TIIK IIYDHOMEDUS.E. .10.3
wliicli ;mv uivcii |)i-<»Mciii |>rf-fiit>. c1c|hii(1. to a \cry ^iH-at <li';ri'«'«", ii|him the accidciils whuli (lin-i-t atti'iitioii !<» »'xaiii|»li'< ami illii«-lrali(iiis whidi iiw >iiii|ilf and i-asy l<» iiiulcr- staiul, or to tliosi- wlu-n- tlu- sim|iU' laws art- ohscmcd or liiddcii under secondary coni- ])licatioii>.
Just as Werner's ^colo-^-ieal s|)eeulations were colored liy llie |)i-ciiliar nature of the rejfion where he hved, so the spi-cuhitions of zoologists upon tlie ori^^^in oC the medusa', and theii- relation to liydroidsjiavi- been coniplicated l>y the aeei(h-nt which lias directed tlu'ir attention to the wronj>; end ol" ihi' prolileni and has caused the almost total ne;;lect ot'tlie groups which furnish its solution.
The typical Ilydromedusa', tlu' i'uhularians or Anthomedu^a. and the ( ampanularians or Leptomedusie, are found in al>undance on every coast and the shortest visit at the seashore nnist brin<; them before the eyes of the naturalist ; while the |»elaj;ic Tracho- medusie and Xareomedusa', which are seldom foiuid near the shore, are usually rejiai'ded as minor or al)errant <>'roups and tliey usually occupy a very sul)ordinate and secondarv position in <»in- <;eneral conce|)tion or mental picture of the lIydromedus;e. althou;;:h thev inchule nearly one-third of all the known species of Aeraspeda antl are. so far as di\er- sity of structure is eoneerned, fully as important as the more familiar f:;rouj)s.
Most of the writers who have discussed the orig'in of the niedusje, and the sij^^nilleanee of the alternation between them and the hydroids, have entirely i^nort'd the Xareome- dusa^ and the Trachomedusa'; or else they have made only an incidental reference to these two <irou])s. which actually furnish the clearest, simplest and most direct evidence which is attainal)le.
As soon as we perceive that there is no i-eason why we should ])elieve that the me- dusae which are set free from fixed hydroid conuuimities are the most primitive, simply because they are the most familiar; and that Liriope, ^g'ina and Cunina are not, as Balfour (65) and Grobben (T-t) assert, medusa^ which have lost their ancestral hydra stage, but simply solitary tioatiug or swinuning- hydras which gradually g-row into medusa' and which repeat, more or less exactly during their oavu ontogenetic development and gradual metamori)hosis from the egg to the adult, the phylogenetic history- of the medusa: the comjjlicated jjroblem disentangles itself and Ave feel at once that we have found the right end of the thread.
In ^Eginopsis, as Metschuikoft" shows (30), the egg gives rise to a ciliated swinnning l)laiuda, which accjuires a mouth and tentacles and thus becomes directly and gradiudly converted into a floating hydra or actinula which is at first ciliated like the planula. The tentacular zone of the floating hych-a now groAvs out into a flange or umbrella Avhich carries the tentacles with it; sense organs and a veil are soon acquired and the hydra be- comes a medusa.
The whole process is perfectly simjde and direct; there is nothing like an alternation of generations and the single (^^^ becomes a single medusa Avith an actiiuda stage, a floating hydra-like larval stage and a swimming medusa stage. The life-history is as sim- ple and uninterru]jted as that of any other animal which undergoes a metamor])hosis, and it uiaA* be represented by the foUoAving simple diagram in Avhich the sign of equality (=) denotes that the change is direct growth or metamor|)h()sis rather than nndtiplica- tion.
.jQ(; \V. K. nnOOKS ox TIIK LIFE-IIISTORY
I. .T^c.isorsis — Egg = Planula ^ Adinula = Medusa X <^ Eggx.
As tlio floatinii- hvilra slayi- ol" 'i'nhularia is woll known under the familiar name Actl- titila tuu\ as it sooms ilesirahle (o use a sjieeial term for the free hydra stage of medusa' as distinguished from a sessile hydroid, I shall em])loy this Avoi-d for this purpose, desig- nating l>v it a free or Hoating hydra whieh mayor may not be ciliated.
I have shown that we have in Liriope and its allii's a life-history whieh is very similar to that of .Kginopsis. Avith numerous secondary modilieations, most of Avhieh are due to the faet that the gelatinous suhstanee of the lunhrelia ])egins to be secreted between the endoderni and the eetodenn at a very early stage in the life of the embryo. The accel- eration of the formation of llie umbrella is exactly jjaralleled by inmunerable similar jihenomena in the lives ol" marly all of the higher metazoa, and it therefore j^i'esents no dilHculties; and if we imagine the gelatinous substance absent, the mouthless, xintentac- nlatitl, ciliated Liriope larva, shown in PI. 41, tig. .'}, is obviously a planula with an outer laver of ectoderm and a ci'utral capsule of endoderm. It has a spacious digestive cav- ity; the two layers are sejjarated by a gelatinous substance; and in our species, the cilia are restricted to a small i)art of the outer surface: but, in spite of these secondary modi- fications, it is clearly a jjlanula. It soon acquires a mouth and four solid tentacles, and lu'comes converted into the floating hydra or actiiuila, shoAvn in PL 41, fig. 8, with ecto- derm, cndodei'm, stomach, mouth, lasso-cells, and four tentacles, but Avith neither sub- umbi-ella, sense organs nor Acil. This larva becomes convei'ted into an adult medusa by the groAvth of the tentacular zone into an umbrella, and by the acquisition of sense oi'gans, I ])recisely like the yEginopsis larva, and as each egg gives rise to only one adult the life- ^■ history is simple and direct, with a planula stage, a hydra stage and a final medusa stage, and it may thereftjre be represented by the same diagi-am as that which was used for ^Kginoj>sis.
II. IviKioPE — Egg = Planula = Actimda = Medusa X <C Eggs.
In f)ur common American Xarcomedusa, Ounina octonaria, the fact that the larva is a true hydra Avas long ago pointed out by ]\[cCrady. The planula stage of this species has never been observed, but the resemblance between the ciliated, l)itentaculated hydra shown in our PI. 43, fig. 1 and Metschnikoff's account of the ^ginopsis larva at the same stage is so close that we have every reason for believing that, in this species also, the hydra stage is preceded by a planula stage A\nthout a mouth or tentacles. The hydra sfxin acquires tAvo more tentacles and is then fundamentally like the four-tentacled hy- dra of LiriojK'. The number of tentacles soon increases to eight, and as is shoAvn in our figs. 3,8 and'4, the hydra becomes converted into a medusa by the outgroAvtli of the ten- tacular zone and the acquisition of sense organs. .So far, the life-history of our Cunina is j as siinjjle as that of ^•Eginopsis or Liriojje, but it is complicated by the occurrence of a sexual multiplication in the larva and also by parasitism. The actinula, or floating cili- ated hydra, af\er gaining access to the sub-umbrella of a Turritopsis, gives rise to buds from the aboral end (jf its body, behind the circlet of tentacles; each of these buds is a
OF TIIK IIYDKOMKDUS.F.. 407
li\ ilia liki- till' |i;uvnt anil, like it, Ik-cumi'^ diifctly convi-rti-d iiiti) a iiicilii^a. As tlu-si- Diidaiv hydras orijfinatc as Imds, tlu-y aiv at lirst st'ssilo, Imt tiny Ih-coiiic drtat-lu-d while in tlif hydra staj^^t-, or at k-ast ht'lori- they art- cnmitK'tfly coiiviTli'd into triif inc- (liis;e: till' tinu' ufdi-tachuu'Mt is nut c-on-itant and althi)n;ih tht- larva- art" at first sessile, and, thei-efore, not ai-tinula-, they serve to show that the hoiuidaiy line hrtwitii a lloat- in<; aetiiuda and a sessile hydra is an extrenu-ly I'aint one.
()win<; to the oeenrrenee of asexnal nndtiplieation. each ( 'unina e^;j may ;^ive rise to an indi'linite nnniber of adnlt niednsa-, hnl as eaeh larva lieeonies directly converted into a medusa hy a |)i(>cess of <jfrowth, there is no alternation and the life-history may be rep- resi'iited hy the following" iliaiiraMi:
Hyrlra = Medusa X < Eggs. X lit. CixiNA ocTONAuiA Eg'j = I'lantila ^ Actiuiila z= ifcditsa X <Ci Eggs.
X
Il'nha = Mediisd X <' Eggs.
Here we have asexual uiulti])licatii)n withoiU alteiMiatinn, hut in the Cuniiuu which 1 Ijanin and ^[etschnikott" studied there is a true alternation which is obviously of second- ary origin and luidoubtedly due to a very slight modification of such a life-history as the one shown in diagram III. The planula itself is very peculiar and is furnished with an anomalous pseudojxxlial ajiparatus for clinging to and fastening u])ou the gastric proc- ess of the Geryonid within which it becomes a parasite; and the aetiiuda, or primary hy- dra, into which it becomes converted, never completes its develo[)ment into a perfect, free medusa. It remains as a brood-.stock, from which other larva' arc budded, and these are set free and become converted into medusae so that the life-histoi-y is represented by the following diagram, in which for the first time, we find a true alternation:
( Ilifdrn =: ^fedu.1a X <C Eggs. IV. CcNiKA (Ccsocaxtiia) parasitica Egg= Pla7nda=z Actinula X ) Hydra = 3fedusa X <C Eggs.
^ Hi/dra = Medusa X < Eggs.
A comparison of Metschnikoff's account of the development of Cunina {Cunocanthd) parasitica, and that which I have given of Cunina octonaria, will bring out an interest- ing and significant difference between them which I have not yet pointed out. In the American Cunina, the hydra-stage is well marked in the larvae which are jjroduced by budding as well as in the one which hatches from the Qgg. In ^letschnikotrs sjiecies, however, the characteristics of the adult medusa begin to make their appearance in the secondary buds, almost as soon as the buds themselves ajipear, and it would be difficult to recognize a hydra-stage in the life of this species if we were not acquainted Avith the simpler life-history of the American Cunina. In MetschnikofTs species, the primary hy- dra is also greatly modified to fit it for its parasitic life, but in other respects its life- history is ver}' similar to that of the ordinary hydroids; and if the acquisition of the medusa characteristics by the secondary buds Avcre a little more accelerated so that tlieir hydra characteristics were entirely, instead of almost, crowded out, we should have a life-history like this:
,,jj> -VV. K. liROOKS ON THE LIFE-HISTORY
V. Eijg — I'hnnihi = Jitinnla X \ Mcdiim X <^Eijgs
C Medusa X <C ^OT^-
< Meihtt:a
C Mediisit X <C -E'fl'9'''*'
I knt>w <if nolivdra wliicli pix'sciits this lifV'-liistory witliout inodifioatiou, l)ut tlieiv are inaiiv C'ampamilariaiis and 'riilmlaiians in wliifh tlic only luodilicatioii is tlu' acquisition l»v till' artinula <»r primary iiydra of tin- power to produce, in addition to the Imds which lu't-oine nicdusH'. otiier l)uds whicli i-euiain in the hydra condition, and share witli their jiarcnt. thi- primary liydra. the power to produce both kinds of buds. Thus in Perigo- nomns (Stomatoca). tlie e'><i- <>ives rise to a i)hnHda wliich becomes the first hydra, and this produci's other liy(b-as Mke itself and l)uilds up a liydroid cormus; and ultinialely all these hvdras jyive rise to buds which become directly converted into medusa', the hy- dra-like stage being complelel}' suppressed, and Ave have a life-histoiy like this:
^ Medusa X <C Egqs. Ill/dm X ^ 3/i,,,„.,j, X <::Eggs.
77 ''^i w S Medusa X <Egqs.
w ( Medusa X <C Eggs.
VI. Eqq ■=^ Planulaz=Act!mda or Primary Hydra X -^ ,, , ^ JJ •
■■' J ^ ^ Medusa X < Eggs.
X f 3fedusa X <C ^UO'^-
Hydra X \ j^^^^usa X < Eggs.
j^r , ^y i Medusa X < Eggs.
Hydra X < ,, , „
•^ I Medusa X<C Eggs-
In Turritopsis we have essentially the same life-history, except that there is a second- ary alternation Ijetween the j^rimary hydra and the others. The planula does not be- come a hydra, but a mouthless, untentaculated root which is iindoul)tedly a degraded actiiuda or primary hydra. It does not give rise to medusa buds, but remains as a brood- stock or embryonic hydra fnmi which fully developed hydras are formed by budding, and all of these produce medusa-buds, so the Hfe-history is as follows:
r Hydra X \ ^^'"'"''" ^ < ^^^'- I ( Medusa X <C Eggs.
.... „ _ 7r 7 v^ < Medusa X <' Eqqs.
VII. rvRnnopsis Egg =Plantda = Boot X - -"2«"« X S ,r 7 ..^ J
^•' ^ 3fedusa X < Eggs.
I Hi/dra X 5 Medusa X < Eggs. [^ ( Medusa X < Eggs.
In the ordinary Cam])anularians, with free MedusjE, we have a new element of coni- plexitj', owing to the a])pearance of pol3nnorj)hism. The ordinary hydras no longer give ri.««e to niedusa-1)uds, and these are jjroduced only on the reproductive hydras or blasto- Ktyle.«. In Eutima, which I shall take as an example of this group, we have another com- plication, which is very significant. As in Turritopsis, there is a secondary alternation of generations, for as I have shown above. PI. IW, fig. <), the planula no longer becomes converted into a hydra but forms a root from whicli the primary hydra is budded like those which appear later.
OF TIIK lIVIiKOMKDl S,K. 4()9
As I liMVf >liu\vii. lliis sccuikImiv allciiiiirnm ncciiis in iiiaiiv l)V(li()i<ls. siirli a- llv- (Ir acliiii.u Iliitiinn, 'riirfitopsis, ( )lirlia ( Men jkuwskv ) ami ntlicis, ami it was cniicftlv tlis( riltitl hy Wiijrlit in Hydiactinia in 1S."»<»; hut. so liir as I am auair, m» i»m- lia.s |Miiii(i(l out tiiat it is a true all»TiiatiMii, i-xactly liki- tin- altiTiiatiun Itct wi-cii tin- liydi-a ami tile iiudiisa. It is ct'itaiiily a sccdiitlaiy a<<niisiti<>ii, as wt- may st-i- Iniin tln' lacl that ill Tiihulaiia, Eii(K'mlriiim and Dthcr liydroids, tin- plannia l)cc(imcs din-ctly con- Vfiti'd into a liydia. So far as this point is coiiccrm-d, the lili-histoiv of lOntima or IIv- drai'tinia, and that oC 'riilmlaria oi- l^ndnidrium presL-ut ihf iollowiii;; contrast.
Ifylni
X Tlul'lakia Kijij = I'liinula = Actintila r= Hydra
X Ilydni
with no altciMiatioii. wliiU' in tiic other I'ornis wi- havf
KuTiMA Eijy :=. Planuhi =. Hoot X
witli an alternation.
Tlu' c-onipk'te life-history of Eutinia with its double alternation between the root and the hydranth.s, between the hydranth.s and the medusae, and its polymorphism, and divi- .sion of the hydranths into nutritive persons and blastostyles, may be represented as fol- lows:
f Medusa <^ Eggs.
I Blastostyle X J Medusa <^Eggs.
( Xutrilive Hydra X ■{ I Medusa <^ Eggs.
I I
I {^Xutrilive Hydra
VIII. Eltima Egg =z Planula — Root X ■{
I ( Nutritive Hydra
I 1
I XutritiveUydra X ■[ ( Medusa <^Eggs.
I I
l^ Blastostyle X ; Medusa <^ Eggs.
u
Medusa <^ Eggs.
In Podoeoryne (Dysmorpbosa) we have an extremely eomplex life-history which, however, is readily derivable from one like that of Eutima as Just given. There is a sec- ondary alteinati(m between the root and the hydranths as in Eutima, and the jxjlymorph- ism between the hydranths is more specialized, as we find not only nutritive jjolyps and blastostyles but defensive polyjis as Avell; and as each medusa, in addition to its sexual function, also possesses the power to ])roduce other medusjc by budding, the number of sexual animals which may be derived from a single i^gg is unlimited.
The following diagram represents the life-history of this species, except that the first generation of meduste, like the second, gives rise to reproductive elements.
410
W. K. lUJOOKS ON THE LIFE-HISTORY
Nutritive IJi/dra X { Blastosiyle
Nutritive Hydra \ MedtiM < Eaqs
\ Defensive Hydra [^...^^.^ ^ [ \f;''- <^39S.
^ \ Medusa < Eggs.
INiitrilive Hydra X
Nut) Hive Hydra Blaslostyh " X
Defensive Hydra
71 r J vx S Medusa <' Eggs. Medusa X { . "
( J/edHsa <^ Eggs.
J Medusa <^ Eggs. \ Medusa <^ Eggs.
(^Medusa X
IX. ronociivsE Egg-=. I'lamda z^iJtoot X
,r , ., i Medusa <C Eggs. Medusa X < ,, , ^ J
I Medusa < Eggs.
Defensive Hydra \ 3^^,,,^^ ^ | ij^-J"- < ^^^*-
\ Medusa <^ Eggs.
( Nutritive Hydra ]
Xutrilive Hydra X •' lilastostyle X
NiUritive Hydr
a X I
Nutritive Hydra )
Blustoslyle X <(
Medusa X
Medusa <^ Eggs. Medusa <^ Eggs.
Defensive Hydra I ,. , ( Medusa < Eggs.
I Meausa x ^ ^/eci^sd <; £j,j,s.
Medusa <; -E^g's.
/ JSntntn \ Nutritive Hydra X < Blastost
^ I Defensi
C Medusa X ]
Medusa <^ Eggs.
Nntrilive Hydra f
Blastostyle X <
fensive Hydra ,' , , ^ ( 3/«Z«sa < £(/grs.
Nutritive Hydr
r Nutrdive Hydra | ( Medusa < i^g-j/s. a X < Blastostyle X S
( i?e/enst«e fi*/(?)-a , , , f Medusa <iEggs.
I Meausa x j ^/et^^sa < Zj/j^s.
It is voiy probable, that future research will show that even this comjjlex diagraiii is too simple for some of the Hjdroniedusa', and that there is, in some cases, a secondary alternation between the first jjenei-ation of free medusie and those which are produced by budding- from this generation. The life-history of these proliferous medusae has not been studied, as they are seldom found near laboratories and appliances for research, but there is reason to suspect that in some of them only those medusa; which are budded from the bodies of the medusa; of the first generation become sexually mature; and if future re- search should jirove this we should have still another alternation between the asexual proliferous medusa; and their sexual descendants.
In Ilydractinia, the cormi of which are so similar to those of Podocoryne that a draw- ing of one will correctly represent the other, the life-history begins to simplify itself by the degradation of the sexual medusa; into sessile buds, or reproductive organs, which, however still retain traces of their fonner independent locomotor existence; traces which have almost totally disap]>eared in Eudendrium and in many of the Campanularians.
The life-history of Ilydractinia may be represented as follows:
OK Till-: llYl»l{(JMi;iJUSvE.
411
( yiitiilice t .\uti-itiiv //i/iiiit { Mrilitfu-liml <^ Eijija. Jlydni X •! Mtnlo.ih/le X ]
( JJefvnnive Hydra \ MeduMi-Bud <[ Lijys.
Nutritive ( Nutritive Hydra ( Meduna-Dud <^ Eijys. X. UwKACTim A Eijij— I'lu)iula = liuot X -J Hydra X I Bluatostyle xl
\ DeJ'eusive Hydra { Afeduna-Iiud <^ Kggs.
Nutritive t Nutritive Hydra i Medusa-Bud <^ Eyr/a, Hydra X I BlnMoMyle X -
( Defensive Hydra { Medusa-Bud <^ Eijija.
Xow, what is the sigj^nificancc of this ivinarkahlc scrirs of life-histoiifsV Most of tiie facts Iiavi' lonii" ht'i'ii known. I)ut tiic most conllictinu; intorpivtations of thcin havt- hccii advanced, and tlic student who sccd<s in the \aiiiius niMno<:;raphs upon the sulijcct an ex- position of tlic I'chition lictwcen the direct (h-velopnu-nt of a single athdt I'roni eacli e;^<i^, which is characteristic of most animals, and the circuitous histor\ which is so i-emarkal)Iv' e.xhihited hy tlie medusie, will find a speculative literature which is almost unlimited, hut a total lack of aj;i-eement as to the true solution of this, the most interest iii<^ of all the proi)lenis involved in tlie life of these most interesting animals.
The view w hich I helieve to he the true one is that the remote ancestor of the hyflro- medusjv was a solitary swimming hydra, or actinula. with no medusa stage, hut prohahly with the power to nudtiply hy hudding. 1 l)elieve that this pelagic animal graduallv he- came more and more highly oi-ganized and more perfectly ailapted for a swinnning life, until it finally hecame converted into a medusa with a swinnning hell and sense organs, (k'veloping directly from the egg without alternation, hut cxhihiting during its growth the stages through wliicli it had passed during its evolution. After this stage of devel- opment had heen reacheil I helieve that the larva derived some advantage from attach- ment to other hodies, either as a parasite within other medusje, or as what may perhaps he called a semi-parasite, upon other floating hodies such as the fronds of algse; and that it multiplied asexually in this sessile condition, giving rise to other larvie like itself, all of wliieh became medusa\
I helieve that the sessile or attached mode of life of the larva' proved so advantageous to the species, that it was perpetuated by natural selection, and that the primary larva then gradually lost its tendency to become a medusa, but remained a sessile hydra, giv- ing birth by budding to other larvae w hich became sexiial medusa- ; and that the medusa- eharaeteristies of these secondary larvae were accelerated, and that the primary larva gradually acquired, at the same time, the power to produce other hu-vje which remained permanently, like itself, in the hydra-stage; that in this way the sessile hydra-connnuni- ties with medusa-buds and free sexual niedusa were evolved; and that finally these com- munities became pohnnorphic by division of labor, and that the sessile habit j)roved so advantageous that the free medusae became degraded into mi'dusa-buds, or sexual buds on the bodies of the sessile hydras or on the blastostyles.
The view which is most generally accepted is the revei'se of this. Thus Huxley (34) tells the student that the medusa issim])lya re])roductive organ which was originally ses- sile upon the body of the hytb'oid, and that it has gradually accpiired its free habit of life
412
\V. K. 1UU)0KS ON THE LIFE-HISTORY
nml its i»i»\vrr (tf loroiiiotion in ordi'f to si'cuiT tlu' ditfiisiou of tlu' irpriHluctivc cli'iiu'iits. Gt'"i'iilt;uir (-<)) and liallonr (<).")) toll him that tlic nicdnsa is not an organ bnt a piT- son. Iionioloi^ous with a whoU' hvdroid, not \vitli a i)art of it as lluxlcy teaches; that the separation of the eonnnnnity into sessile nutritive hydra-persons and loeoniotor re- ])n>dm'tive medusa-persons has lieen brought about by division of labor; that the hy- ilra eouuuunitv is oldi'f than the medusa; that originally all the members of the com- nmnilv were alike: that gradually eertain ones became set apart Ibi- reprochieticm; and that, linallv. these- latter Avere set free, and acquiring- reproductive organs l)ecame loco- motor meilusje and that this change was bi-ought about in order to secure the ditfusion of till' reproductive I'lements. These authors also believe that after medus;e had been •••raduallv evolvi'd in tiiis way i'nv this purpose, eircmnstanccs changed in some unex- plained wav. so that the wide diHiision of the reproductive elements was no longer so essential and that the medusie took tlii' l)aclv track and retrograded into sessile inedusa- buds.
Ilamann {IV2) who also believi's tliat tlie sessile connnunity is the 2)rimitive form, and that the medusjt have been produced l>y the grsidual specialization of certain members which were set apart as the i-epi-oductive members, holds that they gradually acquired the power of locom(.)tion in order to secure ci'oss-fertilization rather than the diffusion of the v'ft'^fi.
In ISTS Bohm (i)) showed that the opinion that the sessile connnunity is the primi- tive fonn, presents insupei'able diiliculties and he points out many reasons for believing that Ixtth the fixed hydra and the locomotor medusa have been evolved from a floating actinula, and Clans, tw'o years aiUr (IT), 1880, states very briefly his belief that the hydra-stage is a larva and the medusa simply the adult and that the alternation of generations is due to the fact that the larva has the power to multiply asexually and thus to j)roduce a number of larvae like itself. This view is identical with the one which I reached independently at al)out the same time, before I was acquainted w ith the conclu- sions of Bohm and Clans, from the evidence which I am noAv able to present in full Avith illustrations, and Avhich is not the same as the evidence which led Clans and Bohm to the same result, for neither of these authors makes any special reference to the life-history of the Xarcomedusje and Trachomedusai.
It seems to me that the facts Avhich are gixen in this paper establisli this view beyond contrrjversy and I shall shoAv in the review of the literature of the subject which is given failher on that it is the only hy[)Othesis to which there are not insuperable olyections. Even if this Avere not the case, I think that a comparison of the life-histories which are represented in the nine diagrams given aboA'e would convince every one that they stand in some derivative i-elationto each other, and it is surely simpler to beheve that the com- plicated life-history shoAvn in diagram VIII has been deriAX'd from a sinqjle one like that shf»Avn in diagram I, than it is to believe Avitli Balfour, Ilamann and (frobben that the Narcomedusa- and Trachomedusie have been produced as the reproductive members of l>o]ynior]»hic conni and that they have afterAvards lost all traces of this ancestry.
Most of the reasons which compel us to this conclusion will be brought out in the re- vieAv of the literature of the subject, but I Avish to call attention here to one argument Avhich in not noticed elscAvhere, although it seems to me to be entitled to great Aveight.
OF TiiK iiydromkdis.t:. ii:;
The iiiiioii 111" tin- si'xos is so iiii|i(iit:iiit to :iiiiiii:il» w liitli mic not locomotor that, aiiioii;^" tlic .Vi-tliro|>o(la, a ^i'oii|i which iiuliuh-s far more tiiaii liall' o|' all the aiiimaU kiioun to lis, the si'ssilc hai'iiaclcs arc almo>t the oiilv hcrma|thrtnlitcs.
If the nu'dusii' have heeii roriiud li\ the specialization of niemlier'- of a commnnitv, anil if the sessile hvdroid cormi are, a~ this hypothesis reipiire^, verv old an<l primitive, ue should eirtaiidv expect to lind them cxhiliitin;^; the |>o\ver to |trodiiee from a single coiiniis medusa' of hotli se.\i>, for livdra, which is one of the most primitive hydroids, is hermaphrodite. The polymorphism hypothesis j^ives no e\])lanation of the remarka- ble fact that, with the exception of Hydra, all the numerous descendants, often many thousand in munhcr. of any |)aiti(iilar planula, are of om- sex; Itnt we can readilv under- stand how llii- minhl In- the ca<e if the li\cd hyilroid cormi have liecn produced a^ I supposi', for if the sexes are distinct in adult medusa-, tlu- larva ol" any particular me- dusa nuist he I'ither a male or a female, and tln-re would 1)1- nothing- stranj^fc in the fact that its iicmmi|)an)us otf-priui;' >lioiild re-cmhic it in this ri's])ect.
Section VI.
A Tii:vii:w of thk LiTKiiATriir: ox tiik KiiLATiox HiiTWKiox Tin-; IIvdka and Till-: Medusa and ox the Oiiigin of Altei?xatiox of Gexeuations.
Tile fundamental >imilarity hetwceii a hydra and a medusa is so ohvious that it hardly seems neeessary to dwell upon it, hut the history of opinion upon the subject shows that this has been 1)V no means uniform, althoiijih ueai'ly all iiatuialists now aj^ree that a sin- gle hydra is directly c()niparal)le or honiolo<idus with a sinjile medusa, and that the va- rious hydromedusa? are also directly comparable with each othei-; that both the hydra and the medusa are in that stage of individuality to designate wliich Haeckers ti'rm "person" is now almost universally employed.
The general jilan of structure is vei'V nnich alike and the histoi-y of such foi-ms as the Geryouid;v and ^Eginida-, where the hydra-like larva becomes directly ti"uisformed into the adult, shows that a medusa is little more than a hydra with sense organs and a loco- motor apparatus. The hydroids are not furnished with sense organs, although there is every reason to believe that the sense organs of the Xarcomednsa' ai'e modified ten- tacles, homologous Avith the solid tentacles of hydroids ; and I know of only one writer who does not regard the cavity of the sub-und)rella of the medusa as the homologue of the space which lies on the oral side of the circlet of tentacles in such a hydroid as Eu- tima, PI. 08, fig. 10. The month of the hydroid is homologous with the mouth of the medusa, and where this is mounted nj)on a proboscis oi- manubrium, this structure is di- rectly comparable Avith the proboscis or pendent stomach of the medusa.
The ectoderm of the peristome of the hydroid, or the area included lietween the bases of the tentacles, is homologous Avith the ectoderm of tlu' sub-umbrella and i)roboscis of the medusa; Avhile the convex dorsal or aboral surface of the hydroid coi-responds to the convex ex-uml)rella of the medusa.
The oral tentacles of such a hydroid as Tubularia or Pennaria are to be compared with those of Maro-elis and T reu-ard them as strictlv homologous structures, while the zone
^1^ W. K. BROOKS ON THE LIFE-IirSTORY
which mrrios the circU-t ol" tcntiU-lrs ol" {he (';iinp:inul;ifi:m liyilroids, or Iho ;il)<)ral ten- tJU'K's of IVnnari:!. is li()iU()li)!::ous \vitli llu' l)i'll inarjiiii of tlio inodusa Avitli its tentacles. Tlif Vfhiin is not repiTsi'ntod hy any distinct liydroidcan structure.
Tlic diircstivc cavity of thi' medusa witli its tubes or pouches is (piite ditfereut from that of a liydroid, aUhou-ili the history of tlie oriji,in of tliese parts in niedusa-huds, oi' in the e^jr-en>l>ryo of Liriope or in Cunina, shows tliat the union of the ex-umliral and 8uh-unil>ral layers of endoth'rm has converted the |)eri|)heral portion of the simple diges- tive cavity of the hydroid into radial canals or |)ouclies arranged around the central stomach of the medusa. Avliich therefore does not coiivsi^md to the whole stomach of the hvdroid. hut <mly to its axial or central portion, while its peripheral portion is homolo- gous with the canal system of the medusa. For a more extended statement of the sul)- ject see Koch (38) and Ilaeckel (78).
There can he no doubt that this, the genei-ally accepted A'icw, is correct, and the fact that tlie hydra-larva of the Trachomedusae and Narcomedusae becomes directly con- verti'd into a medusa, furnishes very direct and conclusive proof. I doubt, howevei-, wlu'llu-r it could be so satisfactorily estaldislied if we were not acquainted with these forms; for many of the phenomena in the life of the Antho- and Leptomcdus;T3 which are lu'ged in proof of it are in themselves inconclusive. The retrograde metamorj)hosis, whicii accoi-ding to Tan Beneden (8), Hinks (33), Allman (6) and Merejkowsky (50) «irten results in the convei'sion of a niediisa into a hydra-like organism, through the dis- ap])earance of the umbrella and the return to a sessile habit, seems to show that the two fonns are mutually convertil)le; but Merejkowsk}^ confirms Van Beneden's statement that in these cases of degeneration the resemblance to a hydra is entireh^ superficial.
Tin- fact that the chymifei'ous tubes of a medusa-bud are formed by the development of areas of adhesion in the lateral portions of a digestive cavity Avhicli is at first contin- uous like the stomach of a hydra, is often adduced as evidence of fundamental similar- ity, but there is no reason for believing that the ontogenetic history of develojiing buds repeats the phylogenetic i-ecord. '^riie history of Cunina and Liriope shows that the ]»eri>tome f)f the hydra is the siib-umbrella of the medusa, and if biid-ontogeny were a re<-apitu]atif)n of phylogeny, we shoidd expect the sub-umbrella of a budding medusa to arise as it does in Cunina; l)ut we find, on the contrary, that in the medusa-buds of all the Canipanularians and Tubulai-ians, as well as in the Siphonophores, it originates as a bud nucleus, Knosjmngsl-ern, which gives rise by splitting, before the mouth is formed, to the sub-umbrella, which has at first noo])ening to the exterior. It is therefore unsafe to trust any of the evidence fui-nished by bud-embryos; but the evidence from egg-embryol- ogjis not open to this dfmbt, for in all cases where there is no reason to suspect second- ary modification, we may safel}' regard this as a recapitulation of phylogeny; and the life-liiston' of those few medusse which develop directly from the egg is therefore of the greatest importance as a basis for comparison of the medusa with the hydra.
In all these egg-embiyos, the ^' l)ud-nucleus " is absent, the mouth appears befoi-e the bell cavity makes its ap]K'ai-ance and this is never closed but is foi-med by the folding of tlic brxly; while the chymiferous tubes are formed by the modification of a sim})le di- gestive cavity as we should expect if the hydra and the medusa are representatives of the saiiif' fiiiii1.'iiiiciit:i1 tNTie.
i)V Tin: lIVDUOMKDUSvK. 41.';
So I'ai' .i-^ I ,'iin iiw.irc, mily oiii- iiioili'ni wiitci- has adv urati-d aiiv other hoinolMH^y hf- t\\ tell till' two lorms tli.iii tlic oiu- whicli 1 havi- staled. Kay Ii!iuk»'ster has proposed (l'») to liomolo^ize the siili-iiinl)rella of a hydroniediisa with tlie stoiuaduMiiii of Aiitlio/.oa, Ctenophi)ra ami other Metazoa, hasin;^ this view upon the unproved and very iinpi'oli- al)le hypotliesi-; tliat the youn<^ speeinuns of Linnioeodiuni whi<di he has deserihed are ejffi^-enihi-yos. He does not state his view very clearly, hut lie must either believe that those Metazoa which are I'nrnished with a stonia<la'nni arc the niodilicd descendants of a form like an adult medusa, or else he nuist hclieve that the youii;.^ Ijimnocodiuni repre- sents the ancestral conditi(M) of" the medusa-, and that tin- prcsi-ncc ol' a hell (-avity is a very old characteristic. If he intt-nds to advocate tin- lattei-view, it is plain ilmi In- cin- iiot rcjj^ard the medusa as an ordinary hydroid specializfd for locomotion.
Many authors who have fully reco>^nizi'd the close similarity helwecn the iiviiia and the mi'dusa, and some who have been ainon^ the most important conti'ibutors to our knowled;j,e of the sid)ject, have nevertheless held that a medusa is not t'(iuivalent to a siniifle hydra, but to a ])olymorphic hydroid community; that a medusa is not a person but a connns.
This view has long been a favorite one, and it a])pear8 in many forms in the literature of the subject. The following extracts from my notes Avill servo to show how frecpiently it has been advanced, although I do not believe that the writers cpiotod are al! who might be referred to. In IS-jt W. Thompson compared the reproductive ))ro-e63 of hy- droids to that of plants and ])ointed out the resemblance between a medusa and a flower (59), and in ISGO Jager (35) enlarged upon this familiar cqmparison and attempted to show that the medusa bears the same relation to the hydroid colony that the flower docs to the plant, not only in position and in its reproductive function, but in its ultimate morphological structure also. lie says it is made up, like the flower, of several circlets of individuals; that the tentacles, sense-organs, reproductive oi-gans, etc., are all mor- phological individuals; that the swim-bells of Siphonophores are sterile flowers; that the medusa-buds of Il^'dractinia are flowers without calyces and that alternation of genera- tions should more properly be called "antlior/enesis.''''
In 185(j Wright advanced the opinion (6o) that a veiled medusa is to be compared with a polymorphic liydroid community like ITydractiuia, which he regards as a single person, not a cormus; that the umbrella is homologous with the flat, spreading root of Ilydrac- tinia,its ch3Mniferons tubes with the canals of the root; that the stomach of the medusa is a nutritive hydranth, its tentacles spiral zooids, its reproductive organs medusa-buds, etc.
At a time when homolog}'' was not regarded as having any phylogcnetic significance, there was little check upon such fancies as those of Jager and AV right, but they arc clearlv of little more scientilic value than M(3rch's suggestion (53) that the Acalephs should be placed with the Mollusca on account of the imaginary resemblance between Lima and a medusa.
In 1856, Leuckart (47) in his account of the structure of a Trachomedusa. Agalma Peronii, figures and describes the reproductive organs. They form a circlet of eight hollow-stalked pouches, within the walls of whicli the eggs are developed; while their central cliambers are outgrowths from the digestive cavity. The pouches are arranged in a circle around the base of the pendent stomach, and he calls attention to the marked
IK; W. K. nUOOKS ON THE LIFE-IIISTOUY
rci!iMHl)ljUKO Itc'twi'i'ii tlu 111 Jiiul till' iiuHliisa-buds, whic-li ;ire proiliiced by man}' siiecies in oxni-tlv tlic saiiio situation. lie tlu'irrore advances the hy[)othesis that the sexual poiK-hos of A;.iahna are not org'ans but buds, which instead of becoming free sexual me- dusa'remain in a rudimontarv or arrested condition; and, like the degraded medusa- buds of Ilvdractinia, give rise to ova or spermatozoa. lie says "our sexual organs are tliorefore to be ri'garded as sexual animals, which, remaining sessile, form with the mother a i)olymor|)hic colony. The relation between these ap])endages and the medusa which carries them is in this species at bottom an alternation of generations." He is careful to state that he does not oiler this as an interpretation of the reproductive organs of other species, and he says that while he is not prepared to decide whether the repro- ductive organs of Agalma are homologous with those of other medusa', he inclines to the view that they are not.
Three vears later Allmaii {'•]) advanced almost the same hypothesis, but in the form which he gives to it, the reproductive organs of Agahna and those of all the Antho- mcdusa' are simply t)rgans, while the reproductive bodies of the Le])tomedus;v are not or- gans but persons.
The fact that Leuckart fust advanced the hypothesis as an explanation of the repro- duc'ive organs of Agahna while Allman excludes Agahna and brings forward the hypothe- .•iis as an explanation of the nature of the reproductive organs of quite different forms, is in itself enough to raise a suspicion that the whole conception is unscientific and fanciful.
As Bohm has shown in his valuable paper on the LeptomedusjB of Helgoland (9) that there is no such resemblance between the various stages in the development of a me- dusa-bud and the stages in the develoi^ment of the reproductive organs of a Leptomedusa as AUman's hypothesis rerpiircs, it seems unnecessary to give any other reasons for rejecting it. Although Allman has devoted a paper to the attempt to show that the GeryonidiT? are blastochemes (G), the life-history of Liriope, as I have detailed it, is absolutely irreconcilable with the belief that it is a cormus, and the hypothesis is com- jilctely overthrown by the recent discovery (76) that in many cases, the ova of the Lep- tomedusa; arise in the proboscis and migrate along the radiating canals to the ovaries.
One of the oldest opinions upon the relation between the hydra and the medusa is the one which Huxley adopts (3-4), that the medusa is a free locomotor rei)roductive organ. This is almost the p])posite of Allman's view, that the reproductive organs of a medusa are them.selves persons, and that the medusa is in reality a communit}'. Huxley says (34, p. 149), "A medusoid, though it feeds and maintains itself, is in a morphological sense simply the detached generative organ of the hydrosoma on which it is developed," and on p. 34, "Morphologically the swarm of medusa^ thus set free from a hydrozoon are as much organs of the latter as the multitudinous pinnules of a Comatula, with their genital glands, are organs of the echinoderm."
The authors who have accepted this view have appealed to the fact that we have a complete senes of species which present all the intermediate stages betw^cen the simple reproductive prominences of Hydra and the free sexual medusa of Tui-ritopsis or Eutima. In Hydra the reproductive oigan is simply a protrusion from the surface of the body; in Eudendrium it is more prominent and it contains a stomach-like outgrowth from the
OF Till: iivi»i:().MKi)is.i:.
ir
dij^cstive cavity I )(' tlir liydiuid ; in II ydractiiiia tliis oiit^rowlli i-< a t iiic prohoscis or mainii)iiiiin, wliicli |in)jtc*ts into a snl)-ninl)ral, i-cloili-i inal cliaiiihci- opcniii;^ to tlic I'X- torior, and u^ivcs rise to a pcriplu'ral {•lianilx-r wliicdi coriTsponds to the canal system of nicihis,!'. In some species of Tnhuiaiia tiie peripliei'al cliamhcr Is not continuous, l>nt is divided into toiu" radiatin;^ canals and a circular canal, and in other species the openin<jf of the umbrvUa is furnished witii tentacles, so that we have all the chai'acleri.stic Ktruct- ures of a locomotor medusa, althouji^h tlie medusa-huds of Tuhtdaria are never set free, and serve simply to mitin-e the ci^iifs and embryos. In a closely related form, lOcto- ])li'ura, the ova or spermatozoa are matui-ed In-fore the medusa is set free, as is the case in Tubulai-ia, hut the medusie of Kctopleura are nevertheless set free, and live for some tinii' as swimming medusa', while in still other forms the reprodiielive elements are very innnature at the time the medusa is set free, and are gradually developed and rijiened during its swimming liA.^
The series of forms is so CQm|)lete that we cannot doubt that there is a genetic rela- tion between them, and that they are actually steps in a process of modification; and it at first seems natural to conclude that the simplest forms show us the first steps in this ])rocess, and the more complex forms the later stages, and that they therefore prcjve that the free locomotor medusa has been gradually evolved IVoni tiie simple sexual organ; but we must rememl)er that the ])rocess of modification may possiI)Iy have gone in the other direction, and that the simple reproductive buds of Hycb'actinia and Eudendrium may possibly be degraded medusic which have gradually Ijecome sessile and have lost, by successive slight modilications, their locomotor apjjaratus.
So far as I am aware, Koch (38) was the first to point out, in 187;}, that this is not only possible, but that there arc facts which compel us to believe that it is actually true, such as the homology between a medusa and a hydroid and the fact that the medus:c of Avidely sejjarated hydroids are fundamentally alike, while closely related species of hy- droids may give rise to sexual buds which are very different from each other. For ex- ample, the hydroid communities of Hydractinia and Podocoryne (Dysmori)hora) are so much alike that they can be distinguished only by the most careful examination, but Hy- dractinia produces sessile medusa-buds without radiating canals or tentacles, while Podocoryne sets free perfect locomotor medusjc. A very similar case is presented by Tubularia with its sessile medusa-buds and Eetopleura with its free medusae; and the medusa-buds of Tubularia are essentially like those of Hydractinia, while the free mc- dusjB of Ectoideura and Dysraorphora (Podocoryne) are again very much alike. If we put these facts into tabular form, wc shall have something like this:
Hydractinia Podocoryne
Sessile buds Medusje
Tubularia Eetopleura
1 and 2 are much more closely related to each other than to either 3 or 4, while 3 audi stand in a similar relation to each other; and, if we believe that medusjc have been jjro- duced by the gradual specialization of reproductive buds, we must believe that 2 has
418
W. K. HRO0KS ON THE LIFE-HISTORY
been piwliKHnl hv the niodification of 1. and 4 In the modification of 3, and tliat the lo- ooniotor linbits of 2 and 4 have been independently acquired.
In each case we have a pulsating, gelatinous bell, with sub-iimbral muscles and a veil; a pendent stomach with ova or spermatozoa developed in its walls; four radial canals, a circular canal and hollow marginal tentacles; and the two medusae are almost as much . alike as the hvdi-oids 1 and 2, or the hydroids 3 and 4:. The chances are very greatly | aijainst the inde])endent modification of the two forms along lines which are so perfectly ]iarallel. and when we Ijear in mind that the hypothesis compels us to believe that this has taken place not in two but in many cases, the difficulty becomes a very great one; but. if we adopt the opposite hypothesis, and regai-d the medusa-bud as a degraded, ses- sile medusa, there is no such difficulty, for similar medusae would give rise, by degrada- tion and the loss of their locomotor apparatus, to similar medusa-buds. Then, too, if the medusa-buds are stages in the process which has led to the formation of free medusae, we cannot account for the presence in buds which never became free, of structures which like the bell-cavity and velum are of functional importance only in the swimming niedusfP, although we should expect these organs or their rudiments to be retained by medusa^ which had lost their swimming habits and become sessile.
These and other facts have led most naturalists to believe with Koch that the me- dusa? are not specialized i-eproductive organs, but modified hydras, and that the sessile medusa-buds are degraded medusa3 rather than stages in the evolution of medusae. The lifc-histor}' of Liriope seems to be totally irreconcilable with Huxley's view, for this Avould require us to believe that the egg here gives rise to nothing but a reproductive organ and that this process is continued generation after generation.
I think, therefore, that the facts justify the statement that our present knowledge of the subject disproves the view which Huxley advocates and that this view is now unten- able. As a matter of fact, nearly all naturalists reject it in favor of the " polymoi'phism " hypothesis, which the student Avill find presented in the text-books of Gegenbaur and Balfour, but examination of the special literature will show that the various advocates of this hypothesis are b}' no means agreed as to the precise manner in which the two polymoi-phic forms, the hydra and the medusa, have been produced.
Balfour, for exam])le (65), adopting essentially the views which had been brought forward many years before by Leuckart, says, "The chief interest of the occun-ence of alternation of generations among the Hydi'omedusae and Siphonophora is the fiict that its origin can be traced to a division of labor in the colonial system of zooids so charac- teristic of these types. In the llydromedusae an interesting series of relations between alternation of generations and the division of the zooids into gonophores and trophosomes can be made out. In Hydra the generative and nutritive functions are united in the same individual. * * * A condition like that of Hydra in which the ovum directly gives rise to a form like its parentis no doubt the primitive one. * * * The relation of Hydra to the Tubularidaj and Campanularidse may be best conceived by supposing that in Hy- dra most ordinary buds did not become detached so that a compound hydra became formed, but that at certain periods particular buds retained theii- primitive capacity of becoming detached and subsequently developed reproductive organs, while the ordinary buds lost their generative function. It would obviously be advantageous to the species
OF TIIK IlYDKOMKDUSiE. 1I<»
llijit the (Ictaclifd l)ii(ls \\\\\\ i;ciici';ilivc' oi\ii;ms sliuiild I»i' locomutivt'. so as (o dislriljule llie spocics as widfly as possible, and such l)iids in coniU'C'lion wilh tlicir free existence; would naturally acquire a higher orii^anization than their attaidied tro|)hosr)ine.s. It is easy to see liow, by a series of steps su«'ii as I have sketched out, a division of labor might take place, and it is obvious that the embryos ])roduced ijy the highly oiganized gonophores would give rise t(j a fixed lorin IVom which the Hxed colony would be budded. Thus an alternation of generations would be established as a necessary serpiel to such tlivision of labor." lie goes on to state his belief that the sessile medusa-buds are de- graded niedus;e,and that the medusa", which like Liriope develop diicctly from the o>i;'^, are forms in which the hydra stage has disappeared from the developmental cvcle; and sunnning up liis views he says tluit thi'ee types of development are presented bv the Ily- dromedus;v'.
1. No alternation of generations: permanent forma sexual hydra or iiydra community. Example: Iiydra.
2. Alternation of genei'ations: hydroid stage fixed, medusa stage free. Example: most hydroids.
3. No alternation of generations: permanent form a sexual medusa. Exavij^le: Trachomedusa'.
But, in his explanation, which we have quoted, he recognizes the following six succes- sive stages in the evolution of the Ilydromedusa;.
1. Solitary hydra, no polj-morphism, all buds detached, all persons sexual.
2. Community of sexual persons, giving rise also to detached buds which also become sexual persons.
3. Polymorphism, community of asexual nutritive pL'rsons, detaching buds which be- come sexual persons.
4. Same, detached sexual persons specialized as locomotor medusiv.
5. Polymorphic community consisting of nuti'itivc asexual persons and sexual ses- sile medusje-buds, or
6. Derived from 4, medussB without a hydra stage.
Grobben (74) advocates a view which is very similar to that given by Balfour, and he believes that the alternation has been produced by the following series of steps:
1. Solitar}' hydroids, like Ilydi'a.
2. Communities without polymorphism, each individual sexual, like Ilydrella.
3. Communities, with polymorphism, with sexual and asexual persons, all sessile.
4. Same, with free reproductive persons.
5. Same, with free reproductive persons specialized as locoinotoi' medusa?. G. Same, with medusiii degraded to sessile reproductive buds.
7. Derived from 5, meduste without a hydra stage.
While Balfour believes that certain members of the conmiunity first became free and afterwards became specialized for reproduction, Grobben believes that they became specialized for reproduction while sessile, and that the tendency to become free was afterwards acquii'cd, but in other respects these two authors are in substantial agree- ment.
fJO
■\V. K. BKOOKS ON THE LIFK-IIISTORl'
Ilanianu {-VI). liowcvcr, adopts n soinowhal dilVcMTut view and says that il was possi- ble to lu'Iu've that tlio altornation, or the orii>in of the medusa on the hydroid, came about throusxh division of hibor. so long as it was supposed that the reproductive elements oriirinato in the medusa^; but tlie discovery that the eggs, in many cases, originate in the iMvnosare of the hvdroid and migrate into the medusa-buds, shows, he says, that this is not tiio true view, and he advances another which was suggested to him in conversa- tion with AVeismann. Starting with a communit}' in which the reproductive elements mav oriirinate in everv part, he supposes that certain persons wei'e set free from the stock as in Hvdra or in Tiarolla, and that the persons thus set free were at first driven about l\v wind and tide, obtaining their food by the use of their tentacles; that they were simplv lloating hydras. Those which became adapted to this new life would, retaining their power to ])roducc eggs, give rise to fixed communities, in which locomotor persons would be set free earlier and earlier, until fmally the reproductive function would lie- come restricted to the free stage which would gradualh^ acquire a locomotor ap[)ai-atus and thus become a medusa.
These various opinions which are selected from a great number Avhich might be quoted show that the "polymorphism" hypothesis, wdiich is the one most generally accepted, is itself polymorphic and that authorities are far from an agreement as to the precise form which it should take and this lack of agreement is in itself sufficient to excite a suspi- cion that it may be merely an hypothesis unsupported by proof.
All these authors agree, however, in the opinion that the reason for the evolution of the locomotor medusa is the advantage which comes from the distribution of the sexual elements and embryos, and the analogy of the polymorphic hydroids seems at first sight'. to be a reason for believing that the medusa has originated according to the law of divi- sion of labor. The h3'droid blastostyle is undouljtedly a hydranth which has in this way lost its nutritive function, and has become exclusively a reproductive zooid, while the or- dinary hydranths have lost their reproductive function and have become simply nutritive persons, and there is every reason for believing that the polymorphism of such a hydroid as Ilydractinia has been bi'ought about b}' division of labor; but is there any real anal- ogy between a blastostyle and a medusa? The medusa is very fjxr fi-om being, like the Ijlastostyle, a reproductive zooid. The blastostyle has no mouth, but the medusa is a highly voracious animal, furnished with organs for perceiving and capturing its prey, and with highly developed digestive organs. There is nothing in the sti'ucturc of a medusa to indicate that it is a reproductive zooid. It is true that in a few Tubularians such as the Eucopella, recently described by Lendenfeld, or in Corymorjjha, it is simpli- fied in structure and is little more than a locomotor reproductive pouch; but these cases are plainly the result of recent modification, and the t3q)ical medusa has all the character- istics of a perfect adult animal with all the powers necessary for a complete life, and in many species it produces other medusa? by budding. There is certainly nothing in its own structure to indicate that it has like a blastostyle originated by division of labor. It does not show any tendency to lose its nutritive function, and its locomotor and sensory functions are not lost, as Ave should expect them to be in a zooid specialized for reproduction, but they are, on the contrary, much moi'c liighly developed than they are
Ol' TlIK IIYDKOMKUUS.E. 421
in tlu' nuliitivr liydiM. It is tiiii- tliiit tiii- li\(li-;intlis liiivc, :is tin- tlicm-y rc(|iiii-fs, ihj w- l)i-(t(liictivt.' liiiKlioii. l)iit this is no ni«>ri' than we shunid c'X|H'ct, if tin- liydia i< a nnihisa hirva.
Halfouf says that " it Avonhl oltvinnsly he ailvaiita,i;'fons lor the s|ic'ci('s that the de- tailicd hiids witli ^i nt'iativt- of^ans sliould he locomotive, so as to distfiliutc tin- spet-ii-s as widely as ])ossil»Io, and such huds in connection with their Iree existence would natu- rally aciinire a hiiiher or<iani/ation than the attached trophosonies." It 8eenis at first sight as il" tills must be true, hut more careful examination will give us many reasons for questioning whether the high organization of the medusa has been acquired for the |)ur- pose of distributing the species, rather than for the benefit of the individual. We know that, in many species, of all the gi'cat groups of hydroids, the medusa- have become de- graded into sessile gonophoi-es which have lost their locomotor power, and in manv cases all tlieii- complicated oiganization as well. This degradation must be for the ad- vantage of the species, and in view of its prevalence I think we must hesitate to beHeve that the production of free reproductive zooids wouhl be for the good of the species, and that after such free zooids were produced, they might be expected to acquire a comjili- cated organization and highly specialized locomotor and sensoiy organs. AVc know that changes in the opposite direction have been to the advantage of the species, since they have been preserved, and if sessile gonophores are so useful that free medusa; have been degraded into sessile gonophores, there is no a priori reason for believing that it would be to the advantage of the species for reproductive zooids to become locomotor. The distiibution of the species is well provided for in the swimming planula and the hab- its of the medusa often carry it very far from any proper habitat for the hydra, and as a matter of fact, genera and species without free medusa? are as widely distributed as those in which the medusa is a perfect swimming organism. Eudendrium and Cordy- lophora have no means of dispersal except the cilia of the planula, yet Cordylophora is found on both sides of the Atlantic and from Boston to Baltimore, and Eudendrium is found all over the world. Turritopsis is an extremely active medusa, living in the open sea, and it is often swept by- the gulf stream as far north as Cape Cod, yet its hych-a has been found nowhere except ujjon the North Carolina coast.
I think that we may safely conclude that while the view that the complex structure of the medusa has been acquired as a means for distributing the species seems at first sight to be very ])lansil)lc, more careful examination renders it probable that this is not the case, but that the purpose of the organization of the medusa is to enable it to live out its own life; that it has been acipiired and preserved on account of its direct benefit, rather than from any indirect advantage to the species as a whole.
In 1871 Koch advanced an hypothesis which escapes this difficulty, since he believes that the medusa stage has been acquired to prevent self-fertilization rather than to secure the distriltution of the si)ccies, and his hypothesis is therefore more satisfactory than those which have been noticed.
He says (38) that the ancestral form was a hydra, with solid, scattered tentacles, re- producing both sexually^ and asexually, and that in some species the new buds were set free as in Hydra, while in others they remained attached and formed communities.
i-2-2
W. K. BROOKS OX THE LIFE-HISTORY
Those which wore sot froo i'IUut lastoned tlicmsplves like Hydra, or they remained float- iu"' in tlu' water, and gradually became adapted to a iree life, and thus furnished the in- itial point t\)r the formation of the medusa, which as Koch clearly shows, as Clapcrcde had also shown years before (13), is not essentially different from such a h3'droid asTu- bulai-ia. In a species with both sessile and swimming persons, the latter, if both were sexuallv matnre. would be much less likely to interbreed closely than the former, and the [j sessile forms would therefore gradually lose the power of sexual repi'oduction, while the swinuning forms would become the i'ei)roductive persons of the species. This speciali- zation of the reprodnctive function would tend to secure cross-fertilization and it would therefore become established on account of this advantage.
He then supposes that some of these hydroids with free medusae became established in places where the locomotor medusa? were exposed to the danger of being swept out to sea, awav i'rom proper localities for the attachment and growth of the sessile hydras, before these were born. Natural selection Avould, under such circumstances, lead to the preservation and perpetuation of those medusa' which reproduced their young very early in their own life, and we should thus gradually obtain medusae which became sexually mature before they Avere detached; and as these medusjc would derive uo advantage from a locomotor life they would gradually become converted into sessile medusa-buds. '
According to Leuckart, Gegenbaur, Hamann, Balfour and others, the locomotor or- gans have been acquired for the purpose of distributing the species, and the free persons tirst became the sexual members of the species, and then became locomotor, while Koch believes that the locomotor life has not been acquired for the purpose of distribi;ting the species; and that the free pei'sons became locomotor medusae before they became special izcd for reproduction, and that the reason for this specialization was not the need for dis tributing the species, but the advantage of crossing. So far as simple plausibility goes, i this hypothesis is certainly a little more satisfactory than any of the others, but the test of the truth of an hypothesis is an appeal to fact, rather than its neatness. •
"While the various writei's who have advocated the hypothesis of polymorphism differ so greatly in their accounts of the process by which the medusa has been evolved, by the * specialization of persons detached from a hydroid community, the " proofs " which they-| advance in support of the belief that it has originated by such specialization are essen- tially the same. As the fn-st step in the argument, they point out the homology between the h^'dra and the medusa, and justly claim that this proves that both are modifications of some common type, and they then proceed to make either on words or by implication the further assumption that this type must have been either a member of a hydroid com- munity or a medusa. Thus Koch says, " in the attempt to study the relation between the hydra and the medusa in the light of the theory of descent, we have to decide between two hypotheses; ^first, that the medusa is primitive and that the hydroids are only larvje which have been independently modified, or second, that the hydroids are primitive and that the medusa; have been derived from them. The fact that the hydra bears a close resemblance to many other organisms, such as sponges and corals, while the medusa shows no such resemblance to other groups, leads us to reject the first hypothesis and to adopt the second alternative." If we were compelled to accept one or the other of these alternatives, there is no doubt that this reasoniu"- would be of Sfi'cat wei<>ht. but it is
:!
OF TIM-: IIYI)I10MKI)US;E. .123
quite possible that neither liypotliesis may he eonn-et, ami thai the in-imitive foim may have been neither a sessile liytlra nor a highly specialized medusa, but something mid- way between; for example, a ciliated locomotor organism with simple hydra-like struet- iu"e. But overlooking this third alternative, and deciding that the homology between the hydra and the medusa can only be explained on the hypotliesis tliat one has been derived from the other, they go on to show, cpiite correctly, that the view that the me- dusa; have been produced by the gradual specialization of medusa-buds, or medusiform gonophores, leads us to a series of untenable positions, and that we are compelled to be- lieve that the medusa-buds are degraded medusa?. They therefore conclude that the medusa' nuist have originated as modified hydroid persons, which have become adapted to a swimming life, and have assumed the function of sexual reproduction, which has at the same time been lost by the sessile unmodifu'd hydras.
In the absence of all direct evidence, this reasoning couM be terme(l " proof" only by showing that we are compelled to accept one of the two hypotheses, and a very great step was made towards the solution of the question when Bohm showed in 1878 (0, p. 153) that the primitive foi-m may have been intermediate between medusaa and hy- droids, and that both these forms may have been developed from this connnon foi-m in two divergent directions.
Bohm points out tluit the long path from the slightly specialized sessile hydra to the highly complex swimming medusa is greatly shortened by the assumption that they are both derived from an intermediate form; and on p. 174 he says that an additional reason for the belief in such a form is to be found in the fjict that in certain families, as in the Eucopidiv, the very simply organized medusjc are so much alike that it is diflicult to find any distinctive specific characters, although the hydroids are often very different fi'om each other, thus proving that they have diverged more than the medusaj.
As he justly remai-ks, it is much more difficult to understand the origin of locomotor medusjc by the modification of sessile polyps or the reverse, than it is to understand the origin of both from an intermediate form which has served as a basis for tAvo lines of modification ; and he therefore believes that both the hydra and the medusa are de- scended from a free, solitary' hydra-like organism with solid tentacles and with lasso- cells, which were peculiarly abundant at the tips of the tentacles. The life-history of Liriope, as I have described it, furnishes us with a stage of development which is ex- actly like Bohm's hypothetical form in every particular, except that its endoderm and ectoderm are separated from each other by a thick gelatinous layer. The ciliated, ten- taculated larvfe of ^ginopsis and Jllgineta which Metschnikoff has figured (ol), and the Cunina larvie shown in Plate 43 of this paper, are also free h^'dra-hke larva? which become directly converted into meditsa? without the intervention of a sessile "nurse" stage, and without metagenesis. Bohm himself does not refer to the Trachomedusa? or the Xarcomedusa> in this connection, although he calls attention on p. 1G2 to the fact that the actinula of Tubularia is an exam[)le of the persistent retention of this locomotor ancestral stage.
He says very little about the actinula larva, however, and he selects Eleuthei-ia as the best modern representative of the hypothetical ancestral form, and treats of its structure at considerable lengtli. This selection seems an unfortunate one to me, for Eleutheria
9
^■2i "\V. K. 15R00KS OX THE LIFF.-IILSTORY
itsi-If has an altornatioii of "eiioratioiis, and tlie Elontlioria stage docs not occuf at the bi'-nnninfj of the Hfo-historv, bnt at the end. The Cladonemadjv are simply ordinary Antli »:n-\lu<;i>, with a tiibnhirian hydra-stage and medusie produced by budding; and it niav be due to the unfortunate selection of Eleutheria as an illustration, that Bohm's view, the correetness of which seems to me to be proved by the occurrence of a locomo- tor solitary hirval hydra stage in the Trachomedusie. has attracted so little attention.
His contribution to the sul)ject is a decided advance beyond the views which we have noted, for he shows clearly that we are not compelled to choose between the two alterna- tives which seemed to the other writers to be the only ones, but that the third, viz.. that the jirimitive form was not a sessile community but a locomotor person, has much to commend it; and that we are not compelled to believe Avith Kleinenberg (75, p. 33) that the alternatitni is primitive, but that it may have been gradually and secondarily acqnired| (!>. p. !.")!>). Having thus cut himst-lf paitially loose from tradition, so far as the antiq- uity of the nurse stage in the history of the medusae is concerned, he rests satisfied with the old explanation in other particulars, and states, on p. 159, his belief that the diver- gence from his stem-form, which resulted in the production of the sessile hydra and the locomotor medusa, was brought about by division of labor and polymoi'phism ; he further says that the locomotor stem-forms multiplied asexually, and thus gave rise to cormi, and that some of the persons of the cormus then became gradually specialized for nu- I ti-ition, aiul were thus converted into sessile hydras, while other persons became special- I ized for reproduction, and wei'e gradually converted into true medusfe. I
liohm's paper was published in 1878, aud in the same year Clans (15) also showed 2 that the hydra and the medusa are modifications of a commou type, of which the actin- ula is the living representative (p. 50), and in his Grundzuge der Zoologie, 1880, he advances an explanation of the origin of the alternation between the hydra generation and the medusa generation, Avhich, so far as I am aware, had never before received at- tention, although there can, I think, be no doubt that it is the true one.
lie discusses the subject very briefly and simply says, on p. 62, that alternation of generations ma}' be between two stages with similar organization, or it may be between the larva and the adult as in the Medusce. He goes on to point out that we must there-* fore recognize tAvo distinct kinds of alternation Avhich have originated genetically in two ^ different Avays, and have ditferent explanations. We must believe that the second sort ' of metagenesis, that Avhich resembles metamoi-phosis, has originated, in most cases, through the retention by the larva of the poAver to multiply asexually at a stage of de- A-clo|)ment Avhich, Avhile it may be more or less subject to secondary modification, cor- responds to a remote ancestral stage in the evolution of the species; aud that a larva-like nurse stands in the same genetic relation as the lar\'a itself, but the original stem-form, Avhich is now represented by the larva, had in addition to the poAver of sexual reproduc- tion, Avhich is now restricted to the highly modified adult, the po\ver of asexual multiplica- tion by budding, Avhich has been jireserved by the lai'va in the course of the i)hylogenetic evohition of the siiecics. On jip. 215-246 he also calls attention to the fiict that the^^ actiuula larva of Tubularia is a modern representative of the ancestral stem-foim. andf Telraplfron voUtam a locomotor ciliated larva Avhich is neither a liydroid nor a medusa, but an indiirerent type which might be modified in cither direction.
OF rill'; IIVDKO.MKDLS.K. 425
111 ]\\< \):\pt.'v on Ti'traptcroii (Ki) he says tliat lie has cviii-csscd liis view <>|' ilic iiian- uci' in which altcrnalion ()ri<;inaU'(l ainonj; (he nirilnsa' in his |)a|i('i" on I laiislcnima (1")), l)Ut I am nnahlf to lind il tliuri', or to linil any statnncnl ol' his view caiiicr than ISSO.
A recent writer in Xatni'e (28) states, p. (J!>, that Chins snpports tlie view ori^^inally foi'mnlated by Lenckart, that alternation ol" {fenerations has ori;jfinate»l anion<jf thi- nie- dnsiv throngh ])olynior|)iiisni. rather than tlirongh a modification <jf metamorphosis, l)ut he gives no references in snpporl ol" iiis statement, wliich is pr<»hahly an ei'ror like many others which occur in the pajjcr.
Til 1S8:5 r pnl)lished a paper in which I gave a very briel" exi)lanalion ol" the (Jiigin of alternation in tlie mednsiu. My view is identical with that wliich I have cpioted from Clans, although I reached it independently and in ignorance of Hohm'sand Clans' writ- ings on the subject. The paper is a short abstract without illustrations, but my conclu- sion was based upon the life-history of the Narcomedusae and Trachomcdusoe, which seem to me to furnish much more conclusive proof than any which these writers bring forward.
The statement is as follows: '' It is hardly possible that the form of development which wc now liud in most of the IlydromednsoB can bear any close I'esemblance to their prim- itive life-history, and. tliere are many reasons for believing that alternation of genera- tions has gradually arisen tlirough the modification of 'metamorphosis.' In Cunina we seem to have the ancestral form of development: a direct metamorphosis without alter- nation * * * Tlie larva of Cunina is a hydra with the power of asexual multiplication; but, instead of giving rise to medusa-buds, like an ordinary hydroid, it becomes directly converted into a medusa by a process of metamorphosis: it is a true larva and not an asexual generation, although the occurrence of asexual reproduction renders the gap be- tween this form of development and ti'ue alternation very slight indeed.
In Cunina avc have a scries of this kind:
Larva - Larva - Larva
III Adult Adult Adult If the larva Avhich is produced from the egg were to remain permanently in the hydra stajre wc should have a scries like this
Ilvdra - Ilvdra - Hydra
1 I
Medusa - Medusa and such a history Avould be a true alternation." (12).
A few months later, March 1884, Fewkes published a paper (19) in which he says "That exceptional form of development, called alternation of generations, which exists in the fixed hydroids may be regarded as the irregular not the normal method. It is an adaptation resulting from peculiar circumstances and a departure from a rule in one di-
420 '^\'- 1^- 15R00KS OX THE LIFE -HISTORY
rvctioii as that of ilu> Siiilidiioplioros is in aiiotlier. The Cunina colonics have rcscni- hlaiit'o willi Iioth lixcil liychoids and Siplionophoi-a, but have not departed as widely as either IVom the normal nulhod in their older larval and adult condition " (p. oOo).
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und Messina l)ool)aflUoto Quallen. 18G1. ~2. IIvKcivKL, E. Monographic der Meduscn. Zwcitcr Tliiel; 2, Der Organisnius der
Moduscn. 73. GHOHnp:N'. C. 1882. D.ilioluni und scin Gencrationswcchscl, nebst bemerkungen
fiber dem Gcncnitionswechsel der Acalephcn, Ccstodt'n nud Trenjatoden: Ai'bei-
ton aus dcni Zool. Inst, der Univ. Wcin, 1882, p. 70. 71. Ki.KiXKNHHUc, N. lfy(h-a. Leipzig, 1872. T.*". ITahtlauh, Clkmkxs, 1884. Beobachtungen liber die Entstehnng der Sexualzel-
len bei Obelia: Zeit. f. wiss. Zool. XM, 2, p. 1, Taf. xr, xir. 7<i. Ml'ller, Fhitz. Ueber die systematische SteUung der Char^bdeiden: Arch. f.
Xaturgescliichte, 18G1, xxyn. 77. Vakkxxe, AxnuK de, 1882. Recherches sur la Reproduction des PolyjJS, Ily-
draires: Arch, de Zool. Exp. et Gen., 1882, 10, p. Gil.
Sectiox I.
Sfxtiox IL
Section IIL Section- IY. Section Y. Section VI. Section YII.
CONTENTS.
The N"arcomedus;c 3G0
Cunocantha octonaria ....... 3G1
The Life-IIistory of Cunocantha octonaria .... 3G2
The Evolution of our Knowledge of the Life of the N'arco-
medusaj ......... 3G6
The Trachomedusse 372
Liriope scutigera 373
The Embryology of Liriope, and the Life-History of the Gcryo-
•litl:'-' 374
Literature of the Development of Geryonidre . . , 384
The Anthomedus;c 3^6
Tun-itopsis iiuti-icula • . . 388
Entima ........... 393;
The Embryology and Metamorphosis of the Eutimidfc . 398'
The Origin of the Alternation of Generations in the Hydro-
Medusjc 404
Review of the Literature on the Relation betAveen the Hydra
and the Medusa, and on the Alternation of Gencraticms . 413
List of References 426
MprouiT> ^ -
OEN tCO BALTIMORE
TURRIT0P3I3.
-^,
i. MOEN &. C<- BALTIMORE
EUTIMA
Memoirs Boston Too N^l.Hi si V \ !"
P!40
HOEN &.CP BAUIMORE
:UTIUA
■>
/v
•"^^ ' ■ r
a c.
-" e d'
Meini^irs Boston Cor Nal Hi.':l V..'.. !I!
Pi4;>
OEN i CO BALTIMORE
LIRIOPE.TURRIT0F3I3.
<l
I
cy
ir
XV. The oldest kxown In.sect-lauva, M<ii;>r<)r,ucoiDES auticulatus, fi:om the
Connecticut liivKit Rocks.
By SaMIKL II. SCL'DDEK.
KlmU Fc'brnarv li, 1884.
JL ROFESSOR Eilwanl Hitchcock, who published .so extciiglvelj' upon the footprints found in the sandstones of the Connecticut River was the first to make known the presence in the triassic shales at Turner's Falls, Mass., of insect remains.' These he first mentioned in his report on fossil footmarks published by the state in 18.j8, giving illustrations upon one of his [ilates, which are too obscure to be of any value. Judging the creature to be a crustacean, he sent specimens to Prof. J. D. Dana of Xew Haven, who, in a letter published in this volume by Professor Hitchcock, considered it to- be "probably a larve of a neuropterous insect," and sent to Hitchcock the cut avc here reproduce, in which he regards ji as the head, B to C as thoracic, and G to JD, abdominal segments. This, reduced, is the figure given in Dana's Manual of Geo]og3^
Some years after this, the late Dr. J. L. Leconte, having expressed the opinion from an examination of the figures alone, that Professor Dana was correct in his judgment of the heuroi)tcrous character of these remains, and having further referred them more definitely to the Ephe- meridae. Dr. Hitchcock, who never lost the opportunity of changing the name of a fossil, if he thought he could thereby indicate more closely its affinities, proposed that the name of Mormolucoides articulatus, he had at first given it, should be altered to Palephemera mediaeva. The first name, being in no sense misleading, must, of course, be retained, and indeed fortunately, since this is not the end of the opinions whicli have been held (and may perhaps yet be held) I'egarding it.
Having an opportunity some years since, of studying a slab lent me by Prof. O. C. Marsh, containing twenty or thirty individuals, and of comparing them Avith others in the Museum of the Boston Society of Xatural History, I published ni}' views of the structure and relationship of this fossil larva in the Geological Magazine of London, in whic-h I came to the conclusion that they were coleopterous larvae, and sug- gested that they " remind one of some Cebrionidae," but the only larva of that group whose history is known "lives on the roots of plants and would not be likely to occur in
S, fig., PI. 7, figs. 3-4.— D.vxA, Ibid.— Scudi>i;r, Proc.
Fig. 1, Mormolii-
coiiles .irticulatiis
Hitchcock.
' Mormolucoidi's ortienlnlns Uitciicock, Ichiiol. N. Engl., pp. Bost. Soc. Xat. Hist, xi, p. 140; Id., Geol. Mag., v, pp. 218-20.
Palephemera mediaeva Ilnciicocrc, Aiiiei'. Jouru. Sc, [2] xxxiit, p. 452
MEMOIUS UOSTOS SOC. NAT. HIST. VOL. III.
-I'ACKAP.n, null. Essex Iii<t., iii, p. 1.
(131)
i;V2 SAMUEL II. SCUDDER ON THE
such a deposit ns tlint in whic-li tliosc i-omnins Avcre found." In this communication, Inulinu: anionic tho specimens I examined none -with any lateral appendages, I concluded tliat the figures which had heen given were inaccurate in that particular, a conclusion based, as will he seen, on insullicient material.
A few years later, Dr. A. S. Packard pul)lished a short note upon them, in which he expressed the opinion lliat llu'V were ''acpiatic coleopterous larvae, belonging- perhaps near the family Ileteroeeridae."
It will thus he seen that some din'erence of opinion has been expressed concerning the aMinities of these fossils, though they have uniformly been considered larvae, and as belonging either to Neuroptera oi* Coleoptera.
Having recently heen able through the kindness of Professors Emerson and Hitch- cock to examine the considerable collection of these remains in the cabinets of Amherst College, and by favor of Professor Marsh to study all the specimens in the Yale Muse- um. I have examined with care some hundreds of these larvae, and reviewed the whole snl)Ject anew. Xotwithstanding the considerable differences which show themselves, I am strongly convinced that all the specimens I have studied belong to a single species, dilfering somewhat in structure from what I formerly believed, and whose affinities are pretty cleai-ly different from Avhat I formerly supposed, several new features, not before observed, being now apparent. This point, however, will be discussed after the struct- ure has been set forth in full.
The body is composed of thirteen apparent segments, of which the head forms one, and three are diflei-entiated, sometimes very obscurely, as thoracic. The statement that the head forms but a single segment is at variance with my former conclusion, for the two segments of the description then given by me form together what I now look upon as the head. There are doubtless a good many specimens which lend color to my former conclusion, and I reproduce upon the plate (fig. 3), a copy of a drawing made fifteen or more years ago of what I then considered the first three segments of the body. A sim- ilar development of the first segment may be seen in fig. 13, and to a much less extent in fig. 9. AVhether these lateral antei-ior lobes of the head, ahvays separated from it by a more or less marked suture, are inferior appendages showing only when projected for- ward, can hardly be determined, but this seems the most probable explanation. The de- cided diftcrentiation of the thoracic segments in certain individuals (see figs. 1, 5, 1-4 for example) leaves no room for doubt that the smaller segment in front of them, usu- ally single, at other times ai)parenlly double, represents the head.
The head then is a rounded segment, usually a little broader at base than in the middle (.see es])ecially figs. 12, 1(3) and slightly broadei- than long, the front well rounded. It is genei-ally about as lai-ge as the hindmost segment of the body, but occasionally is larger than it whej-e the final segment api)ears but partially exteiuled, and in a few in- stances is much larger; it is then also out of all due proportion to the segments behind it, as in fig. 10, where it does not appear to be crushed and unnaturally expanded, but rather as if the lower appendages of the head, forming in other cases the protruded an- tenor lobes, had been laterally spread out and lay beside the head, of which, as in the other case, they seem at first sight to form an integral part. That this is the correct view is tlie more probable because, Avhen the surface is not absolutely fiat (as may be the case
Ol.DKST KNOWN lNSi:CT-LAi;\A. .l;j;j
in any fossil iii-ict, im inatltr how liij^lilv ini;4iilai- its siirlaeo may have ht'i-ii in lili-), llie lioad is provided with hitei-al Ixtsses, which may 1)0 partly explaiiu'd as due to tlii" undcr- lyiiig- appendairos; for wlu'ii thesi- siipposi-d appi'iulaires arc thrust forward and (brm the anterior lateral hjbes, it is these lolu-s which are eml)ossi'd, as dcscrilied in my pi'i-vious paper; while when, as in fig-. 10, they arc supposed to lie outside the lateral limits of the head, the protuberances are still found connected with them. What appendages these lohes may represent it would he dillicult to say. ( )nc would moi'c naturally expect such evidently coi'ncous organs, forming bosses even where they arc separated from the head, to l)c mandibles, but their liroad and rouniU-d shape gives no clear i-videncc of their use in such a way; and in such a llattcncd larva it couhl not be supposed th.il I hey formed a vertical fang, the c-rushing of which, from above downwai-d, woidd bi-ing all the chiti- nous i^ortion together in a mass, and so ])i'oducc a boss upon the stone.
The three thoracic segments are almost invariably larger, generally considerably broader than the others, and are often distinctly differentiated as a separate region, both hy theii- breadth, greater than that of the nniform segment behind, as well as by the slight forwaid inclination of their sides. This appears clearly in lig. .j, but is generally less marked than thei'e by the smallness of the hindmost thoracic segment, which is not ol\en l)roader than the following abdominal segment, as in figs. 5 and 1-1. I'sually also the middle thoracic is larger than the front thoracic segment, so that their relative size is ir, I, III (see figs. 1, 11, 12, 14) but not infrequently the front one is the largest, as in figs. 5, 6, 10, and there are some cases where the broadest ])ai-t of the body is behind the thoracic segments, and the order of breadth in the thoracic segments is III, II, I. In these cases, as in figs. -1, 7, 13 and particularly 9, the whole aspect of the insect is changed, and yet ji careful study of the sijecimens leads one to the conviction tliat all belong; to a single species. In some, of which fig. o may be taken as an extreme type, we are re- minded, in form, of the larva of a longicorn lieetle, while the other extreme, as in fig. 9, recalls rather some of the 8ili)hidae. AVhat may be looked u])on as the average or normal thoracic segment, is about three times as broad as long, sul)f{nadrate, with verv slightly concave front margin, and a littk- more distinctly convex hind margin, the sides well rounded and the hinder angles more broadly rounded off than the front lateral angles, giving a slight sublunate form to the entire segment. These segments ai'c further marked l)y more or less distinct lateral marks, usually impressed, either angular (figs. 5, 1-1) or rounded (figs. 1, 10, lo), Avbich are the only indications, if such the}' are, of appendages. I had thought they might be taken for the marks of veiy short legs, and perhaps they eau; but the figures given b}- Schiodte of the larvae of the coleopterous gen- era ^ecrophorus, Anisotoma and Agathidium, where similar marks are purely sculjjtural, leave me in doubt. Every one must have seen in nature similar marks on longicorn larvae, but tbese are more g-enerally mesiall}- disi)osed, and do not, as here, reach so dis- tant a point from the middle line. Whatever tbey are, there is nothing else on a single specunen examined by me — many hundrcnls in numbei- — which could be refen-ed to legs.
The abdominal segments invariably taper to some extent toward the tail; sometimes the tapering- is scarcely visible on the anterior segments, and it is always more pro- nounced posteriorly, but here as before there are nearh* all shades of ditt'ercnce between
^j. SABIUEL II. SCUDDER ON THE
imlividiials, tlir oxtri'iiu's ol' whicli may a<>-ain l)e represented in lig-s. ;> and 9 ; in the formei- «if tliese the hasal ahdoniiual segments are only about half as broad again as long, and the middle ones are about sciaare; Avhile in the latter, the basal abdominal segment is more than twice as broad as long and it is only the terminal segment which is square. As a ^•er^• general rule, the segments are quadrate, with very gently convex sides, and slightly and equally rounded anterior and posterior lateral angles; but in a few cases, as in ivj;. 9. the anterior angles are considerably more rounded than usual, and the posterior an<i-les, liesides l)eing square, are furnished Avith a faint posterior extension, bristle, or taperingcluster of hairs (it is impossible to say which, but the last is the most probable). This same posterior set of appendages may be seen more or less distinctly in some of the other specimens, where the segments have the posterior angle as rounded as the anterior, but otherwise resemble this fig. 9 (as in fig. 4), or in which the segments are of the nor- mal form, as in fig. 0, which represents the specimen which apparently furnished the figure which has hitherto been current, and in which these appendages appear more decidedly as hairs, being more spread out, and also as attached to the posterior thoracic segments.
The surface of the abdominal segments is in general flat, but not quite imiform, at least on many specimens. There ajDpear to be tAVO Idnds of inequalities, one of Avhich from its infrequency and position seems to be accidental, perhaps due to pressure. This is seen in fig. IG, in sharp lines close and parallel to the margin. The other, hoAvever, though often obscure, is too common to be so considered, and consists in a longitudinal series of slight ridges, laterally convex, and. extending the whole length of the abdomen, diAiding the segments into equal or subequal transverse thirds, of Avhich the nuddle third is apt to be the largest. This may be seen in figs. 1, 6, 15. Besides these, there is nearly ahvays some median mark of greater or less intensity, indicating probably the track of the alimentary canal. Taa'O specimens Avhich I liaA'e figured (figs. 2, 11) shoAV this in a marked degree, the remains of a tube Avhich extended the entire length of the body being \dsible. It is much more pronounced on the abdominal segments than else- Avhere, Init in fig. 2 more distinct on the anterior half of the abdomen, Avhile in fig. 11 it is more distinct on the posterior half, Avhere it is clearly at least double, being turned upon itself betAveen the fifth and sixth abdominal segments, forming there a distinct rounded loop, and again more obscurely on the front of the eighth segment. To cor- respond Avitli this, Ave have in fig. 2 a distinct horse-shoe shaped depression superposed a little laterally on the median groove at the posterior end of the fifth abdominal seg- ment, and a shallower, smaller, circular depression in which the groove appears to ter- minate on the fi-ont of the seventh alxlominal segment. From these it Avould appear tolerabl}^ clear that a slender alimentary canal, noAvhere expanding into a Avell marked stomach, doubled shar])ly upon itself at or near the seventh abdominal segment, and again, by doubling at the hinder extremity of the fifth abdominal segment, resumed its former course, the Avhole of the sixth segment and at least a part of the seventh having therefore three sections of the canal passing through the middle.
The A-ariations in form of the different segments of the abdomen haA^ebccn mentioned. It noAV remains to speak of the curious variations of the terminal or ninth abdominal segment and of its special appendages. The general relation of this segment to the
OLDKSr KNOWN INSIXT-LAKVA. 435
pi'ocodins,' as avc-II as its onliuaiy I'onii is shown in fii;s. 1. 10 and lU, where it is ipiad- rate hut well roiintU'd, tapering and ahoiit two-thirds as hu'ge as the jtreeeding j(»int. In some oases, however, as in tig\ 9, it is very small, and its separation from the preced- ing joint hardly noticeable, while at the other extreme, as in fig. 7, it is scaix-el y smaller than the preceding segment and longer, if anything, than broad. But the most inter- esting feature in this segment is the discovery in a few specimens, as in figs. 9 and 14 and to a slight degree in figs. 2 and l(j, of appendages. There is an outer paii- of slender styles, a little shorter than the penultimate segment, directed backward and a little divergent; and a much shorter pair, or perha2)s only projections of the pygidium, lying between the longer styles.
As there is not a single specimen among the hundreds I have seen showing a lateral or even a partially lateral view% the insect could not have been cylindrical but must have been considerably flattened. The variation in the general form of the specimens, as pre- served, indicates a not very corneous or rigid integument, since the shape of single seg- ments varies considerably. Yet the general form is as a rule so uniform (as appears in fig. 8, Avhere a number of specimens are exhibited just as they lie on the stone, much better than my selection of other specimens to be drawn for some jjarticular feature) that we must consider the integument to have been at least coriaceous, and the varying jn'oportions of single segments to depend, partl}^ at least, upon the greater or less ex- posure of the intersegmental membrane.
"When we come to consider the probable aflinities of a larva having the structure above described, Ave are at a loss. No living form seems to be at all nearly allied to it. It Avould appear on general grounds to be either coleopterous or neuropterous, and from its aquatic habit to be more likely neuropterous than coleopterous; but further than this one must tread largel}^ on conjectural ground. The structure of the head, in which the only recognizable appendages appear to be nearly or quite globular and chitinous, the absence or extreme brevity of the legs in connection Avith a plainly flattened bod}', and a terminal segment provided Avith cerci, are combinations and features very extraordi- nary. The only coleopterous larvae Avhieh seem at all to remind one of their general appearance are the Silphidae, all the larvae of Avhich noAV known prey upon decaying animal and vegetable matter or live upon fungi, and none are aquatic; the LampA'ridae, which are equall}' out of the question; and the Heteroceridae, Avhich have no terminal appendages. These larvae, besides having a general form somewhat resembling that of !Mormolucoides, haA'e a flattened bod}^' short legs, and the Silphidae also a small head and distinct anal cerci, besides postei-ior lateral extensions of, or appendages to, the ab- dominal segments; but they have also comparatiA'ely small and tender mouth-parts; and the Silphidae stout, jointed antennae of considerable length, Avhile their legs are usually, at least, as long as the greatest Avidth of the body; and besides the ordinary nine seg- ments of the abdomen, there is in the Silphidae the strongly i^rotruding pipe-like pygid- ium, for Avhich there is no homologue in Mormolucoides, unless the inner pair of cerci be taken as representing a comi)letely forked pygidium. When Ave add to these differ- ences the peculiar habitat of the living Silphidae, and the similar terrestrial haunts of
' lu Ileterocerus it is cylindrical.
i;u;
SAMUKL II. SCUDDER ON THE
the Lainpvritlac and llotoroc-oritlac' we sliall hv loth to assert a close adinity with these •Toiips. Siieli <>-i-<)iips ol" Coleoptera as have aquatic larvae show, however, no points of rosemhlanco at all to ]\ronni)liicoitles, and it seems, therefore, far more probable that thev are ncuroptcrous.
In supi>ort of this view, avc have on general grounds, the flattened and posteriorly ta- ]KM-ing form, nnich more common in Ncuroptera than in Coleoptcra, besides the ter- minal ceroi. and posterior lateral appendages of the abdominal segments — features much more in accordance with the structure of those grouj)s of Neuroptera to which they seem most nearly related, than willi tlie structure of any Coleoptt'i'a.
These groujis arc the Perlidae, Ephemeridae and Sialidae, in all of which the larvae are at least in large part aquatic. In each of the first two of these groups, there is a re- markable uniformity of larval organization, and they seem to differ so much from Mor- molucoides as to make it unwarrantable for us to look for intimate relationship with them. In Perlidae, for instance, we have a prothorax distinctly diffei-entiated from the other thoracic segments, and the latter bearing at a comi>aratively early age, as in Blat- tariae, indications of the coming wings in the form of pad-like expansions of the outer angle of the said margin; we have also long and prominent antennae, very long and large flattened legs, anal cei'ci of great length, and no sign of an inner pair of cerci. In Ephemeridae, we have an entirely different form, equally discordant in its relations to Mormolucoides. The legs are nearly as long and stout as in Pei'lidae, lateral respiratory filaments cover the dorsum of the abdominal segments, the head bears stout, and often long antennae, Avhile the terminal segment is almost invariably armed, not only with outer large, long, feathered anal cerci, but also with a similar, single, median style, even when the latter is absent from the imago; tAVo inner styles ai"e never present.
The comparative unifoi'mity of larval structure among the divei'se genera of each of these two groups prevents ns from believing that Mormolucoides with its very different structure could by any possibility be included in either of them. Not a trace of thoracic wing pads or abdominal respiratory filaments can be seen on the hundreds of specimens examined. The great length and size of legs and multiarticulate antennae in both the groups, find no counterpart in Mormolucoides, and the ap[)endages of the terminal seg- ment are altogether different.
Xot so, however, or not by any means to so great an extent, when we compare the larvae of Sialidae. Here we find a considerable greater range of characteristics, so that it is not so ea.sy to recognize a common facies among them. But Ave may note one or tAvo characteristics by Avhich they approach much more closely our fossil tyjie. All the ap- pendages,— antennae, legs and (often) the cerci, are shorter and slenderer than in the two groups la.st mentioned. In some, the antennae at least are comparatively insignificant. The mandibles in some are very stout, and though long in all that are known may well be believed to be capable of modification in this regard. The abdominal segments are provided with lateral filaments, projecting backAvard from the posterior outer angles. The appendages of the terminal segment vai-y very much, some having a single median style of considerable length, othei-s a shorter lateral pair, in some cases furnished api-
' The HeteiocorUUie live iieav but not in water.
OLDKST KNOWN INSIXT LARVA. .1M7
callv witli ivcuivi'd Imoks. Tlu' olijcclioiis to CftiisicU-iiiiji^ tliis as the iii<is( luaily nlliiil group are tlie coiisitk'rable si/.c ol' the legs even when h-ast divcloped, tlie great si/e of the head, which is at least as hirge as the segments behind, and the sliglil diHereiitiatiou of the prothoraeic segment shown at least in its larger size.
I had reached the conclusion that n[)itn the whole we might loi>k npnn the Sialidae nt the grou[) of insects to which Mornii>hic<iides was tlie most nearly allied ( though still regarding the conchision as provisional) wlu-n it received a cnrious support Irom an unex[)ected quarter — the internal structure of thi' larva. I have said that several spec- imens of Mormolucoides showed traces of the alimentary canal, and that in two of them (figs. 2, 11) in the posterior part of the body it doubled twice upon itself, covering with its triplication the sixth abdominal segment and partsof others, indicating a convolution of the small intestine. Looking at the published accounts and figures of the internal organs of tlie larvae of the three gronps of Xeuroptera we have been discussing, I find that the digestive tract, so fav as known, is invariably straight and simple in both I'er- lidae and E[)hemeridao, while a trii>lication of the small intestine is not unknown in Sial- idae, being distinctly figured and described by Lcidy in Corydalis cornulus,^ where it covers the fifth aljdominal segment, or the one next in advance of that in which we have found it in ^Mormolucoides. The only other figure of the digestive tract of a Sialid larva, which I have found, is that of Slalis latarln.^ published in the same year by Dufour,- ■\vhere it is figured as perfectly straight and described similarly as ''droit comme celui de rinsccte aile." Several species in their perfect state, in gronps closely allied to the Sial- idae and sometimes placed with them, such as Panorpa, have a similar triplication of the small intestine, and it is also found in the larva of Myrmeleon as figured by Dufour.' These seem to be fair corroborations of the conclusion independently reached, that Mor- molucoides is probably the larva of a Sialidan neuroptcron. It has special interest from the fact that it is the oldest known insect larva.
EXPLANATION OF PLATE 45.
All the figures reprascnt MormoUicoMes articiilaluf, and nil bul(l|j;. 3 wure drawn by J. Henry Blake. Fig. 8 is nnturni size: llj:. 3 enlarged about 5 diameters; the others enlarged 3 diameters.
Fig. 1. A specimen from Montague, Mass., collected by I'rof. O. C. Marsh audio the Peabody Museum of Yale Col- lege. Tlie head is smaller than usual.
Fig. 2. From the same place and collection as the last and on the same slab as fig. IG. Although imperfect, the head and Hrstthoracic segment wanting, it shows remarkably a sharp median groove, which can be nothing else than the diges- tive tract, with the indication of its twice doubling on itself at the end of the fifth aud base of the seveulk segments. A slight indication of one of Ihe anal styles is also seen on the last segment.
Fig. 3. Tlie head and lirst thoracic segment of a specimen in the Yale College Museum, as drawn, many years ago, by S. 11. Scndder. It shows the apparent division of the head into two segments, then supposed to be head and (Irst tlior- acic segments.
Fig. 1. Specimen from Montague, Mass., collected by Professor Marsh and now in the Peabody Museum at New Haven. It shows a head of unusual breadth, basal abdominal segments which are larger than the thoracic, aud slight in- dications of the lateral appendages of the abdomen.
Fig. 5. Specimens from Turner's Falls, Mass., marked No. 1,405 in the Sliepard collection of Amherst College. Figs. 11 and 12 are on the same slab. This specimen shows well the lateral marks of the thoracic segments interpreted as possi- bly legs, a well marked diflerenliation of the thoracic and abdominal segments, aud an unusually uniform bre.idtli in the latter.
Fig. 0. This specimen appears to be the original type of Mnyinnhtcoides arliculatit.i. It is on the same slab with (Ig. 15, marked as coming fiom the Horse Itace, Gill, and numbered }; in the .\mherst College collection. There is not more
' Mem. Amer. Acad., iv, 1C2-1C8, PL 1, 2(,1S48). 'Ann. So. Nat. (3), ix, 91-99, PI. 1 (IS4S).
^Mem. Suv. Elrang. .Vcad. Sc, vil, PL 12, figs. 175, 177 (1841).
4;{S
SAMUKL II. SCUDDER ON TRICIIIULUS.
Uiaii one oUiPr slat) iii llic collocl\oi\ which bears a very old printctl label with the orlsinal name, and this specimen Is the onlv one in wliich the hitoral appendages are distinct. It has, moreover, been tooled to some extent and bears no small resi'inldancc to the rlaures in Ilitchcock'.s plate. .Apart from its interest it wonld have been drawn at this time if only to show llic lateral appendages of the abdomen, which seem here to be supplied also to the last thoracic segment.
Fi". 7. Untabellcd slab tn the .\mhcrsl College Cabinet. Keniarkablc for the very small size of the tlioracic seg- ments, which are not only narrower than the anterior, l)ut no wider than the posterior abdominal segments. It is the only specimen I have seen showing snch a feature, and is tlie more marked because the thoracic segments are, if anything, shorter than usual. Figs. 9 and 13 are on the .same stone.
Fi". 8. A slab from Montague, Mass., nundiered 1,037 in the Yale College Museum and collected by Prof. O. 0. Marsh. This is Itgured to sliow the abundance of larvae on a single .stone, althongh otlicr instances could have been given ■when; lliey src two or three times as numerous. Tliis was selected simply on account of the small size of the slab. The specimen marked a is represented enlarged in (Ig. 10.
FI". n. Specimen from tlie same slal) as tigs. 7 and i:!. It is one of tlio most interesting sc'en, as it is remarkable not only for the nnu.sually symmetrical and perfect development of both the lateral and terminal appendages of the abdom- inal se"ment«, wliich together show in no other specimen seen, but also for the symmetrical and unusual fusiform shape of the body. The last segment is unusually small. The head too shows some signs of the frontal lobes.
Fi". 10. The specimen marked a on flg. 8 enlarged, in which tlie main interest centres in the head, wliich is unusually brond, apparently from a lateral displacement of the frontal lobes, as explained in tlie text.
Fi". 11- On the >ame slab as tigs. 5 and 12. This is drawn to show the unusually clear douliling of tlie alimentary canal at the suture between the llfth and sixlli abdominal segment. On the front part of tlie eiglitli segment, the left hand tube is seen lo pass beneath that on the right on tlie comnieiiceinent of its recurrent conr.se, but it does not sliow clearly in the plate.
Fig. 12. On same slab with figs. 5 and 11. Head of more than the usual size, showing an nnnsnal basal expansion.
Fi". 13. On the same slab with tigs. 7 and ',). It is especially interesting on account of tlio line development of the frontal lobes of the liead.
Fig. U. Specimen from the Horse Race, Gill, Mass., numbered JJ in the Amherst College Collection. Tlie head is un- usually circular and rather small; the thoracic appendages (or sculpturing) nnusually distinct and angular; the abdomen tapers with great regularity, and the last segment is supplied with all tlie appendages. As drawn on the plate the last segment is perhaps a little loo long.
Fig. 13. On the same slab with fig. G. Tlie special feature is tlie nearly uniform size of the body throngliout and the position of the head, sunken nearly out of sight williiu tlie tlioracic segment behind it.
Fig. 16. From the same slab as flg. 2. The specimen is of unusual size, tlie head has an unusual basal enlargement, and a slight sign of one of the terminal styles is seen on the last segment.
X^'I. KOTE ON THE SUPPOSED MyRIAPODAJv^ GeNUS TrICIIIULUS.
By Sa3iuel H. Scuddek.
Reajl April 21, 18S6.
JL "\V0 years ago I published in the JVIenioirs of the Boston Society of Natni-al History tlie description of a genus of supposed hairy myriapods, Trichiuhis, from the bed.s of Mazon Creek in Illinois, of which three species were distinguished. A short time ago m}' attention was again called to these specimens by Mr. R. D. Laeoe, whose collection is ver}' rich in remains both of plants and animals from the carboniferous period, and in which are all the types of the species described. Mr. Lacoe was convinced that at least two of them should be regarded as the terminal circinate portions of ferns. Dr. II. B. Geinitz of Dresden (who had made a similar mistake in regarding a frond of Scolecop- teris as a myriapod, to which he gave the name Palaeojulus) also wrote mc somewhat to the same effect, and I have accordingly reexamined the original specimens by the favor of Mr. Lacoe in the light of half a dozen undoubted coiled fern-tips from his collection, sent me with them ; with the result that there is no doubt whatsoever that they are ferns of the genus Pecopteris or one of its allies, ])reserved obscurely at the time of their i)ar- tial unfolding, and that the name Trichiuhis must disappear. The only specimen not re- examined is that of T. nodulosus, figured on pi. 27, fig. 1.
X\'ll. A Ki:\ii:\v of Mksozcjic Cockkoaciiks.
liy SaML'KL II. SCUDDKK.
Head .lanuaiy 20, l>'>'i;.
JoIX years a<^.'), wIilmi I puhli-^licd a revision of" all the paleozoic eocki-onclics ilu'ii l<no\vn, I was ol)ligccl to resort entirely to existing foi-nis in the com|)arisons institnted between the wing strncture of the aiifient ty|)es and that of those of later times. Illnstralions indeed and partial descriptions existed of more than thirty mesozoic forms, bnt sinee many of these were very imperfect, and many vaguely drawn, any attempt to reach definite conclusions concerning them, without specimens themselves from that period to examine, seemed futile.
It was my hope that, since structural distinctions of fundamental importance and of complete unifoi-mity were shown to exist between paleozoic and recent cockroaches, rendering an examination of the mesozoic forms most desirable, some English nat- uralist Avould undertake the task; for it was evident, from the illustrations ali'cady given by Brodie and Westwood, that the British Lias and Oolite were especially prolific in these forms, and that abundant material must exist in public and private collections for the elucidation of the problems suggested.
This hope has not been fulfilled; but an unexpected discovery of Triassic cocki'oaches in considerable a])undance in the South Park of Colorado rendei'cd the examination of other mesozoic forms still'more desirable, and T determined, therefore, to study the ques- tion myself as best I could. My venerable friend, the Reverend P. B. Brodie, the pioneer student of Bi-itish fossil insects, kindly came to my aid by sending me, from his unex- ampled collection of British mesozoic insects, such specimens as seemed to be cockroach wings. In this way, I have not only been al^le to study from the siiecimens themselves as many as ten of the wings which had before been dcsci-ibed and figured, but nearly three times as many forms now published for the first time. The study of these natu- rally threw much light upon obscure points in the illustrations of species not studied from the specimens, both in England and on the continent, — a number less than those seen, and most of them easily interpreted Avith their aid and often without it. The fruits 'of that study are herewith presented, with my best thanks to the Rev. Mi'. Brodie for his generosity. The number of mesozoic tyi)es now slightl}^ exceeds the paleozoic, though their relative propoi-lion to the rest of the synchronous insect fauna is far less than in the earlier period.
MEMOIltS BOSTON SOC. NAT. HIST. VOL. III. 1 (139)
MO
SAMUKL II. SCUDDER ON
As ill llu" paK'ozoio coc-kronilu's, so Iioii'. most of the i-emains consist exclusively of front wiiiirs, ami the ])rinci|)al guide to our knowledge of these early forms comes uec- cssarilv fn»m a study of the ueuration of these parts. This study, in the case of the paleozoic cockroaches, led to the discovery of some features of fuudamenlal importance, in- which the front wings of paleozoic cockroaches could be invariably distinguished from those of existing tvpes. In pileozoic forms all of the main veins are completely inde- pendent, and the anal nervules fall at regular intei-vals upon the inner margin. In exist- ing tvpes, two or more of the main veins are amalgamated, either completely or to a large extent, while the uervules ol' \hc anal aica strike the anal furrow, or at least compose a fusiform hunch directed toward the lip of the furroAV. In consequence of these distinc- tions the paleozoic foi'ms were distinguished as a separate group under the name Palaeo- hlattai'iae.
This discDvery naturally led to the euquii-y: Which of the veins in tlie modern teg- niina have undergone the blending process? An examination of existing species showed that, as a rule, the veins were still independent in the hind wings, and an opportunity was therefore afforded of investigating the subject by the comparison of the front and hind wings of many modern types, and the conclusion reached that in modern tegmina tlie scapular and externoniedian veins were those Avhich had blended.^
This conclusion was shortly shown to be incorrect for mesozoic types, by the discovery, above mentioned, of cockroaches in the Triassic beds of Colorado, where a series of forms "were found associated, some of them belonging to the Palaeoblattariae, and some Avith blended veins, allowing a more exact comparison than had before been possible. The conclusion newly icached from their study was that "when we compare the series of gen- era near tlie boundary line of the departure of the Palaeoblattariae toward later forms (those paleozoic cockroaches allied to Petralilattina) and especially those [Palaeoblatta- riae] bi'onght to light by the discoveries at Fairplay, we find that in the mesozoic species at least, it is the mediastinal and not the externomedian vein which has blended with the scapular, although the externomedian also may become blended with the others in living types. This amalgamation has proceeded by the enlargement of the scapular area, Avhich has crowded the mediastinal toward the base of the wing, whose few remaining branches finally become attached to the scapular vein, no ti-ace of their former depend- ence remaining visible.''^
The present study shows that this conclusion must also be modified by a somewhat further extension. The above statement is true of about tAvo-thirds of the species, but there are also others, both in the Lias and the Oolite, in which a different or even a greater vai-iation is found, the externomedian vein being sometimes united, throughout at least part of its length, with the scapular, or it may be wholly united with the inter- nomedian, and in both cases, the mediastinal nia}^ or may not also be united with the scapular. Tlie variation is therefore already very great in Liassic times, although it reached its maximum only in the later Oolite. With the excei)tion then of about a dozen si>ecies of Palaeoblattariae in the Ti-iassic rocks, all of the mesozoic cockroaches, like the living, have front wings in which two or more of the veins are coalesced.
As regards the other distinction, diawn from the anal area, there is much diversitj^,
'Mem. B08t. Soc. 'Sat. Hiet. III, 28. =Amer. .Iiiuiii. Sc. (.■!) xxvin. 201.
MKSOZOIC COCKIJOACIIKS. 441
ami in ("act very iinpi'ilei-t kiioulcdi:^*', this i(.'j::i(>ii hciiij; IVtMHnnlly iiii-;^iii;4' in 'In- lossils. In most of the gemra tlio anal lu-ivnh's, so far as known, stiikc the niar«;in, hut in smnc the species vary in this respcet; in others their course ismtireiy unknown, whiU' in sueli as are perfectly preserved in the most proli lie genus, Mesohlattina ( Jeinitz, they impinge indeed upon the margin, Itut show a decided tendency to direct tlu'insflvcs toward the tip of the anal furrow, as in many modern forms. 'I'his feature cannot therefore he said to have hecome fairly estahlislu-d in mesozoic times.
These changes in the general structure of the front wing arc no doiihl hiil one ev- pression of the increasing heterogeneity in the neuiation of the front and hind wing which was almost entirely unknown in paleozoic times, hut which has reached a high development at the present day. The remains of the hind wings of mesozoic cock- roaches are indeed not sulliciently almndant to jirove this, hut we have grouped here under one generic name, Aporuljlattina, such single detached wings as seem to be prop- erly considered as such, and here the veins ai-e entirely distinct. Another indication (jf this specialization on the part of the front wing is their increasing density, by which the neuration is in part obscured. This is not very marked, but in some species is un- mistakable.
A further i)eculiarity of mesozoic s[)ecies, as a general rule, is their small size. In a previous paper, before the number of paleozoic forms known was as great as now, the average length of their front wings was estimated as 20 mm., and there is no reason to suppose that that measurement would be altered by later discoveries to any extent worth mentioning. On the other hand, even the Triassic Palaeoblattariae already show a ten- dency toward that diminution in size which is well marked in the mesozoic IJlattariae, for the average length of the former is only l(j mm., while in the mesozoic Blattariae as a whole it is still further reduced to 12.5 mm. Even this would be somewhat diminished (to 11.5 nun.) if we should omit the species from the middle Oolitic beds of Solenhofen, all of which were large and some gigantic, one reaching a length of GO mm. That this srifeuld be the case seems a little unexpected when we find the species of tlic upper Oolite (of England) a little smaller as a general rule than the Liassic forms. This somewhat curious fact led me to ask what should be considered the average size of the modern cockroach. I accordingly took Brunner's Systeme des Blattaires and tabulated the measurements of the front wings given there whenever the material was at hand for the purpose, to the number of 243 species. One measurement only was taken for each species and where the sexes differed (as often excessively) these also were averaged. Of course the apterous species had to be omitted, and it was plain that the result would be too large as the larger species find their way to collections much more rapidly than the smaller forms. The general result was that the average size of the front wings of recent cockroaches is 18.2 mm. which is considerably more than that of the mesozoic spe- cies, and much less than that of the paleozoic forms.
As regards the relative geological position of these mesozoic cockroaches two Hicts are patent: 1". iS'o species has been found in more than one deposit. 2°. While all three of the genera of the Trias are peculiar to it (some of the genera of the Triassic Palaeo- blattariae have also heen found in lower paleozoic rocks) and two genera are found only in the upper Oolite, all of the genera found in the intermediate Lias also occur in the
H-2
SAMfKL II. SrUDDER ON
OoUti'S. Tlu* giMU'i-a pociiliarto [hv n\>\>vv Oolite arc liowevor very poor in species, one h:iviiiir onlv one ami the other only two representatives, while the genera conunon to the Lias and Oolite are generally prolilic in this respect.
Oniie seventy-seven species of IJlattariae nientionetl in the following pages, not in- chhling those found in the Appendix, tliree are found in the Trias, seventeen in the Lias, three in the middle Oolite and forty-six in llie upper Oolite, besides three whose precise horizon is unknown.
A comparison of the venation of the teginiua of mesozoic and recent cockroaches, to determine, as far as possible, the immediate i-elations of the former to existing forms, "■ives little satisfaction. Still, ]S[esol)lattina and Rithma may be said to bear considera- ble rcsembhince to the Phyllodromidae — us Phyllodromia, Apolyta and Thyrsoccra, for e\auii>U — and the peculiar neuration of Elisama is in part repeated in the Panchloridae (e. a., I'anchlora, Leucophaea, Nau|)hocta) and also occurs in some Phyllodromidae (Thvrsocera) and Ei)ilampridae (Pai-atropa, Epilampra). Scutinoblattina also reminds one in certain features of some Lpilampi-idae, like Phoraspis. The other genera, and particulai'ly Blattidium and Pterinoblattina, appear to have no relations to any special tvpe. As a whole, then, it would ai)peai' as if the Blattariae sjnnosae approached closer to the mesozoic foi-ms than the Blattariae muticae.
As I have already stated, the most fundamental distinction separating the mesozoic from the ])alcozoic cockroaches is in the change Avhich the pi-incipal nervures of the nppcr wings have inulergt>ne, by the basal or total amalgamation of some of them, — a change which reaches its culmination in living cockroaches.
(^n the basis of these difterences, mesozoic cocki'oaclies may be divided into three groups: a, those in -which only the mediastinal and scapular veins are amalgamated; h, those in Avhich the externomedian is united with one of the veins on either side of it; and c, those in which cither the mediastinal, scajjular and externomedian veins are all united: or there are two lines of union, one between the mediastinal and scapular, and the other between the externomedian and internomediau veins, i.e., where, besides #ie miion of the mediastinal and sca])ular veins, the externomedian also allies itself in whole or in i)art with the miited mediastino-scapular, or with the internomediau. In all meso- zoic cocki-oachcs, excepting the Triassic I'alaeoblattariae, amalgamation of some of the veins occurs; lor a further study of Pterinol)lattina convinces me that my first interpre- tation of its neuration was incorrect, in that what I had takeu for the internomediau vein is i-eall}- the anal, and that what was looked upon as the externomedian must be regarded as the united externomedian and internomediau veins.
a. The mediastinal and scapular veins of the ivpper ivings, and these only,
are amalgamated.
CtENOBLATTINA gen. nov. {xt-z.wzo^).
In the wings of this group, which are minute, the humeral angle, usually consider- ably developed in cockroaches, is obliquely docked, and the united mediastinal and scap- iil.u- veins occupy a broad area, at fir.st nearly one-half of the breadth of the Aving, and i nearly to the tip, provided with numerous jjarallel more or less forking branches.
MKSOZOIC toe Ki;(>A( IlKS. 443
Tlie 'md'i'niiiiu'ilian ()ccii|t"H's a very .siinil;ir licit mi lln- iiiiuT hide, fxtc'iiiiiii;^' ik iirly (ir (liiito t()tlu'ti|>; and hi-twi-rii liicin tlu' pinchi-il »-\tL'i-iii)iiir(liaii, riilar;^injjf a JillK' iDward till' tip, linds iiari'()\V(|iiaiti'is. TIk' anal aii-a is vcit hiit-l", hnt tlu- iliaiactcr<)|' its vi-na- tion is \\n{ known.
'I'w'o 111" tlu! si)L'ciL's conii' from tlu' l"]n;4lisli Purlii-fks; ihc tiiinl IVnni tin- (Jcrnian Lias.
Ctenoblattina arcta sp. nov .
ri. IG, llgs. 1, 2.
This niinntc speoii's, as may I)L' .si'cn by n;j^. 2, has its venation sonicwliat oliscinH-d, partially pci'liaps by the' thickness of thi' internment. In its interpretation, in li;^. !, it is |irolial)K' that the inlernonu'dian area is given too little width, as its ajiical nervnles are <;ivon to > little curvatnre. The form of lig. 2 is moi-i' correet. The winj^ is broadest at the extremity of the anal area, jnst l)efore tin- end of the basal third; np to this j)oinl it increases rajiidly in size, the humeral angle being strongly docked, and beyond tapi-rs ver^' gently to a well rounded tip. The costal area (as the united mediastinal and scap- ular areas may be tei-med) is crowded with uervules, every alternate one appearing a little heavier than the others, so that the intermediate are probably intercalary veins, as <ine would judge also from their absence from the internomedian area, where the veins are more distant. Excepting for the simple division in the middle of the basal half of the wing, the externomedian vein does not fork before the middle of the wing, and then liut narrowly, but the whole of this region is obscure, though it seems certain that it occupies outwardly ueai-Iy the whole tip of the wing. The anal furrow is distinct and very strongly arcuate. The anal area is neither elevated nor depressed, the whole wing being entirely flat. The wing is about 2.7 times longer than broad, its length being 5.5 nun. and its greatest breadth a little more than 2 mm.
The specimen comes from the English Purbecks (precise locality not known), and occurs on a stone of a very pale sordid brown color, on Avhich the veins appear dark lirown ; it Avas received from Rev. P. B. Brodie.
On account of the obscurity of the venation, and its apparent derivation from the thickness of the integument, I formerly, from partial study, considered this a specii'S of Ileer's genus Legn<iphora, from the Trias, and so referred it, without name, in Zittel's IIandl)uch der Palaoutologie (IT, 70(5) ; but a severer examination has enabled me to trace the neuration, which cannot be made to accord with that of Legnophora.
Ctenoblattina Langfeldti.
Blattlua Langfddti E. Gien., Zeitschr. deutsch. geol. Gescllsch., 1880, 521, PI. 22, fig.
8; iiit?., 1884, 571.
This species seems certainly to fall here, l)ut Geinitz appears to have confounded the costal and inner margins. The externomedian vein resembles the foregoing more than tlie following species, but first forks much farther i'rom the base. The wing is ~)~) mm. long and about 2.2 mm. broad. It comes from the Lias of Dobbertin, German3^
jlj SAMUKL II. SCUDDKR ON
Ctenoblattina? pinna.
["Without name] Bnulie, Foss. In.s. Eng-., 118, PI. 5, fig. 5.
Jildfta pinna Gieb.. Ins. Yorw.. 322.
lilatthlinni pinna lleer, Viertelj. nalurf. Gesellsch. Zurich, 18G4, 290.
This species appears to beloag here, but I have not seen the specimen and the obscii- ritv of the drawing renders its location uucei'tain. It is badly broken at base, so that the humeral angle and anal area are (probabl}-) entirely obliterated. The fragment is represented as nearly 4.5 mm. long, and its real length was probably about 5 mm. It ditVors from the preceding species in the uniform width and greater extension of the cos- tal area, which must reach the ver}'^ tip of the wing, the apparent absence of spurious nervules in the same area, the even slenderer externomedian area hardly expanding api- callv, and the very great width of the internomedian area, which occupies fully half of the wing.
It comes from the English Purbecks.
NeORTIIKOBLATTIXA Sciuklor.
XcorthroUattina Scudder, Proc. Acad. Nat. Sc. Philad., 1885, 108.
In this genus the wings are about two and a half times longer tlian broad, with fairly well rounded apices, the costal area extending nearly to the tip, and in the middle of the wing occupying nearly one-half its width. The internomedian vein is of varying importance, and in the hirge anal area the veinlets terminate on the margin; the anal furi-ow is strongly arcuate, and deeply impressed.
All the species come from the American Trias.
The four species are N. alholineata, jSF. Lcikesi, N. rotundata and JS^. atteniiata, all found at Fairplay, Colorado. They were briefly described in the Philadelphia Academy's Proceedings, and will be fully discussed and figured in a paper devoted to this Triassic locality, so that it is only necessary here to indicate their apparent position in the series.
RiTHMA Giebel (emend.).
Rilhma Giebel, Ins. Yorw., 318; Scudd., Proc. Acad. Nat. Sc. Philad., 1885, 113.
The wings of this group, as it is limited by me in the place above referred to, are gen- erally rounded wedge-shaped, i.e., slender and tape)-ing (though the latter peculiarity is wanting in some even of the slenderest species) with the costal area large, occupying nearly or quite half of the wing, the main vein sinuous, generally conspicuously sinu- ous, rarely almost straight, terminating close to, sometimes even below, the tip. The anal area is generally pretty lai-ge, vaulted, and filled with arcuate parallel veins which terminate on the margin. The externomedian and internomedian veins are also sinuous and divide the remaining space about equally between them, each forking considerably and radiating apically. Their nervules, and especially those of the internomedian vein, are rarely more longitudinal than oblique. The genus stands midway between Neor-- throblattina and Mesoblattina, the flatness of the humeral field, and the great extent of
MESOZOIC COCK'KOArilF.S. 445
the cDslal area (li-i|iiit;-iiisliiiii;- it IVuin the f'lniu'i-, tin- ;^rcatci' <ilill<|iiil y i>\' tlir iiilcrior lUTViiU's ami pai-ticrnhifly thi)si' of iho iiili'i-HDincdir.n an-a, as well as thr |iaiallil and sim'dai- course ol" the anal nei'Viiles, separating- it Ironi tlu' latter.
Most of the species come from tiie |]iii;Iisli I'm hecks, hut two occnr in the Lias of Enghind and Switzcrhuid.
Rithnia Stricklandi.
I'l. IC, tiu's. I, .-,.
Jilal/a Strirhl<i)i<Ii IJiodic Foss. Ins. Kn-I.. :;i^. IIS. I'l. I. li-. II d li-s.) ; (iidi., ins.
^'or^v., .'ill. Blattidlum S(ricJiI(i)i(h' I leer, \ici-|clj. natmC. (iodlxii. Zmicli. IX, liDO.
liy the favor of ^fr. lirodie, I have had llic opport unity of stndyin<;' and redrawing the oi'i.u'inal of tiiis species, which shows a complicated cross-nenration hy the ovcrlap- j)inji' of the four wing's and the tennity of the niemhrane. This has eiiahled me to trace out the separate neuration of the tegmina, as shown in (ig. 4, which wouhl not have heen ])ossihle I'roni the original drawing, which was in other respects not wholly coi-rect. Xo desci'iption accompanied the ligure.
The most perfect wing is the upper wing of the left side, and this is only prcser\cd sufficiently to show tliat it prohahly helongs in this genus and cannot he idi'iililicd with any other of tin- species here referred to Kithma. The humei'al area is very narrow, and is not ditferentiatcd from the rest by its flatness; the costal area of nearly equal hi-eadth until close to the li[) as in the next s])ecies, bi;t the main vein has a slight sinuosity and no terminal inferior forked vein, and its branches aiv comparatively few and distant. So too, are the l)ianches of the externomcdian, whicli in other respects do not differ from the next species. In the hind wing, the costal area is much narrower and distinctly tapci's apically. The inner bases of all the wings are wholly obscured by tlie nieso- and meta- thoracic scnta, which come to the surface as large spots, so that there is no indication even of the anal furrow; they indicate, however, the position of the bases of the wings, enabling lis better to .judge of then- exact length, Avhile the curves show w'herc the tip must lie. Judging l)v these, the length of the wings Avas 12 nun.; the breadth nf the two wings at rest 5.5 nun.; tiiat of one of them. ])rol)ably about 1 nnn.; and the width of the niesothorax, 3 nnn.
The specimen comes i'l'oin the I'ui])eeks of tlie \'ale of Wardoni', Wiltshire, I'higland, and is of the same color as the dirty l)rown stone on which it rests, exce])ting that parts of the thorax are black, the veins varying fi-om light to blackish brown. The surface of the specimen is very slightly convex, and the veins are slightly impivssed.
Rithma Gossii sp. iiov.
ri. IG, fig. 1.5.
This species is founded on a nearly perfect wing in which only the anal ai'ca is miss- ing. The wing is of nearly uniform width, nearly three times as long as l)road, with a well ronnded tip. Tt is of the same color, veins and all. as the dirt}', chalkj'-white matrix;
440
SAMUKL II. SCUDDER ON
till' wiui:- >li<>\vs tlu' iippiT siii-laco ami is arc-lied traiisvei'sely, the costal area roof-liko, tho Vfins nnmiiiti- in slight riirrows. It is pi-culiar for having-, like li. Stricldamll,i\ veiy stnii»-lit anil nniibrni costal area, but the depressed humeral tield is of the usual Avidth, thouiih rather short, the costal A'cins are numerous and crowded, and a supplementary inferior, forked, apical vein carries the area quite to the tip of the wing; the latter char- aeteristie ma\ well he indixidual. The externomcdian and inteniomedian veins divide their space hetwi-en them very ecpially with abundant, forked, almost perfectly straight veins, the intcrnomedian area tci-minating just Ijefore the apical curve of the wing, and the externomedian iirst forking far before the middle of the whig. The anal furiow is no more depressed than the other veins, strongly arcuate in its basal half, straight be- yond, with a slight outward curvature at the tip, which is opposite the first foi-king of the externontedian vein. The course of the main externomedian vein is almost exactly down the middle of the Aving, and the nervules on cither side of the Aving are about equally crowded.
Length of Aving, G.o mm.; breadth, 2.2 nmi. The species is named for Mr. Herbert Goss, Avho has done so much in recent j^ears to foster in England an interest in fossil insects. It comes i'rom the English Purl)ecks and Avas submitted to me for study by the Kev. P. B. Brodie.
Rithma disjuncta sp. nov.
ri. JO, fig. u.
A single Aving in Avhich the characteristics oi" the neuration are Avell shoAvn, although only fragments of the Ijorder appeal". It is possible neA'ertheless to judge Avith probable accuracy of the formof the Aving, Avhich seems to have been pretty regularly obovate and a little more than two and one-half times longer than broad. The Aving is perfectly ilat on the dirty broAvn stone, AAith black veins and more or less broken black intercalary veins, especiall}^ in the costal area. The humeral field must haA^e been \'ery slight; the niediastino-scapular A'ein pretty strongly sinuous in the basal half, nearly straight api- cally, the costal area occupying in the middle nearly half the Aving, terminating just aboA'e the apex, and being filled, including the intercalaries, with numerous, croAvded, oblique, simj>le veins. The externomedian vein follows the same sinuous course, is forked not far before the middle of the Aving, the lower branch again forked at less than half-Avay to the margin; proliably all fork again beyond, but the specimen is broken here. The inter- nomedian reaches just about as far out as in R. Gossii, is doubly arcuate, and has three or four inferior, straight, parallel, oblique branches. The nerA^ules of the inner are not nearly so croAvded as those of the costal margin. The anal furroAV is not dej^ressed, strongly arcuate at base, straight and oblique beyond, reaching the margin opposite the first forking of the externomedian Aein.
Probable length of Aving, 5.3 mm.; breadtli, 2 mm. The species is the smallest of the genus, comes from the AViltshire Purbecks, and is in the collection of the Rev. P. B. Brodie.
MKSOZOIC COCKROACHF.S. 447
Ritbma liasina.
ri.ir,, n^r. 7.
[Witliout name] Brodie, Foss. Tiis. Kiii;!.. lol. Tl. .-;. li.-. IL'. Jilaffiiialiasitia Girl).. Ins. A'orw., iJlT.
Blaltlilinm Jiasinum lli'cr, Vierti'lj. natiirf. (u'scllscli. Zriiicli. i\', 2S0. lilthma Hasina Seiuld., Proe. Aciul. Xat. Sc. I'liilad., ISS.l, 1 1 4.
Hy the kindness of Kcv. Mr. Brodic, I have liad tlie opportunity of studying' the orig- inal speeinieu shown in PI. 8, tig. 12, of his work, and find that it differs so nnieh from the figure given that a new drawing is neeessary, whieh shows helter than the original that it helongs in Jxithnia. The wing I'xhibits an under surfaee on a dirty light hrown stone, on whieh the veins show slightly darker; it is very slightly eoneave, the interspaces being slightly depressed in general, and rather markedly depressed where figured in white. The wing is largest just hefore the middle, tapers regularly beyond, and probably had a Avell rounded tapering tij), but the api'X is niueb broken. The eostal margin is gently arcuate and tlu' inner margin straight. Tiie humeral Held is very large, broad and ex- tends to the middle of the wing, is flat, and does not partake of the concavity of the rest. The mediastino-scapular vein is rather strongly sinuous and terminates just above the tip of the wing, the broadest part of the costal area being in the middle where it occupies nearly half the wing. The veins of this area are tolerabl}' niunerous, longitudinally ob- lique, parallel, the basal ones simple, tbe apical forked. The externomedian vein and its brandies are disposed almost exactly as in R. disjimcfa, but occujn' a little less space on the margin, being more displaced by the internomedian veins, which from base api- cally change their course conspicuously, the basal branches being almost transversely oblique with a slight terminal curve outward, the outer arcuate at root and nearly longi- tudinal beyond; the branches on the costal and inner margins have a similar distance apart. The anal area is A-ery large, the furrow being roundly bent in the middle and transversely oblique beyond, but yet reaching nearly or quite half-way down the imier margin and opposite the basal forking of the externomedian vein; it is not ])rominent, and would appe^ir to have been no more strongly depressed (on upper surface) tlian llie other veins.
Length of fragment, 12 mm.; ])robable length of wing, 14.5 mm.; breadth of same, 5.2.5 mm. The specimen comes from the Lias of Wainlode, Strensham, England.
Rithma formosa.
Blattina formosa Heer, Lias-Ins. Aarg., 15, PI., figs. 41, 42; Id., Urw. Schweiz, 8-3, PI.
7, figs.'l, U. Bithma formosa Scudd., Proc. Acad. Xat. Sc. Philad., 1885, 114.
In this species, in which the typical rounded wedge-shaped form of the wing is excel- lently shown, and only interfered with by the lateral expansion of the anal area, perhaps due to displacement by the crushing of its vaulted form, the humeral field is very narrow and small, the costal area broad, equal and appearing to embrace the tip (the figures are
MEMOIRS BOSTON SOC. SAT. HIST. VOL. III. i
118
SAMIKL II. SCTDDER ON
not (iiiito clear nor consistent), Avhilo in no other species is the fan-hke disposition of the ravs of the externo-and internoniedian veins so well shoAvn as here; they divide the field voVv cqnallv between them, the cxternoniedian vein forldng far back toward the base; and thc'lar"-c anal area with its almost regnlarly arcnate anal fnrrow and parallel veins oc- cupies about a thiid of the inner margin. The nervnles on the two sides of the wing are of similar distance apai-t and rather crowded. I have not seen specimens of this sjiecies but desciibe it biiefly from the figures.
The length of the wing is 15.5 mm; its breadth 5.5 mm; it comes from the Lias of Schambelen in Switzerland, and is known from a single wing.
Rithma Morrisi.
[Without name] AVestw., Quart. Journ. Geol. Soc. Lond., x, 390, PI. 18, fig. M. Jiithma J/on-m Gieb., Ins. Yorw. 319; Scudd, Proc. Acad. :N'at. Sc. Philad., 1885,
113, 114. Blattidium Morrisi Heer, Yiertelj. naturf. Gesellsch. Ziii-ich, ix, 290.
A single nearly perfect wing, known to me only by AVestwood's figure, is closely relat- ed to B. formosa, but is smaller, has its greatest width close to the base, has even more crowded veins, with more abundant dichotomizing and a much smaller not protruding anal area. The humeral field is very small but not slender, the costal area as in R. for- mosa,h\\i terminating just above and not embracing the tip, the median veins much as there but with more abundant forking of the branches. The anal furrow appeai-s to be bent roundly in the middle and to be oblique apically, yet not to reach even a fourth way down the inner margin.
The length of the wing is 10 nnn. and its breadth nearly 4 mm. The specimen comes from the Lower Purbecks of Durdlestone Bay, England.
Rithma purbeccensis.
[Without name] "Westw., Quart. Journ. Geol. Soc. Lond., x, 390, PI. 18, fig. 32. mtlima purheccensis GiQb.^lws. Yorw., 319; Scudd., Proc. Acad. Nat. Sc. Philad., 1885,
113, 114. Blatlidium purljeccensis Heer, Yiertelj. naturf. Gesellsch. Ziirich, ix, 290.
This wing is only known to me as the last, and it is less perfect, but has characteris- tics which easily distinguish it. It is probably broadest in the middle of the basal half and has the typical wedge shape. The humeral field is large and broad, tapeiing much apically and reaching more than one-third way down the costal margin. The mediasti- no-scapular vein is very sinuous, making the costal area broadest in the middle of the apical half of the wing where it occupies two-thirds of the entire breadth, but as the vein curves upward again apically andpro])ably strikes the exact tip of the wing, it nar- rows rapidly at the end; the area is filled Avith crowded, sinuous or arcuate, partially forked nervules, which are much more crowded than the distant, slightly forked, sinuous branches of the externomcdian and internomedian veins, Avhich appear to divide the space to the anal furrow about equally betAveen them. The anal furrow is strongly arcuate in
MKSOZOIC COCKUOACIIKS. | |<»
\]\v niidcllc aiul U-nninates as far out as tlu' liuiiu'i-al lu-ld and far hi-VDud iht- Iiasal branch- iii^- of tlie exteriiomedian vt-'in; anal vi-iiis not prosorvod.
TIk' k'ligth of the fragment is 10..") mm. and the presiuni'd length of tlit- w'lujf 11.3 mm.; its breadth is 3.5 mm. It comes from the Lower Purbeclcs of Durdlestone Ba}', l^ngland.
Ritbma DEdtoni sp. nuv.
PI. 46, fig. IG.
The single wing sent to me by Mr. Brodie is preserved in a similar manner as 7i*. j)ur- hcccensis and was at first taken to be the type of that species, but a closer examination -bowed that if the latter has been correctly drawn by Wcstwood, this must be distinct tVoni it. The wing is of the same color as the dirty chalky white stone on which it rests, the veins even showing no color distinction. These are finely impressed, showing as well as the slightly arched surface' that its upper side is seen; there are some faint inter- calary veins in the costal ai'ca not shown in the figui-e; the anal furrow is no more deeply incised than are the others, and the humeral field is flat and at a lower level than the rest. The wing is uudoubtedly broadest in the middle of the basal half, is wedge-shaped, ta- pering very regularly and considerably, with a straight inner and gently convex costal margin, to a somewhat pointed (here broken) tij). The humeral field, at fii-st erpial, tapers in the apical half which reaches nearly to the middle of the wing. The medias- tino-scapular vein is broadly sinnous, giving the costal area the same shape that it has in It. piirbeccensis, including the entire tip of the wing, the extremity of the vein passing a short distance below the very apex; its branches are nearly straight, parallel and oblique, the early ones simple, the later, arising in the broadening field, forked, the forks originating on a line with the bases of the simple veins. The remainder of the Aving is as in R. jnirheccensis, only the branches are equalh^ distant on the two sides of the wing.
Length of the fragment 10.75 mm.; probable length of wing 12 mm.; its breadth prob- ably 4 mm., though the extreme breadth at the tip of the anal furrow is slightly less, or 3.85 mm. The specimen comes from the English Purbecks, and the species is named lor Mr. AV. H. Dalton of the Geological Survey of Great Britain.
Ritlima Westwoodi. PI. 46, fig. 11.
[Without name] Westw.. Quart. Journ. Geol. Soc. Loud., x, 390, 396, PI. 18, fig. 22.
Ji'i(/ima Wesficoodi Gieb., Ins. Vorw., 318-319.
Blattidium Westwoodi Heer, Viertelj. naturf. Gesellsch. Ziirich, ix, 290.
Among the specimens sent me by Rev. P. B. Bvodie, one occurs which seems to be the type of AVestwood's figure, since in all that I have seen the figure is reversed, and in tliis instance the resemblance is close. I am able, therefore, to describe this S])ecies fi-om the iii'iginal and find the doubts I expressed concerning its position (Proc. Acad. Xat. Sc. Philad., 1885, 113) hardly to be confirmed, though of all the species of Rithma it is the most closely related to Mesoblattina.
The under siu-face is exposed, the specimen being transversely concave, with elevated veins and concave interspaces : all are of the same color as the dirty chalky-white stone.
4.*i(>
SAMUKL II. SCUDDER ON
Tho will"' is cxri-rdinglv sli'iidiT inn\ siiluimfironn. 1)c'inj>;- iiciirly four tinics lonnvr than bnt:ul. its liii'iiti'st hivailth Just hol'oir tlii' middle, both costal and iimcr margins <>ently lUTuatt,'. and the tip soinowhat producod. llie outer half of the inner margin a])pears to be slightly broki-n, but is apparently narrowed to the very slightest degree. The hu- meral lield is large. Hat, rather regularly euneiform, reaching about two-fifths way down till' eostal margin, sejiarated by a ridge (furrow, if it were viewed from above) from the adjaci'ut parts. The niediastino-seapular vein is .strongly simious and terminates far b(.li>w the tip of the wing, so that the eostal area, which in the entire apical half of the win"- occupies more and genei-ally nuich more than hall" the breadth, embraces the entire tip and is tilled with regular, straight or gt'utly arcuate, simple or forked, parallel, not crowded branches. The externomedian and iuternomedian areas divide equally between them what little space is letlt between this bi-oad costal area and the anal furrow. The anal area is large, the furrow, which is no moie ])rominent than the other veins, being bent roundly and sharply in the middle, and yet reaching almost as for as the humeral field, and as iar as the basal fork of the externomedian vein. Xo anal veins are presei-ved. The externomedian branches are only three or four in number, sinuous and longitudinal; those of the iuternomedian quite as few, nearly straight and oblique.
The length of the wing is 10 mm. ; its breadth, 2.6 mm. It comes from the English Purbecks, and according to Westwood, from the lower members at Durdlestone Baj!-.
It is possible that the obscure speeunen figured in PI. 46, fig. 6, also belongs to this species. It is too unperfect to determine. The slenderness of the wing and the resem- blance of the humeral field and anal furrow are very similar, but the form is less tapering, and the nervides, especially toward the tip, are much more crowded and more directly longitudinal. It is possible, however, that it should be represented as broader, as the inner edge comes against a slight elevation in the dirty chalky-Avliite stone. Perhaps a closely allied species is indicated. It comes from the English Purbecks and was sul)- mitted to me with the other by Mr. Brodie.
Another species, apparently belonging to this gciuis, is indicated l)y the obscure speci- men figured in PI. 46, fig. 8. It differs from any in the decided tapering of the apical half to an almcjst ])ointed tip, but the neuration is too imperfect to indicate any further characters. Probably the right hand margin is the costal. The wing is flecked with reddish-bi-OAvn, contrasting with the light brown color of the stone, the veins dusky. Its length is 7.2.") mm., and its breadth, 2.6 inm.; and like the la.st it comes from the English Purbecks and was connuunicated bv Kev. Mr. Brodie.
Rithma? minima sp. nov. PI. -18, tigs. 2, 8«, 8rj,\l.
["Without name] figiux-d with others by AW-stwood, Quart. Journ. Geol. Soc. Loud., x, 383-384, PI. 1~), i\<r. 14, the uppennost and the left hand.of the two lowest objects. Two objects which probably belong together, as their relative sizes agree perfectly.
are foimd on the same light brown stone, and ai-e referred here from slight indications
ME.SUZOIC COCKH()A( IIKS. 451
only ill the cliai;utir oltlu' wiiiji. 'llu- >|)i'ciis is ciTlainlv (li>liii(t liniii ;iii\ Uiinuii on account of it.s ^^izc alone, and tlic diicction of tlic inc<liastino-sca|)iilar vein i> sudi as to lead one to presume it teiininated at the very tip of the win;^, whicii is of an oval slnqte and rather broad for its length, tapering in the apical half to a rounded tip etpially slop- ing on lioth sides. The anal liirrow is not very strongly aicuate, hut uiuisually trans- verse and the anal veins impinge on the margin. .Vii upper surface is shown which is elightly domed. Length, 4 mm.; hreadth. l.S> mm.
The other object is a pronotum of a cockroach, S.lJ."* mm. broail and LM5 mm. long', broadly and transversely oval, the hinder margin less i-ounded than the front margin, tlie disc slightly convex, with slight irregularities like gentle longitudinal plications, as seen in the figure (lig. 2), the delicate edge very slightly marked by a darker line. As it corresponds exactly to what we should expect of a jtronotum belonging with the wing on the same stone, and is only about 2 cm. removed from it, and as no other known mesozoic species ajiproaches it closely in size, there can be little doubt that they belong together. The specimens come from the middle Purbecks of Dorset. England.
The other objects found on this same stone ai'c also figured on the same jilate. One of them, Pterinohlattinajiluma, is described elsewhere in this pajH-r. Fig. 4 (8i) is fig. 14;^ of AVestwood and considered by him as the wing of a grasshopper. Fig. 10 (S/") is fig. 14- of AVestwood and considered by him as one of the Trichoptera. Fig. VI ( ^d) is fig. 14* of Westwood, also considered by him as trichoptercjus. Fig. 13 (Se) is fig. 14;^ of AVestwood and named by him Cercojyidiiun Telesphorus. These will be dis- cussed at some future time, and are only mentioned here to explain the plate, accord- ing to AVestwood's views.
MksOBLATTIXA E.Geinitz.
Mesollattina E. Gein., Zeitschr. deutsch. geol. GcseUsch., 1880, .jU)-."i20; Scudd.,
Proc. Acad. Xat. Se. Philad., 188.3, 114.
Tliis genus, proposed at first by Geinitzas a suli-genus for a couple of species of mes- ozoic cockroaches, on account of the course of the anal neivures, Avas afterwards ex- tended by him to include another species, which disagreed in this particular from the others. In this he was right, inasmuch as the grouj), which should be accorded generic value, contains forms which vary considerably in this resjiect. The chaiacters leferred to in my paper on mesozoic cockroaches (see above) relating to the course of the inter- nomedian and externomediau nervules seem to be more important. The genus was the most prolific of any in mesozoic times. The wings are generally slender and parallel sided or nearly so, though in not a few thev' taper as conspicuously as in most of the species of Kithma, and one species at least is broadly oval. The flat humeral field is nearly always large and conspicuous, and the costal area large as in Rithma, from which it is distinguished mainly by its greatest peculiarit}', which is the basal sinuosity and subsequent almost completely longitiidinal course of the externomediau and interno- median veins and all their branches, the latter even rarely touching the boi'der before the apical half, and generally not befoi-e the apical fourth or fifth of the wing, while the anal furrow does not extend out after them, but meets the border at a broad angle. In addition to this, the veins of the anal area show in a considerable number of species (in
i:.ii
SAMUEL II. SCUDDER ON
nianv this part i^; not preserved) a strong tendency to run in a similarly longitndinal cotirse, so that thev trend from ditterent parts of the area toward the outer lower exti-emity of the area, where they are closely clustered. This is an approach toward the generally longitudinal course of the anal veins in recent cockroaches, where they abut upon the anal furrow and not on the margin. The genus stands midway between Rithma and Klisama, the latter being a genus in which the peculiar course of the median veins is more conspicuous than here, but which has no such lai'ge anal area as is common to the species of this genus. Mesoblattina is far more abundant in species than any other meso- zoic genus, being found in considerable abundance both in the Lias and in the Oolite, but especially in the latter. The species may be separated into two groups.
1. The anal veins are i^arallel and end on the margin at equal distances apart.
Mesoblattina Blakei sp. nov. ri. 46, fig. 12.
A single wing from which a considerable jjortiou of the tip is lost, but which shows all the characteristic parts of the neuration ahiiost completely. As restored on the plate, the Aving is exceedingly slender, nearly four times as long as broad, with very parallel sides, the costal 1)order gently arcuate, flattened in the middle and the inner margin neai-ly sti-aight. The humeral field is very long, lancet-shaped, extending nearly to the middle of the wing. The mediastino-seaijular vein is exceedingly sinuous, the area being bi'oadest opposite the tip of the humeral field, where it is nearly half of the breadth of the wing, and extending (probably) only a little distance beyond the middle of the outer half of the Araig; the nervules are oblique, simple, parallel, tolerably abundant. The ex- ternomedian vein first forks somcAvhat l)efore the middle of the wing and has long, so far as can be seen simple, wholly longitudinal, or upward curing branches Avliich trend so as probably to terminate on the tapering apex of the wing wholly above the middle line; probably they fork near the tip. The internomedian vein is divided back of the first forking of the externomedian into tAvo branches, the upper of AA'hieh forks near the mid- dle of the wing and resembles one of the externomedian oflshoots; the other has three or four inferior, sinuous, very longitudinal branches, all impinging on the outer half of the loAver margin and rather more closely crowded than the costal nerAitles. The anal area is very large, extending very nearl}^ as for out as the humeral field; the anal furrow is depressed, very uniformly arcuate, and the anal veins are very peculiar, appearing to consist of a mid-vein parallel to the anal furroAV, dividing the area into tAvo nearly equal halves and furnished Avith longitudinally oblique parallel nerA-ules Avhich appear to terminate at equidistant pcjints on the margin ; and second, of a single slight vein midAA^ay between the first and the anal furrow, the termination of AA'hich is uncertain since the outer loAver half of the anal area is broken aAvay, revealing beneath the very closely ap- proximated, parallel, oblique offshoots of (probably) the anal area of the hind Aving.
Length of fragment 1.5 mm.; probable length of Aving 19 mm.; Avidth 5 mm. In the structure of the anal area this Aving is totally difft-rent from any other species. It comes from the Upper Lias of Alderton, Gloucestershire, England, and Avas sent me by Kev.
MESOZOIC COCK ROACH KS. .| r^-,}
r. 1>. Bi-odie. It rests on :i dirly l»ro\vii stoiu-, lliu vt-iiis lu-iiio; l)I;icki>li. I liavi' naiiR-d it for lic'V. J. F. ]JIako who lias inadi' soiiiu ivst^airlics upon (he Lias insects.
Xc'xt to tills T place, (loul)t Cully, a couple olTorins which are evidently nearly i-elated, :nul ajjparcntly belong in this vicinity, but ai-e too iniperlcd 1<> di-ciiss fully until bet- ter material shall ofi'er.
One of them (PI. 46, fig. 3) has a large and long costal area in wiiich the main vein is regularly arcuate and its oblique branches are distant at base and apically forked; an ixteruomedian vein of little importance with two or three wholly longitudinal branches running down the middle of the wing; an internomedian with three or four inferior, at liist rather distant, bent branches, terminating far out; and an anal furrow which is ob- lique and straight apically, indicating a rather large anal area.
It should be noted however that the internomedian area is entirely separated from and lies at a slightly lower level than the rest of the wing, so that it is not impossible ( though not probal)le) that there are two wings here. Both i)arts are perfectly Hat with brown- ish veins.
The length of the fragment is 5.75 mm. and its breadth 4.5 mm. indicating a wing about 12 mm. long, and perhaps 5 mm. broad. -It comes from the English Purbecks and was sent me by Eev. P. B. Brodie. On the same stone, close beside the upper frag- ment, lies the specimen of Diplurohlattina Bcdliji descril)ed further on and figured on PI. 48, fig. 5.
The other (PI. 46, lig. 13) has a broad costal area which would be rather short, but that the otherwise rather strongly arcuate main vein is reinforced apically by two or three superior longitudinal branches, while the inferior branches are numerous, simple, parallel and oblique; the externomedian veiu is much as in the preceding and the inter- nomedian has almost equally longitudinal veins, forking considerably and gentl}' arcuate at base indicating a long anal area. The slight depression of the veins incUcates an up- per surface, but the surface itself is perfectly fiat. There is a slight ferruginous tinge to the Aving which Avith the blackish brown veins distinguish it quickly from the dirty light brown stone. The length of the fragment is 9 mm. and its breadth 4.25 mm., in- dicating a wing about 13 mm. long- and perhaps 4.5 nun. broad. It was received from Eev. Mr. Brodie but without indication of locality or horizon.
Mesoblattina Bensoni sp. nov. ri. 46, tig. 17.
An almost perfect Aving, being broken slightly at the base. It is ver}- slendci-, being almost four times as long as broad and of the same shape as M. Blcikei is presumed to be. An under surface is sIioaati. The humeral field is moderate, extending over some- what more than a quarter of the Aving. The mediastino-scapular A^ein is gently sinuous near the base, beyond nearly straight, terminating just above the extreme apex and giving the costal area nearly half the Aving; the veins are ntunerous, slightly elevated, parallel, longitudinally oblique, and in the outer half of the Aving ahvaA's foi'ked to a moderate degree. The externomedian first forks opposite the end of the humeral field, and has ul-
454 SAMri:L ii. scudder on
tiinntolv about oiiijlit or uiiu' hi-am-lios wliich have a very g-raceful longitudinal coxn'sc, soaroelv arcuate downward and occupying the whole of the lower half of the wing tip. Tlie intornom!.'ili,in is first forkod even earlier than the preceding, and its similarly abundant and crowded branches have a very graceful and gentle, longitudinally sinuous sweep, all falling on the margin in the apical two-fifths of the wing. The anal area is ample, the furrow being very regulaily arcuate, terminating near the end of the second fifth of the wing, depressed, especially iu the apical half; the anal nervules of a similar abundance to those of the rest of the wing, mostly forked near their base, arcuate and jiaralU'l to the furrows.
The length of the wing is about 18.2.3 mm. its breadth .").! mm. It comes from the Upper Lias of Dumbleton, Gloucestershire, England, where it was obtained by Rev. R. L.Benson, who gave it to Rev. P. B. Brodie, to whom I am indebted for an opportunity to study it. It is of a dull fuliginous color with here and there a reddish tinge on a blu- ish gray .stone.
Mesoblattina Swintoni sp. no v.
PI. 16, fig. 10.
A fragment of the most important parts of a wing shows so great a resemblance to M. Bensoni that it can hardly be doul)ted that it belongs in this immediate vicinity, while its diflerences will scarcely allow us to place it in the same species. The general distribution of the branches of all but the anal veins (which are not preserved) is es- sentially that of M. Bensoni, even to the relative origin of the earliest forks of the ex- terno- and internomedian veins and their relation to the humeral field; but the course of tlie mediastino-scapular vein (which is quite straight just where in M. Bensoni it is most sinuous, and gives the costal area about two-fifths of the area of the wing), and the less strongly arcuate and ajiicalh' moi-e straight anal furrow, which gives the area a gi'eater longitudinal extent while the straightness of the superior veins lessens its breadth, give it at once a different asjject from 3/. Bensoni and renders it most probably an entirely distinct species. It is also probable that it is not so slender a species as the preceding, being probably but little more than three times as long as broad.
The fi-agment is 8 mm. long, and 5 mm. broad, but the probable length of the wing was about 18 mm. and its probable breadth 5.5 mm. It comes from the English Pur- becks and is in the collection of Rev. P. B. Brodie. The species is dedicated to Mr. A. II. Swinton who has contributed somewhat to our knowledge of English fossil insects. It occurs on a dirty chalky-white stone, and is faintly fuliginous in color. An upper surface is shown and the wing is faintly arched transversely but is otherwise flat; the veins are channelled, the anal furrow and internomedian less than the others, but the anal furrow is not depressed below the level of the other veins.
Mesoblattina Geikiei sp. nov.
]'1.46, fig. 9.
A nearly perfect wing, beautifnlly preserved, shoAving an ujiper surface. It is slender, Ijeing slightly more than three times as long as broad. The humeral field is moderate
MKSOZOIC COCKROACIIKS. 455
ht'iii;^ about as loiii^ as the wiilili <il' llic wilier, ami laiicf(->lia[)c(l. The iii<'<liastiii<>- scapiilar vein is <jft'ntly and broadly sinuous tcrniiuatin;^ a lilllc above thr very api-x of the wiuj^, making tliu costal aiva broadi'st in the nruhlle and a little less than two-lilths the width of the wing; its branches are tolerably numerous, longitudinally obrKpic, the basal ones simple, the others which are more obliqu" forked about their middle. The ex- ternonu'dian vein forks iirst o|)posite the tip of the anal furrow, and terminates as far below the tip as the upper vi-in aljovi- it; it has two or three simpli' or forked longitudi- nal branches. The internomedian forks opposite the end of the humeral lield and has three or four more or less longitudinally simious branches impinging on the outer half of the inner margin, which, like the costal l)ranches, are less crowded on the margin than tlie ejcternomedian. The anal furrow is rather deeply depressed, strongly and very regu- larly arcuate, terminating a little beyond the end of the itasal third of the wing; the anal nervules are [larallel to it, but sinuous mesially (as if i)y an accident of inhnmrition) and apically forked, terminating at equidistant ])oints on the margin; they an; about as dis- tant as the costal branches. The whole wing, excepting in the basal half of the costal area and of course the humeral field, .shows a cross venation between the nervules, breaking them into pretty I'egular quadrate cells.
The length of the specimen is 1'2.2~) mm.; probaljle lengtli of wing liJ.o nnn.; its breadth 4.5 mm. It comes from the Lias of Brown's wood, Moreton liagot, Warwick- shire, England, and was sent me by Rev. P. U. Hrodie. It is named for the present director of the Geological Survey of Great IJiitain. The wing, which glistcne a little, is scarcely darker than the slate-gray stone on whii;h it rests; the veins, which run in depressions (while the inteicalai'ies keep the ridges of the roof-like interspaces) are reddish brown, interrupted frequenti}' by obscurer portions giving them a flecked ap[)ear- ance under the lens; the same is true of the cross veins in the anal area.
Mesoblattina dobbertinensis.
Blatllna (Mesohlattina) dobhertinensis E. Gein., Zeitschr. Dcntsch. geol. Gesellsch;,
188-t, 570, PI. 13, fig. 1. Mesoblattina dobbertinensis Scudd., Proc. Acad. Nat. Sc. Philad., 1S85, 115.
This species has been described with some care by Geinitz, and needs no further men- tion than to say that its nearest ally appears to be 3/. Geikiei, a species twice as long; it dilTers from it also in the greater brevity of the anal area and the much gi-eater breadth and importance of the costal area.
Its length is 6.5 mm. and it comes from the Lias of Dobbertin, Germany.
2. The anal veins are directed toward the tip of the anal furrow.
Mesoblattina Higginsii sp. nov.
PI. 47, fig. 14.
This species and the ne.vt, of neither of which is the anal area known, are placed in his group because of their general relations to the species which unquestionably fall here, though it may readily be found hereafter that they must be transferred to the
MEMOIRS BOSTON' SOC. SAT. HIST., VOL. III. 3
I.IG
SAMUEL II. SCUDDER ON
pfoi'oclinir U'nnip, lo llio Inttor sjiccios of Avliich tlioy bcnr ni:my mailss of roscmblnnce, but from wliich thov also both diiler much in the immense extent of the humeral field.
A sinjrle wing with a fragmentary tip repre.scnts the upper surface of this species. It is of a dnll, ]ialc yellow color on a dii'ty chalky-white stone. The surface is flat, the veins depressed and slightly dusky. Eestoring the form of the apex frcm the course of the existing margins and veins, the wing ajipears to have been elongate elliptical in shape, probablv thive times as long as broad, witli uniformly and considerably arcuate costal marijiu. The humeral field is depressed lancet-shaped and of unusual extent, i-caching certainly over one-half the wing and probably moi-e. The mcdiastino-scapular vein is pretty strongly sinuous, especiall}' arcuate a little beyond the base and terminates at the tiji of the wing, the costal area occupying in the oiiter half of the wing fully half its breadth; the branches are longitudinally oblique, straight, parallel and not crowded, the basal ones simple, the outer forked and more longitudinal. The externomedian is closelv attached to the preceding vein in the basal third of the wing, beyond that arcu- ate with superior, forked, longitudinal branches, the first fork opposite the end of the anal fnrrow. The internoraedian is pretty strongly sinuous and obliquely longitudinal with three or four inferior, rather distant, arcuate branches, strongly arcuate and sublon- gitudinal as they approach the margin, which they touch only in the outer half of the wing; it first forks opposite the divergence of the upper veins. The anal area is very large, the furrow no moi-e impressed than the other veins, strongly and pietty regularly arcuate, terminating, by reason of a slight outward sweep at the tip, not far short of the middle of the wing. The ultimate branches are more crowded on the apical than on the costal or inner margins.
Length of fragment, 11 mm., probable length of wing, 15.5 mm., breadth, 5.4 mm. The specimen comes from the English Pnrbecks, locality not stated, and was submitted to me by Rev. P. B. Brodie. The species is named for Rev. II. II. Higgins of Liver- ■ pool. *
Mesoblattina Murcbisoni.
PI. 47, fig. 5.
["Without name] Westw., Quart. Journ. Geol. Soc. Lond., x, PI. 18, fig. 43. liithma Murchisoni Gieb., Ins. Vorw., 319.
Blallidivm Murchisoni Heer, Viertelj. naturf. Gesellsch. Zurich, ix, 290. Mesoblattina Murchisoni Scudd., Proc. Acad. Nat. Se. Philad., 1885, 114-115.
Among the species with which I have been favored by Mr. Brodie is the type of West- wood's figure, and as this is defective in some particulars, I have drawn the specimen again. It is in much the same state of preservation as the preceding and though nearly related to it is nevertheless very distinct in the sweep of the inferior veins. It shows an under surface, nearly flat, the humeral field being a very little higher than the rest, th( veins seated on .slightly convex ridges. The specimen is of the same color as the dirty. chalky-white stone. Apparently no part of the inner margin is present, but the course of the inferior branches leads us to ])resume that it is straight, and the restoration of the wing on this basis, with the regularly aicuate curve of the costal, leads us to presume it
MKSOZOIC COCKKOACIIKS. .] -,7
wa-^ a little ini>re tliaii tliivi' times as loiij^ as hniad, and, while nearly <'iiiial iiisviillli thn)ii<jhr)iit, Ijroailest in the inidille. Tlie hiiineral field is lar^^e, laueet-sliapi'd i)iil hiuad- est shortly before its pointed tip, reaehin;;^ jnst ahont to tiie middle of the win;^. The iiii'diastino-scapular vein is jiretty stronj^ly .sinuons and espeeially arenate a little hc- V'liid the hase, exaetly as in M. Jfii///iii.-<ii, enrvin^^f upwards apieally and li-rrninatin^ he- i'wif and above the tip, niakinj;; the eostal area I)roadest in the middh-, where it is a little less than half the wiilth of the wing; the nervnles are exaetly as in M. JIi//f/iji.'iii or per- haps a little more o'oliipie. The entire struetnre of the extttrnoniedian is a repetition of what is foiintl in the'last species, excepting that the basal .divergence from tiic npper veins, is a trille earlier and that all the nervides impinge on the apical border above, in- stead of all below the tip. The inti-rnomedian veins are more lynnerons and crowded than in. 3/^. Iliyfjliisi!, have a more deeided basal curve, and so throughout nearly their entire length are almost completely longitudinal, sub-parallel to the mediastino-scapular vein, and undoubtedly parallel to the inner margin. The anal area is tolerably large, Init not so large as in the last species; the furrow, which has the character of the other veins, is strongly arcuate in the basal half, bent beyond the middle, and transversely ob- licpie and straight beyond, terminating proljably at about the end of the basal third of the wing. As stated, the anal veins ai'c al)sent, and it is only ])resumed to belong in this - i-lion by its allinitiesto others and especially to 3^. Bucklaiidi.
Length of fragment, 11.5 mm.; probable length of wing, l.'J mm.; breadth, 3.8.3 mm. The specimen studied is the original of Westwood's figure and comes from the Lower Purbecks of Durdlestonc Bay.
Mssoblattina Bucklandi sp. nov.
PI. 47, fig. 2.
Although a slight fragment is broken from the base and from the apex of the si)ecimen representing this species, it is practically perfect, and though the costal mai-gin is con- siderably less arcuate, it is of much the same .shape as that presumed of 3L 3Iiirchisoni with which it agrees closely in all other particulars. It shows an under surface, being concave, the anal area separately and to a considerable degree; the veins run along the top of convex ridges. The humeral field is, however, simide, lancet-shaped and only about two-fifths the length of the "vving, though still extending further than the anal area. The costal area is almost a complete du2:)licate of that of 3/. Murchlsoni, but is a little broader in the middle, almost equalling half the breadth of the wing. The cxter- nomedian vein arises in the same way but first forks a little later, just beyond the tip of the anal area, and the branches, diverging very slightly and uniforml>', cover a con- siderable space on the margin, so as to occupy nearly all the arcuate ])oi-tion of the apex below the costal area. The internomedian veins are hence a very little less longitudi- nal, trending slightly downward, though they strike the margin only in the apical half of the Aving. The anal area is of about the same size, but the furrow, which if an upper surface w'ere shown Avould be uniformly and rather deeply impressed, is almost uniformly arcuate, wdth no median bend, striking the margin obliquely, a little beyond the basal third of the wing. The anal veins, next the furrow subparallcl to it, form as a
158
SAMUKL II. SCUDDEIl ON
wholo a sub(usir<iiin Immllo. its outor apox dircctod toward tlio extremity of the anal rurn>w : lliev seem, liowever, to terminate rather on the innermost vein Avhich rnns par- allel to the margin, than on the margin itself. The anal area and the onter adjoining parts show a line cross-veining l)reaking np tlie interspaces into tolerably regnlar quad- rate eells.
LrtMiglh of fragment. 10 nnn.; presnmable length of wing, 11 nnn.; its breadth, 3.25 mm. The specimen, received throngh the favor of Mr. lirodie, comes from England, but its location and horizon are not indicated. It is ])robabh' from the Pui'beclvS, and is named in memory of AVilliam Buckland. The wing is of the same color as the dull blu- ish grav matrix, but the veins, generally scarcely darker, are in places quite black.
Mesoblattina elongata.
[Without name] AVestw.. Quart. Journ. Geol. Soc. Loud., x, 391, PL 15, fig. 23.
Blattiiia dongata Gieb., Ins. Vorw., 322.
Mtsohlattina elongata Scudd., Proc. Acad. Nat. Sc. Philad., 1885, 115.
This species is too obscurely figured to enable me to describe its structure in detail, but it certainly agrees closely with M. Bucklandi, with which it agrees avcII also in size. As, howevei', they difter in several points of importance, I have not thought it right to consider them identical; in particular maybe noted in this species the comparative brevity of the humeral field, which ajjpearsto be broken off, the abundance of the costal nervures, and the upward sweep of the median nervules.
The species is represented as 11.75 mm. long, and comes from the Middle Purbecks of Durdlestone Bay, England.
Mesoblattina protypa.
Blattina ( ^fesohlattina) protypa E. Gein., Zeitschr. Deutsch. geol. Gescllsch., 1880,
519-2fJ, PI. 22, fig. 1 ; Id., iUd. 1884, 569-70. Mesoblattina protypa Scudd., Proc. Acad. Nat. Sc. Philad., 1885, 114.
This species, distinguishable among its neighbors by the comparative brevity of the humeral field, the narrowness of the costal area and the straiglitness of the mediastino- scapular vein, has been carefully described and figured by Geinitz, and needs no further mention here.
The wing is 8.5 mm. long and comes from the Lias of Doljbertin, Germany.
Mesoblattina Murrajri sp. nov.
PI. 47, fig. 4.
This species, known by a single example broken in the middle and lacking the tip, is still so nearly complete as to be satisfactory, and its evident relationship to the next two '^pecies shows that, although the anal veins are wanting, it must fall in this group. The specimen is scarcely dingier than the dirty chalky-white stone on which it lies, the veins concolorous. The upper surface is exposed and it is well arched, the veins impressed, the interspaces convex, and when narrow, as at apex, prominent. The wing is broad- est a little before the middle, and tapers very gently owing to the arcuation of the
MKSOZOIf COCK UO AC I IKS. l.-,9
costal margin ; llif lip is pnthaMy pretty liilly i-ouiuK-d. 'I'lu- luimcial lit-ld is will de- veloped, well marked, Hat and strongly de|)ressed, slenderly laneeolate, extending over the basal two-fifths of the wing, the costal hijrder delieately uiarginnte. The nu-dias- tino-sca;)nlar vein has an entirely similar eonrse to that of M. Mitrc/iisoni, making the costal area broadest in the middle of the wing, bnt there only two-liflhs the width of the wing; the nervules are simple, rather li>ngiliidinally obliiiue, parallel and nnnuions. The base of the externomedian vein is obscnred, but the bianelu-s, which are oeeasionally forked in the apical half of the wing, are all straight, crowded and completely longitu- dinal or tiend slightly upward, occupying on the margin the greater, especially the upper, part of the tip. The internomedian vein first forks before the middle of the basal half of the wing, is very sinuous, the basal branches strongly bent near the outer angle of the anal area and afterwards sweeping outward with a slight obli<piity. The anal furrow is not depressed, sti'ongly arcuate, its tip slightly sinuous, reaching a little be- yond the basal third of the wing.
Length of fragment, IS-C) mm.; probable length of wing, 10 mm.; its breadth. ").;}."> mm. The specimen, the study of which I owe to Mr. lirodie, comes from the English Piu'- becks, locality not stated, and is named for the late Andi-ew Murray, Esfp, who found time amid other valuable studies to describe the only known fossil insects of British India.
Mesoblattina Brodiei sp. now
n. .17, lig. 7.
The species is represented l)y an excellent specimen showing the u|)per surfaci- of the wing, a little dingier than the dirty chalky-white stone on which it lies; it is slightly con- vex with the flat humeral field dcclivcnt, its inner border deeply imjjressed like the anal furrow; all the veins are impressed and of the color of the wing, those of the exteruo- median and internomedian areas much more faintly than the others. The wing is obo- vate in general form, but is of somewhat irregular shape, in which it agrees in part at least with M. .^fantelli. The costal margin is strongly arcuate up to the tip of the hum- eral field, and beyond that straight to the very broadl}' rounded apex of the wing. The inner margin has two pretty strong and independent curves; one that of the anal area, and the other that of the remainder of the wing, where, while the curve is uniform, the effect is gained of being subparallel to the costal margin until half way to the tip, when the wing tapers somewhat by the rounded excision of the lower outer angle. The wing as a whole is about two and one-half times as long as broad. The humeral field is lanceolate, its inner border bent in the middle, its pointed tip reaching two-fifths way down the wing. The mediastino-scapular vein, parting from the humeral field at its an- gle, runs subparallel to, but a little divergent from, the costal margin in a very broadly arcuate curve to the tip, throwing off' many jjarallel, oblique nervui'cs, the basal ones of which are sim])le and croAvded, the apical more distant, more longitudinal and forked, forming a costal area which occupies considerably more than two-fifths of the width of the wing. The externomedian vein runs close and parallel to the preceding, first forks just before the tip of the humeral field, and has three or four generally simple, inferior, sweeping, arcuate, longitudinal branches, followed by the even more arcuate, simple, api-
Kill
SAMUEL II. SCUDDER ON
i-allv louijitiidinnl. inliM-nomcdian braufhes. which arise earlier and cover an area of about equal extent. The anal furrow is strongly arcuate, being bent stronglj' in the middle and terminating slightly further out than the humeral field. The anal veins consist first, of two rather distant nervules subparallel and next to the anal furrow, and next, of two sets of ortshoots of the inner of these, the outer of which form, with these, a subfiisiform series directed toward the tip of the anal furrow, the other inner set sinuous, crowded, and apparently impinging on the basal half of the border within the anal furrow. The length of the wing is 10.5 mm.; its breadth 4.1 mm. It comes from the English rnrbecks and was kindly sent me for study by Rev. P. B. Brodie to whom I take pleas- ure in dedicating it.
Mesoblattina Mantelli sp. nov. ri. 47, tig. 9.
An almost completely preserved wing, curiously resembling and curiously different from M. Brodiei. The veins are of the same color as the rest of the wing, which is slightlv dingier than the dirty chalky-white stone. It shows an upper surface, but is somewhat distorted by lying on an uneven surface, so that its convexity is not quite so apparent as it would otherwise be. The anal area has its independent and somewhat marked convexit}', and the anal farrow, as well as the inner limit of the flat depressed humeral field, is deeply impressed. The wing is obovate with subparallel sides, but with somewhat ii-regnlar shape, the costal margin being straight from the middle of the hu- meral field to the middle of the outer half of the wing, and then curving strongly and jiretty regularly downward to the lowermost part of the rounded apex, where it is met by the uniform and slight arcuation of the inner margin from the anal furrow outward; for the margin of the anal area has an independent arcuation, also regular but much stronger. The whole wing is a little less than three times as long as broad. The humeral field is sublanceolate, finely tapering, reaching more than two-fifths way to the wing tip. The mediastino-scapular vein is very strongly sinuate, terminating just above the tip of the wing, and the costal area is broadest in the middle of the wing where it is scarcely less than half its width; the branches are longitudinally oblique, the basal ones simple, the ai)ical compound, arcuate, and less longitudinal than the basal. The externomcdian branches, which are considerably forked apically, arise from two forked branches, which unite close to their divarication opposite the tip of the anal furrow and far within the tip of the humeral field; as a whole they are longitudinally and broadly arcuate. The interaomedian branches, few in number and hardly forked, arise scarcely earlier and have a similar course, but are more strongly arcuate basally; they extend far out to the lower angle of the tip of the wing, while the externomcdian branches occupy the tip only. The anal furrow is strongly bent in the middle, turning sinuously outward at tip but even then does not extend quite so far as the humeral field. The anal nervules are obscurely preserved, but appear, as in M. Brodiei partly to impinge on the basal half of inner margin, partly to converge toward the tip of the anal furrow.
The wing is 10.4 mm. long, and 3.65 mm. broad. It comes from the English Pur- becks, and was received from Mr. Brodie. It differs from M. Brodiei in the form of
MESOZOIC COCKROACIIKS. ICl
the winu:, tlir sliapi' of tlio lumu-ial aiT;i, the foiirsc of tlu- nu'diastliio-scapular vfiii and till! character of its hranclu's, and in the" inulti|>lirity of tin- apical t'Xti'rnoiiU'<liaii iicr- viiles. It is namt-'d in memory of MaiittU tin- lOn^rli-^li ;,^toIo;,Mst.
Meeoblattina Hopei -i > '^ l'l.^7. (I;;. 11.
'I'lii- fiajiinciit of a winj; i-i-|iri'si'ntiiij; this spccii-s laiks the apical fil\h of the \\\n<r and a coiisiderahle fia<;inent of the hnmeral reg'ion as well as tlie anal area. It shows the under surface of the wing, wliich is a little dingier than the dirty chalky-white stone, heing uniformly concave tranversely, with the veins slightly sunken on the sununits of ridges; although the anal area is gone, tin- furrow sIkjws slightly prominent as a ridge. As restored in the ligure, which seems to indicate its jjrohahlc form, it was parallel sideil, •witli a scarc-ely perci'i)til)le taper, and i)rol)aI)ly a little more than three times as long as liroad, for the remains of the costal and inner margins are straight and almost parallel and the veins have a veiy longitudinal aspei-t. I'he mediastino-seapidar vein was hroadly and gracefully sinuous, plainly terminating at some distance before the tip, most of its branches somewhat longitudinally oblique and compound, the costal area being broadest at the end of the basal third of the Ming, where it is scarcely less than half its entire breadth. The externomedian and internomedian veins are longitudinal beyond their base, and even, especially the externomedian, swing upward, the division between the two being probably at the very apex of the wing. The anal furrow, roundly bent vei-y strougly before its middle, takes an oblique course beyond it, but probably does not ex- ceed the basal fourth of the wing.
The length of the fragment is 11.2.5 mm.; the probable length of the wing 14.2.'* nun.; its width 4.7.") mm. It comes from the English Purbecks, and is named for Rev. F. AV. llupe who has contiibuted to our knowledge of fossil insects.
In this vicinity appears to fall another specimen from the English Puibecks (PI. 47, fig. 6) which is too obscure for extended description. It is a nearly perfect wing, showing the upper surface, but being of the same color as the dirty brown stone it is hard to deter- mine the venation excepting in the most general way. In form it appears to resemble rather closely that presumed for J\L Ilnpei, except in being slenderer and having a more acuminate tip. It appears to be more than three times as long as broad, with a large, prominent, sunken humeral field ; a scarcely sinuous mediastino-scapular vein, terminating probably above the apex of the wing and having numerous oblique branches, fonning an area which occupies nearly half the wing; longitudinal and closely aj^pi'oximate parallel median veins; and a comparatively small anal aiea,thc furrow not reaching one- fourth the Avay out.
Length of Aving, 1G.7 mm.? ; breadth, a.." mm.
Mesoblattina Peachii sp. nov. PI. 47, fig. 10.
The nearly perfect specimen Avhich represents this species shows the upper surface of a Aving. Avliich is a little dusky on a dirty. chalky-Avhite stone. It is gently convex Avith
4r.2
SAMUEL II. SCUDDER ON
tlif vfiiis tli'licatolv iinprossod, tlu> niial fun-ow iijipaiTntly no more deeply thnn the (UluTs. The win;? i^ very regiihirly elongate elliptieal in form and abont two and three- fourth-^ times longer than broad. The extreme base is broken, but the flat humeral field is apieally pointed and tapering, and apparently just about as long as the width of the wing. The eharacters of the costal nervules are just about intermediate between those of J/. Brodiei t\m\ M. MantelU, the area being broadest in the middle, where it is verv nearlv half the width of the wing and extends to the exact tip of the wing. The oxtenumiedian and intcrnomedian veins are also about intermediate between the same two species, though their terminal area is almost exactly as in M. Brodiei. It differs, however, from both of these species in the very regular form of the wing. The anal furrow is precisely as in M. Ilopei and terminates on the margin just short of the tip of the humeral field.
Length of fragment. 10.5 mm.; probable length of wing, 11.6 mm.; breadth of same, •i.l mm. It is named for Mr. B. N. Peach of the Geological Survey of Scotland, and eoines from the English Purbecks.
Mesoblattina angustata.
Blallhia angustata Heer, Yiertelj. naturf Gescllsch. Zurich, ix, 288, 299-300, PI., fig. 6. Blatllna {Mesoblattina) anyiistata E. Gein., Zeitschr. Deutsch. geol. Gesellsch., 1880,
.-)19-.520. Mtsohlaitina angustata Scudd., Proc. Acad. Nat. Sc. Philad., 1885, 111.
Tills species, which is well figured and described by Ileer, is conspicuous among the species of Mesoblattina for its wedge-shaped form, iu which it closely resembles a Kithma. The course of the intcrnomedian branches contends, however, against this, and besides, all the anal veins cluster apieally toward the tip of the anal furrow, as often in Mesoblattina, and never, so far as known, in Rithma. The costal area occuj^ies half the wing and the humeral field, of Avhich Ileer makes no mention, must be very small, slender and short.
Length of wing, 8 mm.; breadth, 2.5 mm. It comes from the Lias of Schambelen, Switzerland.
Mesoblattina Mathildae.
Blattiaa Mathildae E. Gein., Flotzform. Mecklenb., 29-30, PI. 0, fig. 1.
This somewhat aberrant form of Mesoblattina has been wrongly interpreted by Dr. E. Geinitz, as he has mistaken the inner for the costal margin and vice versa. The base of the wing is broken, but the fragment seems to represent an elliptical wing, a little more than two and one-half times longer than broad, with the lower outer edge rounded off, so as to bring the tip of the wing above the middle line. No trace of a humeral area can be seen, and it must be confined to the broken base and therefore short. The mcdiastino-.scapular vein (anal and ])art of intcinomcdian of Geinitz) is pretty strongly and regularly arcuate in the fragment (probably with a reverse curve, so as to be sin- uous, toward the base), terminating just above the elevated tip of the wing, broadest in the middle, where it is more than two-fifths of the breadth of the wing, all its branches a little longitudinally oblique and parallel, the basal ones simple, the outer forked or
MFCSOZOIC fOCKROAfllKS. .i<\:\
cnmpDiind. 'i'lu' cxti'i-noiiu'iliaii is arcuate at l)a'^t', tirst (oikiii;:^ i)|i|H)>.itc tlic tip of tiit- anal I'linow, shortly after whicii tlie forkiiij^ braiiclios become coinpli'tely loii;j^itinrniaI and occupy apically a very narn)\v portion of tlie extreme apex. Tlio iiiteniomediaii first forks back of the fraji^ment and witli its branches has a (leci(h'dly arcuate sweep, all tlie veins In the apical half of the win;^ bcinij almost completely loni^iliidinah and im- Jiinf^ini;" at subeqiial distanci-s alon^ the whole inner mar^jfin beyond the anal fmrow. In this ])articnlar it rather i-escmbles Ivithma, bnt this is bronj^ht abont by the sinj^le fact that the innermost branch, jnst opposite and close to the ti|) of the anal fnrrow. has a forked i)ranch which sends three shoots to the marf:;in dose beside it. bnt foi- which, all the terminal branches wonld reach beyond the miildle of the win;.:^. The anal furrow is only seen near the end, where it is strai<:fht and obliipie and probably strikes the mar- gin before the end of the basal third of the win^i^.
Lenji'th of fragment, 18 mm.; probable len.y;th of winj^, 22..") mm.; breadth, H..'{ mm. It comes iVom the Lias of Dobbcrtin, Germany.
Mesoblattina antiqua.
[Wilhont name] AVostw., Quart, dourn. Gcol. Soc. Lond., x, .'U)."!, I'l. 17, lig. 10. lilthma antiqua Gieb., Ins. Yorw. 319.
Blattldium antiquum Hccr, A'iertclj. naturf. Gesellsch. Zurich, ix, 2f)0. Mcsohlaltina antiqua Scndd., Proc. Acad. Nat. Sc. Philad., 1SS5, 115.
This species is peculiar for its rcmai'kable form, the costal margin being nearly straight and the inner and apical margin strongly curved, throwing the apex of the wing far above the middle; in this respect no species but M. JSfathildae resembles it; but the form is exaggerated in "Westwood's figure from the fact that the base is wanting, Avhich, if supi)licd, would probably make the wing about two and one-half times longer than broad, iilstead of the extreme brevity of oid}' twice as long, as the fragment is. Marginal field and anal area are altogether wanting in the preserved portion, although it is probable that the anal furrow is shown; in which case the latter must hi^e had a sinuous course from a strong outward curve at tip, and have terminated considerably beyond the basal third of the wing. The mediastino-scapular vein is very sharply sinuous, terminating at the elevated tip of the wing and making the costal area twice as broad (half the breadth of the wing) in the middle of the outer, as in the middle of the inner half of the wing, its branches very longitudinally oblique, the generally simple basal ones more so than the outer ones. The externomedian is much more important than the internomedian vein, occupying more than twice the area, and as much marginal space, its forking branches nuiformly and rather strongly arcuate throughout, apically parallel to the outer branches of the costal area.
Length of the fragment, 7.2.') mm.; probable length of wing, 9 mm.; its breadth, 3.5 mm. It comes from the Lower Purbecks of Durdlestone Ba\-, England. It will pos- sibly be found to belong in Elisama.
UGMOIES BOSTON SOC. NAT. UIST., VOL. III. t
J
4(J4 SAMIKL II. SCUODER ON
Mesoblattina? lithopliila.
J/h.sv., iiihnphila Cioi-m., Ac-ta Acad. Lcop.-Caro]., xix, 222, PI. 23, fig. 19; TVeyeiib., Arch. >riis. Tovl., ir, 2oG-2.")7, PI. 34, fig. 2; Assm., Bcriclit Yers. deutsch. Naturf. I.. 102. lihittnlitim lierohlhifiianum ITocm', Viertolj. iiaturf. Gcsdlsch. Zurich, ix, PI., fig. 8.
Assniaim is ]irobal)ly correct in referring Ileer's species to tlie one earlier describe by Germar, and it appears probable that it belongs to this genus, though no figures good enough to make it certain have yet' been published, and its reference here is onl\ by way of .suggestion.
The upper wings are IG mm. in length and the species comes from the Jurassic beds of Solcuhofen, Bavaria.
ElISAMA Giebel (cmeml.)
IJlisoma Giebel, Ins. Torw., 320; Scudd., Proc. Acad. Nat. Sc. Philad , 1885, 113.
Although Giebel misinterpreted the neuration completely, interchanging the costal and inner margins, the species on which he founded the genus form a natural group, to which I am now able to add others; his name may, therefore, be retained. The wings are not so slender, generally, as in Mesoblattina and Kithma, and are more nearly allied to the former, ])ut the characteristics by Avhich that is distinguished from Kithma are here intensified. In none of the species known to me are there any specimens in which the base is comjiletely preserved, but what remains are preserved show, without reason fin- doubt, that the wings are most peculiar in this very region. There is no sign in an}^ of them of any separate humeral field, so characteristic of Rithma and Mesoblattina, and if it existed it must have been very slight. The anal area is also exceptionally .small and unimportant, rarely extending a fifth way down the wing and having a veiy slight breadth, the anal furiow ajjpearing to be either straight or bent in a sense the reverse of usual, taking rather the direction of the anal angle of the wing. In consonance with this, the median branches and especially the internomedian are more sharply bent than even in Mesoblattina ^though some species of the two genera agree fixiily well here) and fill the inner half or more of the wing Avith longitudinal veins, so that this region is in marked contrast to the costal with its oblique bi-anches. The median I)ranches seem to be always numerous, and, excepting in one instance, do not reach the border before the distal half of the wing.
The genus is tolerably abundant in species, most of which arc found in the English Purljecks; one, however, doubtfully referred here, belongs to the Swiss Lias.
ELLsama Molossus.
JihilCllum Molossus Wcstw., Quait. Journ. Geol. Soc. Lond., TX-, 384, 394, PI. 1.";,
fig. 26. Xffllinnia MoJossns Gieb., Ins. A^orw., 321.
Giebel founded the genus Nethania upon this single species, upon characters drawn
MESOZOIC COCKHOAfllKS. K;.-
fri)in thu siipi) >>itii)n tlial tlic ohliinu' vt'iiilcls wi-ii' tlmsc of tlu- anal, while llicy arc really tii )se ofcDStal arei, tlu- in iru;ius oftlK' wiiii^ li,iviiii:f l>('i'u iiiU'i-cliaii;;t'(l in his con- ception of it. The genus Xethania then miglit Ins allowi-d to drop out of sight, oven if it did not appear that the species in question should fall into (he sanu- genus as the spe- cies referred by him to Elisama, in the <-onceplion of which, as pointed out ahove, he made an exactly similar error. The species seems in (act to fall ne.xt to E. Kiuri, hav- ing a very similarly arcuate mediastino-scapular vein, terminating, probably, higher tlian theie, and a similar swec|) and manner of forking oj" the medi.in veins, and, besides, a spot near the base of internoniedian area (but farther out than in E. Kneri) apparently made up of nuniLM-ous cross veins; but the basal sinuation (d" the main vein is much greater than is possible in I'J. Kneri and the basal arcuation ol" both t-xternomeclian and inter- noniedian nervules, especially the latter, is so much less marked, so comparatively slight indeed, that it was not at first recognized as a member of this group, of which indeed it must be looked on as a rather alx-rrant foi-m.
Length of Iragment, 8 mm.; probable length of wing, ]0..> mm. The breadth is too uncertain in the figure to give any definite statement. The specimen comes from t lie middle l*urbccks of Durdlestone Bay, England.
Elisama Kneri.
PI. 47, fig. 1.
[Without name] Brodie, Foss. Ins. Engl., 118, PI. 5, fig. 1.
Elisama Kneri Gieb., Ins. Vorw., 320.
Blattidiam Kneri Heer, Yiertelj. naturf. Gesellscli. Zurich, ix, 291.
I have received from Mr. Brodie the original of his illustratitjii, of which I give a new figure showing the wing to be less complete than his plate would lead one to suppose. Only about half the Aving remains, but this the most important part, more than a third, probably, of the tip being broken off, and a not unimportant part of the base. The straight, scarcely divergent costal and inner margins of the fragment indicate, Avith the neura- tion, a form like that restored, which, if correct, would make the wing about two and one-third times longer than broad and broadest just beyond the middle. The media.s- tino-scapular vein has a very strong arcuation, strongest on the basal side, since beyond, by successive forks, it loses the strength of its arcuation and is probably carried to the very tip of the wing; the greatest Avidth is before the middle of the wing, where the costal area is considerably more than two-fifths the breadth of the wing; the basal branches are simple and oblique, those beyond forked or compound and increasingly longitudinal. The externomedian branches are all superior, the internomedian all inferior, but all take a common arcuate sweep so as to be longitudinal in the middle of the Aving, and the former probably occupy on the margin only the lower half of the tip. BetAveen all the veins Avhich reach the margin are intercalai-ies, and Avhere the internomedian nervules commence to become longitudinal, i. e., just where the lowermost approaches the border, they are obscured by a large roundish fuscous spot, Avhich nearly crosses the entire field. The anal farrow and anal area are lost in the broken base of the wing, but must have
MW
SAMUEL II. SCUDDKll ON
hccn viM-v sinnll. An uiulor suiTace is exposod on tlu' dirl y li^ht brown stone, scarcely tlnrkiT tlian llio stone itself, with veins and interealaries black; the surface is almost iH-rfeitiv llal, onlv a slij;lit concavity being discernible, and the A'cins are elevated in the slijrlitest possible degree.
Tiie length of the fragment is 8..") mm.; pr()l)al)lL" length of the wing, 13.0 mm.; its breadth, 5.75 mm. The specimen comes from thePurbecks of Wiltshire, England.
Elisama minor.
ri. 47, fig. 13.
(AVithout name] Brodie, Foss. Ins. Engl., 118, PI. 5, fig. 20.
Elitfama muior Gieb., Ins. Torw. 320.
lilattiiUum minor Ileer, Viertelj. natnrf. Gesellsch. Zurich, ix, 291.
A specimen received from Ivev. Mr. Brodie seems to me to represent pretty cer- tainly the original of his illustration of this species (represented, as usual, reversed on hi< ])late). But even if it is not, it certainly belongs to the same species, and its exam- ination shows that, as in the single specimen oi E. Kneri,i\\Q base is badly broken, and about a quarter of the tip lost; nevertheless the most important part of the neuration re- mains and enables us to restore the wing with considerable confidence, by which it would appear to be nearly two and one-half times longer than broad and to have had a more convex costal margin than E. Kneri. An under surface is exposed, of the same color as the dirty brown stone on which it lies, with black or blackish brown veins and interealaries. The surface is flat or scarcely concave, the veins scarcely elevated, and the interealaries slightly sunken. The mediastino-scapular vein is moderately and very regularly arcuate throughout, terminating probably just above the extreme tip of the wing, its branches quite as in E. Knei'i; the Avidth of the costal area, which is broad- est just before the middle of the wing, is here scarcely less than half that of the wing. The extcrnomedian and internomcdian branches, by a strong ai-cuation at base, almost immediatel}' take on a longitudinal and pai'allcl course, filling the space below with very straight veins, those of the extcrnomedian occupying apparently a very narrow space on the extreme tip of the wing. On their basal half or third, farther out next the inner margin than above, these veins are crossed by numerous cross veins, and in the same l)lace as in E. Kneri is a ]iretty lai-ge roundish dusky jiatch. There are interealaries be- tween all the veins. The anal furrow, which is perfectly flat, is bent in the mitldle at a broad angle in the same direction as the inner angle of the wing.
The length of the fragment is 5.5 inm.; the probable length of the wing 7.75 mm.; its breadth 2.1 mm. The specimen comes from the English Purbecks and bears also the name "Blake," probably the collector.
Elisama Bucktoni sp. nov.
PI. 17, figs. 8, 12. Two specimens, submitted to me by Mr. Brodie, represent this species, neither of them with the base quite perfect, and one with about one-fifth broken from the tip.
MKSOZOIC COCKUIJACIIKS. KJT
Both of tliiiii n1i(»\v tile uii|iii' siirfacf li.iiisvt rsclv, sli^ihtly nml icjiuliirly :ircln-(l, witli tlic (li licntc veins impicssi'd slKiipIy and sli^ililly in tin- I)a>al liall" <»(" tlic win^, wiiili- in tliL' apical hail" tlicy run as sli;j,liL riilj^vs at tin- ixittoni oC llatli-ncil Cniiows Iti-lwii-n slijjflit, ronndid lid^cs, tlic rid<jf('s scaret'ly narrower than the I'nrrows and the passngcs from one to the other l)ein<jf "gradual. One of thoni, li;^. 12, is of the same c(»lor, veins and all, as the dirty lii;ht hrown stone, and has the anal furrow a little more deeply im- ])rcssed than the other veins; the other, lij^. S, is slij;htly discolored and rests on a dirty ehalky-white stone, and the anal furrow is ohscure, although apparently impressed no more deeply than the others; where the costal horder of this specimen is host preserved it is seen to he narrowly mar<i,ined. The wings arc somewhat more than two and one- half times longer than hroad, arc hroadest just helbre the middle dI' \hv hasal half, lie- yond which they taper very slightly and regularly to ahout the middle of the apical half, when, especially hy the rounded excision td the inner margin, they narrow nnieh more rapidly and terminate in a somewhat pointed shapi-, the apex ahove the midiUe line of tin- wing; along most of their course hoth costal and inner margins arc straight or very nearly straight. The mediastino-seai)ulai" vein is very hroadly and ])retty imiforndy arcuate, teiniinating just aI)ove the extreme apex of the wing, and, excepting two or three sim[)le ones close to the hasc, all the hranches are arcuate, parallel, ol)li(|ue and strongly compound, so that comparatively few originate directly from the main stem, while a very large number of crowded ncrvules reach the margin; at its extreme hreadth, ahout the middle of the Aving, the costal area occupies a little more than two-fifths the ■width of the wing. The externomedian and internomedian veins are broadly sinuous, being almost longitudinal in the middle, pretty strongly arcuate in one sense next the base, and gently arcuate in the opposite next their prett}' uniforndy forking tips where they curve downward to strike the margin, the externomedian terminating upon the apex and extreme apical end of the inner margin, the internomedian beyond the middle of the inner margin. The anal furrow is a straight oldique line, apjiarently curving down- ward at extreme tip, in one specimen (fig. 12) terminating at no fuilher than one-fifth of the way from the base, and leaving necessarily an extremely small anal area.
Length of one specimen (fig. 8) 10. G mm.; breadth 4 mm.; of the other (fig. 12) 8 mm.; probable length of wing 10.1 mm.; breadth 3.7.> mm. Both specimens come from the English Purbecks; the species is named for Mr. G. B. Buckton, who, in a recent monograph of British Aphides, has not neglected the fossil species, whether Biitish or foreign.
Elisama Kirkbyi sp. iiov. PI. 47, fig. 3.
A wing from which the base and one-third of the tip are lost represents this species, which nevertheless plainly belongs in this genus and is very distinct from the other spe- cies, the neuratioa being so regular that it could be restored iu the missing apical por- tion with high probability of accuracy, though the form of this part is more conjectural. As restored, the wing Avas probably rather more than two and one-half times longer than broad. It represents an under surface, being uniformly concave, and is of the same
408
SAMUKL II. SCUDDEK ON
color, voins ami all. ns tho ilirty, clialkv-whito stone on Avliicli it rests, the veins beinp^ sli"-litlv impressed on the snmmits ol" rounded ridg-es separated by transversely rounded lurrows. The niediaslino-seapular vein is straight in the basal half of the wing; beyond curves slightlv and probably terminates a little above the tip with, so far as can be seen, onlv simple or basally forked, parallel, oblique, scarcely sinuous branches, the costal area being slightly less than two-fifths the breadth of the wing. The externomedian and internomedian veins are strongly arcuate at the extreme base; beyond completely longitudinal in the externomedian area, probably terminating in a narrow space at the extreme tip of the wing, and the same, but slightly declivous, in the internomedian area, where from this cause they terminate along the entii'c inner margin, even within the liasal half of the wing; in the median areas, the interspaces are generally seen to be broken by dull cross veins into quadrate cells, but near the middle of the wing both veins and cross veins are cftaced by imfierfect preservation. The anal furrow is trans- versely oblique with no distinction of impression and must terminate at a very short dis- tance out. The species is remarkable for the straightness and simplicity of its costal area, the early termination of its earlier internomedian nervules and its uniform breadth.
Length of fragment, 7.5 mm.; probable length of wing, 14 mm.; breadth, 4.5 mm. The specimen was received fi'om Kev. Mr. Brodie, as from the English mesozoic beds, but without further indications. It is named for Mr. J. W. Kirkby, Avho has made ns acquainted with some of England's earliest fossil cockroaches.
Elisama ? media.
Blnttidium medium Ileer, Viertelj. naturf. Gesellsch. Zurich, ix, 289, 300, PI. fig. 7.
An obscure and imperfect specimen, which agrees better with this genus than any other and pi'obably belongs here and to a species distinct from any others known, being distinguished for its tapering form, its straight inner margin, while the costal margin is convex, the regular narrowing of its costal ai'ea, which is broadest close to the base and which probably terminates at the very upper extremity of the apex, its intercalary A'cins and the complete longitudinality and straightness of its median veins.
Length of fragment, 8 mm. ; probable length of wing, 10.25 mm. ; breadth, 3.5 mm. It comes from tlic Lias of Schambelen, Switzerland.
h. The externomedian vein of the nj)j)er wings is amalgamated either
with the scapular or with the i^iternomedian, and all
other veins are independent.
PtERINOBLATTIXA Scudder.
PierinoUattina Scudd., Proc. Acad. Nat. Sc. Philad., 1885, 105.
Among the fossil cockroaches figured by Westwood thirty years ago, was one which Giebel afterwards named Blatta jduma, on account of the resemblance of its neuration to the barbs of a feather, with the shaft on one side. Several species are now known, including one described as an hemipteron by Germar nearly fifty years ago, and on
MESO'^OIC COCKI{OA( IIKS. 409
account ftftliis cuiioiis anani^^enu'iit of tlio veins, I proposed recently tlie f^eneric n:\un' here eni[)l()yecl. The winj^'s are very l)i'oa(l, expandinjj: e()nsi(K'ral>ly heyontl the base, broadest beyond the niiiMIe, and lilU-d with an abiuKhmee f)l' braneliinj^;' veins, 'i'ln; mediastinal, scapular and eonil»iued externoinedian and internomedian veins run close- together, side by side, in a perl'eelly straight course (the shall of the leather) from near the middle of the base of tiie wing toward and nearly to a ])<iint on the costal margin a little within the apex of the wing, and the superior mediastinal and scapular and inferior externoniedian and intei'uomedian branches, crowded closely together, part from this apparently common stem at neai'ly similar angles on either side of it; Avhile the anal area, at least wheie known, occupies a considerable and nearly crpial band along a considerable portion of tin- inner margin, running into and often strongly interfering Avith the internomedian nervules. As stated in the introductory portion of this paper, what was formerly regarded by me as internomedian is now looked upon as unrpiestional)ly anal, so that we can only interpret the neui'ation by supposing the externoniedian and internomedian veins to be amalgamated, and this will remove the genus from the Palaeoblattariae.
The genus was tolerably prolific in species, which vary greatly in size, the two spe- cies from the middle Oolite of Solenhofen being particularly large, while one of the Liassic species fi'om Germany is one of the smallest of mesozoic cockroaches. Four species (including two doubtfully referred here) are known from the middle and lower Purbecks of England, two from the middle Oolite of Bavaria and tliiee from the Lias, one in Germany and two in England.
Pterinoblattina pluma.
n. IS, figs. 7, 8°.
[Without name] AVestw., Quart. Jom-n. Geol. Soc. Lond., x, 384, 304, PI. lo, fig. 14'
(2 figs.) MloWi pluma Gieb., Ins. Vorw., 322. Pterinohlattlna pluma Scudd., Proc. Acad. Xat. Sc. Philad., 188o, lO.j-lOO.
The specimen, the original of which I have had the privilege of .stud3ing, by the favor of my kind iriend Kcv. P. B. Brodie, is rather imperfect, and a little decejitive from the fact that just that portion of the tip is missing which contains the scapidar branches ; it is probable, hoAvever, from the longitudinal chai-acter of the apical offshoots of the me- dian vein tliat the sjiecics more closely resembles P. chrysea than P.intermixta. There is no discoloration of the stone to mark the wings, though the veins are pale; no portion of any margin is preserved; it lies flat njion the stone, but the scapular vein is slightly depressed while the others with their branches are slightly elevated, by which it would seem that the under surface were uppermost. All the mediastinarbranches are simple, parallel, equidistant, almost straight, closely crowded, andjjart from the main stem at an angle of about 45". The median branches, the only others preserved, part at a less an- gle, gradually become quite horizontal apically, are nearly as close at base as the scapu- lar branches, and as most of them fork and even i-e-fork, though Avith entire irregularity, become excessively crowded toward the margin.
470
SAMUEL 11. SCUDDKR ON
The lonii'tli »>l" tin- frnii-im'iit is 9 inin., its Invadth "> mm. Probahly tlie win,<>- was 12 nun. l(»nii\ ami .").."> mm. hroail. It Avas foinul in the Corbula or Pec-ten beds of the niiiliUe i'urbeeks of Dorset, England.
Pterinoblattina penna.
n. 48, fig. 14.
rtirinohhitlliKi penna Sendd., Proe. Aead. Xat. Sc. Phihid., 1885, lOG.
The sinjxie specimen of this si^ecies at hand is preserved in much tlie same manner as I tlie hist, but shows a fragment of the anal region. The specimen is of the same color as tlu' dirty chalky-white stone on which it rests. The median area is scarcely concave, the vein depressed; the mediastinal area is slightl}' convex and its main stem is elevated aboA'c the two next below it. The three principal veins approach each other very gradually so as to give them the appearance of a tapering rod. The mediastinal branches part from the stem at nearly a right angle near the base of the wing, gradually increasing in oltliqnity distalh', until they form an angle of 45" mtb it; they are slightly cnrved, the concavity outward, veiy closel}^ crowded, and about every third one forked near the mid- dle, but with no regularity. The scai)ular branches are not preserved, but as in P.pluma, and for the same reason, they probably resemble P. clirysea rather than P. intermixta. The median branches arc A^ery closely croAvded, generally straight, part from the stem at an angle of •45" next the base, and become almost wholly longitudinal at the apex ; they fork about as frequently as, and more irregularly^ than, the mediastinal branches. The anal area extends flir out on the wing, and its l>ranches (Avhat fcAV can be seen) resemble those of the preceding area, and at its extremity are parallel to them.
Length of fi-agment, 13 mm. ; width, 9 mm. Probable length of Aving, 15 mm. ; prob- able Avidth, 9 mm. Described from a specimen from the English Purbecks* sent me for examination In' Rev. P. B. Brodie.
It is not impossible that the fragment of a larger Aving figured Avithout name by AVestwood (Quart. Journ. Geol. Soc. Lond., x, PI. 17, fig. 7), from the Lower Purbecks of Durdlestonc Bay may be a species A'ery close to this, if indeed it is not the same.
Pterinoblattina chrysea.
BhUtinn chrysen Gein., Zeitschr. Deutsch. geol. Gesellsch., 1880, 520, PI. 22, fig. 2. PkrlnoJAoltiuu chrysea Scudd., Proc. Acad. jS'at. Sc. Philad., 1885, lOG-107.
In this ease we have a more perfect Aving, the tip being almost completely preserved. The mediastinal vein terminates before the middle of the outer half of the costal border, and is furnished AA-ith simple, straight, oblique branches, not so numerous as in the other species, to judge by the figure, though they are spoken of by Geinitz as "very numerous and closely ci-oAvded." Just before the scapular reaches the tip of the mediastinal, it tunis parallel to the costal mai-gin, runs to the upper tip of the Aving, and emits branches .similar to those of the mediastinal, but of course of equal length. All the median branches nin almost longitudinally, are straight, sometimes forked, and appear from the
MKSOZOIC COCKHOAfllKS. 471
fii;ui*e to be loss crowded tliiin llic iiu'diii-;liiial ln-anclu--^, llii>u;^li tlicy aiv coinpari'd l»y < 'linitz to till' barbs of a fi'athi'r. Tin* anal runs to just bc'y<»nd tlu' broadi-st partoftbe w iiiii;', boini? tbus lon^i^cr than tin- nu-diastinal, aiul st-nds b-ss crowded, j^eiitly ftu'ved, usually forked, rather short braneln's to tlu' border. Tlie ("ew anal liranches curve and strike the inner niarj^in.
Length, .") nun.; lireadth about L'.L'.~) mm. I'lmii the Lias of Dobberlin, (Jerniany. Till' deseri|)tii>n is drawn iiji tVom the data given by (irinit/.
Fterinoblattina Curtisii s|>. nov. IM. 4S, fig. 10.
The fiaf;nient of only a tip of a winLi: rej)resents a species a|)parently about midway bo- lu\'en P. clifijxea and P. infanni.cta, approaching the latter in delicacy and multiplicity of its crowded neuration, the former in the disposition of the scapular vein and its branches. It is independent of both in the pointed, almost falcate shape of the tip of the winy. Thescapular and median veins and branches are the only ones preserved. Tiie for- mer runs parallel to, and at but a short distance from, the declivous curve of the outer part of the costal margin and sends frequent, longitudinally oblique, a])ically forked branches to the margin, ending at the extreme pointed tip of. the wing. The median veins are numenms, straight, jxuallel to each other and to the apical portion of the scapular vein, and forked pretty uniformly Avheii al)out as far from the margin as the Avidth of the scapular area.
The length of the fragment is 19 mm.; probably the wing was of twice this length. It comes from the Upper Lias of Alderton, Gloucestershire, England, and was received from Kev. P. B. Brodie. It is named for one of the first English naturalists who inter- ested himself in fossil insects.
Fterinoblattina intermixta.
PI. 48, fig. 9.
Plerinohlattina intermixta Scudd., Proc. Acad. Xat. Sc. Philad., 188.', 107-108.
A nearly complete "VAdug of this species has almost the same shape as P. chrysea, but the iipper part of .the apex is more produced, though not at all pointed as in P. Curtisii. The mediastinal vein terminates before the middle of the outer half of the wing, and the area narrows more gradually than in any of the others; its branches are gently curved, and often forked, but not excessively croAvded. Just before reaching the tip of the me- diastinal, the scapular vein suddenly bends toward the apex, running subpai-allel to, but aAvay from, the costal margin, terminating at the tip and emitting a croAvd of curved and forked brandies. The closely crowded median branches part at an angle of 40" Avith the stem, are straight, and fork only just before the tip, forming a tolerably regular belt of croAvded veinlets along the mai-gin. The basal branches, lioAA'cvcr, arc interfered Avith and atfected by the anal vein, Avhich is nearly straight, at first running plump against the median branches, curA'os theu doAvmvard parallel to these and tenninates a little before the mediastinal; it is fiu-nished abundantly Avith branches cur\iiig like its extremity and
MEMOIRS BOSTON SOC. SAT. HIST., VOL. III.
j-o SAMUEL II. SCUDDER ON
hnuu-hinsriH'Xt the bonier like the imnlinn brniKlu's, but where it abuts against these hit- ter. tlu'V f^imuhite the a}iiiearaiK-e of the anal branches so as to appear as if a part of the anal area, and thus give the latter the ai)pearance of extending out beyond the broadest part of the wingr. The specunen is of a slightly glistening, dark brown color on a dirty bn>\vn stone, the veins and'all the nervules sharply though only slightly impressed, while the whole wing is at a dead level.
Lenirth of fragment, 10..1 mm.; probable length of wing, 12 mm.; breadth, 5.75mm. Keeeived from Eev. P. B. Brodie, as coming from the Upper Lias of Alderton, Glouces- tershire, England.
Pterinoblattina hospes
Jiicania Jiosjjes Genu., Acta Acad. Leop.-Carol., xix. 220-21, PI. 23, fig. 18. Pterinohlaitina hospes Scudd., Proe. Acad. Xat. Sc. Philad.. 1885. 108.
Germar took this for one of the Fulgorina, in the neighborhood of Ricania and Poecil- optera. Assmann thought it a neuropteron, falling in the neighborhood of Drejaanop- teryx. It is pretty plain, however, that it belongs here, though the figure given by Ciermar is not sufficiently clear to enable one to formulate any characteristics. It would seem, however, that the scapular veui probably terminated on the costal margin some wav before the tip, and that the latter is shaped nmch as in P. intermixta, and occui)ied bv median branches only; these are more oblique and the lower outer angle much less prominent than in P. intermixta, while in the present species the anal angle is prominent and the anal area extended by that alone, occujiying a very oblique equal basal band.
It comes from the Oolite of Solenhofen, and measures about 25 mm. hi length and 13.5 in breadth.
Pterinoblattina gigas.
Ricania gigas AVeyenb., Arch. Mus. Teyl., ii, 270-71, PI. 35, fig. 23. Pterinoljiattina gigas Scudd., Proe. Acad. Xat. Sc. Pliilad., 1885,108.
Following Germar, "Weyenbergh placed this enoniious sjiecies in Ricania, but it evi- dentl}- falls here and bears a close general resemblance, excepting in size, to P. j)cnna of the Purbecks. It differs from P. hospes, which it most resembles, in the greater ex- tension of the scapidar area, which nearly reaches the tip, and in the farw ider extension and angular protrusion of the anal angle.
It measures 60 mm. long and 35 nun. broad, and comes like the last from the Oolite of Solenhofen, Bavaria.
Pterinoblattina? Sipylus.
Sialium Sipylus TVestw., Quart. Journ. Geol. Soc. Loud., x, 390, 396, PI. 18, fig. 24.
"NVestwcKKl considered this to represent ''a wing of an insect allied to Sialis," while of the closely allied fonn, P. Binneyi, he says it appears '' to be orthopterous." An exami- nation of the series of wuigs here ranged under the name of Pterinoblattina Avill con^^nce any one of the close jjroximity to them of these two abnonnal wings; in their elongated form they are indeed entirely different, and were they certainly comparable as front wings
MKSO/OIC COCKIJOACIIKS. .j7;i
tlicy should hi' st'p.iiati'il j;fm-i'iciill\ ; l»iil llicif clusc rc^(iiil»l,iiicc in iiciir;iti<»ii, \\lii(li is at the same tiuu- in most parts of the winj; less (hii-f. liails me losiispi-et tliat thi-y may iially he hinil \vinj;> of s|)eeii's of Pterinohlattina ol" a nioif cloni^atc form than any yet known (the speeies vary eonsidt'rahly in this direelion), and that fur this n-ason it may be well at least lor tlu' present to place them here, doid)tfidly. 'I'he wiii;^ referred to the present speeies is hutween three and four times lon^j^i-r than liroad, snhiMpial, taperiii'^ to a somewhat pointed hnt rounded tip, the latter on the middle line. The scapular branches sueeeed the mediastinal, in a eonnnon. e(pial, narrow ])and, which follows the costal margin to just lielow the ti|): tin- anal art-a, in a broader, apically tapering band, Avith nuich more distant nervules, ivaches to the middle of the outer half of the wing; while thi' long and sinuous, basally distant, apically crow(h'd and forked median veins occupy the intervening spaci-.
FAMigth of fragment, 21..") nun.; jjrobable length of wing, Ul nun.; breadth, G.(i mm. 1 1 comes from the lower Purbeeks of Durdlestone Bay, England.
Pterinoblattina? Binneyi
[Witliout name] Westw., Quart. Journ. (ieol. Soe. Lond., x, :500, ;}J)G, PI. 18. fig. 42.
This wing has the same general fonn and propor4:ions as P. Sipt/lns excepting that the extreme tip of tlie wing is next the lower margin and not on the middle line, but the scapular area still holds the same relation to it as in that species, bending downwards and embracing it. The anal area is more uniformly tapering and does not extend quite so far, giving ampler spaee for the median nervules, whieh appear (they ai-e not s(j ex- actly delineated) to have the same charaeter as in P. Sipt/lus. It is a eijnsiderably smaller speeies.
Length of fragment, 10..") mm.: probable length of wing, 12 nun.; breadth, o.T.j nun. Iviwer I'urbeeks of Durdlestone Bay, England. !N^amed for Mr. E. "\V. Binney.
BlATTIDIUM Westwood (restr.).
Blattidium "NVestwood, Quart. Journ. Geol. Soc. Lond., x, 304, .'iOG, without descrip- tion; Seudd., Proe. Acad. Xat. Se. Philad., 1885, 111-112. Westwood designated four of the considerable number of mesozoic cockroaches which he figured in 18.j(l by the name of Blattidium. One of these, B. Molossns, was af\er- Avards taken b}' Giebel as the type of his Xethania, based on an entirely wrong concep- tion of the neuration, and Avliich, as Ave have seen aboA'e, falls properly into his genus Elisama. A second species, B. Achelous, is probably neuropteroid, and will not be con- sidered hei-e. The other tAA'O form a second very peculiar type of cockroaches, quite as strange as Pterinoblattina, though Aery different from that, both from their long, slender and parallel-sided form, and from the union of the externomedian and scapular veins for nearlv half their length. Tiie mediastinal vein terminates not far from the middle of the Aving, and sends out a multitude of crowded offshoots to the margin. The united
47t
SAML'KL II. SCllDDEU ON
sfiuuilar and I'xli'nioiiU'irKiu vein I'uns pni-alli'l to llu- bordiT, to Avliicli, as well as to the nu'tliastinal vi-in Ih-Ioix' it tonninatcs, it si-iuls ratluM- distant, ol)li(iiie voins, hcsidos an in- IVrior lou"-itndinal hranrli. which has sovc'ral Vfrv distant. inCcrioi-, ciinally lon<>itndinal olVshoots. 'I'la- intoniomediau vein is wholly hmgitndinal, and has few distant branches these apparently terminate only in the ai)ieal border, while the main anal vein, longitud- inally ttblicine, i-xlends nearly as far as the mediastinal, and the outer half of the innei mari^iji of the wing seems to have no veins falling on it; the veins of tlie anal area run olifuinelv from the margin upward and outward to the main anal vein. The two .<peeies known eome from the LoAver Purbeeks of England.
Blattidium Simjnrus.
ri. 48, fig. 17.
1 Without name] Brodie, Foss. Ins. Engl., 118, PI. 5, fig. 19.
BlattiiUum Sinnjrus AVestw., Quart. Journ. Geol. See. Lond.,x, 390,39(),P1. 18, fig. 33.
G'n/Uidiinii Oiceni Westw., Quart. Joiu-n. Geol. Soc. Lond., x, 387, 39."), PL 17, fig. 19.
The figure here given is made up from two specimens, obverse and reverse, of the tvjte of Westwood's B. Simyrus, which Mr. Brodie has kindl}^ sent me. The mediastinal area is slightly lower than the rest of the wing and the mediastinal vein deeply depressed. The species is peculiar for the fineness and irregularity of the mediastinal nervules, which are in strong <-ontrast to the distant and regular scapular sui3erior branches, and these in their direction and brevit}' to the dozen longitudinal Aeins belonging to the median series. I'lie anal area is filled with oblique transverse veins having the same direction and al)out the same elistance apart as the superior scapular nervules. An inferior marginal vein borders the under surface of the wing.
Length of fragment, 25 mm.; possible length of the wing, 42 mm.; breadth, 6.5 mm. It comes from the Lower Purbeeks of Durdlestone Bay.
It seems highly probable that Gryllidium Oweni Westw., which comes from the same jilace and is of the same size, is a sj^ecimen of the same species, in which the subordinate nervules of the mediastinal and anal areas are not preserved; the latter are not deline- ated in Westwood's figure of this species. Brodie's PL 5, fig. 19, w hich Westwood took to be the folded hind wing of a cricket, seems also probably to fall here, though it may indicate another species in which the superior scapular branches are as crowded as the mediastinal.
Blattidium Nogaus.
Blatlldium Noyaus Westw., Quart. Journ. Geol. Soc. Lond. x, 390, 396; PL 18, fig. 23. I have not seen this species, which has a proportionally much broader mediastinal area, and appai-ently a smaller number of median veins than the other. The wing could hardly have had the excessive slenderness of the other species, the fragment being 18 mm. long and 7 mm. broad, and the whole wing probably not more than 27 mm. long. It too comes from the lower Purbeeks of Durdlestone Bay, England.
il
1
MKSOZOIC COCKUOACIIKS. 17.">
('. The medlastiudl iiikJ srttjmlar reins of fhr iijtprr whufs itri' (tiiiafi/iimafrd, ami in (uidifidn llii' rjlirnoniitlidn n in /.s (iniit/t/uniitfi li cif/nr with (/tc f'oiTi/oin;/ tir with lln inti rnonttdian cein.
XANMUfl.ATriNA -in. iiov. (>'i»",-.)
Ill lliis jiciius, wlicri' nil tin- \viii;;s ;iiv iiiimitc. tlu' (■xtcnioiiicili.-iii s|)riii;j;'s from llic uiiili'd iiK'(liastiiiii-s(;i|»iil;ir vi'iii in llir st'cimil (|ii;irl('r <>l" tin- wiiii;-. 'I'lic co-ital Ili-Iil is wry l)i'i);i<l. u liilc llic iiili'nniiiu'ili;iii ;ivva is (•oii>i(lri-;ilily lot rid cd in u iiltli. lliuii;;-li it cx- tt'iids a good distance toward tlicli|i. Iiiotlicr ri'>|tccts llic diircrciit s|icci(-. \ ary widely.
The three .species conic rimn the upper Oolite of IOii;.^land.
Naiinoblattina siniilis.
Cnri/dalis Hrodii', Foss. Ins. I-:ii-l.. 1 !'.). PI. .".. li-. l'.
JJIalfina siniilis (iiih., Ins. A'orw., .'JIS.
In this species tlie inediastino-scapiilai- area is re;;-nlarly arched on either side of the iniddleof thi' wing" and occiijiies at most more than lialf its width, whiU- the e.vteiiioMie- dian originates neari-r the liase than in tiie otiier species, and li-aves a nearly iinil'oini narrow internoniedian area.
Length of fragment (lioiu which a small jiart of the base only appears to lie Itroken) ~) mm.; breadth '2 mm. It i-omes from the English Wealdeii.
Nannoblattina PrestTwicliii sp. nov. ri. 4,s, (ig. 3.
A nearly perfect wing, bnt with the anal area lost and the ba.sal jiart of the costal area. It is possible, however, to restore the missing' border with a considerable degi-ee of pre- cision, and so to jndge that the Aving Avas tolerably slender, a little less than three times as long as broad, with sti'aight margins, scarcely tapering, the tip well rounded. The me- diastino-sca])nlar vein is well arched, so that in them iddle of the wing the area occnpies nearly half the width; most of its nerAiiles are straight, oblicpie and simple, bnt some of the apical ones are forked. The externomedian vein parts from this in the middle of the basal half of the AA^ng, and Avith its forks occupies nearly the entire tip of the Aving. The internomedian is rather strongly sinuous, its area narroAV excepting at extreme base, the iiervules fcAv, simple, slightly sinuous and longitudinally oblique. The anal furrow is pretty regnilarly and not very strongly arcuate, terminating beyond the middle of the basal half of {he Aving. .Vn upper surface is exposed on the light brown stone, but it is perfectly flat ; it is a little fuliginous, with blackish brown veins Avliieh are just perceptil)ly impressed, the anal furroAV no more than the rest.
Length of fragment 6 mm.; probaI>le length of wing: G.o mm; breadth 2.2.") nun. The siiecimen comes from the English Purbecks and Avas studied by the favor of Rev. P. B. Brotlie. It is named in honor of the veteran English geologist.
.j7(; SAMUEL II. SCrODKU ON
Nannoblattina Woodward! sp. iiov. ri. 48, lig. G.
This inimilt' s|H'cios is ivpivsiMitoil by a siiiglo lunrly ijerlect winj;-, bi'oken <)l)lifiuely across tlu' base. An nmler surfiU-e is oxpdscd on tlie dark grceiiisli gray stone, as ap- iH-ars IVoni its .slight loncavity, and the i)r<)niinent veins; the wing is fuliginons and the stout veins broadly marked in black. The wing is comparatively broad, the costal and iiuu-r margins straight and parallel, the tip broadly rounded, the apex slightly above the middle. The mediastino-scapular vein runs in an ol)li(]ue1y and gently sinuous course, terminating l>elo\v the apex and broadest in the Avhole a[)ieal third of the wing, where it occupit-s fully half of its width, furnished with considerably arcuate, rather numerous, ])aralK'l. simi)le, oblique branches. The externomedian vein arises from this in the mid- tUe of the second fourth of the wing and is ])ut once forked, near the tip. The inter- nomedian vein is strongly sinuous, the area rapidly narrowing and the branches very few, short and somewhat divergent. The anal furroAV is scarcely or not at all more distinct than the other veins, is strongly arcuate and must enclose a very large anal area, but the broken wing will not allow us to determine how much; it is prol>able, however, that it reaches nearly to the middle of the wing; the anal veins are simple, parallel, impinge on the margin, the basal ones turned apically a little outward.
Length of fragment 3.75 mm.; probable length of wing 4.1 mm.; its breadth 1.6 mm. It comes from the Wiltshire Purbecks, Avas received through Rev. Mr. Brodie and is named I'or Dr. Henry Woodward who has introduced to us so much of the life of the past.
DiPLUROBLATTrXA gen. nov. {otg, t:X^u(w;)
In this genus the externomedian vein has become completely amalgamated, not with the mediji-stino-scapular but Avith the internomedian. The humeral field again appears and, notwithstanding the amalgamation mentioned, the mediastino-scapular area occujiies a very large share of the wing, which is of a tapering, cuneiform shape in the only species known. The veins are, therefore, branches of two principal stems which pass down the middle of the wing side by side, but as distant as the principal branches from each other.
The single species comes from the English Purbecks.
Dipluroblattina "BsJlyi sp. nov.
PI. 48, fig. 5.
A nearly perfect. wing represents this species in which the anal area only is wanting, excepting a minute fragment of the tip. It has a tapering, graceful form, both costal and inner margin being similarly and gently arcuate and the slender tip being well rounded. A smooth and flattened humeral field, lanceolate in shape, extends over about a third of the wing. The mediastino-scapular, strongl}^ ai-cuatc near the base, runs in its apical half nearly throiigli the middle of the vnn<^., terminating scarcely above the tip; its rather numerous bi-anches, simple at first, beyond simple or forked, are oblique and tolerably
I
MKSOZOIC COCKROACH KS. 477
str;ii;^lit. '['\\v nudi.ui xciii iims |);ir;illi'l tn tin- incccdiiin- llii<iii;;ln)iil, Iki- lour iiiH riur l)i;mclu's arisiiij^- toli'ialily lu-ar t<i;j:i'tlHT just lu'lurc tin- uiitldli- of tin- win;;, wliicli an- vt'iv stnm<::ly arcuate, siuiplc or I'orkrM, apically loiij^itudiual; in tin- apical third <>\' tin- wiu'j;', dij-tant in ori<>;iii troiu the prcci-din^j:. arc a couple of simple lonji'itudiiiai liranelics. The anal area cannot extend l)eyond the hasal fourth oi'tlic \vin^\
l.enj::th of Irajiiuent (5.7.") nnn.; ol'winj; restored T.."! nnn.; hreadth !.'.<>.") niiu. 'I'he wiu^r, which is scarci'ly diu;;"ii'r than tlu- chalky-white stone on which it rests, showing; its uppt-r domed surface with the slij^htly dusky veins miinitely dcpivsscd, is faintly and very (h-l- icatcly reticulated in the hasal half. It comes from tin- Kn<;lisli I'urhecks, lies side l>y side with the Mesohlattina Hjiuredon IM. Ki, fi;j:. !{, anil was received I'rom Kev. 1*. li. l?ro- die. It i- nanu'd lor Mr. AV. II. IJaily who has interested himself in some of the fo--i| injects of li-eland.
DiKClIOm.ATTIXA gen. nov. {■"'u'xu,)
This <>-cnus is nearly allied to the last, all the veins of the Avin^j: Iteinj^ depeiidi-ncics of two stocks, which as there i)ass down the middle of the win^, the vi-ins diver^in"^ in op- posite directions; Imt here the.se main stems are very elosely approximated and appear to teiminate before the tij) of the win<>-, leaving the lon'X'itndinal branches only to run to the tip. The hnmeral Held also is wantinjjc. All the branches, as a mass, are arcuate, the superior ones with the arcuation openinL"' towai'd the basal hall'oftlie co-tal border, the in- ferior toward the apiial half of the same.
The two species are Ibuncl in the Knulish I'nrbecks.
Diecboblattina Ungeri.
I Withont name] AVestw., (^uait. Journ. Geol. .Soe. Lond., x, .'>l»o, 1*1. 17, lig. V.t. Blatta Unrieri Gieb., Ins. A'orw., IJ22.
This mimite species lias much the ap])earauce of a feather. The two main stems rnn close to<>ether in a regular gently arcuate course nearly to the tip, the arcuation opening toward the costal margin.
Length of wing, o.o nun.; breadth, 2..">. Lower Purbecks of Durdlestone Ba}'.
Diecboblattina Wallacei sp. nov.
I'l. 48, lig. 1.
Restoring tiie wing at its broken base, as in the figure, the approximated stems are seen to run in a straight, scarcely oblique course through the basal third of the wing, be- yond which, in more delicate shape, they are regularly and considerably arcuate, terminat- ing in the middle of the very broadly rounded tip. Most of the nervides are siinj)le, the superior ones rather more crowded than the more strongly arcuate and more longitudi- inal inferior ones, and those arising in the apical half of the wing usually more or less forked. Tlie costal margin is very gently convex, and the apex of the wing i-oundly docked; anal area broken off.
ITS
SAMUEL II. SCUDDER ON
Lmiilli of IVnji'im'Ut. S nun.: |)r()l);il)U' Icnylli (il'win^-. i>.7o nun.; l)r('a(ltli, 1 nnn. The siH'iinuii i>- of till' s;inu' tolor a.« tlu" dirtv, i-halky-wliik' stone on which it is pivscrved jMul i\liil)its appairntly the iniiler .^nrfaee, the veins being- sli<>]itly rai.se(l; the ])nncipal veins aiv .^rareely separable near the base. The species, sent me by jNIr. IJrodie, eonies Ironi the English Purbeeks and is named for the English natnralist, Mr. A. 11. AVal- laee, whose studies have embraced fossil insects.
SCUTIN'OBLATTIXA Sciulilcr.
Sciitl)ioUaftl)i<t Scudd., Proe. Acad. Xat. Sc. Thilad., 1885, 110.
The ti'gmina ai-e more or less coriaceous obscuring somcAvhat the nenration. The nu'diastino-scapnlar vein is nearly or quite straight, terminating a little below the tip of the wing, while the median vein (the externomedian and internomedian being united) runs parallel to and somewhat distant from it. The anal veins fall sometimes on the in- ner margin and sometimes on the anal furrows All the species are from the American Trias.
The three species are (S. -Sro»///«"o?-/i, /S*. intermedia and S. recto, all fcmndat Fairpla}^, Coloi-ado. They have l)een briefly described in the Philadelphia Academy's Proceed- ings, and will be fully discussed and figni-ed in a ]iaper devoted to this Triassic locality, so that it is only necessary here to indicate their position in the series.
Legnopiioka Ileer.
Legnopliora Ileer, Yiertelj. natnrf. Gesellsch. Ziirich, ix, 297.
Ileer gives this name to an object of Avhose animal nature he was not wholh' convinced. If, as he supposed, the front wing of a cockroach, it differs from all known forms in the jiarallel and longitudinal course of the veins of the costal area. Apparentl}- it falls near this place, and the Aving itself appears to have been somewhat coriaceous.
The single species is L. Girardi Heer {loc. cit.) fig. 5, from the Trias of Trebitz, Germany.
ApOROBLATTDfA gen. nov. {aznp,,^).
Under this name, I group a series of wings, of three of Avhich I have seen specimens, Avhich appear to me to be in all probability hind wings of cocla-oaches. The}- diiier con- piderably among themselves, but agree in haAang the mediastinal and scapular A'^eins dis- tinct, tlie former occup}Tiig a narroAv belt Avith longitudinally oblique A'eins, and in having a ver)' extensive development of the internomedian Aein, AAnth long, SAA'eeping, arcuate nervules; the exteniomedian, in all cases Init one or tAVo, Avhcre it appears to be either altogether Avanting or amalgamated Avith the internomedian, l)cing very slenderly de\ el- oped in a A'ery nai-roAV area.
Most of the .species come from the upper Oolite of l^lngland, but three species come from the Lias, two of them from England and one from Germany.
MKSOZOIC C'OCKROACHKS. 479
Aporoblattina Eatoni sp. .
PI. 48, fig. r.i.
This sjxcimcii is a lu-arly complotc wiii<!^ of tlu- same color as ilu- li;;l»t, dirty lnowii stone on wliic-h it is pivsi-rvcd, with very <lark hroun veins; it is lu'rlectiy Hat, hnt tlie A'eins are shi^htly inipressi-d in phiees; it lias the appearanee of heinjjj the np])er snrCaee of a liind wing, partly foltU'd in the partially incomplete anal re<^ion. Tlu- costal margin is perfectly straight in the hasal half, then more and more arcuate, meeting at a hroad angle the arenate cnrve of the lower jiart of the wing at the scarcely angulate apex in the middle of the upper half of the wing. The hasal half of the costal area aj)pears to be narrowly folded. The nu'diastinal vein is straight, terminating in the middle of the outer half of the wing, with a few distant, longitudinally olirKjue, l)ul short, simple l)ranches. The scapular vein is also straight, terminates just below the tip and is fur- nished with three or four longitudinal, slightly upcurved branches, compound apically, and originating at equal distances far apart, the second in the middle of the wing. The ex- ternomedian vein is also straight, first divides in the middle of the wing and is very slightly and longitudinally branelu-d. The internomedian vein, also straight, but slightly declivous to beyond the middle of the wing, then bends slightly downward, and has four slightly arcuate, longitudinally oblique, equidistant and rather distant simple branches. The anal vein has branches similar to the preceding, but, apparently by a fold, they are made to take a more longitudinal course.
Length of wing, 15 mm.; breadth, 6.5 mm. It comes from the English Turlteclcs, was sent me by Kev. Mr. Brodie, and is named for Rev. A. E. Eaton who has contrib- uted slightly to our knowledge of fossil insects.
Aporoblattina anceps.
[Without name] Westw., Quart.. Journ. Geol. Soe. Loud., x, 390, PI. 15, fig. 22. Blattina anceps Gieb., Ins. A'orw., 317 (Giebel wrongly quotes fig. 21).
This small species seems to be closely allied to A. Eatoni, but of a very different shape, the costal margin being quite as arcuate as the lower margin, or more so, and the bluntly rounded apex being in the middle of the wing. The characteristics of the neuration are in general similar to those of A. Eatoni, but the externomedian vein (which is piujbably wrongly represented as attached at base of fragment to the scapular vein) is only once forked, near the tip, and the branching of the scajiular vein is much simpler.
Length of fragment, 7 mm.; probably the wing is not much longer; breadth, 4 mm. Lower Purbecks, Durdlestone Bay.
Aporoblattina McLachlani sp. nov.
PI. 48, fig. 18. [Without name] AVestw., Quart. Journ. Geol. Soc. Loud., x, 39(5, PI. 18, fig. 35.
Westwood looked i;pon this wing as neuropterous, and apparently as more complete
MEMOIRS BOSTON SOC. SAT. HIST., VOL. UI.
jSti
SAMUEL H. SCUDDER ON
than it ■•< t iu> lo l>r, its tiiio ilimousion.s being attempted to be shown in the figure here •••i\ en. wliieh is taken, with searcely any doubt, from the same specimen, now in the collec- tion of Kev. P. B. Brodie. The specimen is slightly duskier than the dirty, chalky-white stone, perfeetly tlat, with ilelicately impressed veins which are the clearer for being filled «itli tlirt. Next the anal area another wing ])artly overlies this, but it is not drawai. Thi- wing was of a sub-oval form with a A^ery much fuller curve below than above, the apex, which is rounded though produced, being in the middle of the upper half of the wing. Only the tij) of the mediastinal vein ap^icars on the fragment, and it is very sim- ihu- to that of ^1. Eatoni, terminating probal^ly a little before the middle of the outer half of the wing. The scapular vein differs from that of A. Eatoni considerabl}^, terminating searci'ly above the apex and having only simple oblique branches in the outer third of the wing, and a single longitudinal also simple branch, arising one-third the way from the basi'. The internomedian vein is much as in A. Eatoni, but only branches in the api- cal third of the \\'ing. The externomedian vein occupies an even broader field than in tile last species, with similar but more arcuate, and apically more longitudinal branches, also simple. The anal veins are not seen.
Length of fragnu-nt, 6.75 mm.'; probable length of wing, 8.5 mm.; breadth, 4.75 mm. From the P^nglish Purbecks, named for Mr. R. McLachlan, whose well-knoA\n entomolog- ical studies have extended occasionally to fossil insects.
Aporoblattina Westwoodi sp. iiov.
[Without name] Westw., Quart. Journ. Geol. Soc.Lond., x, 396, PI. 18, fig. 28.
West wood looked on this ^ving as phr3'ganideous, but it plainly belongs in this im- mediate vicinity, reseml)ling closely the preceding species, from which it differs in its greater size and slenderness, in the foi-king of the first branch of the scapular vein (no branch in any part of the wing is forked in A. McLaclilani) and in the generally less regular disposition of the branches of the scapular area.. The externomedian vein is also simjiler and less regidar.
The fragment is 10.5 mm. long and 5 mm. broad. Probably the wdng reached a length of 14 nmi. It comes from the lower Purbecks of Durdlestone Bay.
Aporoblattina Kollari.
[Without name] Brodie, Foss. Ins. P^ngl., 33, 119, PI. 5, fig. 14. JJlatta Kollari. Gieb., Ins. Vorw., 322.
West wood, in Brodie's work, looked upon this as belonging to a family of ^europtera "of which Corydalis is the type." It plainly belongs here, and is apparently not distantly related to the two preceding species and especially to A. Westwoodi, from which it is readily distinguished by its still slenderer form, and the greater straightness and regular distribution of its scapular branches.
Length, 18 mm.; bieadth, 6.5 mm. It comes from the Purbeck strata of the Vale of Wardour.
MESOZOIC COCKlCOArilMS. 481
Aporoblattina incompleta.
[Without iiaiiu'], IJiotlit-. F.>— . In-. Ihi-I.. IM. S. Ii-. ].!. Ulatfina i)t('oiiij)lela (Jichcl, Im~. N'uiw., .'{IT.
Tliis spi'cii's (liftc'is soiiifwliat Inmi tin- pifi rdin;;: lunns and is vi-rv impci-lt-cl, l»ii( seems to belong lieri", and to he not (hstantlv related to A. Wcsln'oodl, hut with the ex- teiiioinedian area iiuieh more fully deviio|)i"d, with nervules siuudatin;^^ those oCthc scap- ular area. IJoth .scapular and anal aivas are wanting.
Lenji^th of fra<?ment, 8.0 mum.; width of same, '.\.1~) min.; prol)al)lc Ien;^'lh of win;;, II MUM.: prohahle hri'adth, t.l2.~) mum. il eoiucs fr<im the I-]ii;;;lish Lias.
Aporoblattina recta.
[\\'itliout nauu-], Hrodie, Foss. In-. I-^u^^l., .'):). ll'.>, I'l. 'y, \v^. '.\. Blatfl)i(t recta (»ieh., Ins. A'orw., 1518.
Tiiis also Westwood looked upon as allied to (/<»rydalis, hut il is clcai-ly related to the otlieis. It is a small and slender species, hut, excepting for the ehan;,'-es in neuration Avhieh tiiis involves, clo.sely resembles A. McLachlani. The ext« 'rnome<lian hranehes oidy near the X\\i and entirely beyond the extremity of the mediastinal area, oecupving the tip with its forked branches, which, in contradistinction Xi) all the other veins are both superior and inferior; all the other branches are simide.
Length of fragment, 0.5 nun.; ])robahle length of Aving, 8 mm.; breadth, 2.75 immi. Il comes from the AVealden of the A'ale of Wardour.
Aporoblattina nana.
Blattina nana E. Gein., Flotzform. Mecklenb., 30, PI. 6, fig. 2.
This niinntc species appears to belong here, though it differs consjiicuonsly in ihe more longitudinal and .straighter branches, most noticeable in the internomedian area. It is a little difKcult to tell where the separation of the scai)ular and externomedian veins should be placed, as the base is broken, but it would api)ear probable that Geinitz's construction of the neuration is correct, in wliich case the vei-y small development of the scapular is a marked featm'e of the species.
Length of fragment, 5 mm.; ])rol)al)le length of wing, G.5 nun.; ])readth, 2.4 nun. It comes from the Lias of Dobbertin, (iermany.
Aporoblattina exigua sp. nov.
[AVithout name], AVestwood, Quart. .loui-n. (reol. Soc. Lond., x,390, 396, PI. 18, fig. 38.
' This species, represented ])y a wing which Westwood regarded as orthopterous, seems
to belong here and to be nearly related Ui'xi. nana, than which it is not much lai-ger.
The mediastinal vein runs to the middle of the outer half of the wing. The scapular
18-J
SAIMUKL II. SLUDDKR ON
vi'iii runs ;ilm<»t straight to tlio tip, and. coniincucing to branch prett}^ near the base, semis lour wiiU-lv and equally distant, superioi", and almost longitudinal branches to the niai-nin, which in the outer third of the Aving are considerably forked, so that the tip is rrowded with terminal branches. The externomedian is similarly branched, but narrowly and only quite bi>yond the middle of the w ing. Even the imusually longitudinal branches of the iiere comi)aratively narrow externomedian area are forked in the apical tliird of the win"-. The anal area appears to be brief and narrow with two or three oblique veins. The narrowness of the wing is its marked feature, disguising its resemblance to its allies, next to which is the general multiplication of branches in the apical third of the wing. It is from two and a half to three times as long as broad.
Length of fragment, which is very nearly complete, 9 nnn. ; breadth, 3.6 nun. It comes from the lower Purbecks of Durdlestone Bay. Heer referred it to Blattidium.
Aporoblattina Butleri sp. nov. PI. 48, lig. 15.
A sino-le specimen and its reverse on a grayish-brown stone, in which the surface, per- fectly flat, is of the same color, excepting for the reddish-brown veins slightly hnpressed on one, slightly prominent on the other, represent this species. It is but a fragment, and is the oidy one jjlacedhere which appears to have certainly no externomedian vein; a mere fragment of the costal margin remains, but a conjectural outline is given on the plate, hardly consonant with the idea that it is a hind wing; indeed the presence and character of the anal vem (which is, however, no more depressed than the others) hardly allows that supposition, so that it is probable that it does not belong in this group. Still the neuration strongly reminds one of that of these species, with the single exception of the arcuate anal furrow, and the absence of the externomedian vein. The mediastinal vein extends beyond the limits of the fragment, but undoubtedly stops considerably short of the tip (running at first parallel to (?) and afterAvards) approaching the not distant costal margin, with few, distant, longitudinally oblique, nearly straight and simple branches. The scapular vein runs, apparently to the tip of the wing, in a nearly straight course far from the costal margin, yet connnences to fork only just before the middle of the Aving and has only two or three superior, longitudinal, so far as can be seen simi:)le, distant branches. The median vein runs in a nearly straight course, parallel to the former, through the middle of the wing, and has only a few similarly distant, longitudinall}' ar- cuate, BO far as can be seen simple veins, all, or all but one of which, arise near together before the middle of the wing. The anal furrow is broadly arcuate, terminating probably a little before the middle of the wing.
Length of fi-agment, 8.2.5 nmi.; probable length of Aving, 12 mm. ; its breadtli, 4.25 mm. It comes from the English Lias and was sent l)y liev. ]Mr, Brodie for examination. It is named after Mr. A. G. Butler, of the British ]NIustum, who has contributed somewhat to our knowledtjre of Enjrlish fossil insects.
MESOZOIC COCKUOACUKS. 183
i
API'KXDIX.
Tlit'iv are a lew ispecies, iiiipirlletiv prestTvecl, cdiRi ruin;;- wliiili \vi' can (••uiic to iiu satisfoctoiy conclusions. Such is liithma ruinijlcata (iielu-l (li^^ui-cd hy \\«stw.. Quart. Journ. Geol. Sue. Loud., x, PI. 1.j, fij^. 20), iii wliicli all tiic veins, or at any rate all hut one are repi-eseuted as ori«i:inatiu<;f froui a single r<jot. It is pei-Iiaps an Klisauia.
Another is Blaftina nice it a ijd^'nntA (Zeitselu-. deufseli. j^eol. ( iesellscli., ISS(, ."JTl, PI. 13, fig. 2), whieli the author compares to Cte/ioblaitina Laiujfddli, a resenihlance which would not have been mentioned if a mistake had not been made in the interpi-eta- tion of the margins of the wing: of the latter species, as mentioned above. \\\ the dis- tance of the meiliastiual vein from the margin, it would appear to be a front wing; l)ut for that and for the corresponding very strongly arcuate front margin, it w<»uld apjtear to be a hind wing, and to be not far removed from tlu' wings J have placed in .Vporo- blattina. As, however, it is clearly a front Aving, as all the veins appear to be independ- ent, and as its general form and the general distribution of the areas are very different from that of mcsozoic cocki-oachcs in general, I am strongly inclined to doubt the Hlaltidcau relationship claimed for it, and to look at it rather as a neuroptcrous wing allied tollagla.
There is also the mere fragment of a wing figured l)y West wood ((^uart. fJourn. (ieoi. Soc. Lond., X, PI. !.■>, fig. 19) which is probably less than a quarter of the whole wing, and the apical portion at that, Avhich is probably quite indeterminate. Ileer refers it to Blattidium.
The fragment of a wing figured by Brodie (Foss. Ins. Engl., PI. ;", fig. 6, cf. p. 121) from the Wealden is apparently the anal area of a cockroach, in which the ujjjjcr curve represents the anal furrow and the lower, with the veins falling on it, the inner margin of that part of the Aving. It seems to have belonged to a .species about the size of liithma Westiooodi.
The insect from Solenhofen (Jura), which Ilcyden (Pala-ontogr., I, 100-101, PI. 12, fig. 5) figures under the name of JJlahera avi.fa, but which he saA'S " einer eigencn Gat- tung angehoreu mag," on account of the shape of the tegmina, has rather on his jdate the appearance of a Cybister or an Hydrophilus, but until further examination of the original or of other specimens, cannot be definitely fixed. There is nothing, either in shape or neuration (which appears to be very obscure), which shows any relation to other mesozoic forms, and with the exception of the Solenhofen species of the abnormal and widely different genus Pterinoblattina, it is very much larger than any other mes- ozoic forms of this family.
Finally a species from the Jura of Solenhofen is mentioned and rudel}' figured by Weyenbergh (Period. Zool., i, 86, PI. .S, fig. 12) under the name oi' J3lattaria Dancl-eri; but all he saj'sof it is that it is characterized by the abdominal appendages and the small head. As far as the figure goes, there seems to be nothing to show that it is certainly a cockroach, still less where it belongs; no wings are preserved.
rkvA
SAMUEL 11. SCUDDER ON EXPLANATION OF PLATES.
ri.ATl:; 4fi.
Ki-. 1. C/<!no6/attina areata. ? nrawii by Katherine Pell-sou. Purbecks, Euglaud. •1. '< " 4 Drawn by J. Henry Blake.
'• 3. Mfsoblatlina, sp. } Drawn by Miss Peirson. Purbecks, England.
4. JUthma Slricklandi. } Showing only the left upper wing, drawn by Jlr. Blake. Purbecks, England.
5. " " } The entire insect. Drawn by the same.
•' 6. J?i7A 1)1(1 IT'csJiroodi? ; Drawn by Miss Peirson. Purbecks, England.
" 7. JUtlivui luisina. f Drawn by the same. Lias, Streusliara.
" 8. i?i(A 1)1(1, sp. + By the same. Purbecks, England.
9. Mrsdlilattina Giikki. f By the same. Lias, Brown's Wood, Warwickshire.
" 10. M'soblntlina Sicinloni. f By the same. Purbecks, England.
" 11. ii'i/Ama llVs/iroof-'i. ^ By the same. Purbecks, England.
" 12. .Vcsd'ilnllina lilakei. | By the same. Upper Lias, Aldertou.
" lo. Mtsnbhilliiia, sp. | By the same. England.
" 14. Silhma disjuncta. \ By the same. Purbecks, Wiltshire.
■■ 15. Jlilhma Gossii. i By the same. Purbecks, England.
" IC. JiUhtiia Dalloni. i By the same. Purbecks, England.
•' 17. MesvblaUina Bensoni. | By the same. Upper Lias, Dunibleton.
PL.iTE 47.
Fig. 1. £';i'sai)i(i yuicri. ^ Drawn by Katherine Peirson. Purbecks, Wiltshire.
•-'. Mesublattina Bucklandi. f By the same. England.
3. Elisama Kirkbyi. i By the same. England.
" 4. Mesoblatliiia Xurrayi. ^ By the same. Purbecks, England.
" 5. Mesoblattina Miirchiso7ti. ^ By the same. Purbecks, England.
6. Mesoblatlina.sp. f By the same. Purbecks, England.
" 7. Mesoblattina Brodiei. ^ By the same. Purbecks, England.
" 8. Elisama Bucktoni. \ By the same. Purbecks, England.
" 9. Mesoblattina Mantelli. f By the same. Purbecks, England. .
" 10. Mesoblattina reachii. ^ By the same. Purbecks, England.
" 11. 3Iesoblultina Hvpei. f Hy the same. Purbecks, England.
" 12. Elisnma Bucktoni. 4 By the same. Purbecks, England.
" 1.3. Elinama minor, -f By the same. Purbecks, England.
" 14. Mesoblattina Higyinsii. J By the same. Purbecks, England.
PLATE 48.
Fig. 1. Diechoblatlina Wallacei. | Drawn by Katheriue Peirson. Purbecks, England.
" 2. 7.'i7//mfi? minima. I Drawn by J. 11. Blake. Purbecks, Dorset (see fig. 8a).
" 3. i\annoWn«iHa Pre«<tric/i!i. 4 Drawn by Miss Peirson. England.
4. Part of the upper wing of an Orthopteron ("Grasshopper," Westwood.) J Drawn by Mr. Blake. Pur-
becks, Dorset (see fig. 85).
" 5. Diphiroblattina Bailyi. { Drawn by Miss Peirson. Purbecks, England.
" 6. AaHHoWa«i«a H'ood?r«)-di. I Drawn by Mr. Blake. Purbecks, Wiltshire.
" 7. Ftevinoblattina pluma. f Drawn by Mr. Blake. Purbecks, Wiltshire (see fig. 8c). •
" 8. Slab of stone from Purbecks of Wiltshire, showing in their natural size the species represented in figures
2, 4, 7, 10, 11, 12, 13. Compare the figures by Westwood in Quart. Journ. Geol. Soc. Lond., x, PI. 15,
fig. 14. Drawn by Mr. Blake.
" 9. Pterin obi attina intermixta. f Drawn by Miss Peirson. Upper Lias, Alderton.
'• 10. Trichopterous wing, according to Westwood. f Drawn by Mr. Blake. Purbecks, Wiltshire (see fig. 80-
" II. Jlilhma f minima, f Drawn by Mr. Blake. Purbecks, Wiltshire (see fig. 8*/).
" IL'. Trichopterous wing, according to Westwood. } Drawn by Mr. Blake. Purbecks, Wiltshire, (see fig. 8d).
" 13. Cercopiditnn Telesphorns, Westw. J Drawn by Mr. Blake. Purbecks, Wiltshire (see fig. 8e).
" 14. Plfrinoblottiiiapenna. | Drawn by Miss Ptirson. Purbecks, England.
" IS. Ajiiirollnttinnf Biilleri. f Drawn by Mi.ss Peirson. Lias, England.
" 16. J'tirinoblattina C'urtisii. ^ Drawn by S. F. Denton. Upper Lias, Alderton.
" 17. Blatlidium Simynis. f A composite figures from the obverse and reverse together. Drawn by Mr. Blake.
Purbecks, England.
" 18. Aporoblattina McLachlani. | Drawn by Miss Peirson. Purbecks, England.
" VJ. A, ■,-, 1,1, ti/i„'i Eatuni. } Drav/ahy Miss VeirsoD. Purbecks, England.
MESOZOIC COCKROACHES.
485
INDEX OF SPECIES.
Aporobliitliiia anceps, 470.
Biillfi-i, 4N2, PI. 48, I1-. 15. Eatoiii, 470, PI. 48, llg. 19. exigua, 4i"<l. incoiiipleta, 481. Kollari, 480.
JIcLachlaiii, 470, PI. 48, fig. 18. nana, 481. recta, 481. Wcstwoocii, 480. Blabeia avita, 483. Blattaria Dunckeri, 483. Blallidium Nogaus, 474.
Siniyrus, 474, PI. 48, flg. 17. ^ .sp., 483.
Blattina incerta, 483. Ctcnoblattina arcta, 443, PI. 4G, fig8. 1, 2. Langfeklti, 443. pinna, 444. Olcchoblattina Ungeri, 477.
Wallace!, 477, I'l. 48, flg. 1. Dipluroblattina Baiiyi, 47fi, I'l. 48, Ug. 5. Elisama Bucktoni, 46G, PI. 47, (Igs. 8, 12. Kirkbyi, 467, PI. 47, flg. 3. Kneii, 4G5, PI. 47, flg. 1. media, 4i;8.
minor, 4GG, PI. 47, fig. 13. JIolos.sus, 4G4. Legnophora Girardi, 478. Mesoblattlua angustata, 462. antiqua, 463.
Bensoni,453, Fl. 46, flg. 17. Blakei, 452, PI. 4G, flg. 12. Brodiei, 450, PI. 47, flg. 7. Bucklandi, 457, PI. 47, fig. 2. dobbertinensis, 455. elongata, 458. Geikiei, 454, PI. 46, flg. 9. Higginsii, 455, PI. 47, flg. 14. Hopei, 461, PI. 47, flg. 11. lilhophila, 4G4.
Mcsoblaltiiia Manlelli, 4G0, PI. 47, flg. 9. .Malliiltlae, 462. Mnrchlsonl, 4.'.G, PI. 47, flg. 5. Murrayl, 458, PI. 47, flg. 4. Peachll, 461, PI. 47, flg. 10. protypa, 458.
Swlntoni, 454, PI. 46, flg. 10. sp., 453, PI. 46, flg. 3. »p., 453, PI. 46, flg. 13. sp., 461, PI. 47, tig. 6. Nannoblnttina Prestwichii, 475, PI. 4H, flg. 3. .similis, 475.
Woodwardl, 476, PI. 48, flg. 6. Ncorlhroblaltlna alhollncata, 444. alteiiuata, 444. Lukesii, 444. rotundata, 444 Ptcrinoblatlina Binncyi, 473. clirysea, 470.
Curtisil, 471, PI. 48, flg. 16. gigas, 472. hospes, 472.
intermixta, 471, PI. 48, flg. 9. pcnna, 470, PI. 48, flg. 14. pluma, 4G0, PI. 48, figs. 7, 8c. Sipylu.s, 472. Elthma Daltoni, 440, PI. 46, flg. 16. di-sjuncta, 446, PI. 46, fig. U. forraosa, 447. Gossii, 445, PI. 46, flg. 15. liasina, 447, PI. 46, flg. 7. minima, 4.50, PI. 48, flgs. 2, 8a, 8f/, 11. Morrisi, 448. purbeccensls, 448. ramillcata, 483.
Strickland!, 445, PI. 46, flgs. 4, 5. Westwoodi, 440, PI. 46, flgs. 6, 11. sp., 450, PI. 46, flg. 8. Scutlnoblattlna BrongniartI, 478. intermedia, 478. recta, 478.
SC'UDUMR (i\: \l( )r;\lf)L.UCOIDr'-« \r;T'i r m m , a'tm w
/ /
w
■\
SCUDDER ON MESOZOIC COCKROACHKS.
. ' V*.'
J
SCUDDER ON
XVIIl. A NORTH AMERICAN ANTIII IMS— ITS STRUCTURE AND DKVEF.OP-
MENT.
Bt Edwakd a. Hikt.
L
AST Se})tembt'r, towjinl tlic close of a prnloii;i;<'''l rain, tlic writer liad the frood fortune to find a member of this line genus of the Phalloideae. The jilant was growing in a sandy cornfield on a hillside near East Galway, New York. (Jatherin;: from the literature at hand that some genera of this family have not been satisfaetorily investigated on account of tin; dilliculty of oblainiii^ sufficient material well preserved for study, a careful search was made which yielded thirteen mature individuals and several "eggs" in various stages of growth. This ample supply of material was preserved in alcoiiol and has remained in very favorable condition f<jr determining^ the structural features and the development of the species.
Gross Structure.
The general aspect of a rather old specimen of the fungus, which will be referred to throughout this article under the name of Anthurus horealis, sp. nov. (see diagnosis at the close), is shown natural size in Fig. 1. A slender clavate stipe issues from a volva, the torn apex of which is just at the surface of the ground. Both volva and stipe are white, and the latter has a pitted surface. The stipe is somewhat contracted above and then divides into six erect and narrowly lanceolate arms which bend in together at their tips. Six seems to be the normal number of these arms, but in some instances the sixth is only partially developed. The full height of the plant is from 10 to 12 cm.; the length of the arms 1 1-2 to 2 cm. ; the diameter of the stipe is about 1 cm. below and 1 1-2 cm. at the broadest part above.
The back of each arm is pale flesh-colored and has a small median furrow extending its entire length. Toward the upper end of the arm the furrow is broader and very shallow, lower down it becomes narrow and correspondingly deeper, and at the base of the arm it widens abruptly, becomes very shallow, and disappears on the surface of the stipe. The lateral and inner faces of the arms are covered by the brownish olive-green
.MrMOIRS BOSTON SOC. NAT. HIST., VOL. lit. (4'*7)
^j^^ EHWAKl) A. BVllT ON A
ffleltii (FiiT. 2) until tlu' plant reaches its maturity. Then deliquescence of the gleba
occurs accompanied by a fetid odor which is, however, perceptible for a distance of
onlv a few feet — and the arm^, ujion becoming bared from their covering of spores, disclose a surface marked b}- irregularly branching transverse wrinkles, which do not cwss the backs of the arms (Fig. 1).
I'pon splitting the mature fungu-; longitudinally, the stipe is found to be thick-walled and with a large central cavity. The surface of this cavity is cross wrinkled (Fig. 4). A longitudinal radial section of the wall (Fig. 4) shows a cavernous structure of about three series of cavities running longitudinally and almost separated from each other, and cut up by plates and folds of the pseudoparenchymatous tissue of the wall.
Near the plane of union of the stipe with the arms a thin diaphragm, having an aperture of variable size and position, but often central, separates the main central cavity of the stipe from a dome-shaped cavity above (Fig. 4). The dome-shaped cavity is closed above, and differs from the central cavity of the stipe in having a wall with an even inner surface. Thin sheets of white tissue pass out laterally from the wall of the dome into the spaces between neighboring arms and extend vertically upward through the glel)a. The plane of section for Fig. 4 is a nearly median one between neighboring arms, and cuts these sheets longitudinally in areas marked T, Fig. 4. The gleba is here marked g. The hymenial surface is borne upon a very complicated system of folds and pockets, or closed chambers, of this tissue [h, Fig. 20), as will be de.scribed further on.
The spores (Fig. 12) are apparently olive-green, simple, ellipsoidal, 3-4 /i, X 1 1-2 /X' They are borne in clusters of from 5 to 8 at the ends of slender basidia which are divided into 4 or 5 short cells and are constricted at the septa (Fig. 11). But this is al.sn considered again further on.
A median longitudinal section through the arm and the dome (Fig. 5) shows that the inner face of the arm is adnate to the dome for about one sixth of the length of the arm. This results in confining the gleba in this lower portion of the arm to the spaces between the lateral faces of the arms (Fig. 8). There exists here in the lower portion of each arm the condition which Patouillard' has shown to exist in Lijsurus mokusin (Cibot) Fr. throughout the entire length of the arm.
Each arm is hollow (Fig. 5). Its outer and inner surfaces are approximately parallel, the wall being really thrown into transverse folds rather than merely wrinkled in its outer surface as seems to be the case when viewed externally after the deliquescence of the gleba.
' PatonilUrd : Fragments raycologiques ; X. Or^am^Atiow (in L>jsu7-us mokusin Fr.. p. C.i-70. .\\u\ also Journ.il de lK>taiiiqae, 16 JuUk-t, 1890, p. 252.
Noirni AMKHICAN A N 11 IT KI'S. 4K9
At the sides of the dome and iioiir the diaphragm, two smaller cavities may he seen (Fiii'. 4). Passages are shown leading out Irom each of these. The passage /• near the diaphragm leads into a •similar small cavity in the next spaee hetween two arms. Hy a serie.s of six such small cavities and connecting passages a complete circuit is made through the wall of the stipe at its upper end. Each of the small cavities is in communi- cation with the large cavity of each of the two adjacent arms ahove hy pa8.sages marked I. Irregularly shaped small cavities extend from the ring-like system just descrihed down into the wall of the stipe. This .system of cavities does not show in this region any direct connection with the (lavity of the dome or with the main central cavity of the stipe.
The course of these cavities from the chambers in the wall of (he siipc up into the arms is of special interest as showing the arrangement and distribution in early .stages of the bundles of hyphae which then Riled these cavities. But this subject will come up again in tracing the development of the plant.
The so-called "eggs" are found undergroimd either singly or in clusters of from two to four upon branching mycelial strands (Fig. 3). In the fresh condition they vary in form from nearly spherical to oval, but upon lying in alcohol they contract more in transverse than in longitudinal diameter. An ''egg'' just beginning to rupture at the apex had a diameter of 2 cm. The wall of the peridium has the usual structure of three layers, of which the outer and the inner are thin white membranes, but composed of very different hyphae however. These layers are separated by a broad layer of gelatinous tissue (M', Figs. 7-9).
Histology and Development. The Mycelial Strand.
Full-grown mycelial strands upon which the "eggs" are borne may have a diameter of 2 mm. These strands show a broad medullary layer of fine hyphae running longitudi- nally and a narrow cortical layer consisting of hyphae more irregular in their form and course, more interwoven, and with occasional short lateral branches extending outwaid to the surface of the strand. There is no sharp separation of these layers— the medullary layer passes gradually into the cortical.
Crystals of calcium oxalate have been found in tlu; cortical portions of some members of the Phalloideae, as by De Barv' in Phalhcs oanlmis and by Fischer' in Claflirxis c<in-
' I)e I3ary : Beitr. z. iiioi-pli. u. physiol. iler pilzp. Ziir - Ed. Fischer: Untersuch. z. entwick. der plialloideen,
morph. der phalloideeii, p. 59. p. 3.
\\<v
KDWWW) A. HURT ON A
cdlatus. SiK'li ci\ stals occur in the cortical portions of Clathrus columnatus Bosc, snociuiens of which, collected in Florida, I have been enabled to examine through the kindness of Professor Fa rlow. The Anthurus shows no crystals.
The Youngest E(j(j Found.
The youngest egg of the Anthurus material, after lying in alcohol, was elliptical in median longitudinal section, being about (> mm. long by 3 mm. wide. After staining with carmine and imbedding in paraffin, one half was cut into longitudinal sections and the other into transverse sections.
In this stage of the egg the two tissues of the mycelial strand can still be made out, but they are undergoing such differentiations as already to show recognizable early conditions of most parts of the mature plant. The stipe is here a slender bod}- extending from the mycelial strand to the central part of the egg (Fig. 14). This central portion consists of the gleba g and fundament of the arms a'. Surrounding these structures is a broad layer M' somewhat horseshoe-shaped in the section and constituting the principal mass of the egg. This becomes the gelatinous layer of the peridium.
The structure of this egg in detail is as follows: —
The medullai'v tis.sue of the mycelial strand is prolonged up througli the stipe in a bundle of slender longitudinally running liyphae, marked M. This bundle is, for the most part, separated from the fundament of the wall a by a slight space, but at some points single hyphae and small bundles run obliquely upward across the space and vip along the wall (Fig. 15). Near the lower end of the stipe medullary hyphae pass into the wall.
Toward the central part of the egg the hyphae of the bundle M spread out in a sheaf-like manner and form an early stage of the gleba and its supporting structure. At n, Figs. 14 and 16, the medullary hyphae from the gleba may be seen running out directly into the broad layer M', which has been mentioned as becoming the gelatinous layer of the peridium.
The layer M' is already somewhat set off from the tissue of the gleba by very fine hyphae which stain more deeply with the carmine than does the surrounding tissue, and which lie in a very thin and open layer covering the future gleba and arms, and pa.ss perpendicularly through the masses of hyphae n connecting the gelatinous layer M' with the gleba tissue. This thin layer of rather scattered hyphae is the beginning of the inner wall of the peridium (/, Figs. 15-16). Under higher magnification (Fig. 17), this layer may be seen to receive some of its hyphae from the gleba tissue, where they seem to have a subhymenial position.
Of the tissues already considered, the bundle forming the axis of the stipe, the
NOKIII AMKKICAN ANTIIIKIS 491
uleba, and the gcliitinou.s layer ol the pernliuiii, are iliiect conlhmation.s of tin- iiiethillary tissue of the mycelial strand and must he regardeil as <>( medullary origin. Tiie inner wall of the peridium has the same origin probably on account of its subhymenial
coiniectioMs.
The cortical tissue of the mycelial strand is continued in the thin outer layer of the egg (C, Figs. 14 and 16). The hyphae of this layer have become mon- irregular in form, and l)ranch and change their course so as to become extremely interwoven. The tissue remains loose, and must allow circulation of air throughout its whole extent. By referring to the cross section (Fig. 1(5), portions C of the cortical tissue nuiy be seen extending inward from the main peripheral mass of this tissue to the glcba. There are six of these portions placed at about equal distances apart in the cn^ss section. They have the position of walls or plates extending from the ba.se of the egg longitudinally upward to a short distance above the gleba mass, and extending inward from the peripheral layer to the fundament of the stipe and arms. In all of the lower and middle portions of the egg, these plates of cortical tissue divide the gelatinous layer .M' into six parts, the hyphae of which do not cross througli tiic partition from any pai-t into the adjacent one. The partitions do not extend to the apex of the egg — at least not in this nor in the more advanced stages which I have examined. Above the level of the upper ends of the arms, the portions extend inward from the cortex only a part of the distance to the axis, and the amount of this inward extent diminishes rapidly higher up, so that near the apex of the egg the partitions become so shallow as to be hardly more than traces along the inner face of the cortical layer. It follows from this that in the upper part of the egg, there is but a single mass of the gelatinous layer M' and that this is divided below by the cortical partitions into the sLx masses already mentioned.
In the lower third of the egg, there is a cylindrical layer of tissue (C", Figs. 14 anrl 15) similar to that of the partitions and into which they pass. This layer completely sur- rounds the fundament of the stipe and wholly separates it from the gelatinous layer of the peridium. Toward the inner face of the layer C", its hyphae anastomose less frequently and are less branched, but become closely and irregularly laterally inflated. In preparation.s stained with paracarmine alone, the walls of these hyphae were but slightly stained as compared with their protoplasmic contents. In such preparations the greater masses of protoplasm at the inflated portions gave to the hyphae a dotted look under low and medium magnification (p, Figs. 14 and 15). In the double-stained preparations with the cell-walls well brought out. these hyphae appeared under high magnification as shown in x and ./;', Fig. 18.
40-2
EDWARD A. 15UHT ON A
Tlie iutlatcHl liyphiie do not wholly compose the fundament of the wall of the stipe; small handles of line hyphae b are also present but cannot be traced long distances. These unintlated hyphae are undoubtedly of medullary origin, as they closely resemble the medullary hyphae of the main cavity of the stipe, and, as stated in a former place, similar bundles of hyphae pass from the medullary portion into the wall of the stipe near its base. The inflated hyphae seem to occupy the spaces between the bundles of uninflated medullary hyphae in the fundament of the stipe.
Tiie stipe seems to be composed in part of tissue of medullary origin, and in part of tissue of cortical origin. Later stages of the egg show that the medullary tissue of the wall becomes the gelatinous tissue of the chambers and finally disappears, while the inflated hyphae of cortical origin differentiate further into pseudoparenchyma.
The arms of the receptaculum are borne upon the upper end of the wall of the stipe. In this stage of their development, they consist of six large masses of longitudinally running hyphae (a, Figs. 14-17) passing upward from the fundament of the wall. In the lower part of each mass, the tissue is very dense and seems to consist of both the medullary and cortical tissues of the stipe wall but with the medullary hyphae collecting into the centre of the mass. Further up the hyphae of the mass seem to be wholly of medullary nature. Each of these masses is the fundament of an arm and lies in a V-shaped cavity extending upward along the surface of the gleba (Figs. 14-17). The arm is in contact with the supporting tissue of the gleba near the lower end — at about the region of the future dome ; but 1 cannot detect any hyphae passing from the one structure into the other here.
The arms arise at the inner edges of the cortical plates (Figs. 16-17). Hyphae from these plates cross the narrow separating space and come into contact with the fundament of arms. I am inclined to think that these hyphae merely reach the fundament and do not enter it, and that we have here, for this part of the arm, the first penetration of the cortical tissue into and across the narrow surrounding space which this tissue takes full possession of later on and in which it builds up the wall of the arm.
The surface of the cavities in which the arms lie is lined by a palisade-like layer of cells closely packed together, which stain deeply with the carmine. They are the swollen ends of branches given off by the spreading hyphae of the medullary system. This layer of cells is the young hymenium (h, Figs. 14-17), and the swollen cells are the young basidia. This hymenial layer is thrown into ii series of folds which, judging from serial cross sections, extend principally in a longitudinal direction and have their hollows directed .somewhat centripetally in between the radiately spreading hyphae of the gleba
NOIMII A.MKU'ICAN ANrillKr.s. 403
(Figs. 16 and 17). In somic places tliese folds liavc their surface thrown into a socondary series. Merc the small depressions of these folds extend into the primarx fold in the direction that the liyphal branches must liave originally taken in passing toward the surface of the cavity from the deeper tramal tissue of that primary fohl. The impression gained from the hranched structure of the chambers is that originally simple chambers have had branclu-s form in the tissue of the gleba thi-ougli the gradual spreading apart of the masses of hyphae whiidi reached to the surface of the first chambers, and that this spreading apart followed from tiie need of a greater surface consequent upon the abundant production of l)asidia in the region of the existing chambers. That the formation of the basidia causes the formation of branches of the chambers, seems to be shown by tlie fact that the UKJst remote portions of the brancdi- chambers are constantly lined with the basidia. Tiiat the basidia form only in the region of already existing chambers seems to be shown by the fact, that upon running through the series of cross sections, small chambers are not found absolutely isolated from the large clnunbers. They may seem so isolated in some sections, but others show the connection.
Plow has there arisen from the simple conditions of the cortical and medullary tissues in the mycelial strand the more complicated and yet symmetrical disposition of these tissues in the egg just described? How have the six masses of the gelatinous layer of the ])eridiuui come to be separated from each other by plates of cortical tissue? How happens it that these masses of gelatinous tissue are connected with the medullary tissue from which they originate, only in the upper part of the egg? Was there a connection down to the base in a younger stage ?
Determination of Edrlhr Development hji Reference to CIdthrus.
No younger egg of Anthurus is available for a direct answer to these (juestions. yet the stage of development just described bears in certain features so much in connnon with the better known genus Clathrus that approximately correct answers nuiy nevertheless be had.
The earlier conditions of Clathri's cancellatics have been examined and illustrated by Fischer.' His earliest stage (Taf. 1, fig. 1) shows the medullary tissue of the mycelial strand spreading out in the pyriform egg and sending several radiating branch-like masses into the cortical region. Broad masses of cortical tissue occupy the spaces between these branches. In a slightly older stage the medullary branches have by growth become much broader in their peripheral portion and have crowded the separating
' Ed. Fischer: Untersucli. z. entwick. tier phalloideen, p. 3, taf. 1 unci 2, fi^. 1-7.
494
EDWARD A. BURT ON A
cortical portions into narrow plates. These stages bring the development up to the conditions shown in Fischer's Figs. 3 and 4. which are quite similar to my Fig. 16 except perhaps in the case of the fundament of the arm.
These early stages of C. canceUaius rather indicate that the arrangement in the peridinin of masses of gelatinous tissue separated from each other by plates of cortical tissue has resulted from the extrusion into the early cortical layer of masses of more viirorously growing medullary tissue; still such stages do not forbid the interpretation that the cortical tissue has taken the initiative and has intruded into the medullary region forming the plates.
The supply of Cfathrus cohimnatus Bosc, to which i-eference has been made on a preceding page, contained one egg in an earlier stage than those of G. canceUatus described by Fischer. Clathriis columnatus in its mature form is characterized by a receptaculum having usually four meridionally ascending arms which are joined together into two opposite pairs above, and then these pairs are joined together by a single connecting portion. The youngest egg of this species, as taken from the alcohol, was pyriform in general form (Fig. 19) and somewhat flattened on two opposite sides, so that a cross section would be elliptical rather than circular. Four well-marked ridges run meridionally and are separated from each other by furrows. Upon sectioning this egg it was found that these ridges are wings of the medullar}^ tissue. The cortical tissue of the furrows is especially loose, and hyphae from two opposite sides seem to be bridging and filling in the furrows. But the important feature is, that the outer surface of the cortical layer conforms to the ridged medullary surface to a much greater degree than in later stages, thus indicating that the medullary layer has taken the initiative in the disposition of the tissues of the egg.
The question in regard to the arrangement in C. columnatus of the gelatinous layer of the peridium in four masses — as in most cases — separated from each other throughout by four plates of cortical tissue, may be answered by stating that it has resulted from the extrusion of the medullary tissue along four longitudinal lines out into the cortical region. Here the entering masses have broadened out in their peripheral portions so as to crowd the cortical portions between the masses into narrow plates. The answer to this question for Anthurus horealis is somewhat the same, but is complicated by the generic differences between Clathrus and Anthurus. In C. columnatus the cortical plates extend from the ba.se to the apex of the sporophore, cutting off all direct coimection of one gelatinous mass with its neighbors. This indicates that the medullary extrusions were strictly lateral. In A. horealis, it has been pointed out that the six cortical plates do not extend to the apex of the sporophore, and that the six gelatinous masses are in direct connection with each other above and also have radial connection with the medullary ti.s.sue of the gleba along six lines (n, Fig. 16). Such connections indicate
N<»R1H AMl-.KICAN ANTIIIHIS. 495
not only that in this species nioclullmy extrusions have occurred laterally along nix lon<j:itu(liniil lines in the region of the arms, as in the Clathrus, hut that such extrusion upward and outward has also occurred from the uj)pt'r end of the medullary column.
With regard to the last question, as to whether in an earlier stage the gelatinous masses of the peridium were connected down to the hase with the column of medullary ti.ssue in the main central cavity of the stipe, 1 thnik that an answer in the negative may be safely ventured. C. columnatita has such connections, and they determine the mature form of the fungus. Were such connections originally present in A. borealis, some slight indications of the fact, as by the directions of the hyphae, or by some slight persisting connection, as by breaks in the uniformity of structure of the fundament of the wall of the stipe, would have been found in .some of the sections. After ])a8sing into the cortical region, tiie medullary masses must have crowded tliejr way down- ward into the cortical tissue by the means that in C. cancellatus has compres.sed the broad masses of cortical tissue shown in Fischer's Fig. 1, of his work already referred to, iuto the compact plates of his Fig. 2. That the medullary tissue which becomes the gelatinous layer of the volva may crowd its way down into a loo.se pre-existing tissue was shown by De Bary in his careful observations upon the egg of PhalluH cuninus.' But it is (juite probable that the greater portion of the length of the gelatinous mas-ses below the level of the arm is to be accounted for by the fact that the arms were at a much lower level when extrusion of the masses occurred, and that while they have retained their connection with the gleba, they have also grown and lengthened with the growth of the stipe and the egg in general.
Development of Anthnrus in yext Olrhr E<j(j.
Let ns now pass to the later development of Antliurus. A more advanced stage tlian that already considered is shown in Fig. 20. This represents in cross section one of the arms, the surrounding gleba, and the cortical plate passing from the arm through the gelatinous layer of the volva to the cortex. The location of the figured portion in the entire cross section may be seen by reference to Fig. 7, although this latter is from a still more advanced stage of the egg.
In Fig. 20, one is struck by the great development of the gleba, as compared with that in Fig. 17. Still the repeated formation of new series of folds upon the surface of those already existing would ultimately give a very intricate structure. Indications of such a method of folding were afforded by the younger stage. The great number of small closed chambers shown in this section and in those of later stages seems to show that
' De Bary : Beitr. z. raorph. u. plivsiol. tier pilze, 1. Reihe, p. 194, taf. 29, fig. 3 und 4.
MEMOIRS BOSTON SOC. NAT. HIST., VOL. III.
41*0
EDWARD A. BURT ()N A
some other factor than repeated folding has aided in their formation. The cavities between the primary and secondary folds of Fig. 17 can now be followed only with great difficulty, and in these cases they seem to be rows of small closed chambers with occa<ional connecting passages. These systems of cavities are also frequently cut off from reaching quite up to the wall of the arm, which is now developing in the narrow space about the fundament of the arm of the younger stage. All of the chambers in that stage opened into this space.
The breaking up of the earlier communicating chambers into the many small chambers of this section, seems to indicate that at those places in which changes occurring in the gleba have caused folds to be crowded into close contact, hyphae from the tramal tissue of the one fold, or of each fold, pass into the other and bring about an anastomosis of the folds. Indications of such anastomoses in formation are not infrequent. In his study of Ithyphallus tenuis Fischer' pointed out that it may be that anastomosis of neio'hboring folds is a factor in the formation of the closed chambers of the gleba.
The deeply staining cells of the hymenial layer are now more elongated and are ba«idia, bearing a cluster of spores at their outer ends. These basidia already show the series of constrictions which become so singular a feature in later stages.
Great development of the arm has been taking place. It now fills the whole of the cavity which in Fig. 17 was only partially occupied by its fundament, and is in close contact with the folds of the gleba. Two quite distinct tissues now compose the arm. There is a central mass of fine hyphae running mostly in a longitudinal direction. This tissue is highly gelatinous and, in the double-stained preparations, takes the same orange color that is taken by the gelatinous layer of the peridium, by the tramal tissue, and by the central tissue of the stipe, — all of which are of medullary origin.
The second tissue of the arm surrounds the gelatinous constituent. It consists of a narrow layer of hyphae connected with the tissue of the cortical plate. These hyphae are branched and irregularly inflated, and are developing into the pseudoparenchyma. This tissue retains in the double-stained preparations the purpli.sh red color given by the carmine, and is sharply distinct from the gelatinous ti.s.sue of the arm on the one side and from the gleba on the other. It seems to find conditions for its development most favorable along the surfaces of contact with the gelatinous ti.ssue of the arm and with the gleba rather than midway between these two surfaces. This causes a rather more compact arrangement of this tissue next to these surfaces than in the middle of the space between them. This appearance has been referred to repeatedly by Fischer, and it is probably this which gave him
'Fischer: Entwick. der fruchtkorper einiger phalloideen, p. 12, taf. 2, fig. 12. In Annales jardin botanique Boiteozorg, vol. 6.
NolMH AMKKK AN A N I III ' lUS. 497
the idea that the psL'iulop;uviii-hyiiia ilfvclups lioiii thu hyiihau Itoth of the gleba and of tlie gelatinous mass of the arm. Tiie hypliae of this narrow hiyer are, liowever, in direct connection witli the iiyphai; of the cortical plate imil tlir<Hi;^h that with the cortical layer, and stain the same.
In Fig. 21, the small portion y <>!' Fig. 'JO is shown more highly magnified. On the one side may be seen tlie gelatinous tissue of the arm. mi the other there are llie tramal tissue and the hymenial snrf.ace with its constricted hasidia here without Hpore.s. In the space between may be seen the coarser and more irregularly sha]>ed hyjihae of cortical nature, marked with irregular lateral iiillalions and taking on the form of intermediate conditions of pseudoparenchyma. 1 am unable to (ind, in any of the many sections examined, hyphae passing from the gelatinous tissue of the arm on the <jne side or from the gleba on the other into tiie space between, and there forming pseudoparenchyma by abjointing or constriction of their swollen tips.
The wall of the stipe is now in an instructive stage of development. Serial radial longitudinal sections are shown in Figs. 22 ami 2'-). Two ([uite distinct tissues are jiresent, as was pointed ou: in the younger stage. One of these consists of hyphae running in general in a longitudinal direction. These resemble the hyphae of the main cavity of the stipe and those of the gelatinous tissue of the arms. At most places in the section, of which only a small portion has been drawn, these hyphae are in small oblong or linear masses separated from each other by a more deeply stained tissue. The oblong masses lie in chambers which become empty at the time of elongation of the stipe. The deeply stained walls of the chambers are not yet folded ; they consist of an early stage of pseudoparenchyma.
Although at some places in these sections and often in wliole sections (Fig. 23), the oblong masses of hyphae in the chambers seem to be completely cut oft" from other masses of similar nature by the chamber walls, yet the examination of the preceding or following sections in the series will show small openings in the walls through which hyphae pass from chamber to chamber. Such an opening is .shown at 2, Fig. 22. This section was next in the series to that represented by Fig. 23.
Sections of the middle and upper portions of the stipe do not show bundles of hyphae passing from the medullary tissue of the main central cavity outward into the chambers of the wall. But near the base fewer layers of chambers occur in the wall, and bundles of hyphae do pass from the medullary tissue of the axis into the chambers thi'ough small openings in their walls. Such entrance of tlii medullary tissue into the chambers may be seen at the points b", Fig. 10, which represents a median longitudinal section through the base of an egg in a still older stage of development.
■IIK^
EDWARD A. BURT OX A
From the above observations it may be concluded that near the base of the egg, bundle-! of medullary hyphae pass into the fundament of the stipe, branch there perhaps, and become loosely interwoven ; at the place of origin of the arms, these bundles are crowded together more compactly — probably by the extrusions of medullary tissue in forming the gelatinous layers of the peridium — and ascend in six masses, each of which is the fundament of an arm. All of these bundles of hyphae gelatinize and disappear ultimately, and leave empty chambers : hence the course of this tissue from the chambers of the stipe-wall up into the arm is shown by the connection of the cavity of the arm with the cavernous structure of the chambers of the wall of the stipe, reference to which was made in describing the structure of the mature plant.
The second constituent of the wall of the stipe is, in the stage represented by Figs. 22 and 23, more distinctly seen to be in connection with the surrounding sheath of cortical nature than in the younger stage of Figs. 14-17. Its hyphae are differentiating into pseudoparenchyma by the formation of irregular lateral inflations, as described in the case of the wall of the arm.
Fischer has stated for Clathrus cancellatus and several Phalleae that the hvphae of the chambers radiate outward and form their pseudoparenchj'ma walls from their swollen tips, contribution to these walls being also made in various Phalleae by similarly swollen tips from medullary hyphae of the main central portion of the stipe on the one side of the stipe-wall and from the primordial tissue (my cortical sheath) on the other." In thick sections there is somewhat of the appearance which he describes and figures repeatedly, but it is due to the packing together of the pseudoparenchyma next to the surface of the gelatinous tissues — to which reference Avas made in the case of the arm — and to the impossibility of determining with certainty in such sections the real connection between the cell-like pseudoparenchymatous bodies. But even here I can in no case find a hypha from the medullary tissue of the main central cavity of the stipe or from the chambers of its walls making a distinct connection with the pseudoparenchyma — such a connection as is easily seen between the tramal tissue and the basidia. In sections cut 6 2-3 /a thick, it may be seen that the pseudoparenchymatous hyphae run in the plane of the wall and not perpendicularly into it. as would be the case provided they had the origin which Fischer has stated.
The conditions which I have described stand out still more distinctly, when such a thin section, after removal of its paraffin and after being run down to water but not fixed to the slide, is then treated with a drop of dilute potassium hydrate. The section should be carefully crushed under the cover-glass so as to spread it out somewhat and
'Fischer: Untersuch. phalloideen, p. 6, 6, and 36, and fig. 26, 27. and 32; and Zur entwicklun^sgescU. der finchtkorper eioiger phalloideen, p. 17, and fig. 18.
NORIII AMKRK AN AMIIIK!^ ^jlQ
separate its hypliae to a slightly ^Teatei- extent, and linally .-tained willi a(na'ous Knlution of safranin. The hypliae of the chaiiihers will he fdiiiid (|iiite free from tlie strands of psoudoparenchyma. while the hypliae of the latter will imw he separated siiUieieiitly to show with greater distinctness such conditions of developniciit as have been rlrawn at x", Fig. 18.
Final iJi ctlopiiiciit.
Such an intermediate stage of the psuiidopareneliyina leads up to its linal condition shown in Fig. 10. The walls of the chambers are no longer straight as in Figs. 22 and 23, but are thrown into folds closely crowded together (Fig. {{). p).
The structure of the wall of the stipe afTords the clue to the formation of these folds. The branched and interwoven bundles of medullary hypliae h make the elongation of the chambers dependent upon the elongation of this medullary tissue during its existence. The more rapid growth of the pseudoparenehyma in the chamber walls tends to make these walls longer than the chambers can become during the existence of their medullary contents. The excess in length of the walls is laid down in the folds.
EIon(jatio7i of the Stipe
Wiien the gleba has attained its maturity and the stipe has completed its folded walls a series of changes occurs in the egg provided external conditions are favorable. Through these changes the elaborately constructed receptaculum bursts from the volva, and rises aloft, conspicuously exposing its spores to the disseminating agency of insects. These changes are: —
a. The gradual elongation of the egg from its nearly spherical form in early life. During the later stages of this elongation, the volva separates from the receptaculum by the splitting of the inner wall of the })eridiuni (i, Fig. 9).
b. The gelatinization and disappearance of the medullary tissue occupying the main central part of the stipe, the chambers of its walls, and the interior of the arms. (The beginning of this change is shown by the main central tissue of the stipe in Fig. 9.) This permits
c. The straightening out of the folds in the walls of the chambers.
As a result of these changes, the receptaculum pushes upward against the apex of the peridiuin, or volva, which becomes thinner there (Fig. 9) and is ruptured finally. The receptaculum then emerges. These changes occur in wet weather.
The straiohtening out of the folds in the chamber walls of Phallus caninus and of Phallus impmdicus was stated by De Bary to be due, in his opinion, to the inflation of
\
500 EDWARD A. BURT OX A
the chambort! by the fonnation of a gas within them.' This idea has found its way into the text-books.' Such an explanation of tlie phenomenon has been objected to, and very properly so, by Fischer in a short paper of great importance.^
In this article Fischer points out that the chambers are not surrounded by air-tight walls ; that all of the chambers are open on one side in some of the forms which he has studied; and that there is no visible indication of tlie inflation of the chambers during their elongation. From these facts he concludes that the walls are not passive in their straightening out, as De Bary's explanation necessitated.
That they are the active agents he deduces from the forms of the cells at the ends of the folds and from their changes in form when the folds straighten out. He shows that at the inner angle of the fold the cells are wedge-shaped as if by compression, while on the periphery of the fold they are elongated and thin as though stretched out there. Upon placing such folds in certain aqueous solutions of slight density, the turgescence of tlie cells increases by absorption of the liquid, they become more nearly spherical, and the effect of such change of form both at the inner angle of the fold and at its periphery is to straighten out the fold.
In Anthurus borealis the cells of the folds have the forms wdiich Fischer figures and the folds straighten as he states. As the elongation of the stipe in plants of this sort occurs only in wet weather or in damp places, it seems to me that Fischer has offered the true explanation of the rapid elongation of the stipe — so rapid as to give rise to the popular impression that such plants attain tlieir full growth in a night.
The H)jmenlum.
It has been stated that the hymenial layer lines the chambers of the gleba. The hyphae of the trama give off numerous short lateral branches, the swollen ends of which form the hymenial layer {h, Figs. 17 and 20). In the youngest egg of Anthurus these swollen ends were unsegmented and did not yet bear spores, and they stained deeply with the carmine. In the later stages spores were present, and the deeply stained and swollen but nevertheless comparatively small and slender ends of the tramal branches were divided into four or five short cells and constricted at the septa (Fig. 11).
It may be urged that the end cell of this series should be regarded as the true ba.«idium. but the preparations do not favor such a view. The figure was carefully made
' DeBary: Bcitr. z. morph. u. physiol. der pilze, I., Eiig. trans., p. 341. (c) Goebel : Outlines of classif. anil
p. 202 aod 207. spec, morph., Eng. trans., p. 139.
^Ed. Fischer: Bemerk. iiber ilen streclcungsvorgang '(a) DeBary: Comp. morph. of the Fnngi, etc., desphalloidcen-receptaculums. Mittheilungen der natur-
Eng. trans., p. 323. (6) Sachs : Text-book of botany, forschenden gesellschaft in Bern, 1887, p. 142-157.
NolMII A.Ml.KKAN ANTIIIIUS. 501
witli the aid of un Abbe caineni liiciila, ami shows acLUiiately tin- ililTfreiice.s in form bi'tweon tlie ItniiitlK-d tiamal liypha and the constricted basidinni. Hut tlieix' are also dilYL-rences in nature lictween the two. which arc revealed by the action of stains. The tranial hyphae and their short branches as far as tin- first cell of the basidia stain bnt very slightly with carmine or eosin, while the 4- and •VceUiMl basidinin stains inteiwely with these substances and its parts all stain alike, the terminal cell not difTering in nature from the three or four below.
This character of the basidia seems to be uniiiue — at least so far a.s my reading and observation go. Still it may have been overlooked in other ca.ses. It is readily demonstrated by crushing under a cover-glass sections that have been treated with potassium hydrate and then staining them with aqueous solution of eosin.
No cystidia were to be seen. In my Fig. 11, 1 have omitted drawing the spores on one basidium, but that was for clearness in the figure. The sterigmata are very short, and the spores are borne in a close cluster of from 5 to 8 at the obtuse end of the basidium. The spores are olive-green, .simple, ellip.soidal, 3-4 X 1 1-- /i. Throughout the gleba they all .seem to be in about the same stage of development and all ripen together probably. No attempt has been made to germinate them.
Ckimp Connectioim.
A form of clamp connection may be seen in the earlier stages of the egg. It was observed very frequently in the medullary tissue of the axis of the plant and in the gelatinous tissue of the pcridium and more rarely in the cortical layer. In the latter case hyphae having such connections showed fewer anastomoses with the other hyphae and were more regular in form than is the case usually with the cortical hyphae. In this form of clamp connection one or both of the adjacent cell ends are very considerably swollen. Fig. 13 a shows one of the cases in the cortical layer and Fig. 13 6, two in the gelatinous layer of the peridium.
Summary of Develojjmenf.
1. All of the tissues of the egg arise from internal differentiation of the medullary and cortical tissues of the mycelial strand. In such differentiation
(«) The medullary portion gives rise to the column of gelatinous tissue in the main cavity of the stipe, to the more persistent forms of this tissue which constitute the diaphragm and the dome, to the entire mass of the gleba, and to the gelatinous and inner layers of the peridium; while
(Jj) The cortical layer gives rise to the outer wall of the peridium, to the cortical plates (or i-adial walls), and to the cortical sheath of loose tissue outside of the stipe.
-,^^2 KDWARD A. BURT ON A
'2. The receptaculum is formed by the joint action of both the cortical and nu'tluUarv tissnos. Of those the cortical constituent develops into the pseudoparenchynia of the walls, while the enclosed medullary bundles of the chambers finally become iTolatinous and disappear, their most manifest function being apparently that of preventing the elongation of the chambers until the completed formation of the folded walls of pseudoparenchynia has provided a mechanism for quickly raising the gleba aloft at maturity under suitable conditions.
3. The straightening out of the folds in the elongation of the stipe seems to be due to turgescence of the cells at the ends of the folds, as first shown by Fischer, and not due to inflation of the chambers bv a gas.
Methods Used.
The material was stained in bulk with Mayer's paracarmine." This penetrated well and gave quite satisfactory results. It was necessary to use an alcoholic stain on account of the gelatinization of the medullary tissues when left in bulk in an aqueous stain for more than a few minutes. After dehydration the material was cleared in oil of cedar-wood or in chloroform and imbedded in paraffin. The sections were mounted on the slide with Mayer's albumen medium. After removal of their paraffin with xylol, they were run down through the grades of alcohol to water and then stained on the slide from 1 to 5 minutes in a dilute aqueous solution of safranin. After washing with water, the series were then mounted in a dilute glycerine consisting of two volumes of concentrated glycerine and one volume of distilled water. An excess of this mounting medium was used, and it was allowed to concentrate for several days by evaporation from under the edge of the cover-glass. Sealing such lai'ge mounts is often troublesome. After cleaning they were closed with hot glycerine jelly and then finished with Bell's cement, after the method recommended by Lee.^
The attempt was made to stain the sections on the slide when brought to the proper grade of alcohol with the mixture of alcoholic safranin and anilin water, after the formula of Zwaardemaker,^ but the differential stain obtained was not so satisfactory as with the aqueous safranin.
The use of Canada balsam, in order to save some of the labor of mounting long series in glycerine, had to be given up as the true relations to one another of hyphae lying in different planes were less satisfactorily shown in that medium than in glycerine.
'P. Mayer in .Mitth. zool. stat. zu Neapel, X, 3, 1892, ^Lee: Microtomist's vade-mecuiu, 3d ei!., p. 252 ami
p. 491 ; also in Lee : Microtomist's vade-mecam, 3d ed., p. 254.
'^- -"See Lee: Microtomist's vade-mecum, 3d ed., p. 65.
4
NOKlll AMKIiRAN AMill Kl S. 503
HiSTORUJAI. A\I) SysTKMATK A< I Ol'NT.
Thert' is but littK' litcr.ituro upuii Aiitlmnis, .iikI wliat tlii-n- i» lia-^ been r(inliii<.'cl almost wholly to brief systematic iles(;ri|)tioiis of the inatuii- foiiiisof the few Hpecies. The earliest form described was Li/s>init< (trcheri Berk., collected in .1, I). Hooker's Antarctic voyage of discovery, 1839-1843. This form was afterward figured by IJerkeley in Flora Tasmaniae, Vol. II., 18tiU, 'I'alj. IS I. From the illustration of an ''egg" given tliere, Fischer was able to decide in 188'J that in Anthurus the arms inclose and arch over the gleba in the young stage.' This seems to be all that has been heretofore directly known in regard to young stages of Anthurus.
According to the view of the genus Lysurus presented by Fischer in Saccardo's Sylloge fungorum,-' .1. hari'iil'iH would be considered a Lysuru-s, for its amis bend inward — not outward.
Patouillard^ has, however, recently objected to such a view of Lysurus and shows from late studies upon a supply of L. mokusbi collected in China by Delavay, that tiie marked characters of that species are the smooth inner faces of the arms and the presence of the gleba upon the outer (externe) faces ol the arm<. An Anthurus, he states, has its spore mass against the inner faces of the arms. This objection has caused Fischer to modify the characters of the two genera in a late addition t<j his monograph upon the Phalloideae,^ so that now he distinguishes Lysurus from Anthurus by the former having the inner faces of its arms smootli and not covered by the gleba, while they are so covered in Anthurus.
Upon such a view of the genera our North American fungus must be regarded as an Anthurus, for the greater portion of the inner face of each arm is cross wrinkled and is in contact with the gleba. It approaches Lysurus in having the lower portion of the inner face of each arm smooth and not covered by the gleba. The erect position of its arms also is like that of L. mokushi.
This species thus comes to have an important systematic interest from its closely connecting Lysurus with Anthurus and so with the Clathreae, where Fi-scher places it.
The fungus is quite distinct from all forms heretofore described and may be regarded as a new species with the following diagnosis : —
'Ed. Fischer: Uutersuch. z. entwick. der phalloideeii. ^ Patouillard : Organisation du Lijsurus mokufin Fr .
p jl Jonnial de botaiiique, IG Juillct, 1890, p. 252.
* Fischer : Neiie untersuch. z. vergleich. entwicklungs- ^Saccardo : Sylloge fungonim. Vol. 7, p. 22. geschichte n. systematik der phalloidecD, p. G and 27.
5Q4 EDWARD A. lURT (IN A
ANTiirBis BOREALis, sp. iiov. Platcs 49 and 50.
Solitary or subcaespitose. Stipe white, clavate, divided above into 6 erect, iian-owly lanceolate, hollow arms Incurved above, and with pale flesh-colored backs which are traversed their entire length by a shallow furrow having its surface continuous with the surface of the stipe; cavity of the stipe nearly closed at the base of the arras by a thin diaphragm opening above into a<losed chamber with dome-shaped wall even on its inner surface and adherent to the amis for about J their length; gleba brownish olive-green, supported upon the dome and closely embraced by the arms; spores simple, olive-green, ellipsoidal;' !| X 14 (i, 5-8 on septate and constricted basidia.
Total height of plant 10-12 cm. ; arms about J of this ; greatest diameter of stipe 15 mm.
Hah. Near EastGalway, New York (Burt), on a cultivated sandy hillside.
Allhou'i^h in its general aspect this fungus bears a certain external resemblance to Anthiints australiensis (Cooke and Massee) Ed. Fischer, as the latter is illustrated by Fischer in "Neue untersuch. phalloideen," Fig. 57, 3^et it differs from that species in the erect position ; in structure of its arms ; in having a dome-shaped chamber separated from.the cavity of the stipe by a diaphragm ; and in its slightly narrower spores.
From tl*e Brazilian species, A. sanctae-catharinae Ed. Fischer, it differs in about the same characters and also in its \vhit%stipe.
It .<eenis to approach more closely to another South American form, A. clarazianus (Miiller) Ed. Fischer.' It differs from this in being about four or five times as laro-e ; in not having the wall of the arms sharply differentiated in structure from that of the stipe ; in having its stipe with a circular outline in cross section, while the form described by Spegazzini is noted by Fischer to have been indistinctly hexagonal ; ^ and in its smaller spores. Seven arms are sometimes also present in that species.''
But it seems to be very distinct from the other species of Anthurus in its approach toward Lysurus. It is the only species of Anthurus at present known in the northern continents.
In conclusion, I desire to express my heartiest thanks to Prof. W. G. Farlow for the use of books from his library and for his direction in this research ; and to Prof. R. Thaxter for his critical examination of certain preparations.
EXPLANATION OF THE PLATES. Figures 4-23 were drawn with the aid of an Abbe camera Incida.
LETTERS COMMON TO ALL THE FIGURES.
M. medullary tissue of axis of plant in young stages — occupies the space of the main central cavity of mature plant. M', gelatinous layer of peridium — of medullary origin, i, inner wall of peridium. C. cortical layer, or outer wall of peridium.
C, cortical plates — portions of cortical layer not pushed outward by tlie extrusion of the medullary masses in the for- mation of H'.
' Fischer: Neue untersuch. phalloideen, p. 28, taf. 2 Fischer: Untersuch. phalloideen, p. 65.
6, flg. 40. 3 j_ Mijller in Flora, 1873, p. 52fi, and tab. 6, B.
NOinil A.MKUICAN AMIILRUS. 505
I . slieatli of cortical tissue sarroundin"; the ftin<laiiieiit of the iillpe. <i. f uiidaiiient of wall of the stipe, consisting of
b, lirplme of molallary origin In spaces which become cavities later anil
/<, hypliac of cortical origin which ilitrercntiate Into pseutloparencliynia. I . fiindnincnt of the arm.
b'. gelatinous tissue of arm of same nature and a part of b.
/>', pseudoparenchyiuatous layer of amis of sanie nature as//. g, fjieba. *
{. tntma.
ft, hynicniftl layer.
H, connection of iielatiuous masses of peridium with .M and not yet cut oil' by completion of Inner wall of perldlum. i. d, dome. j, diaphragm.
I'L.VTE 411.
Fig. 1. .V plant which has passed its maturity. The removal or flowing away of the glcba discloses the cross wrlnkleM
of the arms. Xatural size. Fig. 2. Upper portion of a plant just at maturity. Gleba is i« situ yet. Natural size. Fig. 3. Two c-igs. Natural size. Fig. 4. Half of upper portion of a plant split longitudinally — the plane of division passing between the arms. Shows
cavernous structure of the stipe, it, passage connecting adjacent cavities which are at the base of and
alternate with the arms. /, passage leading into cavity of the arm. T, sheet-like masses of tramal tissue.
i2i. Fig. 5. Half of an arm split longitudiDatly. Same lettering as before, x 2i. Fig. C. .An egg in an advanced stage of development. Cross sections of this at two planes show the position of the
gleba with respect to the arms. Slightly enlarged. Fig. 7. Cross section of above egg at plane I-I'. Gelatinous tissues arc shaded alike. At q the separation of
the volva from the arras and gleba has already occurred. The cortical plates C have lost their connection
with the arms and also with the cortical layer C. x about 2. Fig. 8. Another cross section at plane II-II'. x about 2. Fig. 9. Half of an egg in a very advanced stage of development split longitudinally. Separation of the volva from the
receptaculum has taken place at 7. The cavity of the stipe is also in formation, x 2}. Fig. 10. Median longitudinal section of an old egg, showing the folded structure of the pseudoparenchyma, /*. At fc"
hyphae of chamber are connected with the medullary tissue .Vof axis; pseudoparenchyma passes over Into
cortical layer C at p" . x 10. Fig. 11. Portion of a tramal hypha with 3 lateral branches terminating in basidia. The spores are omitted from one
basidium. x 8G0. Fig. 12. Three spores, x 2400. Fig. 13. 13a, hypha from cortical layer showing enlargements or a form of clamp connections at the septa, x 325. 136,
hyphae from gelatinous layer of peridium, showing similar condition, x 325. Fig. 14. Longitudinal section of the youngest egg found. Lower part of figure was added from second section as the
sections were cut very slightly oblique. .\t n tlie gelatinous masses M' are connected witli tin- niorlnllnry
tissue M. X 17.
PLATE 50.
Portion of Fig. 14 more highly magnified and from a single section, x CO.
Cross section of half of the same egg, showing fundament of arm a', cortical plate C, etc. x 17.
Portion of Fig. IC showing the series of folds and furrows in the gleba that are developing at the surface of
the cavity in which lies the fundament of the arm a'. The hymenium is hers a palisade-like layer of swollen
hyphal ends ft. The inner wall of the peridium is just beginning its development, x 00. Pseudopareuchyraa of the stipe in different stages of development, x and r.' are from the egg figured in Fig8.
14-17 ; x", from that of Figs. 20-23. x 400. Very young egg of Clathrus coJumnatns, having greatest diameter of 1; mm. Shows broad longitudinal ridges
caused by extrusions of the medullary tissue M. x about G4. Portion of cross section of egg in an intermediate stage of development. A portion of the cortical plate and
gelatinous layer that would lengthen the figure 8 cm. has been omitted, i 34. Part of wall of the arm from Fig. 20. y. Barren basidia are at ft. x C70. Radial longitudinal section of wall of stipe of same egg showing straight-walled chambers and connections z of
medullary hyphae of one chamber with the other, x 60. The following section of the wall. This alone might give the impression that the chambers have no connection
with each other, x CO.
|
Fig. |
15. |
|
Fig. |
IC. |
|
Fig. |
17. |
|
Fig. |
18. |
|
Fig. |
19. |
|
Fig. |
20. |
|
Fig. |
21. |
|
Fig. |
22. |
I N D i: X
|
P»Ke |
Page |
|||
|
Acantherpestes brodiei . |
156 |
Brooks. \V. K. The life |
||
|
major |
. 150 |
history of tlie Hydrome |
- |
|
|
Acridites priscus |
325 |
dusae ; a discussioD of the |
||
|
Adiphtebia lacoaiia |
345 |
origin of the Medusae, and |
||
|
Aethophlebia singularis |
338 |
of the significance of meta |
||
|
Amynilyspes wortheni . |
. 178 |
genesis |
. 359 |
|
|
Anthracoblattina dresdensis |
!»2 |
Burt, E. A. A North Ameri |
||
|
porrecta |
<l:i |
can Anthurus — its structure |
||
|
remigU |
95 |
and development |
487 |
|
|
ruckertl |
9G |
Calyptospadix cerulea |
136 |
|
|
sopita |
89 |
Carboniferous cockroaches |
299 |
|
|
spectabilis |
88 |
hexapod insects of |
||
|
winteriana |
94 |
Great Britain |
. 213 |
|
|
Antliracothremma robiista |
327 |
myriapods . 143, 283 |
||
|
Antliurus australieiisis . |
504 |
Cheliphlebia elongata |
. 328 |
|
|
borealis . 48 |
7, 504 |
Chrestotes lapidea |
. 341 |
|
|
claraziaiius |
504 |
Clarke, S. F. New and inter |
||
|
sanctae-catharinae |
504 |
esting hydroids from Chesa |
- |
|
|
Aporoblattina anceps |
479 |
peake Bay . |
. 135 |
|
|
butleri |
482 |
Classification of palaeozoic |
||
|
eatoni |
479 |
cockroaches |
23 |
|
|
exigua |
481 |
Classification of worms |
1 |
|
|
incompleta |
481 |
Clathrus cancellatus . 489, 498 |
||
|
kolhiri |
480 |
columnatus 490^ 495 |
||
|
mclachlani |
479 |
Cockroaches, carboniferous |
299 |
|
|
nana |
481 |
mesozoic |
439 |
|
|
recta |
481 |
palaeozoic |
23 |
|
|
westwoodi |
480 |
Conn, H. W. .?<'« Kingsley |
||
|
Archaeoptilus ingens |
217 |
J. S., and Conn, H. W. |
||
|
Archeogryllus priscus . |
323 |
Corydaloides scudderi . |
350 |
|
|
Archimylacris acadicum |
84 |
Ctenoblattina arcta |
443 |
|
|
parallelura |
85 |
langfeldti |
443 |
|
|
Archipolypoda |
143 |
? pinna |
444 |
|
|
Ay erg. Howard. On the devel |
Cunocantha octonaria |
361 |
||
|
opment of Oecanthus niveus |
Curculioides ansticii |
223 |
||
|
and its parasite Teleas |
225 |
Didymophleps contusa . |
330 |
|
|
Blabera avita |
483 |
Diechoblattina ungeri . |
477 |
|
|
Blattaria dunckeri |
483 |
wallacei |
477 |
|
|
Blattidium nogaus |
474 |
Dieconeura arcuata |
336 |
|
|
simyrus |
474 |
rigida |
336 |
|
|
Blattina incerta |
483 |
Dipluroblattina bailyi |
476 |
|
|
latinervis |
127 |
Distomum crassicolle |
1 |
|
|
tisclibeiui |
127 |
Eileticus anthracinus |
179 |
|
|
venosa |
128 |
Elisama bucktoni . |
466 |
|
|
Bougainvillea rugosa |
140 |
kirkbyi |
467 |
|
|
Brodia priscotincta |
21. |
>, 340 |
kneri |
465 |
|
P»«e |
|
|
Elisama ? meilia |
468 |
|
minor |
. 466 |
|
raolossus |
464 |
|
Etoblattina atllnis |
62 |
|
anaglyptica |
69 |
|
anthracophlla |
64 |
|
carbonaria |
73 |
|
didyma |
75 |
|
dohrnit |
66 |
|
elongata |
no |
|
cuglyptica . |
i;<) |
|
flabellata |
62 |
|
? Insignis |
82 |
|
labachensis |
59 |
|
leptophlebica |
77 |
|
lesquereuxll |
67 |
|
manebachensis |
79 |
|
mantidioldes 7 |
2, 223 |
|
parvula |
81 |
|
primaeva |
58 |
|
russoma |
76 |
|
venusta |
70 |
|
weissigensls |
65 |
|
Eucaenus ovalis |
325 |
|
Eudendrium carneum |
137 |
|
Euephemerites primordialis |
350 |
|
Eugereon bockingi |
347 |
|
Euphoberia angullla |
177 |
|
armlgera |
160 |
|
brownii |
167 |
|
carri |
171 |
|
ferox |
157 |
|
flabellata |
174 |
|
granosa |
168 |
|
horrida |
158 |
|
Eutimamira |
395 |
|
rariabilis |
396 |
|
Fulgorina ebersi |
347 |
|
Genentomum validum |
329 |
|
Genopteryx constricta . |
327 |
|
lithanthraca |
328 |
|
Gerablattina balteata |
110 |
|
clathrata |
100 |
|
fascigera . |
118 |
|
geinitzi |
103 |
|
gerraari |
107 |
|
507 |
508
INDEX.
Psec
Ger»blattina goldenhergi 98
intermedia . 101
niahri 108
raiinsteri 104
producta . . 106
scaberata 102
weissiana . . 109
Gerapompus blattinoides 326
estenstts . . 326
Gerams danae . .345
mazonus . . . 344
vetns . . .344
Hemeristia occidentalis . 342
Hennatoblattina lebachensis 117
■wenimetsweileriensis 115
Hexapoda, carboniferous . 213
paleozoic . 319
Hinckley. Mary II. Notes on
the peeping frog, Hyla pick-
cringii LcConte
Homotbetus fossilis
Huxley's classification of
worms Hydractinia echinata Hydroids from Chesapeake
Bay Hydromedusae, life-history of Hyla pickerineii Insect life in palaeozoic times Insects, geological history of Ithypballus tenuis KiDgsley, J. S., and Conn, H. W. Some observations on the embryology of the teleosts Legnophora girardi Libellala carbonaria Llriope scutigera Lithentomum harttii Litbomantis carbonaria
carbonarius Lithomylacris angnstum
pittstonianum simplex . Lithosialis bohemica
brongniarti 220 carbonaria Lovenella gracilis Lysnms archeri
moknsin . . 488 Megathentoroum fonnosnm pnstnlatum Mesoblattina angustata antiqna bensoni blakei brodiei bucklandi dobbertinensis elongata
311 331
1 HI
135 359 311 13 353 496
183 478 350 373 341 340 223 48 50 51 340 340 340 139 503 , 503 347 346 462 463 453 452 459 457 455 458
Mesoblattina geikiei
higginsii . hopei
? lithophila raantelli niathiUiae iniirchisoiii imirrayi peachii protypa swintoiii . Mesozoic cockroaches . Miamia bronsoni Minot, C. S. On Distomura crassicoUe Rud., with brief notes on Huxley's proposed classification of worms Mixotermes lugauensis Mormolucoides articulatus Mylacris anthracophilum 45 antiquum bretonense . 41 carbonum
heeri . . 43 lucifugum mansfieldii . 47 ovale pennsylvanicum 44 priscovolans . Myriapods, carboniferous 143 Nannoblattlna prestwichii similis woodwardi Necymylacris heros
lacoanum Oecanlhus niveus, develop
ment of . . . Omalla macroptera Oryctoblattina reticulata Pachytylopsis persenairei Palaeocampa anthrax Palaeodictyoptera Paleozoic cockroaches .
Hexapoda Petrablattina gracilis sepulta Phallus caninus
impudicus Phasmidae sp. Phthanocoris occidentalis Polyernus complanatus
laminarnm Polyzosterites granosus Progonoblattina fritschii helvetica Propteticus infernus Pterinoblattina ? binneyi chrysea curtisii gigas
|
Page |
Page |
|
|
454 |
Pterinoblattina hospes |
. 472 |
|
455 |
intermixta |
471 |
|
461 |
penna |
. 470 |
|
4fi4 |
pluma |
. 469 |
|
400 |
? sipylus |
. 472 |
|
462 |
Rithma daltoni |
. 449 |
|
456 |
disjuncta |
. 446 |
|
458 |
formosa |
. 447 |
|
461 |
gossii |
. 445 |
|
458 |
liasina |
. 447 |
|
454 |
? minima . |
. 450 |
|
439 |
raorrisi |
. 448 |
|
333 |
purbeccensis |
. 448 |
|
ramificata |
. 483 |
|
|
Strickland! |
. 445 |
|
|
westwoodi |
. 449 |
1
331 431 307 300 300 304 300 301 308 308 302 307 283 475 475 47G 54 53
225
331 122 341 293 319 23 319 124 125 499 499 223 348 343 343 129 120 119 334 473 470 471 472
Scudder, S. H. Archipoly- poda, a subordinal type of spined myriapods from the carboniferous formation
The carboniferous
hexapod insects of Great Britain '. . . .
The early types of
insects; or the origin and sequence of insect life iu palaeozoic times
Note on the supposed
myriapodau genus Trichiu- lus
The oldest known in- sect-larva, Mormolucoides articulatus, from the Con- necticut River rocks .
— ^ Palaeodictyoptera ; or
the affinities and classifica- tion of paleozoic Hexapoda
Palaeozoic cock-
roaches : a complete re- vision of the species of both worlds, with an essay to- ward their classification
A review of mesozoic
cockroaches
The species of Myla- cris, a carboniferous genus of cockroaches .
Two new and diverse
types of carboniferous myriapods
Winged insects from
a paleontological point of view, or the geological his- tory of insects
Scutinoblattina brongniarti intermedia recta
Strephocladus subtilis
Stylactis arge
Teleas ....
23 439
478 478 337 138 2C1
INUKX.
OO'J
|
I'ttge |
P»B« |
||
|
Teleosts, embryology of |
. 183 |
TricliluliH ammonltlforrois |
. 292 |
|
Termitidium amissiiiii |
. 350 |
no^lulo^ius |
. 2'.»2 |
|
rugosiim |
. 350 |
vlUosus |
. 291 |
|
Trichiulus |
. 438 |
Turrltopsis iiiitrlc'iiln Wi)riii», classitlcatloii of Xeuoucura aotlquoruni
P.(.-
3H8 I
ERRATA.
Page 18, line 5 and note 2, /or Archiroantis read Lltlio- mautis.
Page 19, Hue 15, for Ledrophora read Legnophora.
Page G8, line 20, /or internomedian ryarf externomedinn.
Page 138, heading, /or Sytlactis read Stylactis.
Page 150, line 19, /or arrayed read arranged.
Page 171, line 2, /or flgs. 16, 18 read figs. 16-18.
Page 2-40, 2d line of note, /or Lisyra read SIsyra.
Page 299, 9th line from bottom, Ist column, /or breto- nensis read bretonensc.
Page 323, line 29, /or cold read coal.
Page 323, last line but one, /or Palephemera r«a<i Plale- phemera.
Page 337, line 5, for rri^ read a-rpd^a.
Page 347, in centre, /or Meganthcntomum read Mcga- thentomum.
Page 357, line 31, /or non-ezlsting read now existing.
Page 415, 5th line from bottom, for Agalma read Aglaura.
Page 416, lines 3, 11, 14, 18, /or Agalma read Aglaura.
Page 441, 8th line from bottom, /or size read length.
Note by S. H. Scudder. — By an unfortunate accident, three of the species descriljed in the memoir on Palaeozoic cock- roaches have been ascribed to the wrong discoverer and to an incorrect liorizoD anil locality. Necymylaeris heros (p. 54, pi. 5, flg. 9), Archinvjlacris parallelum (p. 83, pi. 6, flg. 6), and the species described witliout a name (p. 128, pi. C, flg. 13), were all discovered by Mr. R. D. Lacoe, and not by Mr. Manstleld, in tlie neighborhood of Pittston, Penn. Necymylaeris heros, like the single otiier species of the same genus, was found In a heavy black sliale in tlic lowest pro- ductive coal measures, or the roof siiales of vein C. Archimylncris parallelum and the other species came from Camp- bell's ledge, near the bottom of the interconglomerate (Rogers, No. XII). It is due to these gentlemen to state that the mistake is entirelv mine.
IRT. A NORTH AMERICAN ANTHURUS.
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