mes Sree el tease siten “Are is Dew “2 oti oa} “4b, eer als Digitized by the Internet Archive in 2008 with funding from Microsoft Corporation http://www.archive.org/details/danishingolfex4apt1 a2daniuoft THE DANISH foro rer XP EDI LION, VOL. IV a. BY THE DIRECTION OF THE ZOOLOGICAL MUSEUM OF THE UNIVERSITY. TS COPENHAGEN. H. HAGERUP. PRINTED BY BIANCO LUNO A/S 1903-1907. Contents of Vol. IV a. I. Ta. Mortensen: Echinoidea, I, p. 1-193 (21 plates), 1903. II. Tu. Mortensen: Echinoidea, II, p. 1-200 (19 plates), 1907, i i’ frabiestar 2a) my eee (A) )\apent oe gol) eee POFRT. <) Dee: THE DANISH INGOLF-EXPEDITION. VOLUME IV. 1. IE CoB INOu Saves (PART 1) BY TH. MORTENSEN. WILK 27 PLATES AND 12-FIGURES IN THE TEXT. TRANSLATED BY TORBEN LUNDBECK. ap } MA >) d fk Ree Stix N/ aR an N COPENHAGEN. PRINTED BY. BIANCO LUNO. 1903. TS Py - 5 - a : wi a Me ( ; ‘ @ x es dd } Ready from the Press J 4 ac Soe CONTENTS. MELO Gt O rile rar yeytessr ee stapes aeee eyes yi sy Yescts.ord ds eicreay venveye On generic and specific Characters in the Echinoids.... Fam. Cidaride...... Diagnoses of the genera of the Fam. Cidaride Dorocidaris papillata (Leske) Ciddnsgattinism Phil errs. ci nrs-icie ste nieieeine cicis > ie Stereocidaris) insolfiiana nySp:.)/2442 se o--\- cies nes + Porocidaris purpurata Wyv. Thomson................ Table of the Cidarids occurring in the northern Atlantic and the Mediterranean Fam. Echinothuride... Diagnoses of the genera of the Fam. Echinothuride. ... Phormosoma placenta Wyy. Thomson Calveria hystrix Wyv. Thomson ... Arzeosoma fenestratum (Wyy. Thomson) . Sperosoma), Grimaldi Koehler... 093 .5..62 0222s eee Tromikosoma) Koehler nig. 0-Sp:. 4-.000005stn sess Table of the Echinothurids occurring in the northern Atlantic Fam. Temnopleuride Hypsiechinus coronatus n.g., n. sp. Echinoidea. Page 1. | On the Fam. Echinometrade Gray and the Subfam. Tripl- ||| echinidaecAlyAl passa. teen netics eee ‘ 11. | Diagnoses of the Fam. Stomopneustide, Echinidz, Toxo- 28. | pneustidee and Echinometride, with their subfamilies 21 anduGenerape on sncrticeci canes 31. 35. Ram> chinidge..2 fee se 38. Subfam. Parechinine ............ ql. Parechinus miliaris (Miill.) Subfam. Echininze 42 KEchinus elegans Diib. Kor.. || 76 | — Alexandri Dan. Kor. = attinisenisprees cements ee 62. P _ acutus sam kee her ancie ee rier 66. | — esculentus L. Jo. | : | Fam. Toxopneustide ..... 2. : 7 Subfam. Strongylocentrotine. 75: Strongylocentrotus drobachiensis . . . 78. | Table of the Echinids of the Families Echinide and Toxo- pneustidee occurring in the northern Atlantic and the So. | Mediterranean’ ...5- 22.6 -cc ae 81. | Appendix ... 86. | Bibliography Page go. 183. Cr a ee ead cae it. 0d Ge iments ou. «is mae een SUD «6a - Echinoidea. By Th. Mortensen. hg present work forms the first part of a planned revision comprising all the arctic Echinoderms, excepting the Holothurioidea. The basis of the work is formed by the rich material of the Ingolf-Expedition together with the large collections of arctic Echinoderms found at our Zoological Museum from earlier expeditions. To the arctic fauna all the species are referred which are found in the Norwegian Sea, the Greenland Sea, the Denmark Strait, and at the coast of West-Greenland, as also in the White Sea and the Polar Sea with the Bering Strait. Of forms that are only found south of the large ridge between Greenland and Iceland, and between Iceland and the Farée Islands, only such as have been taken by the Ingolf-Expedition, have been included in the work. During the examination of the material the absolute necessity of taking into consideration also other more or less nearly related forms soon made itself felt. By and by I became aware of the fact that the classification hitherto used with regard to the families treated of here, was quite erroneous, and so I have sought to include into the examination as many forms as possible in order to be able to give the new classification that had to be made, so broad a base as possible. Inspector G. M. R. Levinsen placed the whole rich collection of Echinoids of the museum at my disposal with the greatest readiness; but as far from all species and genera are represented in this collection, I have applied to several foreign naturalists, and have everywhere been met with the most obliging kindness and friendliness, so that I have been enabled to examine almost all known genera and species com- prised in the groups treated of here. The following gentlemen have sent me Echinoids on loan or in exchange: Dr. Appelldéf (the Museum of Bergen), Prof. F. Jeffr. Bell (British Museum), Prof. E. v. Beneden (Liege), Prof. Collett (Christiania), Prof. Déderlein (Strassburg), Conservator J. Grieg (the Museum of Bergen), Prof. Koehler (Lyons), Prof. P. de Loriol (Genéve), Prof. E. v. Marenzeller (Vienna), Geh.rath, Prof. E. v. Martens (Berlin), Geh.rath, Prof. K. Mobius (Berlin), Prof. Monticelli (Naples), Prof. P. Pallary (Oran), Prof. G. Pfeffer (Hamburg), Prof. R. Rathbun (U.S. National Museum), Prof. The Ingolf-Expedition. IV. 1. I ECHINOIDEA. I. nN d’Arcy Thompson (Dundee). By this present I beg to offer my sincerest thanks to all these gentlemen. Finally I had occasion for a short stay at the British Museum in August 1gor. By the genial friendliness of Prof. Bell I was enabled to examine a great many forms, especially original specimens from the Challenger-Expedition. It will appear throughout my work, that this stay has been of material importance to me, and my best thanks are due to Prof. Bell for his liberality. Still I have to thank Dr. F. A. Bather (British Museum) for his excellent assistance in several literary questions. Copenhagen, January Igo2. The Author. Loin d’étre nuisible aux vrais progrés de la science, cette multiplication des genres, lorsquwils sont établis sur des caractéres précis, ne saurait avoir d’autre effet que de rapprocher de plus en plus les espéces, que leurs caractéres naturels lient le plus étroitement. Cest 1a le grand avantage des petits genres, et cet avantage est surtout sensible dans les familles, dont toutes les espéces se ressemblent par leur aspect extérieur et par l'ensemble de leurs caractéres. L. Agassiz. On generic and specific Characters in the Echinoids. Everybody who has studied Echinoids, will have felt a considerable difficulty in recognising many of the genera, at all events of the regular Kchinoids. Such was, at any rate, my case at the commen- cement of my researches. I studied the excellent collection of these animals found in our museum, and found it to be more and more hopeless. A great many genera were exhibited, as: Lchznws, Psammechinus, Toxopneustes, Hipponoé, Boletia, Psilechinus, Lytechinus, Loxechinus, etc.; but it seemed to be impossible to discover the characters on which they were established, whether the naked tests, or specimens that had kept the spines, were examined. And the literature did not contribute very much to clear up the question. To be sure, some of these names (— as it will be seen, partly unjustly --) appeared to be synonyms; but nevertheless the other genera were not much _ better characterized. We learned through long descriptions that the spines were thick or thin, few and scat- tered, or many and closely packed; that the tubercles might be small or large, and that they might be placed in more or less regular series, etc. — altogether things easily enough seen, but so relative, that it was impossible to get any any firm hold. It was almost enough to drive one to despair. Still a faint hope was left. Might not the difficulty be in the literature, and the animals them- selves in reality be less intractable? A profound and careful attempt at penetrating into the mysteries of the relationship of the Echinoids was planned, and the plan was the simple, but clear one: to let literature alone for the present, while the animals were studied thoroughly. Everything had to be examined that might in any way be supposed to show systematic characters: the test, the spines, the tube-feet, the pedicellariz, the spicules, the spheeridiz, ete. The beginning was to be made with the “chznus-species. This choice seemed to be the best one, as these species have hitherto been especially notorious for their difficulty, and a very rich material of them is found in the museum of Copenhagen. The result was excellent. The animals proved to be very tractable, the species to be very well characterized (with a few exceptions). The difficulties arise from the literature containing numberless bad descriptions. And what a confusion is reigning in the literature with regard to the names. Almost every species must drag along with it a lot of synonyms, not only specific syno- nyms, but also generic ones. Several species have by and by been referred to a whole series of different genera, to end at last as a separate genus, as badly characterized as most of the other genera. To name only one instance: The genuine Psammechinus-species: variegatus (Lamk.) and semztuberculatus (Val.) have by and by been referred to the following genera: Echinus, Lytechinus, Schizechinus, Toxo- pneustes, but only rarely, in recent times not at all, to the genus to which they decidedly belong. On the other hand the following extraneous species have been referred to Psammechinus: Echinus norvegicus, magellanicus, miliaris, microtuberculatus, angulosus, Strongylocentrotus Gaimardi, intermedius, 1? 4 ECHINOIDEA. I. Spherechinus pulcherrimus, Evechinus chloroticus, Echinostrephus molare. — This instance may be taken as a significant illustration of the generic descriptions. Or should it be necessary also to recall the genera of Cidarids? That under such circumstances erroneous determinations have been frequent, is not to be wondered at. I have had occasion to substantiate several (far too many!) cases, and such cases too where the greatest authorities have been responsible for the determination. We ought therefore to be very cautious in using the existing statements. with regard to the geographical distribution of these forms. The characters that have hitherto chiefly been used for the distinguishing between the genera and species, are the following: the pores, the spines, the tubercles, the mouth-slits, the lining of the buccal membrane with larger or smaller plates, and the calycinal area. All these structures may give excellent characters, and, of course, they are always to be taken into consideration. But most frequently they are so relative, that it is exceedingly difficult or impossible by means of these structures to decide whether a specimen in hand belongs to one species or another. Such is especially the case when the question is of the position of the tubercles; it may be simply irritating to read the descriptions of these in different species that are to be compared, and often the result falls very short of the exertion to get a clear view of the descriptions. To this may be added that the number, size, and position of the tubercles vary very much with age. With regard to the pores, their number and mutual position is no absolutely reliable character either. That in species with. many pairs of pores their number increases with age is a well-known fact. The young S¢rongy- locentrotus drobachiensis has only three pairs of pores (Lovén 250); «Strongylocentrotus» lividus has only 3 pairs of pores in the lower ambulacral plates; Echinostrephus has 2—4 pairs of pores, oftenest 3 pairs ete. By these researches the pedicellariee and spicules proved to be of very great systematic importance; they give the most excellent characters we may want. To be sure, this fact is no new discovery. It has long been known that these organs and structures were more or less differently constructed in the different species and genera; much has been written about this fact, and a great many figures have been published. But nevertheless the fact has never been fully utilised. The history of the pedicellarize is highly interesting; scarcely many zoological objects will be able to vie with these organs with regard to the number of interpretations. From parasites to embryos, and even to vertebrates, and back again to parasites their history passes, until they are generally acknowledged to be what they really are: organs forming integral parts of the animal. v. Uexkull has given an excellent account of their history (406), and so there is no reason to give it here again. I shall only here note a few less important treatises, not mentioned by v. Uexkiill, viz. by Duncan (130), Groom (175), and Stewart (381). A little note by Troschel (Verhandl. d. natur- hist. Vereins d. preuss. Rheinl. u. Westphalen. 1870 p. 137) is also to be mentioned for the sake of completeness; it contains nothing new. The histological structure of the pedicellarize has of late years been very carefully studied, especially by Foettinger (155) Hamann (184), Sladen (366), Prouho (327), and v. Uexkiill (406). The most interesting ones in this respect are the globiferous pedicellarie, which have proved to be ECHINOIDEA. I. c poison-apparatus of a very peculiar and complicated structure with sensitive cilia, poison-glands ete. Only a single point seems hitherto not to have been fully understood, viz. how the poison gland opens through the large tooth at the end of each of the three valves forming the skeleton of the head of the pedicellaria. Perrier') thinks that in some there is a large «lacune mediane» in the end-tooth, in others he finds two terminal teeth beside each other. The latter fact is also stated by Valentin?) with regard to «Strongylocentrotus» lividus. Sladen (366, p. 105) describes the end-tooth as «channelled and presenting the appearance of two or more lateral lamella merged together to form the tip or tooth-like fang». Stewart alone seems to have seen the fact correctly; he says (381, p. gto) of the globiferous pedicellarize in Lchinostrephus: «The jaw terminates in a long, deeply grooved fang; the groove, which is almost converted into a canal by the meeting of its margins, opening at a point near, but never at the tip on the external or distal surface». But this correct description seems to have been overlooked. Neither seems the most recent author on this subject, v. Uexkiill, to have under- stood the structure correctly, although he is not much mistaken. He says (op. cit. p. 364): «Die Ver- dickung (the upper end of the blade where the end-tooth issues) weisst jederseits eine lingliche Offnung auf, von der aus je ein Canal ins Innere tritt. Die beiden Candle vereinigen sich in der Mittellinie zum unpaaren Giftcanal, der bis nahe an die Spitze des Endhakens lauft um hier dorsal zu miinden. Der Endhaken zeigt am 4ussersten Ende noch eine aufgesetzte feinste Spitze». According to this description v. Uexkitll seems to think that the poison-canal runs quite inside the tooth, which would thus be tubular. An essential reason why the authors have not hitherto succeeded in reaching the correct under- standing, is no doubt that Spherechinus granularis has especially been used as the subject of exami- nation, and in this species the structure of the tooth is only to be seen with some difficulty. If, on the other hand, an Achinus or a Psammechinus is used, the structure is easily seen, and when first it is understood, it is also easily seen that the pedicellarize of Spherechinus are in reality constructed in the same way. — When the fang is viewed from above, the poison-canal is seen to be an open groove on the upper surface of the fang (Pl. XVII, Fig. 15), the whole reminding of the poison-fangs in the opistoglypha. As mentioned by vy. Uexkiill, the canal runs out a little before the point; to speak of «eine aufgesetzte Spitze» is misleading. (In the Cidaridz the structure of the globi- ferous pedicellarize is quite different, as described below.) As far as I know there is in literature next to no more exact accounts of the development of the pedicellarize of the Echinoids3). Only Prouho (327) gives some excellent figures of the first stages of development, but only of the histology; the development of the calcareous skeleton is not mentioned. Agassiz, in the «Challenger»-Echinoidea (8) Pl. Il, Fig. 16, gives some figures of deve- lopmental stages of pedicellarie in Gonzocidaris canaliculata; but only the outer contour is given, and mention is made neither of the histology nor of the calcareous skeleton. No further direct observa- tions seem to be found. — Generally, the small pedicellarie have been regarded as developmental 1) Recherches sur les Pédicellaires et les Ambulacres des Astéries et des Oursins. Ann. Sc. Nat. 5. Sér. XII—NIII. 1869—7o. 2) Anatomie du genre Echinus. (Agassiz: Monographies d’Echinodermes.) 1542. 3) On the development of the pedicellariz in Asteroidea Agassiz gives some informations. (Rev. of Echini IV.) 6 ECHINOIDEA. I. stages of the large ones of the same kind. Duvernoy') even thinks all the different kinds of pedicel- larie to be developmental stages of a single, definitive form, pedic. tridens. Valentin (Op. cit. p. 49) writes of the triphyllous pedicellarize: «Je n’ai pu m’assurer si ce sont des pédicellaires d’une espéce particuliére, ou s’ils ne sont que le jeune Age des pédicellaires ophicephales», and Agassiz, in «Rev. of. Ech.» p. 665, says: «, According to Agassiz (Revision of Echini) C. annzlata A. Ag. is = C. tribuloides Lamk., and C.annulata Gray = Phyllacanthus annulifera A. Ag. ‘The figured pedicellaria, however, cannot belong to any of those species, although Agassiz (Revision p.g9) mentions the quoted work of Stewart under C. ¢ribuloides; it seems to be a Gontocidaris, but which species cannot be deter- mined. In (379) Stewart further gives a couple of excellent figures of globiferous pedicellarize in Doro- cidaris papillata. Also Wyville Thomson (395) gives excellent figures of the pedicellarize in Doro- cidaris papillata and Porocidaris purpurata. In «Revision of Echini» and in the «Challenger»-Echinoids (8) Agassiz figures pedicellariz of several Cidarids, but generally the figures are not good. Déder- lein (116), however, is the first author, who has tried to use the pedicellarize in a correct way in the classification of the Cidarids. He has studied the pedicellarize in a larger number of species, and ECHINOIDEA. I. 15 thinks that they often give excellent specific characters, but he was disappointed «in ihrer erhofften Verwendbarkeit zur Unterscheidung nattirlicher Gruppen innerhalb der Familie» (p.1). «Nur mit grosser Vorsicht diirfen Pedicellarien als systematische Merkmale bei den Cidariden beniitzt werden». The small pedicellarize are highly similar in almost all species, but they may vary very much in the separate individuals. (Only the form with a long terminal hook, occurring in Gonzocidaris mikado and clypeata, is especially mentioned). The tridentate ones («l6ffelartige Form») are better, but they are also highly varying in the separate individuals. Most applicable for the classification is the thick- headed form, (the large, globiferous pedicellariz); it is highly constant in form and size, and shows many peculiarities, «die sehr wohl einzelne Arten, manchmal auch Gruppen charakterisiren kénnen». He also tries to group the species according to these peculiarities, without, however, attributing to them any great systematic importance, and therefore he does not mention the pedicellarie in his diagnoses of genera. The fact is that also this form of pedicellarize shows some variability, is some- times even quite wanting in some individuals, so that it is no quite reliable character. An extra- ordinary fact is «dass sehr ahnliche Formen dieser Pedicellarien bei Arten vorkommen k6énnen, die nach den iibrigen Charakteren sehr wenig Verwandtschaft mit eimander bekunden» (C. metularia and verticillata). Wis final result is: «In vielen Fallen hat nun ohne Frage die Vergleichung der Pedicel- larien nicht geringen Werth fiir die Systematik; sie geben jedenfalls sehr brauchbare Charaktere zur Unterscheidung der Arten. — Zur Charakterisierung von grésseren Gruppen innerhalb der Familie finde ich aber Pedicellarien sehr wenig verwendbar» (p. 34). And so the last hope of finding good generic characters in the Cidarids seems to have vanished. Fortunately, however, my researches have given another result than that of Déderlein, viz. that the pedicellariz yield excellent generic characters, while they may only more rarely be used for distinguishing between the species. This seems to be irreconcilable with the above quoted statement of Déderlein that species not more nearly related, may have quite similar pedicellariz. As instances are only named Cidaris metularia and verticillata. Now it is quite correct that they have the same kind of pedicellariz; but then the question is whether the other characters, in which they differ, are sufficient to show that they cannot belong to the same genus. The most essential difference seems to be found in the spines, which are in C. verticillata provided with large thorns placed in circles far from each other, while in C. metwlaria the spines have the whole surface evenly set with homogeneous, small tubercles arranged in longitudinal series. Also with regard to the provision of the interambulacral plates with miliary tubercles a difference is found — they are almost naked in C verticillata, closely covered in C. metularia. As it has otherwise proved to be a fact that the characters taken from the structure of the test have been anything but good as generic characters, and as there seems to be nothing unnatural in the fact that spines as those in C. mefu- laria and verticillata are found in species of the same genus, I cannot but regard the fact of the two species having the same kind of (very characteristic) pedicellariz as proving them to be nearly related, so that they will have to be regarded as not too closely allied species of the same genus. Besides there is another species of the same genus presenting considerably more resemblance to C. verticillata than the C. mctularia mentioned by Déderlein. This is C. daculosa which is by Déderlein referred 16 ECHINOIDEA. I. to the same genus (Zevocidaris) as C.verticillata. In this species the thorns are often placed in circles in a somewhat similar way as in C. verticillata. Especially the large globiferous pedicellarize are of importance in the classification, the blade and partly also the stalk offering a great variety of forms. Also the length of the stalk is very different; this fact, however, has to be used with great caution, at it is very varying. Déderlein seems to put no small weight upon it. Also the small globiferous pedicellariz are of rather great importance; more important, however, are the tridentate ones, which in a single genus, Porocidaris, are two-valved. In this genus (and perhaps in the genus //?sfocidaris) globiferous pedicellariz seem to be quite wanting; on the other hand tridentate pedicellarie are wanting in several other species — but perhaps not constantly. That the globiferous or tridentate pedicellariz may sometimes be want- ing, is mentioned by Déderlein as an objection to their being used in the classification. I cannot see, however, that this objection is sound; a corresponding fact would be, ifwe were to give up using the teeth of the mammals as systematic characters, because now one, now another kind, or even sometimes all of them are wanting. When we now look over the Cidarids, and place together the species with similarly constructed pedicellarize, we shall get a grouping rather differing from all hitherto given classifications. Dorocidaris papillata: the globiferous pedicellarie have a powerful hook at the point, above the large, somewhat lenghtened, not terminal opening; small pedicellariz of the same form; the triden- tate ones simple (Pl. 1X, Figs.7, 25). Quite similar pedicellarize are found in Dorocidaris Blaket A. Ag. (PL IX, Fig. 16), which is accordingly a genuine Dorocidaris. On the other hand the following species that have been referred to Dorocidaris: D. Bartletti Ag., bracteata Ag. and Reini Doderl. differ widely from this genus, and are moreover so different from each other that they must be referred to three different genera. D. Bartletti: the globiferous pedicellariz have a long powerful hook at the point. The opening is exceedingly small, as a fine pore, surrounded by small teeth; it is placed rather far from the point. (PI. X, Figs. 23, 30). The stalk is most frequently provided with a limb of freely projecting calcareous ridges. The small pedicellarize are of the same structure, only the opening is larger; tridentate pedi- cellariee simple. There can be no doubt but that this species must form a separate genus; I propose the name of Tretocidaris'). To this genus’ must further be referred the two following new species, which I found in British Museum, both under the name of Dorocidaris papillata. Tretocidaris annulata n.sp. The globiferous pedicellarize differ somewhat from those of 7. Bartietti the inside of the blade being provided with some dentate transverse ridges and crests forming a coarse, irregular reticulation; at the upper end of the apophysis the margin of the blade is somewhat widened, highly fenestrated in a reticulate way, and bent a little outward (Pl. X, Figs. 22, 31). The stalk (PI. LX, Fig. 4) and the other pedicellarize as in 7: Bartlett. The spines are finely annulated with brown rings, the upper spines have powerful thorns especially on the side turned up; they are tapering, about one time and a half as long as the diameter of the test; the actinal spines were wanting in the specimen. There is a rather deep, naked furrow along the median line of the interambulacral areas, and it continues between the plates outward to where the scrobicular areas join each other. 1) toytog = bored. ECHINOIDEA. I. 5 There are 7 plates in the interambulacral areas. In the ambulacral area there is a little tubercle Oo oe , as in Porocidarts purpurata. The colour of the ol alternately between each two primary tubercles test is redbrown, and therefore the white, naked furrow of the interambulacral areas is especially con- spicuous. — Locality: The West Indies (no nearer information). Should this species perhaps be Gray’s Cidaris annulata? Tretocidaris spinosa n.sp. The globiferous pedicellariz have no such reticulation as those of Zi annulata, and differ from those of 7: Gartletti by the sides forming an almost straight line from the basal surface to the opening. (Pl. X, Figs. 10, 11). The small globiferous pedicellariz as in the two other species (Pl. X, Fig. 16). On the stalk no distinct, freely projecting calcareous ridges are seen, only a marked swelling. (It is, however, possible that the limb of the stalk is found on other specimens; in the two other species it was not found either in all the large globiferous pedicellaric); tridentate pedicellariz were not found. The spines closely grooved, rather finely thorned, widened at the point, of the same length as the diameter of the test. The actinal spines smooth, not serrated, their points not widened. The small spines are strongly redbrown. There is a naked median line in the interambulacral area, but it is only little conspicuous. 9g plates in the interambulacral area; thus the large spines are somewhat more numerous than commonly, which gives to the animal a very charac- teristic appearance. The tubercles in the ambulacral areas as in 7: avnulata. Locality: St. Helena (no nearer information). «Dorocidaris» bracteata Ag. The globiferous pedicellarize much lengthened and narrow, with a powerful hook at the end, and a rather small, triangular opening a little below the point (Pl. X, Fig. 18); the small pedicellarize of the same structure, tridentate ones simple. This form of pedicel- larice is further found in «Phyllacanthus» annulifera (Lamk.), Pl. X, Fig.17, and Stephanocidaris bispi- nosa (Lamk.), and these species will have to be united into one genus, which must keep the name of Stephanocidaris. Dorocidaris» Reini Déderl. The globiferous pedicellarize are of a very peculiar structure; the mouth is placed in the end of the blade, surrounded by well marked teeth on the margin which is bent a little outward. «Schnauzenahnlich vorragend» Déderlein says of the blade in this peculiar form of pedicellariz, and it really resembles a snout to some degree. On the stalk a limb of short thorns is found. The small pedicellarize are of a quite different structure, a well developed end-tooth being found here, and the large mouth situated below the point. This form of pedicellarie is found in a series of species, viz. Cidaris affinis (P1. 1X, Figs.9, 22, 24) (which is in no way synonymous with Doro- cidaris papillata, as has been commonly supposed), ¢rzbedloides, galapagensts — and, I suppose, also in Dorocidaris panamensis Ag.; at all events this species, to judge by the figure, would seem to be most nearly related to Cidaris affinis and Reini; it is scarcely a Dorocidaris. ‘The following species have pedicellariz of the same structure, but are distinguished by having a limb of long, freely projecting calcareous ridges on the stalk of the globiferous pedicellariee: Czdaris metularia, Thouarsit (according to Déderlein (116 p. 19) Cidaris Thouarsti has only a short limb on the stalk; the specimens examined by me have long limbs), verticil/ata and baculosa. Further has (according to the statement of Ddder- lein) Phyllacanthus imperialis the same kind of pedicellarie (whether a limb is found on the stalk The Ingolf-Expedition. IV. 1. 3 18 ECHINOIDEA. I. or not, is not mentioned; I have not been able to find any large globiferous pedicellariz in the few specimens I have examined), and the same, I suppose, holds also good with regard to Phyllacanthus dubia and parvispina Woods. Finally a similar form of giobiferous pedicellariz is found in Govzo- cidaris florigera Ag. («Challenger»-Echinoids, Pl. I. Fig. 12) (Pl. X, Figs. 27, 29); in the latter there is no trace of a limb on the stalk. Do now all these species belong to one genus? — Surely not. We shall first have to separate Goniocidaris florigera. It has no trace of a limb on the stalk, the spines differ considerably from those of all the other mentioned species, and I suppose that a closer examination will show several other peculiarities. D6derlein (116) thinks it to be most nearly related to the species Gonzocidaris clypeata and G. mikado described by him, which species are distinguished by the spines being provided with a peculiar flat widening at the base. Traces of such a widening are also found in G. forigera; but the pedicellariz of this species are so different from those of the two mentioned species that their being united into one genus is out of the question. It differs also from the genuine Goviocidaris-species (G. tubaria etc.) by its pedicellariz; it must form a separate genus, for which I propose the name of Petalocidaris. There can scarcely be any doubt, however, that it is closely related to Gonzocidaris. Next Phyllacanthus imperialis must form a separate genus. It has peculiar large tridentate pedicellarie, the blades of which are quite filled by a close net of meshes forming irregular longi- tudinal ridges closely set with small teeth (Pl. X Fig. 8); (the valve figured here, is from a smaller pedi- cellaria where only two longitudinal ridges are seen). The small pedicellaria have no end-tooth (Pl. IX. Fig. 6). The spines are peculiar, thick, with fine longitudinal striz. Together with this species Ph. dubia has no doubt to be placed — if upon the whole it can be kept as a separate species, of which I can have no decided opinion, as I have had no occasion to examine it. Also Phydlac. parvispina Woods must, to judge by the figure given by Woods (443), belong here; its spines resemble very much those of Ph. imperialis though Woods states them to be «entirely different from any described species». Also Ramsay (331 p.45) says of this species that on the Australian south-coast it is the «representative of P. dubia of the North Coast». — This genus, no doubt, must keep Brandt’s old name of Phydla- canthus. Brandt?) gives Cidarites dubia as the type of the section «Phyllacanthus», and observes that to this will have to be added C. zmperialis, hystrix, geranioides, and pistillarts. The three latter can in no way be classed together with the two former; these two must keep the name of Phyllacanthus. Desor in his «Synopsis des Echinides fossiles» (1855) establishes the genus Levocidaris (p. 48), and as the type of the genus he gives Cidaris imperialis. — Thus there will be no use for the name of Lezo- cidaris, it will only be a synonym of Phyllacanthus. — It will also be necessary to say some words of the much used name of Rhabdocidaris by the present occasion. The genus has been established by Desor (op. cit. p. 39) for fossil species; in a note is added: «Parmi les espéces vivantes on pourrait reporter A ce genre les Crdaris tribuloides et C.imperialis, si leurs tubercules étaient pas complétement lisses». De Loriol (245) has later enlarged this genus to comprise: 1) The fossil species of the genus Rhabdocidaris sensu stricto, 2) the Rhabdocidaris-species with smooth tubercles, 3) the species of Lezocidarzs Desor and Dames (emend.), 4) the recent species of the genus Phyllacanthus Brandt, 5) the genus Stephanocidaris Ag., and 6) the genus Schlecnitzia Studer. «Ainsi constitué, le genre Khabdocidaris 1) Prodromus descriptionis animalium ab. H. Mertensio in orbis terrarum circumnavigatione observatorum. 1825 p. 68. ECHINOIDEA. I. 19 groupera naturellement un assez grand nombre d’espéces vivantes et fossiles et me parait utile a conserver>. The advantage of such a «genus», however, seems to me to be rather illusory; with the limitation given by de Loriol Ahabdocidaris becomes still more heterogeneous than Phyllacanthus, as it is limited by Agassiz in «Revision». As the genus has originally only been used of fossil species, it is quite impossible to decide whether some of the recent forms really belong to it; by the tests and the spines alone the genera cannot at present be recognised with certainty, and no pedicel- larize of fossil species are known. Accordingly the name of Rfabdocidaris is not to be used for any recent Cidarid. On the other hand the other species with terminal opening on the globiferous pedicellaric and limb on the stalk seem to form a natural group; the shortness or length of the limb can scarcely be used as a character for the subdivision of the group. Possibly C.affinds and Retini (and perhaps paxamensts) will prove to form a special group — their spines seem to differ somewhat from the other mentioned species; but this can only be decided by more thorough examinations. For the present all these species: Czdaris affinis, Reini, (panamensts ?), tribuloides, galapagensts, metularia, Thou- arsit, verticillata, and baculosat) must form one genus, which must keep the old name of Czdarzs, Linné’s «Echinus Cidarts», as has been proved by Lovén (252), being Cidarts baculosa Lamk. The name of Luczdarts Pomel, which has of late often been used for species of this group, cannot correctly be used. Pomel (324) enumerates as types of this genus some fossil forms (#orzerz etc.) from the trias, and «trois espéces vivantes», but he does not mention which species he means, and the fact is here, as in Rhabdocidaris, that it is quite impossible to decide whether any of the recent species belong to the same genus as the mentioned fossil ones. Besides the species mentioned here, Déderlein still enumerates «Lezocidaris» annulifera Lam. as belonging to those species, the globiferous pedicellarize of which have terminal opening and limb on the stalk; here C.annulifera is referred to the genus Stephanocidarts which has a quite different form of pedicellarize (see above) — a contradiction which can only have its origin from a difference in the interpretation of the species C. annulifera Lamk. This species together with C. dacwlosa Lam. have caused and still cause many difficulties to the systematists. Lamarck?) in his diagnosis of C.annulifera says: «spinis majoribus longis, tereti-subulatis, asperulatis, albo purpureoque annulatis», and in his diagnosis of C. éaculosa: «spinis majoribus subteretibus, tuberculato-asperis, apice truncatis, collo guttatis»; according to this Agassiz («Revision of Echini» p. 389) states as the only certain character of the highly varying C. dacalosa «the spotted base of the shaft of the spine below the milled ring, which is of a light reddish or reddish-yellow ground-color, with deep violet spots marked extremely distinctly upon the fine longitudinal striation». Loriol (243) later describes and figures a Cidarid by the name of C. avznuwlifera Lamk.; he has had a radiole of the type-specimen of this species for comparison, and has found it completely corresponding to those of the specimen described by him. These spines have «leur base couverte sur une longueur plus ou moins grande de petites taches pourpres, formant des lignes et entremélées de petits points» — the character especially particular of C. baculosa! Thus, somehow or other, an error must have slipped in, and I think it most likely that 1) If C. pistillaris Lamk. be a good species, it must also be referred here. 2) Histoire naturelle des animaux sans vertébres. II. Ed. 1840. T. III. p. 380. oo 20 ECHINOIDEA. I. the spine, which Loriol has got from Paris, has really been of C. daculosa — such a changing of loose spines in a museum is not absolutely inconceivable. The C. Lzitkent described by Loriol in the same work, seems rather to be the real C. annalifera, which must then be very nearly related to C. bispinosa, perhaps identical with it. Bedford (35 p.274) also regards C. Lzitkent as synonymous with C.annulifera Lamk., but at the same time he seems to think it to be identical with Loriol’s C.annulifera, which cannot be correct. Déderlein, who has examined a specimen of Loriol’s C. annulifera, finds this species to be highly consistent with C. dacelosa. «Einen Unterschied zwischen den beiden Arten kann ich nur in der Farbung der Primarstacheln finden; denn selbst die Form der Primarstacheln kann bei bestimmten Individuen beider Arten identisch sein. — Nur die Farbung des Schaftes ist verschieden, indem Z. annulifera Querbinden zeigt, die Z. dbacwlosa fehlen; die eigenthtim- liche und auffallende Tiipfelung des Stachelhalses dagegen, die sonst nirgends zu beobachten ist, findet sich bei beiden Arten in gleicher Weise. Nachdem aber eine Autoritat wie Al. Agassiz auf Grund eines reichlichen Materials die Frage nach der moglichen Identitat der beiden Arten tiberhaupt nicht aufwirft, kann ich es nicht wagen bei meinem ganz unzulanglichen Materiale eine solche zu behaupten. Ich kann hier nur constatieren, dass die oben beschriebene jugendliche Z. axnulifera nach ihren saémmtlichen Charakteren, abgesehen nur von der Farbung der Stacheln, unbedingt als ein junges Exemplar von Z. daculosa gelten kénnte» (116 p.24). Prominence is also given to the fact that the pedicellarize are quite identical. In another work (245) Loriol gives a thorough description and figures of C. éaculosa, but its resemblance with the C. aznulifera before described by him, is not at all mentioned. Thus the fact seems to be: either Loriol’s C. annulifera is really this species — and then C. éaculosa Lamk. and C. annulifera are synonyms — or it has, on account of some error or other, been wrongly determined —- and then C. annulifera is most nearly related to C. dbzspinosa Lamk. (perhaps synonymous with it). The latter is the more probable. An examination of the type- specimens, especially their pedicellariz, will easily decide this question. To be sure, Perrier has figured pedicellarize of these two species, but unfortunately only so little exactly and minutely that he has not at all contributed to the clearing up of the question, especially as of one species he has only figured a globiferous pedicellaria, of the other only a tridentate one. According to Déderlein (116 p. 25) Schleinitzia crenularis Studer is very nearly related to C. baculosa; Studer’s figures (386) agree also partly with it, the separately figured spines having all the characteristic spots on the neck. On the figure of the whole animal these spots, however, are not found, and as, according to informations I have received from both Geh.rath, Prof. E.v. Martens and Prof. Déderlein, spines of at least two different species are found in the glass together with the type-specimen (v. Martens has sent me some of the spines), the safest plan will be to say nothing definite of this species, till the pedicellarize of the type-specimen have been examined. Studer only figures the small form of the globiferous pedicellariz. Among the species referred to Phyllacanthus by Agassiz, still one has not been mentioned, viz. Ph. gigantea Ag. It differs from all other known Cidarids by its peculiar spines, as well primary as secondary ones; also its pedicellariz are peculiar. The large globiferous ones (Pl. X, Figs. 15, 19) have a large cordate opening the lower limit of which is formed like a highly protruding lower lip; the opening reaches to the very point, and no end-tooth is found. No limb on the stalk. The ECHINOIDEA. I. small pedicellariz are of a somewhat different form (Pl. X, Fig. 26), and have a more or less powerful end-tooth. Tridentate pedicellariz about as in Dorocidaris papillata, only with the edge somewhat more dentate. Spicules of the common form. It is obvious that this species cannot] remain in the genus Phyllacanthus as here limited, or be referred to any of the mentioned genera; it must form a separate genus and retain the name of Chondrocidaris, originally given to it by Agassiz’). The splendid Crdaris curvatispinis described by Bell (74), is in its whole appearance so unlike all other Cidarids that it is beforehand to be supposed that it represents a separate genus. The examination of its pedicellarize also confirms this supposition. The globiferous pedicellariz (Pl. VIII, Fig. 37) have no end-tooth; the opening is large, reaching to the point, but its lower limit is remark- ably irregular — the figured one is one of the most regular; sometimes there seems to be no definite limit at all, the calcareous covering running out into irregular dents, as if it was broken off (which is, however, quite out of the question, as the pedicellaria was otherwise quite undamaged). The small pedicellarize are of the same structure, the only difference being that the lower limit of the opening is here often a rather regular transverse line. (The possibility that the described and figured pedicel- laria is really, in spite of its size, only the small form of the globiferous pedicellaria, is not excluded; but on the only known specimen, which by the kindness of Prof. Bell I had the opportunity to examine in British Museum, there seemed to be found no other kind of globiferous pedicellariz). The tridentate pedicellariz (Pl. X, Fig.9) are very peculiar, with some large, dentate crests of thin calcareous lamellze longitudinally in the blade. No limb on the stalk. The spicules of the common form. For this species I propose the generic name of Acanthocidaris. The genus Porocidaris is established by Desor (op. cit. p. 46) for some fossil Cidarids, especially distinguished by a circle of pores in the scrobicular area; to this genus Wy ville Thomson (394—95) referred a Cidarid from «Porcupine» under the name of Poroczdaris purpurata. Whether it really belongs to this genus cannot be decided, till the pedicellarize of the fossil species referred to it by Desor, become known. But to judge by what is hitherto known the species may well seem to be a Porocidaris, and for the present there seems to be no reason to reject this commonly used name, and P. purpurata W.Th. may then be put down as the type of the genus. Peculiarities of this genus are then the depressions in the scrobicular area (not pores as in the fossil species), the highly developed neck of the spines, the highly serrate edge of the actinal radioles’). But the most particular feature are the pedicellariz. Only one form is found which must be referred to the tridentate ones; they are two-valved, highly compressed, and exceedingly large and conspicuous. The spicules of the common form. To Porocidaris have later been referred the following species: P. elegans Ag 3) Sharrert Ag, Milleri Ag., Cobost Ag., gracilis Sladen, gracilis Déderl., mzsakienszs Yoshiwara, and zcerta Koehler. Of these species P. gracilis Sladen is, no doubt, only a young P. purpurata, and this name is then to be omitted as a synonym. P. elegans (one of the type-specimens («Challenger» St.164a) examined in British Museum): the tridentate pedicellarize are widely different from those of P. purpurata. There 1) List of Echinoderms sent to different Institutions in exchange for other specimens, with annotations. Bull. Mus. Comp. Zool. I. 1863. 2) Especially the latter fact is often mentioned as characteristic of the genus; this, however, is not at all reliable, as sufficiently shown by these researches. ECHINOIDEA. I. | N iS) are two forms, a larger and a smaller, both three-valved. In the larger form the blade is filled by an exceedingly rich net of meshes, in which the holes are rather distinctly arranged serially, and radiate in a fanshaped way from the upper end of the apophysis; this net is covered with numerous small thorns, especially towards the point. Also the upper edge of the apophysis is very broad and full of holes. (The figures in the «Challenger»-Echinoids, Pl. XLIV, 6—14, are not very good, especially not figs. 6 and 11, where it is not seen at all that the whole mass filling the blade, is really a net of meshes with innumerable larger and smaller holes). In the other, smaller form the apophysis has the common structure; the blade is highly compressed, deep, and filled with an irregular net of meshes where the holes are not at all serially arranged. Transitions are however found between the two forms, so that they cannot be said to be two distinct kinds. When Agassiz (Chall. Ech. p. 43) says of «the large-headed, shortstemmed pedicellarize» that they are «very similar to those of Dorocidaris», this is only so far correct, as tridentate pedicellarize, of course, always in some degree resemble each other; in the finer structure the large tridentate pedicellarize of this species are especially widely different from those of D. fapillata. The small ones are much more similar. — Agassiz (l.c.) mentions one more form of pedicellariae, «shortstemmed globular abactinal pedicellarize» (Pl. XLIV, 10); they are, as I have been able to substantiate, only developmental forms of the large tridentate pedicellarie. I aim a little in doubt whether globiferous pedicellarize are found. In my preparation of isolated skeleton- pieces of pedicellarize of this species is seen one valve of a small globiferous pedicellaria, which is very peculiar, with two large teeth at the point, and a rather small opening surrounded by well developed teeth (PI. [X, Fig. 2). As, however, only one such valve is found, it may be thought to have come in by chance; in this case it must be abnormal, as no other Cidarid examined by me, is possessed of such pedicellariz. For the present this must be left undecided. — It is obvious that this species has no relation with P. purpurata, and as it shows no nearer relation to any other known species, it must form a separate genus, for which I propose the name of Histocidaris. P. Sharrert: Agassiz (g) unfortunately gives no details as to the pedicellariz, and from the figure (op. cit. Pl. III) it cannot be decided whether it is a genuine Porocidaris. There seems to be no highly developed neck on the spines (in the text nothing is said of this feature); the pedicellarice might. well look like those of P. purpurata, but a close examination will be necessary for the decision. 3y the kindness of Prof. Rathbun I have from U.S. National Museum received a specimen deter- mined as P. Sharrert («Albatross» 1885. St. 2415); it proved to be the new species Stereocidaris ingolfiana described hereafter; it has no relation to P. Sharrert. Further I have in British Museum seen a specimen determined as P. Sharrert, from U.S. Fish Commission («Albatross» 1885. St. 2345). Neither seems this specimen to be identical with the real, figured P. Sharreri, at all events it does not to any striking degree resemble the figure given by Agassiz. It is no Porocidarts. The pedicellariz (Pl. IX, Fig. 26) are much like those of Dorocidaris, only the opening of the large globiferous pedicellariz is more round and of a more definite form than is otherwise the case in this genus; but this fact might very well be interpreted as a specific difference. ‘Tridentate pedicellarize simple. A much more con- siderable difference is found in the spines; they are long, slender — unfortunately they were broken, so that their length and the form of their point are unknown. The base is finely pink, the outer part white. They are quite smooth and shining, as if polished, and the structure of the outer layer ECHINOIDEA. I. dS aes) is peculiar (Pl. XI. Fig. 24) with no trace of roughness on the surface. Perhaps the specimen of Porocidaris Sharrert mentioned by Agassiz (9 p.13) «which was of a light greenish pink color when alive, the spines white with a delicate brownish-pink base» is identical with the specimen described here — in this case this specimen mentioned by Agassiz has certainly not been of the same species as the one he figures; but this latter must, of course, keep the name of Sharrerz, There can be no doubt that the specimen described here is a new species; whether it also is to be regarded as a new genus, or belongs to Dorocidaris, can only be decided, when the systematic significance of the spines has been established. For the present it ought to be classed with ovocidaris, under the name of D. micans u. sp. Neither is P. imcerta Koehler (233 a), of which species Prof. v. Beneden has lent me a speci- men for examination, a Poroctdaris. I have only found one form of globiferous pedicellarize on it; it has no end-tooth, the opening small, round (Pl. VIII, Fig. 31). Most likely another, larger form of globiferous pedicellarize will be found in this species; but the figured form is a sufficient proof that this species has no relation to Poroc¢daris. Koehler also refers it only in a doubtful way to /oro- cidaris on account of the highly dentate actinal radioles. The spicules are simple. Of the other species that have been referred to Porocidaris, P. Cobost most likely is a genuine Porocidaris, but it cannot be decided with certainty, till the pedicellaria have been examined. For the present nothing can be said with certainty of P. Afilleri and muisakiensis; according to Agassiz (13) P. Miller’ is «closely allied to P. elegans». On the other hand it may be said with certainty that P. gracilis Déderl. is no Porocidaris. Its globiferous pedicellariz of which only one form is known, recall to some degree those of «Gontocidaris» canaliculata; tridentate pedicellarie unknown. Perhaps it ought to form a separate genus. The genera Stereocidaris and Goniocidaris to which a whole series of species have been referred, are still left. The species referred to Stereocidaris: japonica, grandis, sceptriferoides, and the here described new species S¥. zngolfiana agree in the structure of the pedicellarie: there is no end-tooth, and the large opening reaching to the very point is broad and well limited below, quite narrow above. The small globiferous pedicellariz chiefly of the same structure, without end-tooth; the tridentate pedicellariz seem to show no special peculiarities (they are not known in all the species). The spicules are rather large fenestrated plates, not thorny bows, as is else the case in the Cidarids — this, however, does not apply to all the species; in SZ grandis they are of the common form, and so the spicules give no reliable generic character. There is no reason to doubt that also S¢ indica Déderl. really belongs to this genus, although we have no informations of its pedicellarice. Doéderlein further thinks (118) that Dorocédaris tiara and alcockt are perhaps only local forms of this species. Of the species S¥. tenwispinus and microtuberculatus Yoshiw. nothing can be said with certainty. — Whether this group of species really belongs to the same genus as the fossil Stereocidaris-species, cannot be definitely decided, until the pedicellariz of the latter are known; but the probability is that they really belong here, and there is no reason, at all events not for the present, to reject the name of Stereocidaris for them. To the genus Goniocidaris, the only one of the hitherto admitted genera that has been com- monly acknowledged, the following species have been referred: geranioides Lamk., tebaria Lamk., 24 ECHINOIDEA. I. canaliculata Ag. (to which Crdarts nutrix W.Th., Gontoc. vivipara Studer, and G. membranipora Studer are referred as synonyms), florigera Ag., Déderleimt Ag., biserialis Déderl., clypeata Déderl., wmbraculum Hutton, and Mortensent Koehler. Types of this genus are the species geranioides and tubaria, espe- cially peculiar by having rather deep pits between the plates, in each of which pits is placed an almost globular pedicellaria. These pedicellariz are very peculiar, short and broad; the opening, which is small and surrounded with distinct teeth, reaches to the point, so that no end-tooth is found (Pl. X, Fig. 20). The small globiferous pedicellaria have a powerful end-tooth; no tridentate pedicel- lariz seem to be found. Spicules of the common form. There can be no doubt that G. geranioides has the same structure of the pedicellarize as G. tubaria; the large globiferous ones are figured by Agassiz (Revision Pl. XXIV, 12—13), and they are obviously very similar to those of ‘¢udaria. Perrier (op.cit. Pl. III, 12) figures a small globiferous pedicellaria, but the figure gives no clear information of the structure of the point; the text, however, leaves no doubt that it is built as in G. tubaria. Most closely allied to these two species is no doubt G. wmbraculum Hutton. The pedi- cellariz (Pl. X. Figs. 13, 21) show only little difference from those of the two mentioned species. Also G. biserialis Déderl. belongs here; to be sure, it is not clear from the figures and description of Doéderlein, in what way the small globiferous pedicellarize are constructed, but Prof. Déderlein has kindly sent me a preparation, so that I have been able to substantiate that they are built as in the other species, with a powerful end-tooth (Pl. IX, Fig. 10). The two species G. clypfeata and mikado are especially distinguished from the other Govzocidaris-species by the spines being highly widened, and having, moreover, a peculiar basal widening; the impressions in the angles of the plates are indistinct; the pedicellariz seem also to be somewhat different from those of the typical Gonzoczdaris- species, although agreeing with them in main features (no end-tooth on the large pedicellarize, an even uncommonly powerful one on the small ones). Thus there seems to be every reason to comprise these species in a separate subgenus, Dyzscocidaris, as proposed by Déderlein (114). Déderlein thinks that G. forzgera must be referred to the same group, especially because it also shows the basal widening on the spines, although only as a trace. It has long been doubtful to me, whether the two forms figured by Agassiz as G. florigera (Chall. Ech. Pl. 1. Figs.7 and 12), were really the same species, and my doubt was confirmed, when I had examined the type-specimens in British Museum. They are not only two different species, they will even undoubtedly have to be referred to two different genera — and moreover it appeared that among the specimens determined as G. ford gera still a third form was hidden, which must also form a new genus. The form meant by Doderlein when he places G. florigera together with clypeata and mikado, is the one figured in Fig. 12; it is this form of which the spines show traces of the basal widening. It has already been mentioned above, and a new genus has been established for it: Petaloctdaris, its pedicellarie not admitting it to be referred to any of the other known genera. Otherwise it is presumably most closely allied to the two mentioned species. The other form, which is figured in Fig.7, shows no basal widening on the spines, which are, upon the whole, very much different from those of Petalo- cidaris; they are highly and rather regularly thorny, evenly tapering. In none of the three specimens (Chall. St. 204) I have examined, large globiferous pedicellariz were found, but only the small form, which is quite similar to the small pedicellarie of D¢scocidaris (Pl. X. Figs.6—7); for the present ECHINOIDEA. I. NOS ion therefore, I think it better to refer it to this subgenus; the spines, to be sure, show no trace of the widenings peculiar to the two other species, but the not widened spines of the latter are rather similar to those of this species, for which I propose the name of Discocidaris serrata n. sp. From st. 192 (Chall.) a specimen is found referred by Agassiz to G. florigera, which it also resembles rather well (i.e. it resembles the one figured in Fig.12, Petalocidaris florigera). The spines are much richer thorny than in this species; the ambulacral areas almost naked. The pedicellariz are very peculiar (Pl. X. Figs. 25, 28). The opening is a long, narrow slit reaching not quite to the point; a powerfully developed end-tooth is found. The small pediceliaric are essentially of the same structure, the opening only being somewhat shorter and a little broader. Such pedicellarie have not been found in any of the other known species, and accordingly this species must form a separate genus, for which I propose the name of Schizocidaris with the species Sch. assimilis n. sp."). According to Agassiz (Chall. Ech. p. 43 seq.), Gonzocidarts canaliculata is exceedingly varying; he thinks that Crdarzs nutrix W.Th. must be regarded as one of the many forms of this species, and also that G. wvipara and membranipora are synonymous with it. After having examined the speci- mens of G. canaliculata in British Museum I must admit that it really appears as if they all formed only one highly varying species, in which a great number of transitional forms connect the easily recognised extreme forms. If we examine the pedicellarize, we shall get another conviction; we shall then see that at all events three different species are found among these specimens referred to G. canaliculata. There is a fact that ought to have made Agassiz hesitate in referring them all to one species. He quotes the description by Wyv. Thomson (397) how the eggs of C. matrix «are passed along on the surface of the test towards the mouth, and the smaller slightly spathulate prim- ary spines, which are articulated to about the first three rows of tubercles round the peristome, are bent inwards over the mouth, so as to form a kind of open tent, in which the young are developed». Immediately after this quotation Agassiz (op. cit. p.45) says: «The specimen (PI. II. fig. 2) shows the manner in which they are held in a sort of marsupium by the folding of the abactinal spines over the young crowded upon the abactinal system». Thus in this species not only a nursing of the brood should take place, but the young should even be placed, now round the mouth, now on the apical area. Even if this were not inconceivable, it would have been worthy of remark; but Agassiz has no word of it, though it might seem to imply that Cvdaris mutrix is really specifically different from Gonioc. canaliculata. Wyv. Thomson (397 p.66) also remarks expressly that in G. canaliculata we have the reverse of the fact in C. matrix: «These spines ... lean over towards the anal opening, and form an open tent for the protection of the young as in Cidaris nutrix, but at the opposite pole of the body». There is also another fact that ought to raise the suspicion against the interpretation of all these forms as one species: most of the specimens are coast-forms, taken on depths of 3—150 fathoms; from this there is a far cry to a depth of 1600 fathoms and more. Beforehand it is very improbable that the same species should be found in so varying depths. This fact is not mentioned by Agassiz either. According to my examinations Crdaris nutrix is specifically different from G. 1) Unfortunately I made no more thorough notes on this specimen, as during my stay at Br. Mus. I had no clear understanding of the fact that it was a genus quite different from the other specimens called G. forigera. I did not get a clear view of this fact till after my return, when I had examined the pedicellarie more exactly. The peculiar pedicellariz may, however, be sufficient for the identification of the species, and therefore I do not hesitate to give it a name here. The Ingolf-Expedition. IV. rt. 4 26 ECHINOIDEA. I. canaliculata; among the deep-sea forms at all events one new species is found, and upon the whole scarcely any genuine G. canaliculata is found among them. In the typical G. canaliculata the large globiferous pedicellarize do not differ much from those of Gontocidaris tubaria, or still less from those of G. wmbraculum; they are somewhat narrower, and the blade is a little curved inward below the rather large opening that reaches to the point; there is no end-tooth (Pl. VII. Figs. 8, 32). The small pedicellariz, on the other hand, are very different from those of the genuine Govzocidaris-species, as there is no end-tooth (Pl. VIII. Fig.6). Spicules simple. — The young are carried on the apical area. «Crdaris» nutrix (Wyv. Thomson’s type specimen examined): the large pedicellariz (Pl. X. Figs. 3—4, 12, 14) very much resembling those of Stereocidaris grandis (D6derlein 116. Pl. VIII. 2); the small globiferous ones (Pl. X. Fig. 24) chiefly as in G. canali- culata. — The young are carried round the mouth. The two species are most frequently easily distinguished as to their habitus. In C. netrix the apical area is densely set with rather long, club-shaped spines, between which large pedicellariz are found abundantly. In G. canaliculata the apical area is set with rather few and scattered, not club- shaped spines some of which are quite small, so that the area looks rather naked; generally no pedi- cellarize are found on the apical area. This difference, however, is not absolutely reliable, and without the pedicellarize the two species are not always to be distinguished with certainty. It is evident that these two species cannot be referred to the genus Govzocidarts; especially the small pedicellariz are different from those of Gonzocidaris, as they have no end-tooth. Doéderlein (116. p. 18) thinks G. canaliculata to be nearly allied to Dorocidaris; to be sure it occupies an extreme position in the «Dorocidaris»-group, and perhaps it might also be regarded as the only representative of a special group. In many respects it recalis the «Aeczdaris»-group. «Wirklich nahe Beziehungen zu einer der bisher bekaunten Arten von Cidariden bietet diese Form jedenfalls nicht dar». — As has already been mentioned, the pedicellarize of C. matrix are very similar to those of Steveocidaris grandis, and these two species would seem to have to be referred to the genus Stereocidaris; at all events there seems to be no objection of consequence to their being referred to this genus, and it might be difficult to point out a character, which would necessitate the establishing .of a special genus for these species. The simple spicules are in accordance with those of St grandis (in the other Stereocedarts- species they are, as mentioned, large fenestrated plates). Of the species « Goniocidarts» vivipara and membranipora the former (according to Studer, 386) is synonymous with G. canaliculata, which statement I am able to corroborate from the examination of a specimen that our museum has received from the museum at Berlin. The other (also according to examination of specimens from the museum at Berlin) is identical with «Czdaris» nutrix W.Th., as has already been supposed by Studer (385). As the paper by Wyv. Thomson (397) bears the date of June rt 1876, and that of Studer (384) the date of July 27" 1876, the name of zzztrzx has the priority. Now we meet here with a new difficulty. Studer says of G. membranipora (384 p. 455): Die jungen Crdaris bleiben auf dem Analfelde der Mutter bis zu ihrer vélligen Entwicklung, von den obern Stachelreihen geschiitzt, die sich kreuzweise dariiber legen». According to this statement this species would seem nevertheless to carry the young now arround the mouth, now on the apical area. As this seems to me to be very improbable, I must suppose a mistake to have taken place, so that ECHINOIDEA. I. BS the specimen (or specimens?), which Studer has had, with young ones on the apical area, is not G. membrantpora (= nutrix), but canaliculata, and then it is scarcely from Kerguelen (comp. the fol- lowing about the occurrence of these two species). When the pedicellarie are not examined — which has evidently not been done by Studer — it is, as has been stated above, not always to be decided with certainty, to which of the two species a specimen in hand belongs; this will especially hold good, when, as the case has been here, the apical area is not to be seen. Among the rather numerous specimens of these two species exam ned by me (from «Chal- lenger» at British Museum), S¢ canaliculata was only taken at the Falkland Islands and a station near those islands, «Chall». st. 315, S¢# wtrix only at Kerguelen. Some specimens from st. 150 («Chall.») near Kerguelen, 150 fathoms, have pedicellarize as those of the typical S¥%. safrix but the spines are much longer, three times the diameter of the test; perhaps it is a separate species. Wyv. Thomson (397) mentions C. xwtrix from Kerguelen, G. cavaliculata from the Falkland Islands. In the same way Studer’s G. wiwipara (= canaliculata) is from Patagonia, his G. membranipora from Kerguelen. ‘Thus it would seem that these two species do not occur together; SZ canaliculata is found at the southern coasts of South America, S¢. zutrix at Kerguelen. Agassiz, to be sure, mentions S¢. canaliculata from several other localities at Kerguelen, but according to what is shown here his statement is not to be relied upon. Until a definite proof of the opposite fact comes forth, I must believe that either of these species has a territory of its own, as represented here. Among the deep-sea specimens referred by Agassiz to G. canaliculata, I have only examined two from Chall. st. 156 (the South Polar Sea, 1975 fathoms). No doubt they represent another species. The large globiferous pedicellariz (Pl. VIII, Fig. 35) recall very much those of the Govzocidaris-species, but the small ones are like those in canaliculata and nutrix; and thus it would seem that this species must also be referred to Stereocidaris. The ground-colour is very dark, almost black; the primary spines are white, the actinal ones highly indented in the edge. Perhaps it may prove to be identical with «Porocidaris» incerta Koehler. I have not examined the specimens from st. 147 (1600 fathoms) and 153 (1675 fathoms), but that they are not identical with St. canaliculata or nutrix, which live on shallow water, may be said a priori with a great deal of probability. Gontocidaris Mortensent Koehler. Koehler (233 a) in his excellent description of this species mentions only one form of pedicellariz with . Even if Perrier has not understood this feature quite correctly, his figures are sufficiently clear and good. Accordingly no excuse can be found for the later authors, when they have overlooked this excellent character and in stead of it have stuck to the useless ones: the number of the pores and the form of the test. If they had made use of this character, they might have avoided the many systematical errors they have now fallen into. Beyond the peculiarity of the globiferous pedicellariz of the Echinometrids emphasized by Perrier, no attempts, as far as I know, have been made to find other characters in the structure of the pedicellariz that might be used for a limitation of larger or smaller groups inside this difficult division of the Echinids. The reason why no such characters have hitherto been found, is partly that far too few genera and species have been examined, partly that the examinations have not been made with sufficient exactness. My examina- tions have shown that in the structure of the pedicellarize such peculiarities are found as yield excel- lent characters, by which the genera may be grouped. In «Echinus» miliaris and some other species the blade of the globiferous pedicellarie is provided with a larger or smaller number of teeth on either side; the edge is not thickened, but thin and sharp, and continues directly into the teeth; there are no cross-beams connecting the edges across the inside of the blade (Pl. XVII. Figs. 1, 7). In Achinus esculentus a.o. the edges are connected by cross-beams across the inside of the blade; they may be few and narrow, or so strongly developed, that the inside of the blade is almost quite covered with the exception of a series of larger or smaller holes along the median line. One or more pairs of lateral teeth are found placed on the thickened edge, but they do not form a direct continuation of it as in the preceding form (Pl. XVIII. Figs. 2, 3, ete). — In “chinometra and the forms allied to it, as already mentioned, only one large lateral tooth is found on one side (Pl. XIX. Figs. 4, 13), and in Strongylocentrotus, Spherechinus etc. no lateral teeth are found at all (Pl. XX. Figs. 14, 16, 26, etc), only a little obliquity near the point shows that this form must be regarded as a further development of the pedicellaria that is provided with one unpaired lateral tooth, — not so much the strongly modified form in “chzmometra as the less modified form in «Lich.» albocinctus. Besides these differences in the structure of the valves, also a few peculiarities in the structure of the stalk and in the neck are to be noted. In most genera the stalk consists of numerous long calcareous threads connected with each other by a few cross-beams; in some forms, Strongylocentrotus drobachiensts and its nearest relations, it is a thin perforated tube. In most forms the neck is quite short, or, more strictly speaking, quite wanting, in a few ones — also the Strong. drobachiensis-group — there is a long neck provided with powerful longitudinal and circular muscles (Pl. XX. Figs. 25, 20). The other pedicellarie seem only to contribute little to the limitation of the genera, still less to the characterization of the larger groups; on the other hand the tridentate and ophicephalous pedi- cellariz yield often excellent specific characters. The triphyllous pedicellariz are exceedingly similar, and yield scarcely any sufficiently certain systematic character, with one exception: Evechinus chloro- ticus; in this latter some digitate prolongations pass from the upper end of the apophysis over the blade (Pl. XIX. Fig. 29), a quite unique feature. As a common feature may be noted that the edge is The Ingolf-Expedition. IV. 1. 13 98 ECHINOIDEA. I. not serrate, and that the apophysis does not widen to a cover-plate, contrary to the triphyllous pedi- cellarize of the Echinothurids. All four kinds of pedicellarize are certainly found in every species; but of some species individuals may often be found, where globiferous or tridentate pedicellarize (sometimes both forms) are quite wanting or very few in number (for instance Achinus Alexandri). This fact, of course, is an unfortunate circumstance, but the value of the pedicellarie as systematic characters are not otherwise lessened by it. If we now examine the genera and species referred to «Zriplechinide» and «Echinometrade: with special regard to the features described above, we shall get a view of their relations very different from the views expressed in the above mentioned systems. The genus chins is notorious for its difficulty. A great many species have been described, but most frequently the descriptions are insufficient, so that the species cannot be recognized by them. One species, “ch. acutus, is very varying, and has occasioned the establishing of a great many «species», which nobody has been able to recognize with certainty, and by which the confusion has only been increased. But even excellently characterized species, as for instance £. e/egans, have often been confounded with other species, what I have repeatedly been able to substantiate; what is hitherto stated with regard to the distribution of the Achzmus-species, must accordingly be used with great caution. The reason of all these difficulties is almost exclusively to be found in the literature: an exact examination of the animals themselves shows that the species upon the whole have rather distinct characters. The following species are referred to the genus Echinus: miliarts Miill., microtuberculatus Blv., angulosus (Leske), escaulentus 1, acutus Lamk., norvegicus Ditb. Kor. lemingti Forb., microstoma Wyv. Thoms., melo Lamk., elegans Dub. Kor. gracilis Ag, Wallist Ag. luctdus Déderl., Robillard: L,oriol, darnleyensis Woods, magellanicus Phil., margaritaceus Lamk., horridus Ag. Alexandri Dan. Kor., albo- cinctus Hutton, diadema Studer, Neuwmayert Meissner, mdlticolor Yoshiwara. A great many older names are cited as synonyms to several of these species in Agassiz’s «Revision of Echini>; a renewed exami- nation of the type specimens of these «species» with especial regard to the pedicellarie might perhaps give other results than those of Agassiz; but until such examinations have been made, we must build on the results laid down in «Rev. of Ech.». Of all the above mentioned species, with the exception of Ech. multicolor, 1 have had occasion to examine authentic specimens, of Ech. horridus, Neumayer, and Alexandri even the type specimens. The result is a considerable reduction of the number of species in the genus Achinus, some of the mentioned species being dropped as synonyms, some prov- ing to belong to other genera. As the type of the genus Echinus LE. esculentus must be put down, the only one of the species established by Linné. Of its characters the following ones must be mentioned here. Only every other ambulacral plate carries a primary tubercle (in large specimens often 2—3 plates without primary tubercle follow each other). All the ocular plates are shut off from the anal area. The buccal mem- brane with numerous small and larger plates; spines on the buccal plates. The globiferous pedicellarice without neck, the blade with a lateral tooth on either side, the edges connected across the inside. The tridentate pedicellariz (Pl. XVIII. Fig. 20) long, narrow, the edge set with numerous small teeth ECHINOIDEA. 1. 99 arranged in transverse series. The stalk of the pedicellarize consists of long calcareous threads con- nected by few cross-beams. Spicules bihamate. With this species must be classed Ach. melo and acutus (under which £. Flemingti, norvegicus, and microstoma are to be named as synonyms, the reasons of which will be given hereafter in the description of Ech. acutws). They are distinguished from 2. esculentus by having fewer and longer spines, by wanting spines on the buccal plates, and by the plates in the buccal membrane being fine and quite imbedded in the skin, so that it looks as if the buccal membrane were naked. Further primary tubercles are also here generally wanting in more or fewer interambulacral plates besides in every other ambulacral plate. The difference between melo and acutus is very slight, they seem only to be differing in form and colour — perhaps they cannot upon the whole be kept as distinct species (for particulars see under the description of Ach. acutws). The pedicellarize and spicules essentially as in £ch. esculentus. Ech. elegans. «It seems almost hopeless to attempt to distinguish the species of Hchimus known as £. elegans, E. norvegicus, E. melo, and E. Flemingit», Agassiz says («Blake» Echini. p. 39), and also Wyv. Thomson classes Ach. elegans among the «critical species » (395. p- 744). In this statement I cannot at all agree with the two celebrated authors. ch. elegans is very different from Ach. acadlus; the question might rather be of referring it to another genus than of confounding it with #ch. acutus. The most essential difference is that it has a primary tubercle on all the ambulacral plates. The globiferous pedicellariz (Pl. XVIII. Figs. 2—3) have generally two lateral teeth on either side, the tri- dentate ones are somewhat shorter and broader than in the preceding species, but the edge is also here set with transverse series of small teeth. In some specimens only quite small tridentate pedicel- larize occur of a somewhat other form than the large ones (Pl. XX. Figs. g, 19), but in other specimens both the small and the large form as well as all transitional sizes are found. Apical area, buccal membrane, and spicules as in Ech. esculentus. — The difference here stated between Lch. elegans and acutus is already seen from the description of Diiben & Koren‘), where it is said that «de primara knélarne bilda paa skalet, fran anus till munnen, 20 ytterst tydliga, aldrig afbrutna rader», while it is said of Ech. Flemingit (p.267): «de 10 rader primara kndlar, som upptaga ambulacralplatarne, aro esom- oftast afbrutna»; this feature is also emphasized by the authors under Ech. norvegicus. To be sure it is not clearly seen in the Latin diagnoses, so that it is perhaps on account of the language that this feature has been overlooked by the later authors?) to great injury for the correctness of the determina- tions; especially Ech. elegans may often have been confounded with quite red specimens of &ch. NOVUELICUS. Ech. Wallisi Ag. In the description of this species («Blake»-Echini. p. 39) it is said that it is readily distinguished .... by the arrangement of the pairs of pores in sets of two». If this be correct it can scarcely be an Echinus, in which genus the pores are always trigeminate; Agassiz himself, however, thinks that it is «closely allied to, if not identical with, Echinws Alexandri>, in which the pores are arranged in the common way. Agassiz further thinks it to be «allied to £&. Flemingt and 1) Skandinaviens Echinodermer. p. 273. 2) Thus in Bell’s «Catalogue of British Echinoderms» it is said of Ack, actus: «each of these (the compound Ambu- lacra plates) has a large primary tubercle set about the middle of each plate». p. 146. T3e 100 ECHINOIDEA. I. F. elegans», according to what has been stated above it cannot be closely allied to both these species, and no inference can be drawn from the quite insufficient description that is not even accompanied by figures. From U.S. National Museum I have received a specimen on loan, determined as Ech. Wallst. It is a large, fine specimen of Ach. elegans (only with somewhat shorter spines and higher than the typical form); but it is unfortunately not certain that it is really identical with Ach. Wadllisi, as it does not agree very well with the description, except in the colour. Thus &ch. Wadlisi must for the present remain somewhat problematic. Most nearly related to Echinus elegans are the species: gracilis, Alexandrit, and lucidus, and the new species described here: ch. affinis n.sp. and atlanticus n. sp.; they have ali of them a primary tubercle on every ambulacral plate; numerous fenestrated plates imbedded in the buccal mem- brane (this feature, however, not observed in /. dzczdus); no ocular plates reach to the periproct; the spicules bihamate; all with rather strong, long, and pointed spines. Ech. Alexandri is rather sharply distinguished from the other species by its tridentate pedicellariz, which are especially broad and comparatively short (Pl. XX. Fig. 1), while in the other species they are long and narrow (Pl. XVIII. Fig. 4). In the smaller forms of tridentate pedicellarize the blade is more flat and broad, and the upper end of the apophysis is a little widened as a more or less perforated plate; in the larger forms there is some mesh-work in the bottom of the blade. As in £. elegans there are in these species all transi- tions between the largest and smallest tridentate pedicellarie; to be sure, I have only seen a few of smaller size in Ach. luctdus, but as these resemble to a high degree, those of a corresponding size in the other species it may be supposed that also in this species large tridentate pedicellariz will be found of the same form as in the other mentioned species. In all these species the tridentate pedicel- lariz are upon the whole so similar, that reliable specific characters can scarcely be found in them (Pl. XVIII. Figs. 15, 2122, 26—28). The globiferous pedicellariz in Ech. Alexandri have generally 3—4 teeth on either side, in the other species there are most frequently 1—1 or 1—2 lateral teeth. Also the globiferous pedicellaria are very similar in all these species (Pl. XVIII. Figs. q—11, 16—18, Pl. XIX. Fig. 18). Ech. affints is distinguished from the other species by the peculiar feature that the two series of tubercles in each ambulacral area are of unequal size or quite irregular; there is, however, always a primary tubercle on every ambulacral plate (see the particular description below). Zch. gracilis is easily distinguished from the other related species by its beautiful green coloration; the tridentate pedicellariz (Pl. XVIII. Figs. 15, 21) are a little more serrate below than in the other species, it is however, scarcely a reliable character. Agassiz, in his description of it (Rev. of Ech. p. 293), says: «this species holds an intermediate position between 4. /lemingw Ball and £. melo Lamk., to both of which it is allied». This, according to what is stated here, is incorrect; its nearest relations are £. elegans and the other species named here. — Ech. lductdus, of which species Prof. Déderlein has kindly lent me a specimen for examination, is most similar to Ech. Alexandri, but may easily be distinguished from this species by its tridentate and globiferous pedicellarize (Pl. XIX. Fig. 18). In Challenger-Echinoidea (p. 114) Agassiz mentions Echinus acutus from st. 343, off Ascension, 425 fathoms. I have had occasion to examine these specimens in British Museum, and I must positively assert that it is not Ach. acutus. The test is high; the peristome very small (15™™ in a ECHINOIDEA. I. 101 specimen of a diameter of 65™™), the edge of the mouth not bent inward. There are very few spines on the abactinal side, almost only the primary ones, and as the plates are very high, the primary spines are also widely separated; on the actinal side there are more secondary spines, they are not, however, very close-set. The primary spines are of a middle length, and do not decrease much in length towards the apical area. A primary spine is found on each ambulacral plate, and they are of equal size in both series. The buccal membrane with numerous, lengthy, simple fenestrated plates outside the buccal plates; inside of these they are small and a little less perforated, as in /. Alexandr. The colour is beautifully red, the point of the spines white. The globiferous pedicellariz (Pl. XVIII. Fig. 17), which are very few in number, have 1—1 lateral tooth, but are otherwise similar to those of Ech, affinis; also the tridentate pedicellaricze are scarcely to be distinguished from those of -. a/finzs. On the other hand the ophicephalous pedicellarize are very characteristic, lengthy, and the teeth in the edge are uncommonly fine, only to be seen under especially high magnifying powers (Pl. XIX. Fig. 37). Triphyllous pedicellarice of the common form; spicules bihamate. — There can be no doubt that this is a new species of Echinus, closely allied to £. elegans, gracilis etc.; I propose to call it Echinus _ atlanticus. Presumably there are among the Echinids obtained by the «Challenger»-Expedition still one or two species allied to those mentioned here. Agassiz has determined these specimens partly as Ech. elegans (from Tristan d’Acunha), partly as Ech. norvegicus (from Patagonia, st. 308, and Japan, st. 232). That these determinations are incorrect is a sure fact. «Ech. elegans» from Tristan d’Acunha is a large form, very similar to Ech. Alexandri, that is to say, to the most long-spined specimens of this species (see the description below), but its tridentate pedicellaria are narrow as in Ech. affinis. «Ech. nor- vegicus» from Japan is absolutely not this species; as far as I am able to see from my notes, it must be Ech. luctdus; the pedicellariz are quite agreeing with those of that species. The speci- mens from Patagonia, at all events, are not Ech. norvegicus; they belong to two different species, of which one (3 large specimens) belongs to this group of species with a primary tubercle on all the ambulacral plates; perhaps it is Ech. affinis, but I am not able to determine it with certainty after my notes. The other species (4 small specimens) is Zch. magellanicus Phil. — The incorrect referring of these specimens to Ech. norvegicus has unfortunately given rise to the fact that this species is now constantly named among the «bipolar» animals. Ech. margaritaceus Lamk. Of this species it is justly said in «Rev. of Ech.» (p. 493) that it has «very marked features», but in the description only one of its peculiarities is mentioned, viz. the nature of its covering with spines; «the plate is densely covered with minute secondary tubercles carrying short, slender, yellowish spines closely crowded together, which are a lower groundwork from which the primary spines, long, slender, and white, project prominently». This description of the spines is excellent, it is only to be added that these spinules are richly set with fine thorns, which gives them a peculiar silky gloss; further that the primary spines round the mouth are curved in the point, and that generally, but not always, some small, club-shaped spines are found on the buccal plates. Only every other ambulacral plate carries a primary tubercle. The apical area is very peculiar, all the ocular plates reach to the periproct, which is large and covered by numerous small plates among which the central plate is especially distinct. In small specimens all the ocular plates are shut off 102 ECHINOIDEA. I. from the periproct. The buccal membrane has inside of the buccal plates numerous small fenes- trated plates imbedded in the skin; just outside of the buccal plates there are a few small plates, as thick and complicate as the buccal plates, and like these set with pedicellariz. Nearest to these plates some small, fine fenestrated plates are found, but all the rest of the buccal membrane is quite naked. The globiferous pedicellariz (Pl. XIX. Fig. 20) are of the same form as in ch. elegans etc., but only one tooth is found on either side. The tridentate pedicellarize are more peculiar and of a rather varying form (Pl. XIX. Figs. 3, 33). The blade is broad and deep, without or with a quite feeble net of meshes at the bottom; the edge is more or less sinuate in the part where the valves join: sometimes almost through the whole length (Fig. 3), sometimes only in the outer half (Fig. 33); it is finely serrate, but not thickened, and has no transverse series of teeth as in the Achznws-species men- tioned above. The «huge pedicellarize.... covering the whole test», mentioned by Agassiz, are the globiferous pedicellaria, which are rather long-stalked and conspicuous, not the tridentate ones. The ophicephalous and triphyllous pedicellarize of the common form; it may, however be noted that in the latter the upper ends of the apophysis do not reach to the edge of the blade, and that there seems to be a tending to a formation of a little mesh-work in the blade. The stalks of the pedicellarize of the common structure; the spicules bihamate, very numerous. — That this species is not «most closely allied» to Ech. norvegicus, as Agassiz thinks (14. p.11) is clearly shown by the characters here mentioned. The description of Ach. margaritaceus given here agrees remarkably well with the description of Sterechinus antarticus by Koehler (233.a.), and after having examined some specimens from «Belgica which Prof. E.van Beneden has most kindly lent me, I must positively assert that it is Ech. marga- rvitaceus; no single character can be pointed out that might be a mark of distinction between them. — Echinus diadema Studer is by Agassiz (Chall. Ech.) Bernard (79), and Meissner (285) thought to be synonymous with Ech. margaritaceus. Studer (386) admits, to be sure, that they are very similar, but thinks that some difference is found in the pedicellarize — i.e. the ophicephalous ones. Now it is true that his figures show a slight difference; but the ophicephalous pedicellariz are generally of very little importance with regard to the distinguishing between the species, and yield only quite exceptionally good specific characters (as in Ech. atlanticus). In this case there can be no question of distinguishing between the two «species», either by the ophicephalous or the other pedicellariz. After having examined some specimens, determined by Studer himself as Ach. diadema, which I have received for examination from the museum at Berlin, I must decidedly follow the mentioned authors; Lich. diadema cannot be distinguished from ch. margaritaceus. Echinus horridus A. Ag. is not closely allied to Ech. norvegicus, as stated by Agassiz (Chall. Ech. p.116); its nearest relation is no doubt Zech. margaritaceus. The spines are quite as in this species, and also the pedicellarize are very similar to those of the latter species. The tridentate pedicellarize (Pl. XIX. Fig. 2) are rather much open and rather sinuate in the outer part, where the valves meet; they may become pretty large (a little more than 1™™), and then they have a rather strong, coarse net of meshes in the blade (it may be described as cross-beams rather far from the bottom). In the globiferous pedicellariz (Pl. XIX. Fig. 22) cross-beams are wanting between the edges of the blade (also in young Ech. margaritaceus they may be found without cross-beams), and there are ECHINOIDEA. |. 103 2—4 teeth on either side. The basal part has somewhat projecting outer corners. The ophicephalous pedicellarize are of the common form, the triphyllous ones resemble those of Ech. margaritaceus. Agassiz says, but wrongly, that only two kinds of pedicellarize are found in this species, «one small- headed, long-stemmed, the other short-stemmed with a conical head». He gives, however, no figures of them. Unfortunately I can give no informations as to the peristome, as I forgot to examine it during my stay at British Museum. Neither can I tell whether the actinal primary spines are curved at the point. Primary spines are found on all the ambulacral plates; all the ocular plates are shut off from the periproct. The central plate little conspicuous. The spicules bihamate, numerous. Echinus Neumayeri Meissner is also to be classed with these species, but is, however, rather sharply distinguished by several characters. In the description by Meissner (285) only the apical area is more thoroughly examined; as the type specimen has been sent me for closer examination, I am able to call attention to several other characteristic features of this species. A primary tubercle is only found in every other ambulacral plate. Unfortunately all the primary spines are broken, so that nothing can be said as to their length, or whether the actinal ones are curved at the point — what is probable. The secondary spines are rather coarse, not fine, silky, as in the two preceding species; they are, however, finely serrate. Three of the ocular plates reach to the periproct, as observed by Meissner; no conspicuous central plate is found. The apical area of the type specimen is, no doubt, abnormal, two of the genital plates being coalesced, and the adjoining one uncommonly broad; by this arrangement the two ocular plates at these genital plates are situated opposite to the latter, and not, as is elsewhere the case, opposite to the interspaces between them. (See the figure of Meissner. Op. cit. p. 12). The buccal membrane contains numerous small fenestrated plates inside of the buccal plates, outside of these it is almost naked, only with quite few, small fenestrated plates. Spines are found on the buccal plates. The globiferous pedicellariz (Pl. XIX. Fig. 14) recall those of Ech. hor- ridus very much, but the outer corners of the basal part are somewhat more conspicuous, and the edges of the blade are connected by cross-beams; there are I—1 or 1—2 lateral teeth. The tridentate pedicellariz (Pl. XX. Fig. 11) resemble those of Ech. margaritaceus, as is also the case with the triphyl- lous ones (Pl. XX. Fig. 7); the ophicephalous ones of the common form. The spicules bihamate, very few; I have only seen a few in the buccal membrane, none in the tube feet. Echinus magellanicus Phil. To the descriptions of this species by Philippi and Agassiz the following informations must be added. A primary tubercle is found on all the ambulacral plates; the actinal primary spines are curved at the point, the secondary spines are coarse as in Ech. Newmayeri and almost smooth. The buccal membrane is quite naked both inside and outside of the buccal plates, and no spines seem to be found on these. The periproct is small, covered by a few, rather large plates, without distinct central plate; generally one ocular plate reaches to the periproct, as observed by Agassiz. The globiferous pedicellariz (Pl. XIX. Fig. 23) chiefly as in Ech. margaritaceus, with 1—2 teeth on either side. The tridentate pedicellarice (Pl. XIX. Figs. 11, 17), which are (always?) very small, o5™", are rather different from those of the other species; in the outer part where the valves join, the edge is finely serrate, in the lower part it is smooth, but rather thick; no net of meshes at the bottom. The valves are apart for a rather long space, but the slit between them is quite narrow. The ophicephalous and triphyllous pedicellariz of the common form. The spicules bihamate, numerous. 104 ECHINOIDEA. I. In «Challenger»-Echinoidea p. 116 Ech. magellanicus is mentioned from Prince Edward Island and Crozet Islands, from the latter place at a depth of 1600 fathoms (st.147). I can assert positively that the latter is not Ech. magellanicus; its globiferous pedicellarize are of quite another form than in this species. I suppose it to be a new species allied to Ech. Newmayeri and the other species belong- ing here, but as I have not a sufficient material of pedicellarize of it, nor sufficient notes of it, I must restrict myself to show that it is no Ach. magellanicus. 1 also take it to be doubtful whether the specimens from Prince Edward Island are Ech. magellanicus; at all events they will have to be exa- mined more thoroughly with regard to the characters mentioned here. That this species is found at Australia and New-Zealand I must also regard as doubtful, until renewed, thorough examinations have confirmed these statements. To be sure, Farquhar (144) enumerates Ach. magellanicus among the Echinids of New-Zealand, but it may, perhaps, be Ech. albocinctus, which, in a communication from Prof. Hutton, is said to be the same species. That this statement is incorrect will be shown hereafter. Perhaps also “ch. darnleyensis may be hidden among the Australian Echinids referred to Ech. magel- lanicus, as has been supposed by Woods (442. p.165). For the present Ach. magellanicus is only known with certainty from the coasts of Patagomia and the adjoining seas. — Some small specimens from Chall. st. 308 (Patagonia), by Agassiz referred to Ech. norvegicus, are magellanicus. Echinus albocinctus Hutton. A specimen of an “chinus-species from New-Zealand which from earlier times is found in the museum of Copenhagen, must, no doubt, be referred to this species, as it agrees exactly with the description. The description by Hutton, however, is far from being exhaustive — what may be applied to almost all descriptions of Echinids — and so some informations of this species are given here. — A primary tubercle is found on all the ambulacral plates; the actinal spines are not curved at the point, the small spines rather thick, almost smooth. One of the ocular plates reaches almost quite to the periproct which is small, and (as far as can be seen) covered by few, rather large plates without central plate. The buccal membrane is quite naked, with the excep- tion of the buccal plates; whether spines are found on these cannot be decided. The globiferous pedi- cellarize (Pl. XIX. Fig. 19) have only one unpaired lateral tooth; the basal part is very varying in form, sometimes with strongly projecting outer corners, sometimes rounded — or rounded on one side, pro- jecting on the other. The tridentate pedicellariz (Pl. XIX. Fig. 25) are most similar to those of kL. magellanicus, but the edge is a little serrate, not thick and smooth where the valves are open; in the little space at the point where the valves meet, the edge is finely serrate. Below the articular surface there is a peculiar arc reminding of that of the ophicephalous pedicellariz; also in other Echi- nids an indication of such an are may be found. The ophicephalous and tridentate pedicellariz of the common form. The spicules bihamate, they seem to be rather few. — That this species is well distin- guished from Ach. magellanicus is evident from the informations given here. — Achinus elevatus Hutton, according to an information received from Prof. Hutton, is synonymous with Amdlypneustes formosus. Echinus fasciatus Parfitt (311), no doubt, is only a young specimen of one of the Echinids occurring at the coasts of England, but to which of these it may belong, it is impossible to see from the description — it may be applied to each and all of them, from Strongyloc. drobachiensis to Ech. miliaris. Philippi (323) enumerates the species Echinus Cunninghamt, lepidus, and rodula without ECHINOIDEA. I. 105 giving any information whatever of them; as far as I can see they are nomina nuda, and Philippi deserves no praise for having introduced them. Echinus multicolor Yoshiwara I have not seen; the description gives no information of pedi- cellariz, spicules, and several other important features, so that nothing can be said with regard to its being a genuine Lchznus or not. The species Ech. miliarts, microtuberculatus, angulosus, verruculatus, Robillardi, and darnleyensts are no genuine Achnws-species. For the present then they may be left out of consideration, while the question of the grouping of the species above mentioned is treated. Do all these species really belong to the same genus, or can there be any question of grouping them into more genera? The question is partly answered already, Koehler having established the genus Sterechinus on E. margaritaceus (without knowing, to be sure, that it was this species). The characters upon which the genus is based, are: the comparatively large central plate, the narrow apical plates, of which all the ocular plates reach to the periproct, and the comparatively great height of the coronal plates. — The character of the apical plates is evidently useless, all the ocular plates being shut off from the periproct in smaller specimens. Also the central plate seems to me to be an only little valuable character; in every young Zchznus the central plate is distinct, it does not disappear till a later stage, other small plates being formed round it, so that at last it cannot be distinguished from the secondary plates. Neither seems the height of the coronal plates to be a valuable character, as it varies much according to the size of the animal. — Now it is not my meaning to say that the genus Sterechinus cannot be kept up, only that the characters upon which it is based, cannot be used; we must seek other characters for it. May, then, other characters be found by which to group the species? Among the characters mentioned above one is found that might beforehand be thought to be of great importance, viz. whether a primary tubercle is found on every or only on every other ambu- lacral plate. In the species esculentus, acutus, melo, margaritaceus, aud Neumayer’ a primary tubercle is only found on every other ambulacral plate, in all the other species it is found on every ambulacral plate. That this feature, however, can be of no primary importance is evident from the fact that it separates Ech. margaritaceus and horridus, two species that are, no doubt, very closely allied. — An- other character of undoubtful value is whether the buccal membrane contains numerous fenestrated plates, or is quite (or almost) naked, at all events outside of the buccal plates. Numerous plates in the buccal membrane are found in the species: escelentus, acutus, melo, elegans, gracilis, Alexandri, affinis, atlanticus, and luctdus (not examined); naked buccal membrane is found in the species: marga- ritaceus, horridus (not examined), Newmayeri, magellanicus, and albocinctus. This character does not separate allied species, but divides them into two groups which seem to be well divided as to habitus, but where the species of each group seem to be mutually rather closely allied. It is evident then that we have here a specially important systematic character. Another feature gives quite the same grouping of the species, viz. whether the edge of the tridentate pedicellariz is thick and provided with numerous small teeth arranged in more or less regular transverse series, or it is thin and simply ser- rate. In the former group, Ech. esculentus etc. the edge is thick with transverse series of small teeth, in the latter group, Ech. margaritaceus etc. it is simply serrate. This character, however, is not quite The Ingolf-Expedition. IV. r. 14 106 ECHINOIDEA. I. reliable, as the small tridentate pedicellarize in the former group have also a simply serrate edge. Other characters giving the same natural grouping of the species, do not seem to be found. The former group may be subdivided according to the ambulacral plates, the species esculentus, acutus, and melo having only a primary spine on every other ambulacral plate, while the species elegans, gracilis, Alexandri, affinis, atlanticus, and lucidus have a primary spine on every ambulacral plate. Thus this group might be subdivided into two genera according to this character. This divi- sion, however, I do not think good; Zch. esculentus differs so much from acu/ws and melo, that it seems to be incongruous to class it with these two species contrary to the other species of the group; in quite young specimens of Zech. acutus a primary spine is often found on all the ambulacral plates, which also tells against using this feature as a generic character. Finally it is also seen in the other group that neither there a natural division can be obtained by means of this character. Thus it seems to be correct to regard this whole group as one genus keeping the name of Achimus. The feature of the ambulacral plates may here be used practically by the determination of the species. The other group, the species margaritaceus, Neumayert, horridus, magellanicus, and albocinctus, shows a series of striking peculiarities, so that the question naturally arises, whether all these species are to be referred to one genus. The characters by which a subdivision might be made, are, whether every ambulacral plate or only every other plate has a primary spine, whether the secondary spines are fine, silky, or not, whether or not the actinal spines are curved in the point, whether the buccal membrane is quite naked, or fenestrated plates are found inside of the buccal plates; finally the question might also be of using the pedicellarize or the features of the ocular plates as a basis of the distribution of the species. E. albocinctus is the most isolated one, especially distinguished by having only one unpaired lateral tooth on the globiferous pedicellarize. As this feature, as will be shown below, is of very great systematic importance, it seems reasonable to separate this species as a separate genus, even if in some features it agrees very exactly with Zch. magellanicus (the quite naked buccal membrane, primary tubercle on every ambulacral plate). For this form the name of Pseudechinus is proposed. — To separate the other four species is scarcely correct; according as one or other of the mentioned char- acters is used as a base of the division we get a different grouping. Here a so curious intermingling of all characters is found, that we only seem to have two chances left: to establish each species as a separate genus — by which nothing is gained — or to unite them all to one genus, which latter I think to be the most correct thing. Then this genus gets the name of S¢evechimus Koehler. Con- sidering the common opinion of the difficulty of these species I shall give the following Table of the Sterechinus-species’). Tae hie secondary iSpines ute. willy eye ere ee eee insert ered ieee 2. — =. | ACOMTS Ce’ n'a a aya ey Vator ree ER OCU o Ree Ae oso veo PRTC 3: 2. Primary tubercle only on every other ambulacral plate; the globiferous pedicel- larize with 1—1z lateral tooth, the edges connected by cross-beams............. St. margaritaceus. 1) A table of the Zchinus-species will be given below, after the description of the northern species. ECHINOIDEA. I. 107 Primary tubercle on every ambulacral plate; the globiferous pedicellarize with Be hate eR ILA erect Rasen reek St. horridus. 3. Primary tubercle on every other ambulacral plate................ Ree an Oe St. Newmayert. 2—4 teeth on either side, the edges not connected _— = ee eambulactalimplatere tech weirs. eee ccks s oauke ree ate St. magellanicus. Echinus miliaris, microtuberculatus, and angulosus form a separate group chiefly characterized by the globiferous pedicellariz (Pl. XVII. Figs. 1, 7). The blade is rather flat, comparatively broad, and passes evenly into the basal part; no cross-beams connect the edges across the inside of the blade; the edges are not thickened, and project into more or fewer teeth on either side. There is no neck; the stalk as usually constructed of long threads connected by cross-beams. A somewhat similar form of globiferous pedicellariz is found in Sterechinus horridus (Pl. XIX. Fig. 22), and sometimes also in Echinus Alexandri (P\. XVIII. Fig.9). A comparison of the figures will show, however, that they are very different, even if it is not easy to point out a particular distinguishing character; the most signi- ficant one is, I think, that here the edge is somewhat thickened, so that the teeth are placed on it, while in Ech. miliaris etc. the edge is quite sharp, and the «teeth» are simply indentations in the edge; also the whole form is somewhat different, as shown by the figures. The following characters of the separate species must be pointed out. In ch. miliaris the buccal membrane is covered by large, thick fenestrated plates. The globiferous pedicellariz have numerous lateral teeth; the tridentate ones have a rather strong net of meshes in the bottom of the blade (only the large ones); the edge is coarsely indented below, in the outer part where the valves join coarsely sinuate, but the sinuations are again finely serrate; the small teeth form no transverse series (Pl. XVII. Fig. 11). The ophicephalous and triphyllous pedicellaricze with no conspicuous peculiar- ities. — All three species have a primary spine on every ambulacral plate; in mzliaris and mucrotuber- culatus the ocular plates are shut off from the periproct, in Z. angwlosus the two (three) reach to the periproct; no distinct central plate. Ech. microtuberculatus agrees exactly with mzliaris in the structure of the pedicellariz; it is only to be observed that the tridentate pedicellarie have rather distinct transverse series of teeth on the edge. The plates of the buccal membrane are especially characteristic (Pl. XVI. Fig. 14). They are large, thick, greenish, and of quite another structure than in mz/iarzs, not consisting of the usual reticulation, but of a homogeneous mass of lime, in which the pores appear as deep, funnel-shaped holes. Also the plates inside of the buccal plates are constructed in this way. Otherwise it is distin- guished from mzliaris by its somewhat finer spines and corresponding smaller tubercles (Pl. XV. Figs. 8, 9); the colour of the test and spines is more intensely green. — In the original diagnosis of Ech. microtuberculatus*) it is said: «ambulacres A denticules trés-arquées et composées de six paires de pores»; in Blainville’s «Manuel @Actinologie» 1834 p. 228 Z. parvituberculatus, de Blainv. «Dict. tom. 37. p. 88, sous le nom @Z. microtuberculatus» is enumerated under the division D. «Espéces réguliéres, de forme un peu variable; les denticules des lignes ambulacraires droites ou arquées de cinq paires de pores au moins». Accordingly it is no doubt wrong when Agassiz and Desor (Catalogue raisonné des Echinides p.64) enumerates it (referring to the passages quoted above) under their fourth type, 1) Dictionnaire des Sciences naturelles. T. XXXVII. p. 88. (1825.) 14* 108 ECHINOIDEA. I. with «trois paires de pores obliques». Now if the two authors had done so consciously, they would certainly have made a remark to the effect that the type specimen had not the six pairs of pores, but only three. Such a remark, as far as I can see, they have not made, and so there can scarcely be any doubt that this species has quite wrongly got the name of mzcrotuberculatus. As a synonym of it Agassiz & Desor (loc. cit.) mention Ech. pelchellus Ag. and decoratus Ag., and the former of these names should then be employed for this species. The description of Ech. pulchellus') may agree rather well with it, even if it cannot be said to be a very appropriate one; it might also agree with young specimens of Strongyloc. lividus. Therefore I think it better to wait for a renewed examination of the type specimens, before the commonly used name of mzcrotuberculatus is rejected. Ech. angulosus is distinguished from the two other species by the two ocular plates reaching to the periproct, and by the plates of the buccal membrane being fine and quite imbedded in the skin; only a few are thick and carry pedicellarie. The globiferous pedicellariz have only two, more rarely three teeth on either side; the tridentate ones are more strongly sinuate in the outer part where the valves join (Pl. XVII. Fig.6); the larger ones have a rather strong net of meshes, the edge is thick, in the lower part with very distinct transverse series of small teeth. The ophicephalous pedicellariz have generally only a simple keel in the middle of the blade, without any net of meshes (Pl. XVII. Fig. 3). These three species must absolutely form a separate genus. Most recent authors use the name of Psammechinus Ag. for them, but wrongly. In «Catalogue raisonné» p. 64 under the fourth type Sous-genre Psammechinus Ag.» are named first the species varzegatus Lamk. and semituberculatus Val. and as no. 3 subangulosus Tamk. There can be no doubt, then, that the two first-named may claim the name of Psammechinus, as it appears that they cannot be classed with the genus 7Zoxo- pueustes, to which they are referred in «Rey. of Ech.», but must form a separate genus (see below). For the species miliaris, microtuberculatus, and angulosus a new genus must then be established; I propose the name of Parechinus. Psammechinus verruculatus Ltk. Agassiz (Rev. of Ech. p. 122) mentions this species as syno- nymous with Parech. angulosus; de Loriol (245. p. 21) objects to this and maintains that they are two well distinguished species. I must not only grant that de Loriol is right in his statement, but shall have to go much farther and assert that it cannot be referred to the same genus, nay, not even to the same family as Parech. angulosus. Prof. de Loriol has kindly sent me a specimen of his Echinus verruculatus tk.» from Mauritius, and so I have been able to compare it with the type specimens of Ltitken, which are found in the museum of Copenhagen. All the type specimens are naked tests, so that it is impossible to tell quite certainly, whether the species of de Loriol is really identical with these specimens; all the most important characters are wanting on the naked tests — nay, it is, moreover, probable that the type specimens really belong to two different species. It is, however, certain, that the description given by de Loriol of the coloration of his specimens?), agrees exactly with two of the type specimens, and I think it very likely that they are really identical. Full 1) Introduction to Valentin’s Anatomie du genre Echinus. p. VI. 2) In the specimen sent me by de Loriol, there is no trace of coloration on the test; only the spines have the colour described by de Loriol. ECHINOIDEA. I. 109 certainty, I think, can never be obtained, and there is nothing to be done but to resolve that the species of de Loriol shall in future be taken to be the Psammechinus verruculatus of Liitken. To the description by de Loriol I shall here make some additions. A primary tubercle is found on every ambulacral plate. De Loriol states that two ocular plates reach to the periproct; in the specimen before me this is only the case with one plate. The genital pores are especially large. The buccal membrane contains numerous small fenestrated plates both inside and outside of the buccal plates; those outside the buccal plates are a little larger, a few are thick and carry pedicellaric, while most of them are simple fenestrated plates, quite imbedded in the skin; a few bihamate spicules are also found in the buccal membrane. The gills contain the usual fenestrated plates. The mouth-slits, as observed by de Loriol, are small, but very distinct. The globiferous pedicellariz are very different from those of the genera Echinus, Sterechinus, and Parechinus; by this reason only this species was to be separated from those genera. The blade is quite closed to a thin tube without lateral teeth, as in Spherechinus granularis; no neck; I suppose that glands are found on the stalk, but this fact could not with certainty be substantiated from the dried specimen in hand. The tridentate pedicellariz (Pl. XXI. Fig. 2) have a broad, deep blade with a slight indication of a net of meshes in the bottom; the valves join for almost their whole length, the edge is rather strongly, but simply serrate. The ophicephalous and triphyllous pedicellarize of the common form. The spicules are very peculiar (Pl. XXI. Fig. 28), small, with a little ball at each end, quite resembling dumb-bells. They are found in especially great numbers in the globiferous pedicellarize, also, however, in the tube feet, but in rather small number. Genuine bihamate spicules do not appear to be found in the tube feet. This peculiar form of globiferous pedicellarize and spicules is also found in «chinmus» Robil- lardt, and darnleyensis, further in the genera Zoxopneustes and Tripneustes, and there can be no doubt that the mentioned species belong here. To which genus they will have to be referred cannot be decided, until we have examined the Zoxopueustes- and Tripneustes-species. Echinus Robillardi Woriol. To the description of this species by de Loriol (245 p.23) I may add the following informations (a specimen received from Prof. de Loriol). A primary tubercle is found on every ambulacral plate. The peristome is very peculiar, quite naked. Inside of the buccal plates a belt is found with numerous bihamate spicules, and in the inner edge a few larger, irregular needles are found (Pl. XXI. Fig. 24. b). At the outer edge of the peristome again rather numerous bihamate spicules are found, and in the gills seem to be found, not the usual fenestrated plates, but numerous bihamate spicules. Otherwise no other plates than the buccal ones are found in the buccal membrane; these buccal plates are not placed in pairs opposite to each other as usual, but one out- side the other; neither spines nor pedicellarie are found on the buccal plates. The very peculiar, oblique apical area has been accurately described by de Loriol, who also points out that the slits of the test are small and indistinct. The globiferous pedicellarie as in Spherechinus, without lateral teeth, the blade a closed tube; I have not been able to decide from the dried specimen in hand whether glands are found on the stalk. The tridentate pedicellariz very peculiar (Pl. XXI. Figs. 4, 11); the lower part of the blade is narrow and quite filled by a net of meshes, so that the edges are quite coalesced; the upper part is a little widened with straight, finely serrate edge. Only this part of the valves join, so that they are wide apart below. The ophicephalous pedicellariz without conspicuous 3@ Ge) ECHINOIDEA. I. peculiarities; triphyllous pedicellariz I have not seen. In the globiferous pedicellarize numerous spicules are found, somewhat thickened in the ends (Pl. XXI. Fig. 24. a), although not markedly dumb- bell-shaped; also a few common bihamate spicules are found among them. In the tube feet the biha- mate spicules are predominant, but the other form is also found. — De Loriol, no doubt, is right that this is a distinct species; but it is no Achinus. Its nearest relations are «Echinus» verruculatus and especially darnleyenszs. Echinus darnleyensts Woods. Of this species I have had occasion to examine a specimen from Thursday Island, Torres Strait, 4 fathoms (the «Alert»-Expedition) in British Museum. (I cannot answer for the correctness of the determination; that it corresponds with the description is no guar- antee for its being the same species, as the description gives only the usual things: spines, tubercles etc, but mentions neither spicules nor pedicellariz.) A primary tubercle is found on every ambulacral plate; according to Woods (442. p.165) the ocular plates are quite shut off from the periproct — but according to an information from Prof. Bell they are not shut off from the periproct in these speci- mens (I have forgotten to ascertain it myself). The buccal membrane is quite naked with the excep- tion of the buccal plates which are placed in pairs opposite to each other, and carry a few pedicellariz. «With ten rounded small openings surrounded by Pedicellarize», it is said in the description by Woods; this, I think, must be the holes in the buccal plates for the buccal tube feet — a rather common feature to note in a description of species! Innermost in the edge of the mouth numerous needle- shaped, more or less irregular spicules are found resembling those of «Ech.» Robillardi; they are arranged parallel to the edge of the mouth; a few are a little fenestrated. Outside of these some bihamate spicules are found, but far from so great a number as in Rodillardz. Near the gills numerous bihamate spicules are found in the buccal membrane. The gills themselves contain the common irre- gular fenestrated plates. According to Woods the auricule are only «slight thin processes, which do not meet»; Prof. Bell informs me that they are here of the common form. (In verrucaulatus and Robil- lardi they are also of the common form.) The globiferous pedicellarie as in Spherechinus, only is the blade uncommonly short (Pl. XXI. Fig. 36). In the tridentate pedicellarize (Pl. XXI. Fig. 7) the blade is broad, open, with only a slight net of meshes in the bottom. The edge is finely, simply serrate in the outer part where the valves join; in the lower part a few larger indentations are found. The valves are rather wide apart. Ophicephalous and triphyllous pedicellarize of the common form. ‘The spicules (Pl. XXI. Fig. 23) of the globiferous pedicellariee arcuate, but not pointed at the ends; in the tube feet only a few bihamate spicules are found. — Woods thinks that it is this species Agassiz has wrongly referred to Ech. magellanicus; that it has nothing to do with magellanicus is certain, although the differences pointed out by Woods: «in the actinostome being larger; in the abactinal system, where the genital plates have only two tubercles, and in the color of spines and test» are quite irrelevant. The principal difference is to be found in the globiferous pedicellarizee and the spi- cules; they show that this species is no Lchinus or Sterechinus at all, but like Ech. Robillard’ and verruculatus is closely allied to Toxopneustes and Tripneustes. To the genus 7oxopneustes Ag. are referred the species: maculatus (Lamk.), pileolus (Lamk.), elegans Doderl., vartegatus (Lamk.), and semituberculatus (Val.); to the genus 7ripneustes Ag. (in Rev. of Ech. this genus is called Hpponoé) are referred the species: esculentus (Leske), depressus Ag., and ECHINOIDEA. I. If! variegatus (Leske). I have had occasion to examine all these species, with the exception of 7. macu- latus; of 7. elegans Prof. Déoderlein has most kindly sent me a specimen, 7: semztuberculatus I have seen in British Museum, the other species are found in the museum in Copenhagen. I shall therefore make a few supplementary remarks to the existing descriptions of these species. Information is espe- cially wanting with regard to pedicellarize and spicules. Toxopneustes pileolus (Lamk.). Some specimens found in our museum have by Liitken been determined as 7: maculatus, but this determination, no doubt, is incorrect. They agree exactly with the description of 7: pzleolus, having especially the characteristic coloration so often mentioned; on the other hand they do not at all agree with Lamarck’s diagnosis of 4. maculatus. Therefore I do not hesitate to refer them to fz/eolws. — Only every other ambulacral plate has a primary tubercle; two ocular plates reach to the periproct. The buccal membrane contains numerous fenestrated plates as well inside as outside of the buccal plates; not a few of them are thick and carry pedicellariz. Besides the fenestrated plates the buccal membrane contains numerous bihamate spicules; also in the gills bihamate spicules are found in great numbers together with the common irregular fenestrated plates. No spines on the buccal plates. The globiferous pedicellariz without lateral teeth and with tubular blade as in SPherechinus, but they are remarkable by the extraordinary length of the blade and the end-tooth (Pl. XXI. Fig. 13); in the apophysis there is a long, narrow slit; no neck; small glands are found on the stalk. The tridentate pedicellariz are very large, the head up to a length of 3™"; the neck very short. The outer part of the blade where the valves join, is coarsely and irre- gularly indented in the edge, in the lower part the edge is smooth, or has a few larger thorns. In the bottom of the blade a strong and very complicate net of meshes is found hiding the usual regular arrangement of the holes, even at the point of the blade (Pl. XXI. Fig. q1). In smaller pedicellarice this net of meshes, no doubt, will be much less developed, but such pedicellarize I have not found in the specimens in hand. For a long way the valves are apart, but not much, so that only a narrow slit is found between them. Ophicephalous and triphyllous pedicellariz without particular peculiarities. The stalk of the pedicellariz compact. The spicules (Pl. XXI. Fig. 21.a) in the pedicellarize are of the typical dumb-bell shape; in the smaller globiferous pedicellarize on the abactinal side they form a thick white border all round the head, the valves being united almost through their whole length by a fine skin. These pedicellarie are almost always open, and give the animal a very characteristic appear- ance — which, no doubt, also holds good with regard to 7: elegans. When they are shut the border of spicules is slackened to as to make a kind of fringe round the point; the large globiferous pedicel- lariee of the actinal side do not seem to have such a border. In the tube feet a few dumb-bell-shaped spicules are found together with more numerous bihamate spicules; most of the latter, especially those nearest to the sucking disk, have some small branches on the outside at the points (Fig. 21. b); the spicules of the buccal membrane are much finer (Fig. 21.c); also here a few dumb-bell-shaped spicules are found. As a synonym of 7. fileolus Agassiz in Rev. of Ech. mentions the species Boletia rosea before established by himself. To judge from the authentic specimens before me of Z. rosea (from Mus. Comp. Zool.) I think it, however, somewhat doubtful that they are really only one species. Besides the difference with regard to colour (the spines uniformly brown, the test only with a slight reddish tint, 112 ECHINOIDEA. I. otherwise quite brown), there is another fact that may, perhaps, be of some significance. In TZ: prleolus the secondary tubercles in the ambulacral areas — on the plates wanting the primary tubercle — are as large as the primary ones, so that it can only be seen from their position, whether they are prim- ary or secondary ones; in vosews the primary tubercles are distinctly larger than the secondary ones on the plates where the primary tubercle is wanting. If this feature proves to be constant, there can scarcely be any doubt that they are two well distinguished species. In spicules and pedicellarie any difference of importance is scarcely to be found. Toxopneustes elegans Doderl. agrees exactly with 7: pzleolus (I have not, however, seen the tri- dentate and triphyllous pedicellarize); as far as I can see it is only distinguished from 7: Arleolus by its peculiarly coloured spines — they have a sharply limited dark band near the point — and by the colour of the test, it being in 7: elegans «yellowish without any indication of coloration, only the median suture of the ambulacral and interambulacral areas is dark violet on the apical side». (Dédder- lein I14. p. 99.) Toxopneustes variegatus (Iamk.). To the existing descriptions I shall add the following remarks. A primary tubercle is found on all the ambulacral plates. The globiferous pedicellarize (Pl. XXI. Figs. 38, 40) with tubular blade, without lateral teeth, not very much lengthened. Glands may be found on the stalk, but are most frequently wanting. The tridentate pedicellarie (Pl. XXI. Fig. 10) are large, the head up to 15™™, and long-necked. There is only little mesh-work in the blade, the edge is straight, rather thick, with numerous, irregularly placed small teeth; the valves are only a little apart below. The triphyllous and ophicephalous pedicellarize of the common form. ‘The spicules (Pl. XX. Fig. 15) are dumb-bell-shaped, exceedingly numerous in the skin of the globiferous pedicellarize (as in all these species); here all transitional forms may be found from small, oval bodies to typical, bihamate spicules (Pl. XXI. Fig. 31), but the really dumb-bell-shaped ones are by far the most numerous. In the tube feet only bihamate spicules are found in small number. Toxopneustes semituberculatus (Val.), no doubt, is most nearly allied to 7) variegatus; especially must be emphasized that it likewise has a primary tubercle on all the ambulacral plates. Spicules and pedicellariz as in 7: variegatus, only the globiferous pedicellaria show a conspicuous peculiarity ‘the lime in the valves being of a deep violet colour, with the exception of a small, oblong, clear spot in the basal part on either side of the apophysis. Glands are found on the stalk. — Otherwise, as is well known, it is distinguished from varzegatus by the less marked plate-covering on the buccal membrane. Tripneustes esculentus (Leske). A primary tubercle is only found on every third or fourth ambulacral plate. The buccal membrane contains numerous small fenestrated plates inside of the buccal plates, outside of these fewer, small, round, thick plates with pedicellarize are found. The pedi- cellariz are numerous, much pigmented, and form a quite black ground between the spines. The globiferous pedicellarize are small, the valves as in the other allied forms (Pl. XXI. Fig. 39). Glands are found on the stalk. In the tridentate pedicellariz (Pl. XXI. Fig. 16) the blade is filled by a highly developed net of meshes; the point rather abruptly widened with the edge exceedingly finely serrate, in the lower part of the blade the edge is more or less coarsely dentate. The valves are rather wide apart, only joining at the point. Together with these a smaller form of tridentate pedicellarize ECHINOIDEA. L. Il3 (Pl. XXI. Fig. 3) is found, with a broader blade and less developed mesh-work; the part where the valves join, is comparatively larger than in the large form; transitional forms are found. The ophice- phalous pedicellariz shorter and broader than usual (Pl. XXI. Fig. 22); the triphyllous pedicellarize of the common form. The spicules of the pedicellarize are typically dumb-bell-shaped (Pl. XXI. Fig. 33. a); in the tube feet common bihamate spicules are found together with very small spicules, also bihamate (Fig. 33. b) or a little dumb-bell-shaped; in the buccal membrane numerous small spicules are found with truncate ends (Fig. 33.c) together with larger bihamate spicules (Fig. 33. d). Tripneustes depressus A. Ag. is, with regard to spicules and pedicellariz, quite similar to escw- lentus; I have not, however, been able to find tridentate and triphyllous pedicellariz on the only, badly preserved specimen before me. As in escelentus only every third or fourth ambulacral plate has a primary tubercle. The difference between the two species is very well given in Rev. of Ech. Tripneustes vartegatus (Leske). A primary tubercle is only found on every third ambulacral plate; the secondary tubercles almost as large as the primary ones, so that the latter are only to be distinguished with difficulty, while in escalentus the primary tubercles form a beautiful, rather con- spicuous series. As in escalentus two ocular plates reach to the periproct; no central plate. The buccal membrane with numerous thick fenestrated plates carrying pedicellarize; even globiferous pedicellariz may be found on the buccal membrane, a fact I have not seen in any other Echinid. The globiferous pedicellarize quite as in esczlentus, the tridentate ones resemble very much the smaller form in escw- lentus; a form corresponding to the larger form in this species I have not found in 7) variegatus. Ophicephalous and triphyllous pedicellarize as in escalentus; the spicules of the pedicellarize typically dumb-bell-shaped; in the tube feet only really dumb-bell-shaped spicules seem to be found, in the buccal membrane there are comparatively few spicules, partly larger, bihamate ones, partly smaller, somewhat dumb-bell-shaped ones. According to Lovén (252) this species corresponds to Linné’s Echinus Gra- fila; this name must then be adopted instead of varzegatus (Leske). According to the definition given by Agassiz (Rev. of Ech. p. 297 seq.) the genera 7oxopneustes and 7Zripneustes (Hipponoé) are chiefly distinguished by the fact that in Zoxopneustes the pores are arranged in oblique arcs of three pairs, while in Z7zpneustes the pores form three vertical series; the series in the middle is irregular, the two outer ones are regular. The other characters — whether the peristome is large or small, and whether the tubercles form more or less regular vertical and hori- zontal series — are of a so relative nature, that it will be better to leave them out of consideration. Unfortunately the mentioned principal character is not reliable either; in larger specimens of 7oxo0- pneustes the pores may form three irregular longitudinal series as in Zyzpneustes, what has already been mentioned by Agassiz in his diagnosis of the genus Zoxopucustes, and in smaller specimens of Tripneustes, wp to a diameter of ca. 20™™, the pores are arranged in quite similar arcs of three pairs as in Toxopueustes without any indication of an arrangement in longitudinal series. Accordingly none of the characters hitherto pointed out are reliable. It must, however, be admitted that the species esculentus, depressus, and gratilla form a group that is, as to their habitus, very different from the species referred to Zoxopmeustes, so that it seems natural to keep them as a separate genus. To this is to be added that, if the genera Zoxopmeustes and Tripneustcs were to be united, it would give rise to a complete rearrangement of the nomenclature; especially the name of Zoxopneustes would then have The Ingolf-Expedition. IV. r. 15 114 ECHINOIDEA. I. to be used for a quite different series of forms: «Strongylocentrotus» tuberculatus ete., which, as will be shown below, do not at all belong to the genus Strongylocentrotus. This would certainly create much confusion, and only to avoid this calamity these genera ought to be kept up, if there are no cogent reasons for uniting them. Now such reasons are not found; on the contrary a closer examina- tion shows that other characters are found, more reliable than those given by Agassiz, which char- acters may also be used for the small specimens, where the characters mentioned above cannot be used at all. While all the species referred to 77zpmeustes are no doubt closely allied, the same thing cannot be said of the Zoxopmeustes-species; they form two well distinguished groups. The species Az/eolus, elegans, and rosews form a group characterized by having only a primary tubercle on every other ambulacral plate, by the peculiar globiferous pedicellariz with a border of spicules and much length- ened blade and end-tooth, and by the branched bihamate spicules in the tube feet. The species vartegatus and semituberculatus have a primary tubercle on all the ambulacral plates; the globiferous pedicellariz have no border of spicules, the blade is not much lengthened, the bihamate spicules in the tube feet are not branched in the ends. That the buccal membrane is more richly provided with plates and the spines longer than in the former group, I take to be less reliable characters, especially as there is a rather great difference between vartegatus and semituberculatus with regard to the plates of the buccal membrane. Thus the two groups are seen to be very well distinguished, and each of them ought no doubt to form a separate genus. As fz/eolus is the type of the genus Zoxopneustes?) of Agassiz, this group must keep this name. The other group gets the name of Psammechinus, which name here gets its definitive place, after having so long been abused (comp. p. 108); the numerous names that in the course of time have been applied to Ps. vartegatus: Lytechinus, Psilechinus etc., become only synonyms of Psammechinus. After having thus limited the genus Zoxopmeustes, it is easy to state the characters, by which the genus Z7zpmeustes is distinguished as well from the former genus as from Psammechinus. A primary tubercle is only found on every third ambulacral plate; no border of spicules on the globi- ferous pedicellarize, the blade not much lengthened; the bihamate spicules in the tube feet not branched in the ends. To these characters is then to be added with regard to the larger specimens the characteristic arrangement of the pores in three separated longitudinal series. — In «Rev. of Ech.» Agassiz has adopted the name of //ppfonoé Gray in stead of Zripneustes Ag. Bell (38) maintains that this is unwarranted, as the name of //zffonoé has originally only been published as a nomen nudum, for which no species is given as the type. That Gray himself has later shown Agassiz, which species he regarded as the type of his genus /Zippfonoé (Agassiz, 7), does not justify the adop- tion of this name, any more than the assertion of Agassiz senior that if the name of //zpponoé proves to be a synonym of his 77zpmeustes, the former is to be preferred (Introd. to Valentin’s Anat. du genre Echinus. p.[X.). As well known the author of a name has himself no more command of it 1) The name of Toxopueustes has first been proposed by L. Agassiz in «Observations sur les progrés récens de histoire naturelle des Echinodermes». (Monographies d’Echinodermes. p.7.) «Dans un travail encore inédit sur les espéces vivantes de l’ancien genre Echinus .... j'ai établi les coupes suivantes, dont je me bornerai a citer ici les types: Temnopleurus (EZ. toreumaticus), .... Toxopneustes (E. pileolus)». Tater, in the preface to Valentin’s «Anatomie du genre Echinus». p. X. Agassiz says of Toxopueustes: «Je prends pour type de ce genre /’Echinus tuterculatus». — As a matter of course pi/eo/us must have the prior right to the name of Zoxopuezstes. ECHINOIDEA. I. IIs than others, when it has first been published. I must decidedly follow Bell and de Loriol in the opinion that the name of 77ipnewstes has the priority. The species «Echinus» Robillard:, darnleyensis, and verruculatus belong, as stated above, also here, but to which genus? They have, all of them, a primary tubercle on all the ambulacral plates; by this feature they are excluded from the genera Zoxopueustes and Tripneustes, this character being here evidently of rather more value than among the “chinzs-species. They must then either be referred to Psammechinus or form a new genus. In verraculatus the buccal membrane contains numerous fenestrated plates, to be sure much smaller and finer than in varzegatus, where the buccal membrane is closely covered with large, thick plates; but in this respect semztuberculatus keeps an intermediate position between the two, so that no definite limit can be given. The feature is quite analogous with that of Parechinus microtuberculatus, miliaris, and angulosus. Otherwise I can see no character that would justify a referring of this species to another genus. The mouth-slits are in no way smaller than in small specimens of variegatus of a corresponding size; in a specimen of verruculatus of a diameter of 21™™ they have a depth of 1™™, in a specimen of variegatus of a diameter of 23™™ they have only the same depth. Further the coloration of the test in young varzegatus is so very similar to that typical of verruculatus, that a comparison gives the immediate impression that they must be very closely allied. Accordingly I can only regard it as correct to refer this species to the genus Psammechinus, where it has already been referred by Liitken — who did not, to be sure, inter- pret the genus Psammechinus in the way it is done here, since he establishes the genus Pszlechinus for Ps. variegatus, and in the same paragraph he names verraculatus as a typical Psammechinus*). The species Rodillardi and darnleyensis are distinguished from Psammechinus by their naked buccal membrane; it is, as described above, quite naked with the exception of the buccal plates, but contains more or fewer irregular spicules in the inner edge. The spicules of the pedicellariz are not quite dumb-bell-shaped as in verruculatus and the other Psammechinus-species, but are formed as bows, which are a little thicker at the ends or of the same thickness in their whole length. These two features, I think, render the referring to the genus Psammechinus impossible, and they must con- sequently form a separate genus, for which I propose the name of Gymnechinus. Whether Zoxopn. maculatus really belongs to Zoxopneustes or must rather be referred to another genus cannot be decided from the existing descriptions. To the genus Avechinus Verr. are referred the species chloroticus (Val.), australie Woods, and rarituberculatus Bell; of these I have examined chloroticus and rarituberculatus (the type specimen), with regard to which I can give the following informations in addition to what is hitherto known. Evechinus chloroticus (Val.). The 4—5 nethermost ambulacral plates have all a primary tubercle, then only every other plate, and above the ambitus only every third plate has a primary tubercle. In small specimens a primary tubercle will thus be found on every other plate on the ab- actinal side. The small spines are club-shaped. The buccal membrane inside and outside the buccal plates is richly provided with rather small, simple fenestrated plates, some of those outside the buccal plates are complicate and carry pedicellariz. No spines on the buccal plates. The globiferous pedi- cellariz (Pl. XIX. Figs.6, 12) are very characteristic. There is only one unpaired, very strong lateral 1) Bidrag til Kundskab om Echiniderne. p. 27. 116 ECHINOIDEA. I. tooth; the outer corners of the basal part are strongly produced in a wing-shaped manner, and the holes in the corners are most frequently somewhat lengthened. No neck or perhaps a short one; as I have only had dried specimens for examination, I have not been able to decide this fact with cer- tainty; the stalk compact. In the tridentate pedicellariz (Pl. XIX. Fig. 39) the blade is rather broad with a strong, somewhat thorny net of meshes at the bottom. The edge is strongly indented, espe- cially in the outer half, where the valves join; in the lower half they are apart, but not very much. The ophicephalous pedicellariz have an almost straight edge, which is otherwise finely serrate as usual; the teeth, as is often the case, continue down the upper ends of the apophysis. The triphyllous pedicellariz (Pl. XIX. Fig. 29) are very peculiar, the upper end of the apophysis forming a cover-plate, from which digitate projections pass over the blade, which is curved strongly inward in the middle. The edge smooth as usual. The spicules are bihamate, very few in number. Evechinus rarituberculatus Bell is by Farquhar (145) taken to be young specimens of £. chio- roticus. It is certain that it is very similar to chloroticus, but I cannot regard it as proved that it is synonymous with this species, as the tridentate pedicellariz (Pl. XIX. Fig. 7) show a considerable dif- ference from those of chloroticus. They have no coarse indentations in the edge, which is almost straight and very slightly serrate, only at the lowermost part there are a few larger indentations; the net of meshes in the bottom is slight, not thorny. The valves join through almost their whole length. — Perhaps similar pedicellarie may be found in chloroticus together with the form described above; in my specimens, however, I have not been able to find such. For the present I must then regard rarituberculatus as a separate species. — The globiferous and ophicephalous pedicellariz are quite as those of chloroticus, the triphyllous ones I have not seen. — Of Avech. australe Woods I know nothing. Agassiz (Rey. of Ech. p. 502) thinks Avechimus to be closely allied to 77ripneustes (Hipponoe); that there is no nearer relation at all between these two genera is seen with all desirable distinctness from the facts given above. The unpaired lateral tooth on the globiferous pedicellariz draws the attention to Pseudechinus albocinctus; but the naked buccal membrane in the latter and the fact that a primary tubercle is here found on all the ambulacral plates, do not indicate a very near relation between the two forms. A quite similar form of globiferous pedicellaria is found in «Strongylocen- trotus» tuberculatus and closely allied species, and these, no doubt, are its nearest relations. A more thorough inquiring into this question must, however, be put off, until these species are treated. In «Cat. rais.» the species variolarts Lamk., paucituberculatus Blainyv., and chloroticus Val. are enumerated under the genus Helocidaris. — For the first of these species the older name of S¢omo- pneustes must be used; according to Agassiz (Rev. of Ech.) paucetuberculatus is synonymous with this. As far as I can see, chloroticus must then be the type of the genus //eliocidaris; the name of Evechinus Verr. (1871) must then be dropped as being a much younger one, and I cannot but wonder, why Agassiz, who otherwise takes great care to reestablish the oldest names, has here preferred the name of Lvechinus. To the genus Spherechinus Desor the species granularis (Lamk.), vosews Russo, australi@ A. Ag., and pulcherrimus (Barn.) are referred; of these I have had no occasion to examine Sf. roseus, but ECHINOIDEA. I. 117 the existing figures and the description (347) show distinctly that it is closely allied to granularts. The other three species I have examined, and can give some new informations of them. Spherechinus granularts (lamk.). All the ambulacral plates have a primary tubercle. The buccal membrane contains outside of the buccal plates only few, small fenestrated plates, but they are thick and carry pedicellariz, inside of the buccal plates there are numerous small, little complicate fenestrated plates. No spines on the buccal plates. The globiferous pedicellariz, which have often been described and figured, have a tubular blade without lateral teeth (Pl. XXI. Figs. 35, 37); the end- tooth is peculiarly furrowed, so that it is a little difficult to see the open canal on the upper side. No neck. Glands on the stalk are found (were formerly only known in this species), the stalk tubular or compact!). The tridentate pedicellariz (Pl. XXI. Fig. 34) with a well developed net of meshes, almost to the point of the blade; the edge is thick with an indication of transverse series of teeth. The valves are apart for about half their length, but the slit between them is rather narrow. The length of the head up to 2™™ The ophicephalous and triphyllous pedicellariz of the common form. The spicules in the globiferous pedicellarize are slightly thickened at the ends (PI. XXI. Fig. 12), but not really dumh-bell-shaped. In the tube feet only a few spicules are found just below the sucking disk; they are bihamate with small branches on the outside at both ends — quite as in Zoxopmeustes pileolus. Yn the buccal membrane, especially nearest to the gills, and in the gills, fine, genuine biha- mate spicules are found; in the gills the usual irregular fenestrated plates are also found. Spherechinus austrahe Ag. agrees with regard to spicules and pedicellariz exactly with granu- lar’s. Whether a primary tubercle is found on all the ambulacral plates, I cannot tell with certainty, as I have omitted the examination of this feature during my stay at British Museum; but as all other polypore Echinids that I know, have a primary tubercle on all the ambulacral plates, there can scarcely be any doubt that the fact is the same in this species. In «Challenger»-Echinoidea (p. 106) SAA. australie is mentioned from st. 162 (Bass’s Strait). In British Museum I have examined the specimen upon which this statement rests, and have found that it is no Spherechinus at all. The globiferous pedicellarize have one unpaired lateral tooth, and recall those of «Strongylocentrotus» tuderculatus very much; otherwise I shall not decide to which genus and species this young specimen belongs, but rest satisfied with having pointed out that it is no SAh@erechinus. Spherechinus pulcherrimus (Barn.), as well by its whole habitus as by its spicules and pedicel- larize, differs so much from the other Sfherechinus-species that there can be no question of referring it to this genus. On the other hand it shows great conformity with some S¢rongylocentrotus-species (intermedius and chlorocentrotus), and so it will be more particularly mentioned together with these species. Agassiz says of the genus Spherechinus: «this genus can hardly rank as more than a sub- generic division of Strongylocentrotus; the presence of deep, sharp cuts in the actinal system and the regularity of the arrangement of the tubercles, although giving to the species of this genus a striking facies, are simply quantitative characters, the value of which a better acquaintance with the subject will determine» (Rev. of Ech. p. 451). I shall readily admit that the difference between the deep slits 1) The so-called «Globiferce> (Hamann 184) can only be interpreted as globiferous pedicellariw, where the glands on the stalk have been highly developed at the cost of the head. The head is perhaps even torn off; at all events it is a sure fact that animals which are attacked by the pedicellaria, can tear off the heads of the globiferous pedicellarie. The so-called Trichelina parvadoxa (Barrois. 28), as is a well known fact, is only torn-off heads of globiferous pedicellarie. 118 ECHINOIDEA. I. in Spherechinus and the small ones in Strongylocentrotus is a quantitative one, as also the difference between the numerous tubercles in the former and the fewer ones in the latter genus. This, however, does not preclude the fact that especially the deep slits are a character very sharply distinguishing Spherechinus from Strongylocentrotus. But other characters are found, not quantitative, but structural, which also make a sharp distinction between the two genera, viz. spicules and pedicellariz (comp. the description below of Strongylocentrotus drobachiensis). There can be no question at all of making Spherechinus only a subgenus of Strongylocentrotus; it is a very well characterized genus, evidently most closely allied to Psammechinus, Toxopneustes ete. To the genus Pseewdoboletia 'Troschel are, in «Rev. of Ech.» referred the species granulata (Ag.) and zzdiana (Mich.); of the latter Prof. de Loriol has kindly sent me a specimen. To the description of this species by Agassiz and de Loriol (245) I can add the following informations. A primary tubercle is found on all the ambulacral plates. The buccal membrane contains, besides the numerous thick plates carrying both spines and pedicellarie, a great number of dumb-bell-shaped spicules and some bihamate ones; inside of the buccal plates numerous small, rather thick fenestrated plates with- out spines or pedicellariz, and a few spicules, most of which are bihamate, almost none of them dumb- bell-shaped. The gills with common fenestrated plates, a few dumb-bell-shaped spicules, and innumer- able bihamate ones. The globiferous pedicellariz as in Spherechinus; they are strikingly different as to size, but otherwise similarly constructed. The figure given by Agassiz in «Challenger»-Echinoidea (Pl. XLIV. Fig. 38) is not quite good, as the end-tooth seems there to be constructed quite as the tubular blade; I need scarcely mention that it is constructed in the common way. In the same place is given a rather good figure of a tridentate pedicellaria (Fig. 39), the only objection is that the oblique striz in the blade give a somewhat coarse idea of the little developed net of meshes in the blade. The edge is thick with numerous small teeth, which in the lower part are placed in transverse series, in the outer part irregularly. Ophicephalous and triphyllous pedicellarie of the common form. The stalk compact. In the globiferous pedicellaria numerous spicules are found of about the same form as in SAherechinus; the same form is also found in the tube feet, especially near the sucking disk, together with bihamate spicules that are not branched in the ends. According to Agassiz (Rev. of Ech. p. 153) Pseudoboletia maculata Troschel is synonymous with Ps. mzdiana. De Loriol (op. cit.) does not think them to be the same species, and Bell (53) follows this opinion, and maintains farther that Ps. grvanudlata is identical with zzdzana. After having examined a couple of specimens of Ps. maculata in British Museum I must also regard maculata as a well distinguished species. The globiferous pedicellariz are as in szdiana, the glands of the stalk are peculiarly lengthened and narrow, almost linear. (Whether this also holds good with regard to zzdiana, I am not able to decide by the dried specimen in hand.) The tridentate pedicellariz (Pl. XXI. Fig. 1) yield scarcely a sure mark of distinction from zvzdana; together with the large form (the head up to r5™") where the valves join only in the outer half, a smaller, somewhat different form is found (Pl. XXI. Fig. 17) where the valves join through their whole length. The ophicephalous pedicellarize (Pl. XXI. Fig. 5) are peculiarly elongate with almost straight, finely serrate edge and little developed mesh-work. It is, however, to be observed that on the buccal membrane of Ps. zzdiana ophicephalous pedicellariz are found, resembling the figured one rather much, and as I do not remember, and have ECHINOIDEA. I. IIg made no note, whether those of Ps. maculata are taken exclusively from the buccal membrane or per- haps also from the test, I do not venture for the present to put too much stress on this feature. The triphyllous pedicellarize and the spicules show no difference from Ps. indiana. — The features stated here, together with those mentioned by de Loriol and Bell: the size of the peristome and the slits etc, and especially the peculiar coloration, which, according to de Loriol, is not found in szdiana, seem to leave no doubt of the fact that they are two well distinguished species. In «Rev. of Echini» Psewdoboletia like Spherechinus is enumerated as a subgenus of Strongy- locentrotus, and at the end of the diagnosis (p. 455) it is thereupon said: «This is an interesting genus, forming, as it were, a link between the Echinometrade and Echinidz; its position is. still doubtful». In none of these statements I can agree with Agassiz. Pseudoboletia is neither a sub- genus of Strongylocentrotus nor a transitional form between Echinometrids and Echinids, and its posi- tion is not at all doubtful — it is a near relation of Spherechinus. It agrees with Spherechinus with regard to the pedicellariz, the spicules of these, the number of pores, and the structure of the test; only in two features a difference of any importance is found: the spicules of the tube feet are simply bihamate (in Spherechinus a little branched in the ends) and — as the more important fact — the buccal plates and the other plates of the buccal membrane are set with small spines and pedicellariz (in Spherechinus only with pedicellariz), That the spines are a little longer and the test somewhat more flattened than in Sfherechinus can hardly be used as a generic character. Thus it is rather unimportant characters, by which Pseuwdoboletia is distinguished from Spherechinus; at all events, however, the peculiar covering with spines of the buccal membrane seemis to be a sufficient reason for the keeping of the genus, and nothing would be gained by uniting it with Spherechinus. The genus Strongylocentrotus Brandt is in Rev. of Echini (p. 276) enlarged to comprise , a little curved, generally with a rather strong point in the middle of the outer side. 1) List of Echinoderms etc. Bull. Mus. Comp. Zool. I. p. 22. 2) Bidrag til Kundskab om Echiniderne. p. 96. 126 ECHINOIDEA. I. That this form is widely different from Zoxocidaris tuberculatus is evident from the characters mentioned here; on the other hand the globiferous pedicellarize show that it is rather closely allied to Strongylocentrotus. But the peculiar spicules and the petaloid pore areas characterizes it sufficiently as a separate genus, which keeps, of course, the name of Azthocidaris. Lttken (loc. cit.) regards it as identical with Echinus homalostoma Valenc.; I do not know whether this is correct, but it is so far of no consequence, as this species will, at all events, get the name of Azthocidaris homalostoma. 1 suppose that this species has hitherto been confounded with Yoxocidaris tuberculatus, which it resem- bles to some degree, and which is also said to oceur at Japan. 7: taberculatus, however, is indigenous in the Australian seas, and until renewed examinations have corroborated its occurrence at Japan, | must suppose a confounding with A. homalostoma to have taken place. As to habitus A. homalostoma is very similar to Psewdocentrotus depressus, which latter has also petaloid ambulacra; but its colour is (always?) brownish red, and it is somewhat more flattened. The examination of pedicellaric and spicules will immediately show them to be two widely different forms. Where the species S¢7. mexicanus, nudus, and globulosus are to be referred, cannot be seen from the existing descriptions. The other species referred to Strongylocentrotus thus prove to belong to no fewer than 6 different genera: Strongylocentrotus, Pseudocentrotus, Loxechinus, Paracentrotus, Toxocidaris, and Anthocidaris, and it may perhaps even be necessary to divide the first one into two genera. And these genera are excellently characterized, and so far from being closely allied, that they are to be grouped into three different families. We can scarcely wish for a more striking proof of the insufficiency of the characters that are taken only from the test and the spines. Stomopneustes variolaris (lamk.). Of this very peculiar form I am able to give some new informations; I have not, however, had material sufficient for clearing up everything that might be wished for. — A primary tubercle is only found on every fourth or fifth ambulacral plate; each ot these large tubercles spreads over more plates — but it is difficult to decide over how many, as no boundary lines are seen between the plates; it may, however, be seen from the pores that the fact is so, aS more arcs are found opposite to each tubercle. Two ocular plates reach to the periproct. The buccal membrane contains numerous lengthened, fine fenestrated plates, of which a few are a little complicate and carry pedicellariz. Small spines are found on the buccal plates. The gills contain numerous, mostly three-radiate spicules (Pl. XVII. Fig. 13), but not the common irregular fenestrated plates. The globiferous pedicellarize are of a quite unique form. ‘There is no end-tooth, but the blade ends truncately with a long tooth in each corner (Pl. XVII. Fig. 17), sometimes two teeth on one side, or that on the one side a little below the corner. These teeth have no poison canal, and upon the whole no poison gland seems to be found (I have not, however, been able to ascertain this fact with full certainty). The blade is open, rather flat, the apophysis ends abruptly without any widening above. ‘There is no neck, and the stalk is very short and compact. This very peculiar, large, and powerful form of pedicellarize is, unfortunately, very scarce; in the two specimens I have examined, I have only been able to find one in each specimen, placed in one of the interambulacral furrows near the ambitus. Besides another, smaller form of globiferous pedicellariz seems to be found, with end-tooth and 1—1z lateral tooth, very similar to those of Paracentrotus hvidus; but I have not been able to make quite sure of this fact. The tridentate pedicellaria are distinguished by the apophysis ECHINOIDEA. I. 12 ™“ continuing some way into the blade as a distinct, a little serrate crest (Pl. XVII. Figs. 16, 20); the form is otherwise somewhat varying, as the blade may be more or less widened in the outer part; the larger ones have a rather powerful net of meshes, the small have almost none. The edge is rather coarsely serrate in the lower part, finely serrate towards the point; there are no transverse series of small teeth. A form as that figured by Agassiz (Rev. of Ech. Pl. XXIV. 31), where, moreover, the apophysis does not continue into the blade, I have not seen. Stewart (381) figures a valve of a tridentate pedicellaria, and mentions this crest. In the same place he figures a valve of an ophice- phalous pedicellaria to which I may refer; they are dentate in the edge to an uncommonly high degree, although some difference is found in this respect, but I have not seen them with so smooth edges as in the figure by Agassiz (loc. cit. Fig. 32). The ophicephalous pedicellarie have almost no neck, as has already been observed by Stewart. The stalk, which is, like those of the other pedicel- lariee, thick and compact, has a little constriction above. The triphyllous pedicellaricze are uncommonly lengthened (Pl. XVII. Fig. 4) without teeth in the edge. What Stewart has taken to be triphyllous pedicellariz (he does not figure them), I think to have been quite small, tridentate pedicellarie. «The great variation in the size of these (the tridentate) pedicellarize, and the broad, spoon-shaped character of their jaws make the smaller forms closely resemble the trifoliate variety and lend weight to Prof. Agassiz’s view, that the latter are rarely (sic! — early) stages of the former» (351. p.g11). That there can be no question of this need not be more nearly explained here, a reference to the informa- tions given above with regard to the development of the pedicellariae, will be sufficient. The spicules of the tube feet are very peculiar; along one side of the tube foot is found a series of large spicules formed as long, fenestrated, thorny tubes; they are parallel to the longitudinal axis of the foot, and are placed in such a way, that the upper end is projecting, while the lower end is covered by the spicule following below. Towards the sucking disk the spicules become smaller, at last only flat, length- ened fenestrated plates. On the opposite side of the tube foot is often — but not always — found an irregular series of much smaller spicules more or less perforated. Stewart!) has given figures of these spicules, to which the reader is referred; I have never, however, seen the large spicules branched, as they are figured here, Stewart does not know in which species it is that he has found these remarkable spicules; later (381) it has become clear to him that it is Stomopneustes variolaris.— Whether Stomopn. atropurpurea Woods (447) is a separate species, or, as Ramsay (311. p. 11) thinks, only a variety of variolarzs, I cannot tell with any certainty, as I have not seen this form, and the description gives no information of pedicellarie and spicules. These structures must be examined, before the question can be definitively decided. Parasalenta gratiosa Ag. 1 can only give little information of this very characteristic form beyond what has been stated by Agassiz, Liitken, and Stewart. A primary tubercle is found on all the ambulacral plates; the buccal membrane contains numerous, rather large, fine fenestrated plates, of which only a few are complicate and carry pedicellarie. No spines on the buccal plates. The globiferous pedicellariz have a tubular blade, without lateral teeth. No neck; glands seem to be found on the stalk, which is compact. The tridentate pedicellarize are long and very narrow, finely serrate in the edge; they remind very much of those in Paracentrotus lividus, but the serrations are finer. 1) On the Spicula of the regular Echinoidea. Transact. Linn. Soc. XXV. Pl. L. fig. 1. 1865. 128 ECHINOIDEA. I. No transverse series of small teeth. The ophicephalous and triphyllous pedicellarize without conspicuous peculiarities. The spicules of the globiferous pedicellarize are bihamate, those of the tube feet of a very peculiar form: biacerate, a little arcuate, with two small, axe-shaped projections on the concave side (Pl. XXI. Fig. 32). — Parasalenia Pohl Pfeffer (314) I have not seen. In «Revision of Echini» p. 423 the family Zchinometrade is defined as «having always more than three pairs of pores to each are»; nevertheless Parasalenia is also referred to this family, although it has only three pairs of pores in each are. Setting aside this contradiction is must be admitted that when only the form and habitus of the test is taken into consideration by the deter- mination of the relationship of the Echinids, Parasalenza must be regarded as an oligopore Echino- metrid. The examination of its pedicellariz and spicules show, however, that it has no nearer relation with the Echinometrids. The spicules remind most of those in Azthocidaris, but are, nevertheless, very different also from these; also the globiterous pedicellarize recall those of Azthocidarzs, but are distinguished from these by having no neck. Thus it is not too closely allied to Azthocidaris, but it does not seem possible, at all events at present, to point out any nearer relation. That the struc- ture of the spines is very different from that of the Achzmometra-spines (Mackintosh 265, Stewart 381) is a further proof that Parasalenia has nothing to do with Echzmometra; now, to be sure, we cannot lay any great stress on some difference in the structure of the spines, when this character is standing alone; but when, as in Parasalenia, it is added to other characters of more significance, it will also get some importance. After it has been pointed out that Parasalenza is no EKchinometrid, this form becomes of con- siderable interest as proving a parallel development within two different families. Echinostrephus molare (Bly.). Also this peculiar form is well known, especially Stewart (381) has figured its pedicellariz with the exception of the triphyllous ones; accordingly only the most important features are to be briefly mentioned here. A primary tubercle is found on all the ambu- lacral plates; all the ocular plates are shut off from the periproct. The buccal membrane with rather numerous fenestrated plates, not only opposite to the ambulacra (Rev. of Ech. p. 457); most of them are thick and carry pedicellarie. No spines on the buccal plates; the gills with the usual irregular fenestrated plates. The globiferous pedicellarie as in Achimometra with one large, unpaired lateral tooth. There is no neck; whether glands are found on the stalk could not be decided with certainty, as the examined specimen is a dried one. In the tridentate pedicellarize the blade is widened in a somewhat spoon-shaped manner, rather strongly serrate in the edge in the outer part, without trans- verse series of small teeth; only a little developed net of meshes. The ophicephalous and triphyllous pedicellaricze of the common form. ‘The stalk of the pedicellariz compact. The spicules of tube feet and pedicellariz bihamate. — Although this genus has most frequently trigeminate pores, it is also referred to Echinometrade in «Rev. of Ech.»; this is no doubt correct, both spicules and pedicellarize being as in Lchinometra. — Ech. pentagonus Yoshiw. (449) not examined. To the genus Lchinometra are referred the species: /ucunter (L,.)"), oblonga (Blv.), AZathex (Blv.), 1) Lovén (252. p. 153) has definitively shown the common Westindian Zchinometra to be the Echinus lucunter of I,inné; thus that species must keep the name, and the name of 2. suéangudaris (Leske) used by Agassiz (Rev. of Ech.) must be rejected. The species from the Pacific for which Agassiz unjustly reserves the name of /wcunfer, must give up this name, and in future be called Echinometra Mathai (Bly.), which name thus, according to Agassiz (Rey. p. 115), becomes the older one. ECHINOIDEA. I. 12¢ van Brunti Ag., viridis Ag., and macrostoma (Ltk.). Whether the last-named one is a genuine Achino- metra cannot be decided for the present, as only naked tests and loose spines are known. The other species agree in the main features, also with regard to pedicellarize and spicules; so there is no reason to enter into details with regard to the separate species, only a few features characteristic of the genus are to be mentioned. A primary tubercle is found on all the ambulacral plates; no ocular plate reaches to the periproct in Ech. oblonga and viridis, while in lucunter generally one plate, rarely two or none at all reach to it. The buccal membrane contains numerous large, but fine fenestrated plates, almost all without pedicellaria. Spines on the buccal plates. The globiferous pedicellarize have one unpaired, strong lateral tooth, as Perrier has pointed out, and he has figured it in an excellent manner!). There is no neck; the stalk is compact. In £. od/onga is found the peculiarity that the stalk has a joint in the middle; in £. van Brunti the globiferous pedicellarize are very small, but otherwise of the common form. The tridentate pedicellarize are narrowly leaf-shaped with little developed mesh-work (see Rev. of Ech. P]l. XXVI. Figs. 9, 12—13); in van Brunt: they are of a quite different form, short, narrow, a little widened in the point, and the blade quite filled by a complicate mesh-work (Pl. XIX, Fig. 21). The ophicephalous pedicellarize with a rather strong mesh-work, a little different in form, although upon the whole of the common structure; the triphyllous pedicellarize of the common form. The spicules bihamate. The genera /Veterocentrotus, with the species mamillatus (Klein) and ¢rigonarius (Lamk.), and Colobocentrotus, with the species atratus (L.) and AZertensi Br. are most nearly allied to Lchinometra, as is commonly supposed; the globiferous pedicellarize and the spicules are chiefly as in this genus. A primary tubercle is found on all the ambulacral plates; no ocular plate reaches to the periproct. The buccal membrane with numerous fenestrated plates several of which carry pedicellarize and small spines as the buccal plates. The gills are in //eterocentrotus uncommonly well provided with fenes- trated plates some of which even carry (triphyllous) pedicellarize; rather numerous small bihamate spicules are also found among the fenestrated plates. In Colobocentrotus fewer fenestrated plates are found, but also here they carry triphyllous pedicellaria. — Only in these two genera I have seen this peculiar feature that pedicellarie are found on the gills. — In Colobocentrotus the globiferous pedicel- larize are quite small and placed quite down among the flat spines on the abactinal side; the edges of the blade not connected by cross-beams (Pl. XIX. Fig.s5). The stalk is curved. (In C. Mertensi I have not seen the globiferous pedicellarie.) Of the tridentate pedicellarie in Heterocentrotus Agassiz (Rev. of Ech. p.665) has the remarkable expression that «the tridactyle pedicellariz are of the type called trifoliate». I do not understand the sense of this expression; otherwise a rather good figure is given of these pedicellarie in 77. mamullatus (XXVI. Fig.2). There is a striking difference between the tridentate pedicellariz in mamzllatus and trigonarius. In the former (Pl. XIX. Fig. 15) the blade is narrow in the lower part, widened at the point, with a pair of rather projecting corners; the valves only join at the point, and are otherwise wide apart; in ¢rzgonarius the blade is of the common leaf-shape (Pl. XIX. Fig. 35), with no widening at the point, and the valves join through their whole length. In both of them the edge is very slightly serrate, but there are some larger indentations in the narrow part of those of mamzllatus. Perrier (op. cit.) thinks that several Heterocentrotus-species t) Rech. sur les Pédicellaires ete. Pl. VI. The Ingolf-Expedition. IV. r. 17 130 ECHINOIDEA. I. may be distinguished by the pedicellarize; after the material before me I must agree with Agassiz that only two species can be distinguished: mamillatus and ¢rigonarius. But then these two species may immediately be recognized by their tridentate pedicellarize (besides by the characters stated by Agassiz |Rev. p. 427 seq.|). The tridentate pedicellarize in Coloboc. atratus are very similar to those of /71. trigonarius; the valves join through their whole length (Pl. XIX. Fig. 1); in C. dertensii I have not succeeded in finding these pedicellarie. The ophicephalous and triphyllous pedicellarize of the common form. The spicules are bihamate; in AWeferocentrotus they are exceedingly numerous as well in tube feet as pedicellarize, in Colobocentrotus they are very few in number. Of the forms referred to «77iplechinide» we have still left Phymosoma crenulare Ag. Hemt- pedina cubensis Ag. and mirabilis D6d. None of these forms I have been able to examine, so that their place must for the present remain undecided. We may, however, draw same conclusions from the existing descriptions. Of Phymosoma Agassiz figures valves of globiferous and tridentate pedicel- lariee (Rev. of Ech. Pl. XXV. 4, 5) from which is seen that no lateral teeth are found on the globiferous pedicellarize; whether a neck is found or not is not mentioned. The spicules are not known. A peculiar feature is seen from the figures given by Agassiz (Rey. Pl. VII. a.f. 6, 8, 9), viz. that the pores form arcs with alternately two and three pairs. As the figures cited are photographs, there can be no doubt of their correctness, although Agassiz, as far as I can see, does not mention this fact. This peculiar feature together with the crenulate tubercles renders it undoubtful that this form has nothing to do with the genuine Echinids. Pomel (324) puts it down as the only recent representative of «Les Phymosomiens», and readopts the name of Glyftocidaris, by which it was originally described by Agassiz. I shall express no opinion whether it really is to be classed with «Les Phymosomiens», partly because my knowledge of these fossil forms is too small, partly because upon the whole I am rather sceptical with regard to the possibility of referring with certainty the recent forms to the fossil ones. Accordingly I agree with Pomel that the name of G/yffocidaris must be readopted for this form, as the name of Phymosoma has originally been used of fossil forms. Of Hemipedina cubensis Ag. are figured (Rev. of Ech. Pl. III. f6—7) a tridentate pedicellaria and a smaller one which is stated to be a young tridentate pedicellaria, but which is rather a globi- ferous or ophicephalous one; neither is given with sufficient details. The spicules are not known. The perforated tubercles show, however, that this form has nothing to do at all with the other « 777p/- echinide», Agassiz says himself that it is a Pseudodiadematid, but to refer all Psewdodiadematide to Triplechinide» is by no means admissible, so much the less as these « 77iplechinide» prove to be so heterogeneous that the genera referred thither must be distributed to three different families. Pomel (324) refers it to «Les Pediniens» as the only recent representative, and he readopts the name of Cenopedina by which Agassiz has originally described it. With regard to the name I must agree with Pomel for the same reasons as stated above under Glyptocidaris crenularts. 1 shall not contest that the referring to «Les Pediniens» is correct, but I must regard it as certain that it has nothing to do with « 7riplechinide». Having thus given a natural grouping of the species I shall have to treat the question of the grouping of the numerous genera. That the systems mentioned above, which are chiefly based on the number of the pairs of pores, give no impression of the real relation of the forms need not to be ECHINOIDEA. 1. 121 pointed out more nearly. By an interpretation of the genera so confused as has been the case here, it is of course impossible to have a clear understanding of the relation between them. Of the char- acters hitherto used any greater importance can only be attributed to one, viz. the deep slits in the test (Troschel, Pomel). The genera with deep slits in the test prove to be all closely allied. But this character is no quite reliable one; partly it is a matter of degree whether a slit is deep or not, and especially there is the unfortunate circumstance that the slits are always small in young’ speci- mens, also in the species where they are deep in the adult ones; partly forms are found with small slits, which are, no doubt, most nearly allied to those with deep slits (Gynnechinus). Then we have left no other characters than the pedicellarize and the spicules, but they prove also to be excellent. Of the pedicellarize only the globiferous ones can be used for the grouping of the genera; the other pedicellariz are upon the whole very similar in all the forms treated here. The simplest form of globiferous pedicellarize is evidently the one found in Parechinus; the blade is open, the edges are not connected by cross-beaims, not thickened, and project in two or more rather long teeth on either side. A quite similar form is found in Loxechinus, only here a short neck is found, while Parechinus has no neck. — This form of pedicellarize is only found in these two genera which form accordingly a separate group; they are very similar as to habitus, so that nothing seems to be found that might prevent a putting together of them. — A somewhat more complicate form is found in the genera Echinus and Sterechinus. The edges of the blade are thickened, and are (with a single exception: Sterech. horridus and |rarely| Ach. Alexandri) connected across the inside by more or fewer cross-beams. One or more lateral teeth are found on either side, most frequently there is a tendency to obliquity in the outer end of the blade, just below the end-tooth, and frequently there are two teeth on the stronger, a little projecting edge, and only one on the other, more straight edge. This form of pedicellariz is only found in the two mentioned genera, and so they evidently form another group; also the forms belonging here show considerable similarity as to habitus. — A simular form of pedicellarize is found, however, in one more genus, viz. Paracentrotus; also here the edges are thickened, with a tooth on either side, but they are not connected across the inside of the blade. It seems that this genus, which is polypore and, with regard to habitus, very different from the other genera mentioned here, must be interpreted as a somewhat farther relation of Achznws and Sterechinus. In all these genera only simple bihamate spicules are found. From these forms the development goes in two diverging directions: complete reduction of all the lateral teeth, or strong development of the one unpaired lateral tooth. In Psammechinus, Toxo- pneustes, Gymnechinus, Tripneustes, Spherechinus, Pseudoboletia, and Pseudocentrotus all lateral teeth have disappeared, and the blade has become quite closed, tubular. Besides all these genera are distin- guished by having small, thick, more or less dumb-bell-shaped spicules. There can be no doubt that they form a separate group. The three first have regularly trigeminate pores, in 77ipmeustes the young individuals have also regularly trigeminate pores, but in the adult the pore areas extend so much, that they look as if they were polypore; but they continue as a matter of fact to be oligopore. Spherechinus and Pseudoboletia are polypore, mostly, however, with four pairs of pores in each are. As the uppermost one in the series of development we find Pseadocentrotus with 5—6 pairs of pores where the pore areas are even somewhat petaloid on the actinal side. 132 ECHINOIDEA. 1. The same form of globiferous pedicellariz is found in Strongylocentrotus, Anthocidaris, and Parasalenia. The two former are distinguished by the globiferous pedicellarize having a well devel- oped neck, provided with circular and longitudinal muscles — an otherwise unknown feature. These three genera are likely to be rather nearly related; their spicules, however, show that the relation is not very close. In Strongylocentrotus the spicules are a little branched in the ends, but otherwise the original form is bihamate; in some species only (?) common bihamate spicules are found. In Anthocidaris the spicules are biacerate, pointed in both ends and with a branch in the middle. A somewhat similar form of spicules is found in Parasalenia; but in this genus the globiferous pedicel- larize have no neck. Thus this latter seems to form a special group; its obliquity and the peculiar anal plates indicate also that it must be interpreted as an aberrant form, of which the nearest, although not very near, relations are: Anthocidaris and Strongylocentrotus. In the genera Helocidaris, Echinostrephus, Toxocidaris, Echinometra, Heterocentrotus, and Colobocentrotus there is a strong, unpaired lateral tooth on the globiferous pedicellariz, and they have all simple bihamate spicules. elioc¢daris occupies a somewhat isolated position; its globiferous pedicellarize are not so much developed as those of the other genera, it reminds to a rather high degree of Sterechinus Neumayert, but especially of Pseudechinus albocinctus; several things favour the belief that Psewdechinws is really a transitional form between Sterechinus and //eliocidaris, and the latter leads on again to Zoxocidaris, Echinometra etc. Thus we have here a very fine series of development where, together with the peculiar develop- ment of the globiferous pedicellariz, a marked tendency to obliquity is seen, reaching the climax in the genera //eterocentrotus and Colobocentrotus. ‘There seems to be no occasion to separate these two genera as a special group on account of their longitudinal axis not being placed in the same direc- tion as in Lchinometra, because their pedicellariz and spicules are exactly agreeing with those of Echinometra. It is constantly seen that spicules and pedicellariz are the most important systematic characters, so that there is no reason for suddenly following a new principle here. The genera /seud- echinus, Heliocidaris, and Echinostrephus must then be interpreted as more or less primitive oligopore EKchinometrids. Stomopneustes occupies a quite isolated position; its globiferous pediceliarize and spicules are so peculiar and so different from what is found in the other forms mentioned here, that there can be no question of classing it with any of them; it forms a special group. The relation between these forms may most easily be surveyed in the following diagram. For safety’s sake I shall expressly remark, however, that I do not mean it to be regarded as a phyloge- netic one. I will in no way maintain that our Parechinus is the ancestral form of Achinus etc. but only express my opinion that it shows the simplest structure of the jorgans most important with regard to classification. We may in the recent forms scarcely find more than an indication of the way the development seems to have taken. Now there is unfortunately only a small chance of finding these fine structures in the fossil forms, so we shall hardly get so far as to be able with certainty to point out the ancestral forms. Otherwise this survey of the relations of the forms shows clearly that here is everywhere a tendency to increase the number of tube feet, a development from oligopore to polypore forms. The most original feature, no doubt, is that all the ambulacral plates are well deveioped with primary spine and three tube feet; then the primary spines disappear from every other ambulacral ECHINOIDEA. I. 133 plate, and these plates become much narrower than the others, but keep their three tube feet. his development is carried on in 7ripneustes and //eliocidaris, where the primary spine is wanting in more ambulacral plates after each other. By this development there is made room for far more tube feet than when all the ambulacral plates are typically developed and provided with a primary tubercle; but there are constantly only three tube feet for each compound ambulacral plate. The same end is reached by the fact that the ambulacral plates are made to consist of more than three primary plates, that they become polypore. In almost all the groups both oligopore and polypore forms prove to be found; only Parasalenta has no polypore relation, and in the Strongylocentrotus-group an oligopore form is still wanting. It may not be thought unreasonable to expect that such a one will be found: it is no far cry from S?¢r. pulcherrimus where only four pairs of pores are found. Pseudocentrotus Pseudoboletia Colobocentrotus Anthocidaris Strongylocentrotus Spheerechinus Heterocentrotus Tripneustes Echinometra ‘Toxopneustes Toxocidaris ‘ Gymnechinus Echinostrephus Parasalenia Psammechinus Heliocidaris = ———______ | Pseudechinus Paracentrotus Sterechinus Echinus Loxechinus Stomopneustes Parechinus The result of the studies of «Echinometrade» and « Triplechinide» represented here, is expressed in the following system. Fam. Stomopneustide n. fam. The spicules irregular, more or less tubular fenestrated plates. The globiferous pedicellaric without end-tooth') The stalk compact. Only one genus known. Stomopneustes Ag. The pores trigeminate. Only every fourth or fifth ambulacral plate with primary tubercle, but this tubercle is large and spreads over several ambulacral plates. The spines long and thick; small spines on the buccal plates. The buccal membrane with numerous fine fenestrated plates, quite im- bedded in the skin. The gills with numerous three-radiate spicules. A deep furrow along the median line in the interambulacral areas. 1) Perhaps here may be found, besides the large globiferous pedicellaria without end-tooth (and without poison gland?), a smaller form of globiferous pedicellaricee of the common structure. (See above p. 126). 134 ECHINOIDEA. I. Species: Sf. variolarts (Lamk.), atropurpurea Woods (?). Distribution: Indian Ocean, Australia. Littoral forms. Fam. Echinidee Ag. (emend.) Spicules bihamate. The globiferous pedicellariz with end-tooth and one or more lateral teeth on either side; no neck; the stalk consists of long, thin, loosely connected calcareous threads. Mouth slits small. Subfam. Parechininz n. subfam. In the globiferous pedicellariz the edges of the blade are fine, not thickened, and project into two or more teeth on either side. No cross-beams connect the edges across the inside of the blade. Genera: Parechinus, Loxechinus. Parechinus un. ¢. Pores trigeminate; primary tubercle on all the ambulacral plates. The buccal membrane with numerous fenestrated plates; they may be very large and thick, or finer and hidden in the skin. The globiferous pedicellariee without neck. Numerous short, greenish spines. Species: Parech. miliaris (Mull.), mecrotuberculatus (Blv.), angulosus (Leske). Distribution: In the Atlantic Ocean at the European coasts, the Mediterranean; the southern and eastern coasts of Africa; the Indian Archipelago, Australia. Littoral forms. Loxechinus Desor (emend.). Pores multigeminate; primary tubercle on all the ambulacral plates. The buccal membrane with numerous fenestrated plates. The globiferous pedicellarize with a short neck only containing longitudinal muscles. Numerous short, greenish spines. Species: LZ. albus (Mol.), ebbosus (Val.), bullatus (Bell). Distribution: The southern and western coasts of South America, the Galapagos Islands’), Littoral forms. Subfam. Echininge n. subfam. In the globiferous pedicellarize the edges of the blade are thickened and commonly connected by cross-beams across the inside of the blade. One or more lateral teeth on either side. Genera: Echinus, Sterechinus, Paracentrotus. Echinus Rond. (emend.) Pores trigeminate; primary tubercle on every or only on every other ambulacral plate. No ocular plate reaches to the periproct. The buccal membrane with numerous fenestrated plates imbedded in the skin both outside and inside of the buccal plates. The spines upon the whole long and strong; the actinal primary spines not curved at the point. Globiferous pedicellariz generally with the edges connected across the inside of the blade. The large, generally long and narrow, tridentate pedicellarize with thick edge upon which numerous small teeth are placed in transverse series or irregularly. ") The occurrence of LZ. a/éus at the Philippines and of g74éosus at the Fiji Islands needs corroboration. ECHINOIDEA. I. 135 Species: Ech. esculentus 1,, acutus Lamk., melo Lamk., elegans Ditb. Kor., gracilis Ag BY A lex- andrt Dan. Kor., luctdus Doderl., af/finis n. sp. atlanticus nu. sp. Distribution: The Atlantic Ocean, the Mediterranean, the Pacific Ocean. Littoral-archiben- thal forms. Sterechinus Koehler (emend.). Pores trigeminate; primary tubercle on every or only on every other ambulacral plate. The buccal membrane most frequently with numerous fenestrated plates inside of the buccal plates, outside of these it is almost or quite naked. Generally one or more (all) of the ocular plates reach to the periproct. The secondary spines often fine, silky; the actinal primary spines curved at the point (always?). The globiferous pedicellarize generally with the edges connected across the inside of the blade. The tridentate pedicellarize broad, leaf-shaped; the edge not thickened, only with a single series of teeth. Species: .Sterech. margaritaceus (Lamk.), horridus (Ag.), Newmayert (Meissn.), magellanicus (Phil.). Distribution: The southern and western coasts of South America, the Antartic Seas. Littoral- archibenthal forms. Paracentrotus un. ¢. Pores multigeminate. Primary tubercle on all the ambulacral plates. The buccal membrane with fenestrated plates both inside and outside of the buccal plates (outside, however, rather few). None or 1—2 ocular plates reach to the periproct. The spines long and rather thick; the actinal ones not curved at the point. In the globiferous pedicellarice the edges are not connected by cross-beams across the inside of the blade. The tridentate pedicellarize long, narrow, without transverse series of small teeth. Species: Paracentr. lividus (Lamk.), Gaimardi (Blainv.). Distribution: The Mediterranean and the adjoining Atlantic coasts. Brazil. — Littoral forms. Fam. Toxopneustide Troschel (emend.). The globiferous pedicellarize with end-tooth, but without lateral teeth; the edges of the blade quite coalesced on the inside, so that the blade is tubular. Peculiar dumb-bell-shaped or somewhat branched spicules are generally found in the globiferous pedicellariz and often also in the tube feet; bihamate spicules are generally also found; in one form (S¢rongylocentrotus pulcherrimus) only biha- mate spicules are known. Generally 1—2 ocular plates reach the periproct. Subfam. Schizechininze Pomel (emend). The spicules in the globiferous pedicellarize dumb-bell-shaped or small bows not pointed at the ends. Generally deep slits in the test. The globiferous pedicellarize without neck; mostly with glands on the stalk. The stalk compact. Genera: Psammechinus, Gymnechinus, Toxopneustes, Tripneustes, Spherechinus, Pseudoboletia, Pseudocentrotus. 136 ECHINOIDEA. I. Psammechinus Ag. (emend.) (Synonyms: Lytechinus Ag., Psilechinus Vtk., Schizechinus Pomel.) Pores trigeminate; primary tubercle on all the ambulacral plates. Slits of the test rather deep. The buccal membrane with numerous plates forming a more or less distinct plate-covering. In the globiferous pedicellariz the blade is not much lengthened. The spicules dumb-bell-shaped, form no border round the globiferous pedicellarize. The spicules of the tube feet bihamate, not branched. The spines of a middle length, greenish. Species: Psammech. vartegatus (Lamk.), semiteaberculatus (Val.), verruculatus Ltk. Distribution: The eastern and western coasts of tropical America; the Indian Ocean. Lit- toral forms. Gymnechinus n. ¢. Pores trigeminate; primary tubercle on all the ambulacral plates. Slits of the test small. The buecal membrane, with the exception of the buccal plates, contains no fenestrated plates at all. In- most in the edge of the mouth more or fewer irregular, needle-shaped spicules are found; also numer- ous bihamate spicules are found, especially nearest to the edge of the mouth and the outer edge. In the globiferous pedicellarize the blade is not much lengthened. The spicules of the globiferous pedi- cellarize arcuate or slightly dumb-bell-shaped, form no border. Smaller, short-spined forms. Species: Gymncech. Robillard: (Loriol), darnleyensts (Woods)*). Distribution: Mauritius, Australia. Littoral forms. Toxopneustes Ag. (emend.). (Synonym: Loletia Desor.) Pores trigeminate; primary tubercle only on every other ambulacral plate. Slits of the test deep. The buccal membrane with numerous fenestrated plates most of which are quite imbedded in the skin. In the globiferous pedicellarize the blade is much lengthened. The spicules in the globi- ferous pedicellarize are typically dumb-bell-shaped and form a thick, white border round the outer edge of the valves; in the tube feet branched, bihamate spicules are found. Large, flat, short- spined forms. Species: 7) Arleolus (Lamk.), roseus Ag., elegans Déderl. Distribution: The Indo-Pacific Ocean. Littoral forms. Tripneustes Ag. (emend.) (Synonym: //ipponoé Gray.) Pores trigeminate; primary tubercle only on every third or fourth ambulacral plate. The pore areas very broad, so that the pores form three separated vertical series; in the small individuals the pores are placed in the usual manner in short arcs. The buccal membrane with numerous fenestrated plates most of which are quite imbedded in the skin. Slits of the test rather deep. In the globiferous pedicellarize the blade is not much lengthened; the pedicellarie upon the whole small and darkly pigmented. The spicules in the globiferous pedicellariz are typically dumb-bell-shaped; they form no border. The bihamate spicules in the tube feet are not branched. Large, high, short- spined forms. 1) Comp. above p. 110. ECHINOIDEA. LI. 7 Species: Zripn. esculentus (Leske), depressus Ag. gratilla (1). Distribution: Cosmopolitan in the warm zone. Littoral forms. Spherechinus Desor (emend.). Pores multigeminate (generally four in each arc); primary tubercle on all the ambulacral plates'). Slits of the test rather deep; the buccal membrane with rather numerous fenestrated plates; no spines on these or on the buccal plates. In the globiferous pedicellarie the blade is not much lengthened. The spicules of the globiferous pedicellarie small bows, not pointed at the ends; they form no border. In the tube feet branched, bihamate spicules are found. Large, short-spined forms, almost globular. Species: Spherech. granularis (Lamk.), roseus Russo, australie Ag. Distribution: The Mediterranean and the adjoining Atlantic coasts, Australia. Littoral forms. Pseudoboletia Troschel (emend.). Pores multigeminate (four in each arc); primary tubercle on all the ambulacral plates. Slits of the test rather deep. The buccal membrane with rather numerous plates carrying both spines and pedicellarize; spines are likewise found on the buccal plates. In the globiferous pedicellariz the blade is not much lengthened. The spicules of the globiferous pedicellarie small bows, not pointed at the ends; they form no border. The bihamate spicules in the tube feet are not branched. Large, high, rather short-spined forms. Species: Ps. zzdiana (Mich.), macelata ‘Trosch. Distribution: The Indo-Pacific Ocean. Littoral forms. Pseudocentrotus n. g. Pores multigeminate; primary tubercle on all the ambulacral plates. The pore areas some- what petaloid on the actinal side. Slits of the test rather small. The buccal membrane with numer- ous fine fenestrated plates; no spines on these or on the buccal plates. In the globiferous pedicellarize the blade is not much lengthened. The spicules of the globiferous pedicellarie bow-shaped, not pointed at the ends; they form no border. The bihamate spicules in the tube feet are branched. The spines rather long and strong; the test rather flat. Only one species known: Ps. depressus (Ag.). Distribution: Japan. Littoral form. Subfam. Strongylocentroting n. subfam. The spicules of the globiferous pedicellarice bihamate (always?), generally branched at the ends; no dumb-bell-shaped spicules, nor such as are not pointed at the ends. The globiferous pedicellarice with well developed neck with longitudinal and circular muscles; tubular stalk. Genera: Strongylocentrotus, Anthocidarts. Strongylocentrotus Brandt (emend.). Pores multigeminate; the pore areas not petaloid on the actinal side. Primary tubercle on all the ambulacral plates. The buccal membrane with numerous fine fenestrated plates most of 1) Not examined in Sph. australia. The Ingolf-Expedition. IV. 1. 15 138 ECHINOIDEA. I. which are quite hidden in the skin. The spicules bihamate, branched or unbranched. The test more or less flattened. The spines very different, from short and fine to long and coarse ones. Species: Str. chlorocentrotus Brandt, pulcherrimus (Barn.), tmtermedius (Barn.), drobachiensis (O. F. Miill.), pzerperatus Stimps., /raciscanus (Ag). Distribution: The Northern Atlantic, the Arctic Ocean (dvobachiensis); the Northern Pacific Ocean (all the species). Littoral forms. Anthocidaris Liitken (emend_.). Pores multigeminate; the pore areas somewhat petaloid on the actinal side. Primary tubercle on all the ambulacral areas. The buccal membrane with numerous fine fenestrated plates most of which are quite hidden in the skin. The spicules in the tube feet biacerate, a little curved, with a rather strong point in the middle of the convex side. The test somewhat flattened, the spines rather long and strong. Only one species known: