el Rane eat amc cecansinecancanan in oe Stet a Tee Nay . SAA aap CAO NON i HSM ; he th ui Ca: Riel POAT 3 i e i we er) oe * wi. re at & ’ T ¥ . (he » i a“ * ’ e ‘ ] ’ + i ‘ * * * ” ¥ * * * 1 dpe a — v= ——— et ee ey Ie Eee, VOLUME Iz. pau v— -- PRINTED BY. i ae SPOTTISWOODE AND CO., NEW-STREET SQUARE ‘LONDON TET ROTIFERA - OR ert a A NEM Aa © Una Ss BOTH BRITISH AND FOREIGN. BY ©. T. HUDSON, LL.D. Cantas., F.R.S. ASSISTED BY PP He GOSSE, EES: IN TWO VOLUMES, WITH SUPPLEMENT. VOLUME IL WITH ILLUSTRATIONS. LONDON : LONGICANS: GHhiLEN, AND: © 0: AND NEW YORK: 15 EAST 16 STREET. 1889. SMITHSON any SEP 23 1986 All rights reserved Those viewless beings, Whose mansion is the smallest particle Of the impassive atmosphere, Enjoy and live like man: And the minutest throb, That through their frame diffuses The slightest, faintest motion, Is fixed, and indispensable, As the majestic laws That rule yon rolling orbs. SHELLEY. Qui curiosus postulat totum suse Patere menti, ferre qui non sufficit Mediocritatis conscientiam sue, Judex iniquus, estimator est malus Suique natureque; nam rerum parens, Libanda tantum que venit mortalibus, Nos scire pauca, multa mirari jubet. GRorIus. CONTENTS OF TAS ene. O NE DS VOR EW Mic ——20 G00 — CHAPTER IX. PLOIMA (IL-LoRIcATA—continued) —. 5 j F : ‘ a CHAPTER X. PLOIMA (LORICATA) : : : . ; : _ 57 CHAPTER XI. SCIRTOPODA . : : : ; ; : ; : 5 be) ADDENDA. 2 : : : é : ; : 134 APPENDIX: THE VASCULAR SYSTEM . : F : : 5 GR 7 THE SETIGEROUS SENSE-ORGANS. : : . 139 BIBLIOGRAPHY OF THE ROTIFERA . ‘ ‘ ‘ . . 140 INDEX . . . . . . ° . . oo 4s CHAPTER IX. PLOIMA IL-LORICATA—continued.) hb Les actions des bétes sont peut-étre un des plus profonds abimes su quoi notre raison se puisse exercer; et je suis surpris que si peu de gens s’en apercoivent.—BaAYLE. Their good is good entire, unmixed, unmarred ; They find a paradise in every field, On boughs forbidden where no curses hang: Their ill, no more than strikes the sense, unstretched By previous dread, or murmur in the rear; When the worst comes, it comes unfeared; one stroke Begins and ends their woe.—Youna. CHAPTER IX. Family VIII. TRIARTHRADA. Body furnished with skipping appendages ; corona transverse ; ciliary wreath single, marginal ; foot absent. The four genera which form this family resemble each other in one striking particular. Each bears spines, or moveable appendages, by means of which the creature can leap through the water. These spines have no connection with the body-cavity, though they are moved indirectly by the usual longitudinal muscles; which, in sharply withdrawing the head, throw the spines forward. In one genus, Pteroessa, which is known only by its lorica, the spines are very numerous, and are of two distinct patterns; in another, Polyarthra, they are clusters of blades borne upon the shoulders ; in the remaining two, Triarthra and Pedetes, there is only one simple spine on each shoulder, but Triarthra carries also a similar spine on the posterior ventral surface. All the genera are more or less loricated. In Pedetes the skin bears hard knobs for the attachment of the spines, while Triarthra has it stiffened chiefly round the edge below the neck. Polyarthra is semi-loricated; the dorsal surface is very tough and there is a still harder shield on each side between the dorsal and ventral surfaces. The ventral surface, however, is soft and membranous. In all, the longitudinal muscles are highly developed, and coarsely striated. The genera differ in their trophi. Triarthra has the malleo-ramate trophi of Melicerta ringens ; in Pedetes the trophi have not been clearly defined; while Poly- arthra, widely unlike either, has a mastax and trophi closely resembling those of Syncheta. Polyarthra, moreover, is still further separated from Pedetes and Triarthra by haying one occipital eye, instead of two frontal. Genus POLYARTHRA, Ehrenberg. GEN. CH. Spines in clusters on the shoulders; eye single, occipital; mastax very large and pear-shaped ; trophi forcipate. It is not easy to decide in which family the genus Polyarthra should be placed. Its mastax and trophi are almost exactly those of Syncheta; its corona bears styligerous prominences similar to those of S. pectinata; its ciliary wreath is marginal and single, though not broken up into curves ; and, like Syncheta, it possesses but one occipital eye. On the other hand its skipping spines naturally place it with Zriarthra and Pedetes, which genera it further resembles by its lack of foot, by its habit of carrying its eggs, and by the partial stiffening of its skin into an imperfect lorica. P. puaAtypTERA, Hhrenberg. (Pl. XIII. fig. 5.) Polyarthra platyptera' A - Ehrenberg, Die Infus. 1838, p. 441, Taf. liv. fig. 3. 59 “5 0 0 Leydig, Ueb. d. Bau d. Réiderth. 1854, p. 42, Taf. i. fig, 10. ” oy : 7 Gosse, Phil. Trans. 1856, p. 435, pl. xvii. figs. 44-49. 2 i F " os Pe 3 1857, p. 320, pl. xy. figs. 27-29. 5 s : ; Plate, Jenaisch. Zeits. f. Natur. 1885, p. 16, Taf. i. fic. 4. 1 Ehrenberg’s P. trigia is possibly P. platyptera with the blades seen edgewise. B2 4 THE ROTIFERA. SP. CH. Spines twelve broad blades with serrate edges. When gliding along under the action of its ciliary wreath Polyarthra seems to have a triangular outline; for the body, though itself truncated both in front and rear, carries four clusters of serrated blades fastened to the shoulders; and these trail behind so as nearly to meet in a point, at some distance from the animal’s body. Every now and then the blades are jerked vigorously forward, and the creature is tossed out of its path, several times its own length. The trunk is partially loricated. There is a kind of chitinous shield running down each side of the body, pointed at its hinder end, and bent at the sides so as to encroach a little on the tough dorsal and membranous ventral surfaces. The edge of the dorsal lorica (if it may be so termed) is plainly visible run- ning across from one cluster of blades to the other. A pair of powerful striated muscles, forming a letter V, is fastened to the lower pointed end of the shield, and to the inner surface of the soft tissues, to which, at the upper end on each side, six of the blades are attached. The contraction of these V-shaped muscles drags the soft tissues sharply down over the hard edge of the shield, and makes the blades fly out with great swift- ness. The blades are curiously like a bird’s feather in general outline (fig. 5d), having a midrib (fig. 5e) and being distinctly serrated on both edges. The corona is slightly convex and bears, towards the dorsal surface, two prominences like those of Syncheta pectinata, each carrying a brush of styles. There are also two long styles facing these, and springing from the corona towards the ventral surface. Mr. Gosse has, moreover, noticed, besides these tactile organs, a small occipital pimple armed with bristles. The very large mastax points obliquely downward to the ventral surface. Both it, and its trophi, closely resemble those of Syncheta pectinata. The contractile vesicle can be easily seen, but neither lateral canal nor vibratile tags have been recorded. Nothing else in its internal structure requires notice.! The animal carries the great female egg singly, and transversely, between the points of the two side shields ; but the small male eggs in clusters of half-a-dozen or more at a time (fig. 5b). The male was discovered by Mr. Gosse in 1850, and described and figured by him in the ‘*‘ Phil. Trans.” for 1856. [Its length is only 31, inch. The head is very large (fig. 5h) and the body tapers quickly to the posterior part, but both extremities are truncate. The front bears two warts between which the rotatory cilia are placed, but the cilia are longer (perhaps sete) on the warts. The hinder part is bifid, the smaller division being the caudal extremity or toe-less foot, and the latter a protrusile truncate penis ciliated at the tip. No internal organization was discoverable.—P.H.G.] Dr. Plate’s figure (loc. cit.) shows the sperm-sac. Length. Female’s body, 5}, inch. Habitat. Pools and ponds: common. Genus PTEROESSA, Gosse. (GEN. CH. Loriea entire, save for a large oval opening behind; beset with arti- culate pinnate styles, and simple sete: foot wanting. P. surDA, Gosse, sp. nov. (JzAk, 2COOLS rakes, {8),)) SP. CH. The only known species. Horny yellow; pinne twenty-four, im sia longi- tudinal rows. The form of this remarkable species is that of an ancient amphora; a long oval tapering to an obtuse point, with no foot, forming a constricted neck, in front, and thence An observation of Mr. Gosse’s Jeads him to think that the rectum is turned far forward as in the Fihizota; and that it is capable of considerable protrusion, though ordinarily invisible. TRIARTHRADE. 5 expanding to a broad truncate margin. Behind there is a great ovate opening, as if a slice had been cut off the entire breadth from the middle to the extreme point. Doubt- less this, in life, is covered with membrane, and its edge is thickened. From the upper margin rise two short sete, jointed to knobs; while from the breast, exactly opposite, there issues another, similarly jomted but of great length, descending far behind the extremity of the body. But the chief peculiarity of the creature is that four-and-twenty styles, regularly arranged, are affixed to the lorica, giving a most unique aspect to it. For every one isa feather in appearance ; the shaft, moderately long and stout, being beset, on its two opposite sides, with regular pinnules like those of a fern (Polypodiwm, for instance), in considerable number, length, and regularity (fig. 9c). These pinne are arranged in six longitudinal rows, three on each side, on the ventral aspect, the middle pair of rows consisting of six each, the next pair four, and the outmost two, each. The shaft of each is evidently articulated on a knob of chitine, which is itself a tubercle on a some- what larger round knob, set in a commensurate orifice in the lorica,—apparently moving freely in it, a true “ ball and socket” joint, worked doubtless by proper muscles within. Thus, adding the three simple styles, which are similarly based, we have here a wonderful array of exterior articulate members, which well illustrate the claim of the Rot1rEra to a place among the ARTHROPODA. The pinnules vary much in their number, their length, and the angle of their expansion. The body ends in a blunt point, with no foot, nor other appendage. The anterior extremity, beyond the marked neck, is short, some- what inclined toward the back, truncate, with an orifice as wide as the widest part of the trunk. Through this, of course, the head is protruded during life; but of this, and of the whole internal organization, I can give no information. The specimen which came under my observation was an empty lorica, in good preservation, as if recently dead, which I was enabled to revolve under the microscope, and so to examine in several aspects. The whole lorica was of a dark yellow-brown hue, with a dull translucency like that of a smoky horn lantern: but whether this is specific, or only accidental, I cannot tell. This most curious form occurred in the sediment of a bottle of water, examined on October 20, 1885, but which had been standing on my table since September 23, when I had received it from Mr. Hood with a colony of Scaridiwm eudactylotum. From the condition of the lorica I have little doubt that 4t had come to me alive ; but being occupied with the new Scaridiwm I did not search closely.—P.H.G.] Length. Of lorica, +1, inch ; to tips of pinne, ,), inch; from brow of lorica to tip of ventral seta, 7, inch. Habitat. Loch near Dundee (P.H.G.). Genus TRIARTHRA, Hhrenberg. GEN. CH. Spines single, two lateral, one ventral; eyes two frontal ; mastax of moderate size ; trophi malleo-ramate. There are three known species of this genus, and they resemble each other very closely ; the main points of difference being the length of the leaping-spines, the distance between the eyes, and the length of the esophagus. The first of these characters is one that cannot be much relied on except in the case of 7’. breviseta; for the length of the spines varies very much in the same species. Ehrenberg makes a further point of difference, in the presence or absence of any well marked separation between the stomach and intestine, asserting that 7’. longiseta possesses this separation and that 7’. mystacina lacks it. This, however, is a character of small value, for the same animal will show at one time an undivided alimentary canal; and, at another, one sharply diyided into in- testine and stomach. 6 THE ROTIFERA. T. Lonetsera, Hhrenberg. (Pl. XIII. fig. 6.) Triarthra longiseta ¢ : Ehrenberg, Die Infus. 1838, p. 447, Taf. lv. fig. 7. i 4 : ; Hudson, Mon. Micr. J. vol. i. 1869, p. 176, pl. vi. ” ” . 5 5 Grenacher, Sieb. uw. Koll. Zeits. Ba. xix. 1869, p. 491, Taf. XXxvii. fig. 3. SP. CH. Body oval; buccal orifice prominent but not beaked, cup-shaped ; spines more than twice the length of the body; eyes wide apart; esophagus long. The habit of this interesting creature is to swim slowly forward while turning round its longer axis, and every now and then to dart out of its course by jerking forwards the three long spines which usually trail behind it. The corona is oval, and bears in its centre one broad, low prominence, with a smaller one on either side of it; and just within each of these latter is placed a red eye. The buccal orifice is cup-shaped and has its inner surface lined with cilia. The buceal funnel slopes backwards and upwards towards the dorsal surface to meet the mastax, whose trophi are almost identical with those of Melicerta ringens. The cesophagus is long and narrow, and the stomach and intestine are usually separated by a deep constriction. The gastric glands (fig. 6a) are curiously shaped, and frequently studded with what appear to be oil-globules. The vascular system is delicately transparent, and difficult to be seen. Ihave traced the lateral canals on each side, for some distance down the trunk, from a plexus of tubes in the neck, and have detected just there a vibratile tag. I failed to discover the contractile vesicle, but Dr. Grenacher (loc. cit.) has seen it, in its usual position, close to the cloaca. There isa large ovary ; and the newly laid eggs remain attached to the parent by a thread for some time after their exclusion. The ephippial eggs (fig. 6/) are as curious in shape as the gastric glands, and are protected by a thick layer of yellowish transparent cells. By bringing into focus the central inner portion of the head, seen sidewise, a bluish and roughly rhomboidal mass may be observed; this is the nervous ganglion, and above it are the eyes, and from it threads extend to a setigerous fossa in the neck, as well as to rocket-headed antenne, one on each side (fig. 6e) just under the surface. Hach eye (fig. 6b) is a clear, colourless, refracting sphere ;,!;) inch in diameter, resting on, and partly imbedded in, a flat plate of red pigment. The longitudinal muscles are very powerful, and are strongly striated; the strie not being straight transverse lines, but irregular obliquely transverse curves (fig. 6c). Indeed they appeared to me to alter both in direction and in size as I looked at them, giving me the impression that I was looking at illusory striw, produced possibly by looking through separated sheets of striated fibre, lying over each other. There is an unusually powerful muscular collar running round the neck. The spines are stiff quill-like appendages, broadest at their attached bases, and tapering at their free ends. The bases (fig. 6d) are like quills that have been obliquely cut across, and it is by these cut surfaces that they are attached, one on each side of the corona, just above the neck; and one on the yentral surface, at the spot from which the foot springs, in those Rotifera that possess one. The spines are notched here and there (fig. 6d), and finely imbricated towards their tips. On looking at fig. 6, it will be evident that if the muscular collar round the neck be suddenly contracted, and the head withdrawn, the spines will be first dragged across the stiff edge of the trunk, below the collar, and then jerked forward by the downward pull of the head. How the third spine is moved is not so clear. Dr. Grenacher suggests that it is dragged forward by the other two, which are often crossed beneath it; but adds that this is a forced explanation. It is probable, I think, that this spine is driven forward by the sudden jerk downwards on its base, when the longitudinal muscles sharply com- press the stif¥ ventral cuticle. Fine muscular fibres surround the trunk at regular TRIARTHRAD AS. 7 intervals, and unite with the broad band round the neck in driving out the retracted head, and restoring the spines to their usual position. Length. Without the spines, ;}, inch. Habitat. Fresh-water ponds and ditches : common. T. mysracina, Hhrenberg. (Pl. XIII. fig. 8.) Triarthra mystacina : 5 : Ehrenberg, Die Infus, 1838, p. 447, Taf. lv. fig. 8. (SP. CH. Body oval; buccal orifice taking the form of a beak projecting from the face ; spines not twice the length of the body ; eyes approximate ; esophagus invisible. In July 1849, from the ditch at Dalston Causeway, near London, I took several of the Whiskered Three-beard. The moderate length of the leaping spines, the approxi- mate eyes, and the absence of any manifest cesophagus—the stomach coming into contact with the mastax—marked the species as Hhrenberg’s mystacina. The absence of the cesophagus is doubtless only apparent, this duct, as is the case with Polyarthra (see Pl. XIII. 5c) and many other Rotifera, issuing from behind the mastax, near its summit. One adult had an egg attached to the hind extremity, which somewhat retarded its motions, as compared with those of its fellows. After a while the spontaneous move- ment of the embryo became more and more vigorous, and the ciliary rotation energetic ; and a clear globule, as of air, was seen within, while yet the egg remained adherent. The front is formed of a ring of six or seven sub-globose masses, in mutual contact, each of which is crowned by a cluster of divergent cilia. The chin descends in a promi- nent hook, like a parrot’s beak, which appears stiff, and projects between the bases of the two pectoral spines. The two eyes are nearly frontal, small, bright red, and approximate. The mastax appears formed on the plan seen in the Bdelloida. ‘he stomach is large and saccate, and is supplemented by a distinct intestine. The animals are very subject to be infested by two species of Colaciwm, which are seen in fig. 8. They cling to its spines as well as its trunk, and appear to give it uneasiness. I have counted sixty-five of these parasites on one individual, and nearly fifty on another. The animal seems to have no power of affixing itself, or of resting. It swims con- stantly; interrupted only by its spasmodic jerks or leaps, performed by the sudden throwing out of the elastic spines, chiefly, I think, the pectoral pair. These are articulated to shelly knobs, which imply a solidifying of the integument around their bases, to supply the necessary resistance. In the act of springing, these two are often shot forward so forcibly as to be projected in front, reminding us of the anal bristles in Podura. This is done with a rapidity that the eye cannot follow; and this, through so dense a fluid as water, requires the exertion of great muscular power.—P.H.G.] Length. To tips of sets, ,4, inch. Habitat. Around London: ditches and orna- mental waters (P.H.G.). T. BREVISETA, Gosse. Triarthra breviscta . : Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 200. (SP. CH. Body cylindrical; breast projecting, but not beaked ; spines not one- fourth as long as the body. This species is more regularly cylindrical than the others; it is diminished toward the front, which is truncate; the hinder end is yentricose, and extends much beyond the base of its spine; the belly is deeply suleate, with thick collops of the skin between ; the breast forms a great rounded projection, but not a beak. Just beneath this is a constriction, where the very short spines are set, each not more than half the body's width in length, very slender. The whole head can be retracted as far as this, by which involution of the skin the spines point straight forward, reverting to their normal diree- 8 THE ROTIFERA. tion as the head emerges. The animal has no power of springing by means of the spines, or of using them in any appreciable manner. The hind spine is similar, and similarly set in a deep sulcus of the lower belly. All are dilated at their bases. At the very front are two minute but distinct red eyes, side by side, seated on a small brain-mass, which tapers into a thread that passes to the occiput, probably to an antenna, not detected. The mastax was obscure, but seemed of the Bdelloid pattern. A very slender but long esophagus leads to a vast sacculate alimentary canal, and this to a cloaca at the very point of the body, behind the spine; which hence, Herr Grenacher’s judgment notwithstanding, I conclude to represent the foot. A momentary action, like that of a contractile vesicle, I perceived, but could not define one; and lateral canals run down each side. Several muscles are discernible. The animal is vivacious, swimming freely and swiftly; I did not see it attempt to spring, nor to crawl; the foot-spine was not whisked about. I first met with the species in a pond in Holly Walk, Leamington, in July 1850; and again lately in water from Keeper’s Pool, Birmingham, sent me by Mr. Bolton.—P.H.G.] Length, ;}, to ;}, inch. Habitat. Warwickshire pools: rare (P.H.G.). Genus PEDETES, Gosse. (GEN. CH. Body ovate, tailed ; toes absent ; eyes two frontal; two leaping styles articulated to the breast. P. sALTATOR, Gosse, sp. nov. (Pl. XIII. fig. 10.) SP. CH. Leaping styles thrice the length of the body. This genus has a very close relation to Triarthra. It may, indeed, be described as a Triarthra with the posterior style wanting. The body, though apparently soft and flexible, must be considered as enveloped in a lorica, since the knobs to which the styles are articulated, are hard, immoyeable, and doubtless chitinous. Its form, viewed dorsally, is ovate, obtusely pointed behind and broadly truncate in front. Viewed laterally (fig. 10a), it is flat on the ventral, and strongly arched on the dorsal surface. The dorsum rises to a marked conical elevation which is a true tail, for the cloaca opens between it and the foot. The latter (or what represents it) is a small ovate terminal member, within which, close to the tip, is a minute vesicle, possibly the contractile bladder. The rotatory cilia are seated on a number of small projecting eminences, with which the front is beset. On each side of what for convenience sake we call the breast, but rather high up, is a large round shelly knob, apparently hard and immoyeable. Dr. Hudson (‘‘M. M. J.) long ago explained the action of the pectoral styles in the parallel case of Triarthra (see T. longiseta, p. 6). We may conclude the mechanism to be the same in both cases; but I am inclined certainly to see more than mere mechanical action in these shelly knobs, viz. special muscles for the forcible and definite motion of the styles, by means of a true (perhaps ball and socket) joint. Hach style is a highly elastic rod, thick at its origin and for a considerable distance, then gradually tapering to a great attenuation, about thrice as long as the body. On the tips of these, which must therefore possess remarkable firmness, the animal, now and then, suddenly jerks itself away, as on a leaping-pole, with great force ; so that they are in an instant seen stretching out at a right angle, or even more, forward. These leaping-poles are composed of transparent refractive material (chitine), resembling glass in appearance. The brain has not been defined; but two eyes, of a translucent red hue, near together, are conspicuous at the very front. The mastax, far down in the body, with vigorously working mallei, was visible near the middle; and below this a great globose, sac-like alimentary canal, without visible division. The only specimen I have seen occurred in HYDATINADAL. 9 a tube, rich in Rotifera, sent me by Mr. Bolton in the autumn of 1884. It had become, in the live-box, accidentally entangled in a small mass of tenacious mucus, which evidently annoyed it, and from which it made vigorous but ineffectual efforts to become free. I have never met with the form since.—P.H.G.| Length of body (without styles), about +} inch. Habitat. A pool near Birmingham (EEEG:): Family IX. HYDATINADA. Corona truncate with styligerous prominences ; ciliary wreath two parallel curves, the one marginal fringing the corona and buccal orifice, and the other lying within the first, the styligerous prominences being between the two ; trophi malleate ; foot furcate. Ehrenberg’s very extensive family of the Hydatinea, under the name of Hydatinade, is here restricted to three genera, viz. Hydatina, Notops, and Rhinops. ‘They are all alike in their corona, ciliary wreaths, and trophi, but differ from each other in their shape, eyes, and foot. The head is truncate with a deep cup-like cavity as it were scooped out of it. This cavity lies more towards the ventral surface than the dorsal, so that a transverse slice would be horseshoe-shaped, the bend of the horseshoe being to the dorsal surface. The principal wreath fringes the outer edge of the cup’s wall, and the secondary wreath borders the inner; both wreaths are continued down into the buceal orifice, which lies just within a deep notch in the wall of the cup on the ventral surface. Styligerous prominences rise in the space between the two wreaths, except in the case of Rhinops ; and in this genus the dorsal side of the corona bears a thick proboscis, around the edges of which the principal wreath is continued. In their habits they in the main resemble each other ; for all but Rhinops tolerate even very dirty water, provided that it contains an abundance of the minute organisms on which they feed. Genus HYDATINA, Hhrenberg. GEN. CH. Body conical, tapering towards the foot; foot short, and confluent with the trunk ; eye absent. H. senta, Ehrenberg. (Pl. XIV. fig. 1.) Hydatina senta . ; 6 : Ehrenberg, Die Infus. 1838, p. 413, Taf. xlvii. fig. 2. A O 0 0 5 5 Cohn, Sieb. w. Koll. Zeits. Bd. vii. 1856, p. 436, Taf. xxiii. a +H a é 5 f Leydig, Miiller’s Archiv, 1857, p. 404, Taf. xvi. 5 + 3 F F A Hudson, Mon. Micr. J. vol. ii, 1869, p. 22, pl. xix. H. senta is one of the largest of the Rotifera, and its flashing styles, ruddy teeth, and yellow stomach, often stuffed with brilliantly green Euglene, make it a charming object for dark-field illumination. Its shape is conical, the corona being the base, and the toes the apex. When seen, however, from the side (fig. 1b), especially if a little arched, the separation of the head and foot from the trunk is distinctly visible. The styligerous prominences are semi-globular cushions crowned with long and rapidly vibrating styles, set fan-fashion. It is difficult to say how many cushions there are, owing to Hydatina’s incessant restlessness ; but there are probably ten or eleven. ‘Two are on the median line; one on the dorsal edge, and one between the first and the cavity of the head. The rest are arranged round the cavity in a sort of quincunx fashion ; mainly on the dorsal half of the corona. The great hollow in the corona is not only ciliated on its edge but 10 THE ROTIFERA. also on its whole surface, and may fairly be considered to be the buecal funnel. At its base, close to the ventral surface, lies the mastax, containing malleate reddish trophi with unci of four arrow-like teeth (fig. le). I have often seen these hand-like unci pro- truded into the funnel to grasp some desired morsel. ‘The thick cellular walls of the stomach are well seen in the young specimen (fig. 1a), in which a thin line of green food marks the hollow of the nearly empty stomach. The secreting and vascular systems are obvious and normal. A rectangular nervous ganglion (fig. 1) below the corona, and just under the dorsal surface, sends off a pair of nerve-threads at each corner. The upper pairs possibly ramify to the stylgerous prominences which are very sensitive ; and which Mr. Gosse has seen individually depressed below their usual position by mus- cular threads rising up to them from the depth of the head. One of the lower pairs supplies the two lateral antenne (fig. la, 1b), and the other two nerve-threads pass to the dorsal antenna (fig. 1b). The ovary in the half-grown animal (fig. la) is very transparent, and the oviduct is then conspicuous; as are also the fibres that tie the ovary to the body-walls. The male was described by Ehrenberg under the name Hnteroplea hydatina, as he was not aware of its sex. It is often to be met with among the swarms of females that haunt dirty farmyard ponds and neglected water-butts. Its general appearance is that of a young female, but it can be recognised at a glance by the absence of the mastax. Its internal structure is precisely like that of the male of Asplanchna pri- odonta, and is sufficiently shown in fig. 1. Disease.—I once found a few specimens of H. senta (fig. 1m) with what appeared to be the mycelium of a fungus growing in the perivisceral fluid, and loosely surrounding the various organs. The infected creatures, however, seemed as vigorous as the healthy ones. H. senta, too, suffers from an internal parasite. It is of a narrow oval form, about +4, inch in length, and swims up and down its host’s stomach by jerking the contents of its body constantly backwards and forwards (figs. 1,1). There are curious bodies inside the parasite itself something like the globe of a lamp in shape (fig. 1/). Length. From {5 inch to ,4 inch. Habitat. In water swarming with Huglene, &c. : common. Genus RHINOPS, Hudson. GEN. CH. Body conical, tapering to the foot ; along dorsal proboscis on the corona ; foot short, and confluent with the trunk, with two minute toes clesely pressed together ; eyes two, at the end of the proboscis. R. virrea, Hudson. (Pl. XIV. fig. 2.) Rhinops vitrea ; B ‘ ' Hudson, Ann. Nat. Hist. 4 Ser. vol. iii. 1869, p. 27, pl. ii. 9 Plate, Jenaisch. Zeits. f. Natur. Ba. xix. 1885, p. 46. ” ” Rhinops vitrea appears to have escaped notice till 1869, when I found it in a pond in Losely Park, near Guildford; so I suppose it must be rare: and yet I have often taken it in the neighbourhood of Clifton, and at times even in abundance. Though not a large Rotiferon, it is easily recognized with a hand-lens by its slow, deliberate way of swimming ; a peculiarity which first attracted my attention to it. Its shape is striking. It is a Hydatina without any styligerous lobes on the corona ; but bearing, in lieu of them, a unique prolongation of the dorsal surface into a sort of proboscis. ‘Two splendid ruby eyes are placed on the extremity of this proboscis, and its under surface is furred with cilia like the prone face of Adineta. The outer ciliary wreath is carried up each side of the proboscis ; but the tip between the eyes is free from cilia, and seems to act HYDATINADE. 11 as an organ of touch. The inner ciliary wreath consists of larger cilia which are some- times held erect. The esophagus is long and narrow, and the gastrie glands so irre- gularly conical, that they generally appear unlike ; probably owing to their being seldom presented to the eye from similar points of view. The nervous ganglion hasan unusual position. It lies near the end of the proboscis, and gives off, above, four parallel nerve- threads; the two outer of which pass to the eyes, and the two inner to the sensitive bare spot on the tip of the proboscis (fig. 2c). The rest of the internal structure is both obvious and normal. The young animal quits the egg while yet in the body of the parent, and may often be seen filling up a large portion of the body-cavity. The ephippial eggs closely resemble those of Conochilus volvox. Rhinops vitrea usually swims at a moderate pace, rolling gently round its longer axis as it goes, and every now and then bending back its proboscis, or turning somersaults as Syncheta pectinata does, only in a much more leisurely manner. Occasionally it darts forward ; and, at each time that it has done so, I fancied I could see the atom which it wished to secure. Then it glides over the stems of Alg@, using its long pro- boscis just as Adineta vaga does its ciliated face; and, when a larger atom than usual has been drawn into the coronal cavity, it compresses the broad flaps of the corona, and rounds the whole front of the body into a long ciliated tube.! Length, J, inch. Habitat. Clifton (C.T.H.): not common. Genus NOTOPS, Hudson. GEN. CH. Body not conical ; foot long and symmetrically placed with respect to the trunk, or short and wholly retractile within the ventral surface ; eye single, occi- ital. Si Of the three remarkable species contained in this genus, two, N. Brachionus and N. clavulatus, are strikingly alike each other, especially in the head and its ciliated protuberances, and also in the trophi. They are, however, curiously unlike in their outline, and in the relative length of the foot. The third species, N. hyptopus, resembles N. clavulatus in the short foot, and in the odd position in which it is placed ; but differs widely from all the Hydatinade in the corona and trophi. Feeble, however, as are its affinities with the two other species of the genus, they are stronger than those it has with any other; so it has been placed here as the best makeshift that could be devised. N. pracuionus, Ehrenberg. (RIS SeVe he. 1) Notommata brachionus . - C Ehrenberg, Die Infus. 1838, p. 433, Taf. 1. fig. 3. : i 3 3 : Leydig, Ueb. d. Bau d. Rdderth., 1854, p. 99. Hudson, Mon. Micr. J. vol. xiii. 1875, p. 46, pl. xci. figs. 1-4, ” ” SP. CH. Trunk square; foot one-third of total length, placed in continuation of the body's longer axis, not wholly retractile; trophi malleate. I found this handsome creature in a small rain-pool in Leigh woods. The summer heat frequently dried the pool up, but a heavy shower or two soon filled it again; and, two or three days after the downfall, I always found N. brachionus there in abundance : no doubt hatched out from eggs:deposited on the rotting leaves which formed the bottom of the pool. These strange habitats of the Rotifera are probably due to their eggs being wafted by winds, or carried by birds; so that it is no wonder that this species should have been captured by Schmarda in a spring near the top of Adam’s Peuk in 1 Dr, Plate (loc. cit.) says that R. vitrea has but one toe. I thought so myself, till I saw the creature, of its own accord, separate the apparently single toe, into two. 12 “THE ROTIFERA. Ceylon. Itisa remarkable Rotiferon, surpassing almost every other in the number and variety of its styles, setw, and cilia. In general shape it is something like a Brachionus, but its head is that of a Hydatina. There are only three styligerous prominences in the corona between the two usual wreaths, and these bear styles arranged fan-fashion and thickened at the base, as if each style passed through a short sheath; a form of style strikingly visible in the young animal, when the styles are short. The whole of the cavity leading to the buccal funnel is ciliated, and at its base is a ring of large curyed styles, pointing upwards. On each side of the wedge-shaped opening, at the entrance to the buccal funnel, are large sete set horizontally above one another in short sheaths, and fringed at their bases with minute vertical setie (fig. 1c). The trophi are malleate, and Mr. Gosse says that they are the exact repetition of those of N. clavulatus (Notommata clavulata) as figured by him in ‘ Phil. Trans.’’ 1856, Pl. xvi. fig. 28. The rest of the nutritive system, as well as of the secreting and vascular systems, is obvious and normal. The ovary is horseshoe-shaped, with its germs set in a single line. There is a nervous ganglion just below the dorsal surface of the head, somewhat rect- angular in outline like that of Hydatina senta; and, like it, giving off nerve-threads at its corners, two of which doubtless pass to the large dorso-lateral antennge shown at the lower corners of the trunk in fig. 1. Mr. Gosse, in a side view, has seen that the nervous ganglion is a truncated pyramid, bearing the red eye on its sumunit. The Male.—N. brachionus carries its egg for some time after exclusion, so that it is possible to identify the male with certainty. The male is very unlike its mother in shape and size, anda side view (fig. 1b) shows that the head slopes back to a hump, on the apex of which is a bunch of tactile sete. A nerve-thread from the nervous ganglioa passes to these, and lies between two fine muscular fibres. A moderately sized sperm- sac ends in a ciliated penis just above the foot, which contains two large club-shaped glands. Close to the sac is a small contractile vesicle, the lateral canals of which can be readily traced on either side of the ventral surface.! Length, ,j, inch. Habitat. Pondsand pools; Clifton (C.'T.H.); Kingswood (P.H.G., T.B.): not common. : N. ciavuxnatus, Ehrenberg. (Pl. XV. fig. 8.) Notommata clavulata . 2 s Ehrenberg, Die Infus. 1838, p. 432, Taf. 1. fig. 5. SP. CH. Body sac-shaped; foot one-ninth of total length, wholly retractile within the ventral surface ; trophi malleate. At the first glance one would say that this animal was an Asplanchna, which genus it greatly resembles in general shape, in brilliant transparency, and in the comparative emptiness of the trunk. But a little examination shows that the two are widely unlike in corona, trophi, and alimentary canal. On comparing, however, the apparently dis- similar creatures N. brachionus and N. clavulatus, it will be found that they are, in many important points of their structure, exact counterparts of each other. The corone, for instance, are closely alike, although N. clavulatus has a greater number of styligerous lobes, and lacks the ring of curved styles that le round the base of the cavity of the corona in N. brachionus (fig. 1). The trophi are identical. The muscular and vascular systems are much alike; the latter, indeed, curiously so, for the sharp bend at right angles in the lateral canals, which is rendered necessary by the shape of N. brachionus, is repeated (needlessly, as it were) by NV. clavulatus. The contractile vesicle in the latter, however, has much thicker walls, and is sluggish in action. The eye is seated on the ' Ehrenberg found a female with a cluster of male eggs; and, misled by their size and number, supposed that the issuing young were those of a Notommata which he named N. granularis, and which he credited with laying its eggs on the backs of Brachionus pala and Notops brachionus. Leydig explained the error (loc. cit.). HYDATINADA. 13 ventral side of the nervous ganglion in N. clavulatus, and on the dorsal side in N. brachionus ; but in other respects the nervous systems are alike; the side view (fig. 3a) of the female of the former showing precisely the same nerve-threads to a dorsal antenna which are exhibited by the male of the latter (fig. 1b). The ovaries in both species are flat horseshoe-shaped ribbons bearing a single row of germs. The chief pots in which N. clavulatus differs from N. brachionus, besides those of the general shape, and of the size and position of the foot, are as follows. The gastric glands are long and cylindrical, and below them there are two pairs of short ceca attached to the dorsal surface of the stomach. The stomach often appears as a long conical tube tapering to a cloaca above the foot, colourless when empty, or tinged above with a faint yellow tint when filling with food. Frequently, however, there is a deep constriction above its lower portion, thus forming an intestine ; and on one occasion I saw this con- striction suddenly disappear, and the contents of the intestine at the same time drawn up into the stomach. Mr. Gosse noticed that the body had its surface marked with minute oblong points, which were scarcely visible except at the edge. He observed also that the discharged egg was carried behind the cloaca, and that its development was extremely slow; no sensible maturation having appeared even several days after its exclusion. The male is unknown. Length, 2, inch. Habitat, Hampstead (P.H.G.); Clifton (C.T.H.): not common. N. nyprropus, Ehrenberg. (Pl. XV. fig. 2.) Notommata hyptopus . ; : Ehrenberg, Die Infus. 1838, p. 426, Taf. 1. fig. 6. SP. CH. Corona without setigerows prominences; ciliary wreath single; foot about one-fifth of the total length, arising from the ventral surface and capable of being wholly withdrawn within it; trophi forcipate. Partially loricated. This must be a rare animal; for, smce Ehrenberg found two specimens in 1885, no one but Dujardin and Perty records having seen it. I haye myself only seen it twice ; but on one of these occasions I fortunately had many specimens, and so I was able to add something to Ehrenberg’s rather meagre details. The first thing that strikes the observer is the creature’s odd, wabbling way of swimming. This is due, no doubt, to its unusual shape ; for it is greatly compressed, having a narrow dorsal surface, but a broad lateral one. ‘The skin can hardly be termed a lorica, yet there are several places where it is much stiffened. The two curved edges down the dorsal surface (figs. 2, 2a), the undulating edge of the trunk beneath the neck, and the rim of the aperture into which the foot can be withdrawn, are all thick and unyielding. The corona is truncate, but bulges forward towards the centre. The marginal ciliary wreath is interrupted on each side by a long vibratile style. A grape-shaped mastax, with feeble forcipate trophi, lies close to the buccal orifice. Ehrenberg says that there is neither esophagus nor intestine ; and if his two specimens had their alimentary canals much distended with food, these organs would have appeared to be wanting. But in front of the true stomach, with thick cellular walls, there is a very thin transparent chamber (fig. 2a) often empty, and constantly puffed in and out, in ever-varying shapes. This, I think, is an @sophagus similar to those in Asplanchna and Syncheta ; and, like them, capable of being distended with food, so as to be confluent with the stomach, or of collapsing to form a narrow tube. The apparent absence of intestine is also a temporary condition of the alimentary canal: my specimens had all a most well-marked intestine. The gastric glands are large and plainly nucleated; and the walls of the stomach are studded with unusually large oil-globules. The contractile vesicle is high on the ventral surface owing to the whole animal being tucked up, as it were, towards that surface. The lateral canals are unusually large and distinct; and lie, with their floceose ribbons, close to the skin: they are well shown in fig. 2b. The same figure 14 THE ROTIFERA. shows the chief longitudinal muscles. he ovary (fig. 2a) is very large, and has large germs: a maturing ovum is visible in fig. 2. A large nervous ganglion of Notommatan type stretches back from the corona to the dorsal surface and bears a large red eye. I failed to find any antenne. The male is unknown. Length, 7; inch. Habitat. Near Birmingham (T.B.): rare. Family X. NOTOMMATAD. (Corona obliquely transverse ; ciliary wreath of interrupted curves and clusters, usually with a marginal wreath surrounding the buccal orifice ; trophi forcipate ; foot furcate. The Rotifera associated in this family may be considered the most typical repre- sentatives of the whole class. They are permanently free, never affixed to other objects, never to each other in clusters. Their bodies are not inclosed in tubes; their integu- ment is more or less flexible, never hardened into a shelly mail. The body is generally cylindrical, with a length twice or thrice the diameter ; the front does not expand into a flower-like disk, but is usually convex, often with a fiat versatile face, inclined down- wards (supposing the animal to be crawling), beset with strong vibrating cilia, so arranged that their combined action produces two vortices, one on each side of the head. The posterior extremity bears a foot of several diminishing joints, capable, in a slight degree, of telescopic inversion ; and the last of these bears two diverging toes, chitinous in structure, used for support and locomotion. The trophi are well developed, all the seven constituent elements—the labrum, the two mallei, the two wmeus-ranu, the fulerwm and the labiwm—corresponding homo- logically to the labrum, the mandibles, the maxille and the labium, of insects,! being present, in relative proportions. The mastax is so placed that the jaws can be freely protruded from the buccal orifice, as has been seen in most of the genera, and used, forceps-like, to slit the cells of Algw, to nibble the flocculent matter which grows on vegetable stems, or to seize, retain, and devour active animalcules. Some of the genera possess a singular apparatus for suddenly augmenting locomotion, in the form of a pair of organs (auricles), ordinarily concealed, which can be thrust out in an instant, by eversion of the skin. The surface which is then external is clothed with cilia, dense, vigorous, and capable of producing ample yortices in the water. The Notommatade@ are the most highly organised of all Rotifera; the most sudden, varied, and energetic in their motions; most highly endowed with external sense- organs; most predatory ; most nearly approaching to the Articulate classes, not only in their manducatory organs, but also in their skin usually firm, elastic, capable of being thrown into transverse folds, or sub-articulations, more or less permanent. If not the most beautiful, they may claim to be the most interesting; best repaying investigation, while they present the greatest difficulties to the student. As this must be considered the central or typical family, without adopting all the fancies of the Circular theories, we may suggest that the relation between the genus Purcularia and the Loricata, through Diaschiza, is very close: that Proales, with its long prone face, leads to the Bdelloida through Adineta: that the skipping species of Furcularia, as longiseta and aqualis, look towards the Scirtopoda: and that in the mucous inyestiture common in the genus Copeus, we perceive a reflection of the excreted tubes of the Rhizota.— P.H.G.] ' See my mem. “On Mand, Organs,” Phil. Trans. 1855 p. 449. > NOTOMMATADA. 15 Genus ALBERTIA, Dujardin. [GEN. CH. Body vermiform, lengthened ; ciliated face sub-prone ; eyes wanting ; jaws minute, forcipate ; foot small, one-toed. Entozoically parasitic im Annellida.— P.H.G.] A. INTRUSOR, Gosse, sp. NOV. (Pl. XVII. fig. 18.) [SP. CH. Body greatly lengthened, nearly cylindric, but swollen behind ; foot of one joint, besides the toe, which is a small cone ; viscera divided by annular constric- tions, within the straight (unconstricted) integument. This species seems distinct from the A. vermiculus of M. Dujardin, if I may judge from his figures (Infus. Pl. 22.14, 8B). The general form of that is uniformly cylindrical, slightly tapering to a great conical foot ; of this, cylindrical, gradually swelling to the ventricose hind parts, where a very minute conical toe terminates a small one- jointed foot. The mastax and jaws of that species are moderately large; of this, excessively minute. That species is parasitic within earthworms and slugs; this, within water-worms (Nais). The discovery of the followmg species makes it almost certain that these differences are specific. The body is greatly elongated, slender in front, thickening behind the middle, so that the diameter of the hind part is just double that of the fore. As, however, a great ovate egg was mature in the ovary, at the very extremity of the visceral cavity, of the specimen figured, the body may have been more than usually swollen. The ciliated face is broad and oblique; the mastax minute, displaying a forcipate incus, with broad blades, resembling those of Diglena, to which are attached slender simple mallei, with long straight arms inflexed at their extremities. All the trophi are frequently pro- truded fully half-way from the ciliated front, and vigorously snapped. A very slender cesophagus leads to a long alimentary canal, which is constricted at short intervals throughout, but appears to be simple. No gastric, or biliary (?) glands were seen. The ovary is long, and occupies the greater part of the abdomen. In all the specimens that I examined, there were seven or eight amorphous nuclei, and one large well-matured ovum filling up the posterior end; its substance minutely granular, with a vitelline globule near the anterior end. Between this ovum and the intestine was a small contractile vesicle. A minute point projects from the front, which may possibly be a sense-organ, but I perceived no sete on it. A long pointed occipital sac descends far below the mastax, but is destitute of any eye-speck. The whole animal is slightly tinged with yellow ; and this is the only trace of colour in it, as the abdomen contains no coloured food, owing to its peculiar economy. For the animal lives as a parasite in the visceral cavity of Nais proboscidea. I was examining a specimen of this aquatic worm (in October 1854), when a slight pressure of the compressorium caused it to separate into t~ parts. I had looked over it with a lens, but had no suspicion that my Nats was any other than a single integer, and unfortunately it was not in focus when the separa- tion took place, so that I did not actually watch the process. The next moment, how- ever, I found that I had two perfect Naides ; the one which had been the tail differing only by being a little smaller, but with a head, eyes, and proboscis, as perfect as the other. The one which must be called the parent had the hind extremity less distinct than the daughter, and there was a slight trace of jaggedness visible. But my attention was arrested by a vermiform animal shooting swiftly through the water; and presently another. They were evidently Rotiferous, and as I was sure that they had not been in the live-box before, I conjectured that they had been discharged from the body of the Nais, at the moment of division. This was immediately confirmed : for, on examining the Nais, I found, within the alimentary canal of the parent, near the dividing point, three or more of the parasites snugly nestled, and actively writhing about. All the 16 THE ROTIFERA. specimens agreed accurately with each other, as described above. In the open water they swam swiftly ; and it was difficult to confine them even with the compressor; for they soon managed, by contraction and elongation, to wriggle themselves out of the field of view. The Nais was from a pool at Walthamstow. Wxamining another Nais from the same phial, I found a single Albertia in the intestine; in another, an egg of the parasite was within the intestine, attached to a pellet of fecal matter, which pushed it along. he opacity of the bowel prevented my seeing whether any matured parasites were present or not in this case.—P.H.G. | Length, ,},, inch; diameter, ;}5 to yolgo inch. Habitat. Walthamstow (P.H.G.) : entozoie, A, waipis, Bousfield, sp. nov. (Pl, XVII, fig. 14.) [SP. CH, Body moderately long, the cervical and pectoral parts the thickest, diminishing to the hind part ; toe minute, soft, papilliform ; integument slightly con- stricted in the hinder half. This species was discovered by Mr, Edward C. Bousfield, who has kindly communi- cated to me his own careful drawings and descriptive MS. notes. He has “several times observed it in situ, in Nais barbata, living free within the cavity of the stomach of its host.”’ ‘Body cylindrical, soft, hyalime, vermicular, extremely flexible and telescopic, espe- cially the hinder part, Anterior extremity truncate. Trochal dise small, oblique, on dorsal aspect of body, {One drawing shows that it is invertile, the cilia being depicted fay down the buccal funnel,—P.H.G.] Jaws very minute, protrusile, snapping. Ali- mentary canal conical, extending through the body, opening at the junction of the last two segments. Gastric gland semi-ovoid. Ovary straight, slender, eylindro-conieal ; the ova deyeloped serially. A minute contractile vesicle. ‘‘Candal appendage [= foot, P.H.G.| papilliform, composed of two joints [of which the terminal is] soft, resembling in its action the finger of an elephant’s trunk.” ‘Habitat. Vicinity of London, Anterior portion of stomach of Nais, in which it moves freely, Weg about one-third of length of parent’s body. Length, 54,5 inch.”’! —P,H.G,] Genus TAPHROCAMPA, Gosse. (GEN, CH. Body fusiform or cylindrical, annulose, furnished with two furcate toes ; trophi forcipate ; volatory cilia wanting or very limited. T., ANNULOSA, Gosse. (Bl. XVII. fig. 12.) Taplrocampa annvilosa , - , Gosse, Ann, Nat, Hist, 2 Ser. 1851, p, 199. SP. CH. Body cylindrical, short and thick, marked throughout with distinct articu- lutions ; brain opaque; alimentary canal simple, wide, cylindrical; terminal fork thick, conical, acute, This animal is very larva-like; the body consists of many well-marked rings or segments which are set within the clear cylindrical integument, apparently touching this only at the points. Tach of these, if viewed through the longitudinal line, would be of a sub-square outline, with four projecting angles, as seen at fig. 12b. In general no yortices are seen, nor any trace of yibratile cilia, so that 1 long concluded ' Thus the three recorded species differ notably in their respective dimensions :—A, vermiculus being ,j, inch to ., inch (Duj.); A. intyvusor, jhy in. (P.H.G,); A, naitdis, 515 in. (Bousfield), NOTOMMATAD AS, V7 rotatory organs to be wanting. Yet, lately I saw one on whose front a strong ciliary action was conspicuous : it seemed as if the ciliate surface were on the prone side of the front. The species, moreover, is furnished with protrusile auricles for augmented loco- motion, like Notommata proper. [have not myself seen these, indeed; but the fact rests on ample evidence. Dr. Hudson was assured by Mr. Brayley, the Secretary of the Bristol Microscopical Society, that he had seen a Zaphrocampa “ put out very small auricles from the head, and swim with a slight vermiform moyement.”’ He had made a pen-and- ink sketch of the creature in both conditions ; which sketch is in my possession, and represents indubitably 7. annulosa. Miss Saunders, too, a careful observer, writes me under date of June 10: ‘* Watching your Taphrocampa annulosa a long time, I saw it thrust out an ear-like lobe on each side, and swim frantically about in a most headlong fashion ; but only one of three did this. ‘The processes were not very prominent, but were quite distinct.’”” his fact affords an interesting link with the present family. The form of the mastax and trophi, too, though not yet quite satisfactorily defined, is evidently Notommatous, and seems to resemble the pattern seen in some of the Mwr- cularie, and some of the Rattulide also, consisting of an incus with a long fulerum and a pair of long incurved mallei. ‘he animal can bring the tips of the jaws to the very front, and nibbles floccose matters with them. An alimentary canal, broad and straight, with no accessory glands, and with no constriction, runs through the cavity to the cloaca close to the forked toes. It is usually empty and colourless. At the occiput, behind the mastax, and almost invariably sharing its motions in contraction and elongation, is a moderate-sized mass of opaque matter, white by reflected light, and probably chalky. Like a similar mass in many Notommate, with which it is another link, it lies at the bottom of a wide and deep sac. T had vainly searched for any trace of red pigment in this mass which might indicate an eye. On one occasion recently, however, I was examining a specimen under direct sun-light, when there suddenly flashed out from the opaque mass a spark of radiance, as if from an eye-lens, though I could not discern any red hue. What represents the ordinary foot and toes is peculiar, It would seem rather to be a forked tail; for T have seen, now and then, projecting beneath this, a very delicate rounded lobe, which is possibly the foot, the cloaca opening between these. Or, rather, it is the optical expression of the lower half of the cylindrical rectum, of which the middle of the crescentic fork forms the upper part or ceiling. ‘The intestine can be traced down to this orifice beneath the fork. The fork, or, if this explanation is correct, the tail, is formed of two incurved taper, chitinous, clear, sharp spines, together making a semicircle; but not separated into toes, nor articulated with the segment that carries them, and so having no power of motion independent of one another, or of their segment. ‘True toes would have both. The animal contracts strongly and continually, like a Notommata; but the sphere of the contraction is the space occupied by the alimentary canal, the parts both before and behind this viscus remaining unaffected, while the parts included contract forcibly, and both ways, but chiefly from behind forward. In most of its movements it resembles Chetonotus, crawling sluggishly about the glass, and the masses of sediment.'—P,H.G.| Length. About ,1, inch. Habitat. Pools and ditches; common (P.H.G.). 1 There are two very distinct varieties of the above, well-marked and constant; yet with hardly sufficient dissimilarity to warrant our separating them as species. ‘he one smaller, with the articula- tion strong, the lateral projections of dark tissue into each segment clearly seen, the caudal points short, stout, and straight. This was the form first recognized, is the form above described, and is by far the more common. The other much larger, the articulation and the interior projections both in- distinct, often imperceptible; the caudal points long, slender, crescentic, wider at their bases, and making together a regular semicircle. In this variety, an excellent observation which I obtained showed the mastax, mallet, and incus, almost exactly of the same familiar pattern as in Notommata aurita (Phil. Trans. 1856, pl, xvi. figs. 16-21), VOL, It. oO 18 THE ROTIFERA. T. SaunDERSL®, Gosse, sp. nov. (Pl. XVII. fig. 11.) Taphrocampa Saundersie . : Hudson, J. Rey. Micr. Soc. 2 Ser. vol. v. 1885, p. 614, pl. xii. [SP. CH. Body lengthened, fusiform, annulate; brain clear; a decurved frontal hood ; wo eyes (?); a distinct tail; foot and furcate toes of normal form. Many examples of this form occurred to my observation in the floccose sediment of water, very rich in Rotiferous life, which was sent me by Miss Saunders of Cheltenham, in May 1885, dipped from a tank which she had used as a preserve of living Rotifera. But Dr. Hudson had observed the same species in water from Birmingham, in July 1884; and had prepared a notice of it for the ‘‘ Journ. Roy. Mic. Soc.” The publication was delayed, however, through press of matier, till the following spring. It is a very distinct species, less abnormal than T. annulosa, more manifestly Notommatous in its affinities. The body is divided into well-marked rings, about seven or eight, not so numerous as in annulosa; each of which rises to what seems a sharp edge; but momentary glimpses, which one has as it turns around the weeds, show a number (not only four) of conical points (perhaps about eight in the dorsal half) in the transverse section (as at fig. 116), the expression of as many series of conical elevations running down the whole (possibly dorsal and lateral) surface. The head is rather large, and sub-globose (fig. 11), and seems permanent in outline; as the restless animal twists and turns itself about con- stantly, causing much change of diameter, the head remaining undiminished, the neck (so to speak) becomes conspicuously slender, to be filled up by the next contraction, in an instant. Very frequent retractation of the hind parts towards the head occurs. There is a marked diminution in these parts, the ultimate segment bearing two moderately short diverging toes; the penult or antepenult segment sending forth a distinct conical projection, which follows the general direction of the body, and may be called a tail, with more breadth than depth, much as in Notomm. tripus, N. pilarius, and others (fig. 1la). The front of the head bears a projection, which, on a lateral view (fig. 11a), looks like a proboscis, and often like a sharp hook, bent forward and downward; yet I think it has considerable width, and Dr. Hudson has found it to be a broad arched hood. Just behind this organ, and so on the very front of the globose head, are a pair of minute colourless globules, quite conspicuous in all aspects, which may be eye-spots. The mastax consists of two stout, curved, pointed teeth, capable of being widely expanded and closed, like the blades of scissors (fig. 11); these appear based on an oblong transparent body, probably the muscular bulb requisite for motion. The points can be brought to the edge of the front.! The front is oblique; it is composed of several fieshy eminences, each bearing a crown of cilia, whose vibrations I have distinctly seen, though they do not appear to constitute a disk or rota. The animal’s motion in the free water, a smooth and rather swift gliding, is doubtless produced by these frontal cilia. Accurate observation, with the high powers required by its minute- ness, is very difficult from its incessant restlessness; as it glides through the open, it is constantly contracting and extending the body; at the nearest atom of sediment it pauses, but instantly throws itself into rapid contortions. A long stomach, capable of much width where it proceeds from the mastax, reaches to the cloaca under the tail, while a large ovary occupies the ventral region. The body is transparent, more or less tinged with yellow. The stomach usually contains particles of dark food, sufficient sometimes to impart a blackish hue to the body; while the entire venter may be filled with a dark egg. I have honoured this species with the name of Miss Saunders of Cheltenham—from ' These seem to be the blades of an ineus (of the pattern Fig. 21 of my memoir in Phtl. Trans. 1856, pl. xvi.); the mallei apparently quite aborted. NOTOMMATAD. 19 whom I have received many specimens—a lady, who, for many years, has given intelli- gent attention to this class of animals, and who has aided me very effectively in my researches.—P.H.G.] ! Length, 3, to 4, inch. Habitat. Pools near Birmingham (C.T.H.); Cheltenham (P.H.G.): not rare. //2 Genus PLEUROTROCHA, Ehrenberg. GEN. CH. ‘“ No eyes; mallei one-toothed ; foot furcate’’ (Ehr.). [There seems nothing very obvious to distinguish this genus from Notommata, but the lack of eyes, both cervical and frontal; and characters that are merely negative are always somewhat unsatisfactory. The form seems scarcely to have attracted attention in Britain. In the close, almost daily, study of the class, which I pursued some thirty years ago, it never occurred to my notice; no example of it appears in Dr. Collins’s richly-stored book of drawings ; Dr. Hudson has no record of it ; and in my recent resump- tion of the study, extending over the last year and more, I have met with but three examples; which, with more or less certainty, I identify with the three recorded species of Prof. Ehrenberg. Doubtless, by us all, it may possibly have been confounded with the obscurer species of Notommatade, and have been overlooked. But yet the common difficulty of discerning the eye in a restless animalcule is more likely to cause a Notom- mata to be taken for a Plewrotrocha, than a Pleurotrocha for a Notommata.—P.H.G.] P. constricta, (?) Ehrenberg. (Pl. XVIII. fig. 3.) [SP. CH. Toes moderately long, acute, straight. If this is identical with P. constricta, the singular and almost unprecedented illustra- tion which Prof. Ehrenberg has given us on the testimony of his own eyes, of its preda- tory instincts, I may cite as adding to it the greatest interest. He has figured the ap- parently weak and unarmed Plewrotrocha as watching a specimen of the swift and vigorous Notommata lacinulata; then, as having seized it; then, as sucking out its juices ; and then, as having dropped away the now empty skin. Well may he give it the secondary title of The Robber. I have seen nothing of this in the little delicate creature which I here represent. It occurred to me in the spring of 1885, and then for so brief a period that I had but just time to make a drawing of it, which is here reproduced. It is indubitably rare. Ehren- berg appears to have seen but two examples, one of which was the above warrior of now historic renown. I had no time for measuring mine, but his length of 4; inch would well enough agree with my estimate. But, a few months later, | met with a specimen in water from Dundee represented in fig. 8, which I conclude to be specifically identical with the above, though there are some slight differences. The front is broader; and, though I could not say that auricles were actually protruded, their presence seemed indicated. (I incline to think the existence of these aids to locomotion more usual in the class than is generally accredited.) The toes also are more slender and more acute. It was active and moderately swift, gliding through the clear water; now and then suddenly darting a little right or left of its course, and apparently seizing some invisible prey. The manner of the action could not be mistaken; it was manifestly predatory. The mastax was large and conspicuous; but I could not obtain a look at it suffici- ently steady to define it. The intestinal canal was ample and filled with dark bistre- 1.In one specimen I observed, on a side view, a long egg-shaped contractile vesicle lying between the hind end of the stomach and the ventral surface, and terminating in a delicate tube entering the cloaca. The vesicle filled and emptied every 24 seconds.—C.T.H. c2 20 THE ROTIFERA. brown granular food. The toes are usually held close appressed when the animal is gliding ; but often expanded. It was lost before I could complete my observation. This individual was found in Monk Mire Loch near Dundee, in August 1885, among slender filamentous weed crowded with minute diatoms, making dense masses of impalpable floccose. The former was from Woolston Pond, Hants.—P.H.G.] Length, ,1, inch (?). Habitat. Woolston; Birmingham ; Dundee (P.H.G.). P. ueprura (?), Hhrenberg. (Pl. XVIII. fig. 4.) [SP. CH. Toes moderately long, slender, acute, slightly decurved ; face oblique. This species is of equal rarity, in my experience, with its two congeners ; a single solitary example alone having occurred to me, and that at about the same time. The ciliated front is much more prone than I observed in the others, and the mastax was at one time so thrust forward that the trophi were brought to the very face, as we see with many of the Notommate. The outline is gracefully swelling, and tapering be- hind; and the form and curve of the slender toes are elegant.—P.H.G.] Length. About ;}, inch. Habitat. Woolston Pond (P.H.G.). P. arppa (?), Hhrenberg. (Pl. XVIII. fig. 5.) [SP. CH. Short and thick in proportion to its length ; toes moderately long and broad, nearly straight. It is with great hesitation that I attach Ehrenberg’s name of gibba to this little species. The general shortness and stoutness of form agree, and, though the lumbar parts of the body want the plumpness whence he has selected an appellation, this may be a variable character dependent on repletion of the alimentary canal. My figure was drawn from life; but the example was lost before I had completed my observations. It was in the early spring of 1885; but I made no record of the source whence it was obtained.—P.H.G.] Length. About ,}. inch: whereas Ehrenberg gives 5}, inch as the average of his. Genus NOTOMMATA, Gosse (nec Elir.). [GEN. CH. Body not annulose, cylindrical, furnished behind with a projecting tail; special organs (auricles) on the head for locomotion, evertile and protrusile ; brain large, containing opaque chalk-masses ; trophi virgate. There are species in which one or more of these characters may not be found. The genus Notommata of Ehrenberg, eyen as it left his pen, was a heterogenous mass of dissimilar species. Many naturalists have indicated the need of dividing and redistributing the unwieldy group; but none have yet ventured upon the task. I propose to break it up into three distinct genera. The family Asplanchnade@ having been already formed, some species of large size, sacciform body, and hyaline transparency, migrate thither ; while others of similar appearance may be associated with the Hydatinade. These being eliminated, there comes the curious species N. copews, which Ehrenberg distinguished by large dimensions, a fusiform body, a distinct tail, and organs of special sense, projecting from the lumbar regions, as well as from the head. As a number of others, allied to this form, have been discovered, I form them into a separate group with the generic appellation of Copeuws. Then there is a group of conspicuous species, marked by auricles, by a more or less distinct tail, and by the brain being unusually NOTOMMATAD 8. 21 developed, and opaque with chalk deposits. This genus may retain the name of Notom- mata. There still remain a multitude of species, mostly of small, none of large, size, with characters mainly negative, yet having much in common with each other, a community more easily recognized than deseribed ; but having the ciliate face more or less obliquely prone. These make the genus Proales. The second of these three is characterized above, and shall still prolong the time-honoured title. It is even now a populous tribe, as usual with typical groups: yet not unnaturally associated. Its constituent species are easy of recognition, by three prominent characters, all fairly constant—1, the tail; 2, the auricles; 8, the opaque brain. The first is moderately conspicuous, and readily dis- tinguished by being always on the dorsal side of the cloaca, while the foot and toes are always on the ventral. The second is not always available, being often inactive and invisible; but if seen, seen without doubt. The third is the best mark: the opaque brain-mass, like a vast well-defined black cloud, striking the eye at the first glance, unmistakably. The genus is widely distributed in our fresh waters.—P.H.G.] N. aurnira, Hhrenberg. (Pl. XVII. fig. 6.) Notommata aurita . 4 : 5 Ehrenberg, Die Infus. 1838, p. 430, Taf. lii. fig. iii. Gosse, T’rans. Micr. Soc. Lond. 1852, p. 93, pls. xii. xv. ” ” [SP. CH. Body swb-cylindric, ventricose ; brain opaque ; head wide, furnished with evertile auricles ; tail minwte. Of this moderately large species, of elaborate organization, and of frequent occur- rence, the anatomy has been given with so much detail, by myself (loc. cit. swpra), that only a very succinct account is needful here. Its opaque brain-mass, looking like a great black ball in the neck, connected by a tube with the front, renders it conspicuous as soon as it is seen; and when it glides through the clear water, the sudden quickening of its speed, as it everts the great ciliate hemispheres from its two cheeks is hardly less notable.! The foot consists of two very short and small joints, telescopically infolded ; bearing two furcate toes, acute cones, also short and small.—P.H.G.] Length, 5 to ;3, inch. Habitat. Fresh waters. Common everywhere (P.H.G.). N. ansata, Ehrenberg. (Pl. XVII. fig. 3.) [SP.CH. Closely resembling N. aurita in form and structure, but smaller ; the brain not opaque ; the toes long. The examples of this species that I have observed I could distinguish from the pre- ceding only by the points mentioned above. Perhaps it is slightly more slender, more cylindrical. Ehrenberg gives no appreciable diagnosis between the two forms; nor can his figures be distinguished, save by the lack of opacity on the brain of ansata. The length of the toes is, however, a good mark, and readily observed. A few specimens have oceurred to me in water sent me by Dr. Collins from Berkshire, containing aquatic moss. They moved in the clear, with great impetuosity, driving round and round, and turning on their course, with no apparent aim. One made its way just within the edge of a moss-leaf, where it worked for itself a little hollow, in which it remained several hours, incessantly turning round and round, or to and fro, as fast as it could move, without a moment’s intermission. In this example the alimen- ' Herr Eckstein (Sieb. w. K6ll. Zeits. 1883, p. 361) describes in this, as in many other Rotifera, specks of crimson pigment near the front, each in connection with a setigerous sense-organ. He con- cludes these to be secondary eyes. I have myself never detected them; neither has Dr. Hudson, nor Dr. Plate. 22 THE ROTIFERA. tary canal was large, not visibly separated, and filled with food of a rich dark-brown hue. The toes are long, slender, acute, and slightly decurved. The auricles, which were freely protruded, are rather small.—P.H.G.] Length, =}, inch. Habitat. Sandhurst, Berks; Epping Forest ; Woolston, Hants (P.H.G.); pools: rare. N. cyrtopus, Gosse, sp. nov. (Pl. XVII. fig. 7.) (SP. CH. Jn form resembling N. aurita, but very much smaller, and more slender in proportion ; brain intensely opaque ; no visible auricles; toes long, decurved. This little species I had known from a single specimen just dead, in August 1851, which I found in water from Widcombe Pond, Bath. I had never met with it again till June 1885, when I found a second in water from Woolston, and subsequently many, from many localities. It much resembles N. awrita; but is smaller; and the toes are slender and decurved. A pair of colourless specks, like air-globules, are in its front, which may be eyes, and a large brain, which carries at its hinder end an aggregation of opaque matter forming a collection of round cells. This, by refracted light, is intensely black, as in awrita, and renders the species very conspicuous, reaching far down into the body-cavity. The mastax is normal; the alimentary canal also large, not visibly divided ; ovary and contractile vesicle as ordinary. In manners it is particularly sluggish, scarcely changing its place, though in con- stant motion. It roots and nibbles among the floccose sediment, and affects conceal- ment, seeking the shelter of the thin integument of decaying Nitella, and such-like plants, under which it hides; and, if it creep out for an instant, presently betaking itself to its refuge again, where it twists and turns restlessly on its centre.—P.H.G.] Length. About ,4, inch. Habitat. Bath; Woolston; Sandhurst, Berks; Epping Forest; Cheltenham (P.H.G.); pools: not common. /” N. tripus, Ehrenberg (nec Leydig.) (Pl. XVII. fig. 4.) (SP. CH. Body thick, arched dorsally, diminished behind to a conspicuous tail, and furcate toes; tail equal in length to the toes; brain opaque; auricles small, slender. I know this animal by a single specimen, which I found among Myriophyllum in a tank in my own garden, near London, in 1854. It has never occurred to me again; and I do not feel quite certain that it is the tripws of Ehrenberg. The body is marked by several strong folds of the skin. Viewed from the side it is arched, and the ventral outline is concave; but the ovary was undeveloped, which fact might modify the form. The frontal cilia are set on a large ovate area looking ventrally (fig. 4), so that ordinarily the front appears rounded and free from cilia. Occasionally, however, the front is elevated and expanded somewhat angularly, and an auricle is thrust out on each side, of somewhat serpentine outline, set on its anterior edge with vibratile cilia, whose effect is manifest in accelerated motion. The brain runs down to a long obtuse point in the occiput, whose extremity, in my example, was occupied (fig. 4a) with some irregular granules of opaque matter; seated on the end of which was a large pear- shaped red eye. The posterior extremity of the trunk runs out into a prominent tail, a tapering cone, with alternate constrictions and swellings. Beneath this are the furcate toes; and as the tail is of the same length as these, and diverges at a like angle, forming three angles of a triangle, the animal well deserves its specific name.—P.H.G.] Length, ;}, inch. Habitat. A garden pan, near London (P.H.G.). /”. NOTOMMATAD.A. 23 N. prInarius, Gosse, sp. nov. (Pl. XVII. fic. 5.) Notommata tripus . c ; . Leydig, Ueb. d. Bau d. Rdderth. p. 37. Taf. ili. fig. 28. [SP. CH. Body (viewed dorsally) rhomboidal in outline, sub-truncate at both ends ; head broad, with great globose auricles; brain pointed, filled to a greater or less extent with opaque matter ; tail and toes as in N. tripus. This little creature has much likeness to the preceding, from which, however, it sufficiently differs in the trapeziform outline, tapering from the middle to the foot; im the size and form of the auricles, which are very large, hyaline, and round, more than a semi-globe being exposed; in the conspicuous eye; in the singular overarching of the edges of the dorsal region, like the carapace of an Oniscus. Mr. Perty mentions this peculiarity in his N. onisciformis ; yet a glance at his figure proves that the two species are not identical. The singular effect produced when the little creature suddenly pushes out, and as suddenly withdraws, its frontal balls of glass, reminded me of the ancient pilarii, or jugglers with balls, and suggested a specific name. The great transverse diameter of the body is remarkable. The rhomboidal outline has much of the appearance of a lorica; for it is constant, and the viscera within take the form of great sacculate lobes, varying, and more or less receding, from this outline. The brain is a large, perfectly defined opaque mass stretching almost wholly across the head.' There seems to be a very minute crimson eye-speck in the centre of the front, discernible with difficulty. The contractile vesicle is very large ; its period of discharge was just two minutes. The globular auricles are exserted only at uncertain intervals, as when the animal wishes to swim swiftly. We may watch one by the hour, creeping up and down the stems, nibbling ever as it goes, or even now and then slowly gliding through the clear water; yet not once see the crystal balls thrust out by the little juggler. Yet is he unmistakable, in whatever condition, when once familiarly known ; and a very pretty, attractive little fellow he is. I first became cognizant of it in February 1855, when examining a tangle of conferva and Nitella in one of my window-reservoirs at Torquay. But I have since met with it on many occasions and in many waters. It is moderately lively, actively grubbing about the vegetation and sediment, now and then swimming across the open spaces, generally with little speed or energy, till the great glassy globes are set to work. The interior structure calls for no special notice.—P.H.G.] Length, 3}, inch; breadth, 3, inch. Habitat. Woolston Pond: common (P.H.G.). N. rorcipata, Hhrenberg. (Pl. XVII. fig. 1.) Notommata forcipata . é : Ehrenberg, Die Infus. 1838, p. 428, Taf. li. fig. 5. [SP. CH. Form lengthened, saccate, large in front, tapering to a small foot, and very minute furcate toes ; occipital end of brain semi-opaque, a small inverted pyramid ; eye a broad transverse lens. This is an active, graceful, attractive animal, somewhat sack- or purse-like, slender behind, but enlarged towards the head, which is in constant contraction. The front is obtuse in the dorsal and lateral aspects; the face is slightly prone. Behind a large mastax of normal jaws, very protrusile, an ample brain descends into the occiput, whose pyramidal tip, for a small space, is occupied by a well-defined granulation of clear brown tissue, not white by reflected light, and so not cretaceous; on the frontal end of which is seated a broad, somewhat square eye of pigment darkly red. Two small ciliate ’ From this transyerse deyelopment of the opaque chalk-masses, I infer that Dr. Leydig’s tripus is this species. 24 THE ROTIFERA. auricles can, at will, be protruded from the head, and I believe there is a small appressed antenna. The cloaca is very manifest, overhung by a minute wart-like projection. Then the foot tapers rapidly, ending in small, sometimes very minute, furcate toes, which about mid-length lessen abruptly, leaving a marked shoulder (fig. 1b). I am indebted to Mr. Bolton for many specimens on repeated occasions.—P.H.G.] Length, =; inch. Habitat. A ditch in Sutton Park, Birmingham (P.H.G.). N. pracuyora, Hhrenberg. (Pl. XVII. fig. 1.) Notommata brachyota . ; : Ehrenberg, Die Infus. 1838, p. 435, Taf. li. fig. 3. (SP. CH. Brain clear; body fusiform; auricles small; foot invisible; toes minute ; no tail. Outline rounded and plump, stout in the middle, tapering to each end. The face is obliquely prone ; a pair of very small auricles are thrust out from the sides of the head, occasionally, when pushing between stalks of Nitella, and not only when swimming. Fore and hind extremities hyaline, but corrugated longitudinally. Mastax large and round ; malleistrong, of several teeth, on a long-stalked incus, much on the pattern seen in N. aurita, which worked vigorously and perseveringly, boring its way into a Nitella stalk, and nibbling till it had cleared a great space of its green pulp-cells. The eye-spot is moderately large, of full crimson. This, in an instant’s good view, I discerned to be a regular globe, of which only the hinder half was red, the anterior half beg quite colourless ; the two halves being distinctly divided by a clean line (fig. 1b). The clear half was doubtless a crystalline lens of very perfect form and of powerful magnification. This eye is seated near the end of a long occipital brain. I could detect no dark spot, on each side of the eye, as figured by Ehrenberg; but have little doubt of the species. A great sacculate stomach comes up, as a brown granular mass, to the mastax, furnished with the usual pair of ear-like gastric glands. It reaches, without any manifest division, nearly to the clear space around the base of the foot; a contractile vesicle intervening. The foot is scarcely distinguishable, the pair of very minute conical toes apparently emerging from the rounded end of the body. No projection could be called a tail. It was not till I had watched the creature a considerable time, actively engaged, that I suspected the head to be other than simple in outline. Then, as it was swimming smoothly, I noticed its motion suddenly augmented ; and at the same instant I saw that two minute clear semi-globes were extruded, but only for a few moments; then with- drawn, and no trace left. The absence of these organs, therefore, must not confidently be inferred from the non-observation of them, particularly in species inadequately observed. The plump body seems very soft, compressible, and flexible; the integument thin, elastic, and yielding. The animal is eager, impatient, persevering, pushing everywhere. It really seemed to haye some sense of locality, which its perfectly-formed eye might assist. For though it often strayed to a considerable distance, beyond many stalks, it invariably returned, and sought out its feeding-ground within the Nitella. I was called away ; but, after nearly two hours, there he was, pegging away at the very same hole !— P.H.G.] Length, +}, inch. Habitat. Woolston Pond: rare (P.H.G.). N. saccigera, Ehrenberg. (Pl. XVII. fig. 2.) Notommata saccigera - ° 3 Ehrenberg, Die Infus. 1838, p. 434, Taf. 1. fig. 8. [SP. CH. Slender, obtusely pointed at both ends ; face prone, greatly lengthened, ending with a prominent chin ; foot and toes small. The form is unusually thin from side to side, compared with the Jength, widening ] NOTOMMATAD.2. : 1) sensibly at three-fourths from the head, and thence, more or less abruptly, diminish- ing. It is rather deeper (viewed laterally, fig. 2a), the dorsal outline rising to about the middle, thence falling to the tail. The ventral line is nearly straight, only that the ciliated face, almost quite prone, extends fully one-third of the length, and there forms a sort of projecting chin. The outline of this part is, however, very flexible and versatile. The dorsum terminates in a minute conical tubercle, beneath which the cloaca opens; so that it is a true tail. Below this is a very short and inconspicuous foot, and two minute furcate conical toes. The front is rounded, and can*evolve two small hemispherical auricles, very observable, because they are freely protruded, even when the animal is not swimming, but pushing its way among the tangled alge. The mastax is ample, and the trophi of the normal pattern ; behind, the brain descends low into the occiput, and carries a dark red eye near the middle of the sac. I have not seen this sac so pyriform as Prof. Ehrenberg has figured it. It is, in general, turbid toward the lower part, and sometimes quite opaque with angular chalk-masses. A large stomach and intestine, with gastric glands; a wide ovary ; indications of a vascular or branchial system, and a small contractile vesicle, are all normal, and require no remark. The animal is usually tinged with an olive-brown hue, especially in the abdominal viscera. Both the form and manners of this species strike the observer, at once, as unusual. It swims almost constantly; and affects the surface when in freedom. It makes a smooth rapid course, devious, and apparently objectless ; probably, however, governed by aims which we cannot appreciate. For it frequently makes little darts and jumps as it goes, with a sensible snap of the jaws, as if it took invisible prey. A number of examples occurred in water collected by Mr. Bolton from a ditch in Sutton Park, Birmingham, and specially marked ‘‘ surface.” I presume this to be the N. saccigera of Ehrenberg, from the general form, the long pointed head, the long prone ciliated face, the short toes and shorter foot. Yet he has not noticed the auricles, nor the opacity of the brain. The former, however, are re- tractile ; and the latter varies much.—P.H.G.] Length, ;4, to;}, inch. Habitat. Birmingham (P.H.G.). N. natas, Hhrenberg. (Pl. XVIII. fig. 2.) Notommata najas . c 0 4 Ehrenberg, Die Infus. p. 429, Taf. lii. fig. 2. [SP. CH. Of large size, fusiform; brain clear; head broad, obscurely auricled ; foot long ; toes short, pointed. This is a large and imposing form, evidently approaching the genus Copeus, yet showing no visible sense-organs projecting from the trunk. Its claim to a place in the present genus is slight, for the brain has no opacity, there is no tail, and the auricles, if present, are small, and appear to be permanent, as globose ciliated knobs, not evertile. Yet there is no prone face, and the general appearance and structure show affinity with these higher forms. The body is nearly cylindric, somewhat ventricose; the head nearly of the same width, divided into several broad but shallow lobes, the cilia on which make independent whorls. The mastax is ample, the jaws of the normal pattern. A brain descending into the occiput, and carrying a transversely ovate dark-red eye near its middle,! is flanked by a shorter sac on each side ;—another point of resemblance to Copeus. A small antenna projects from the occiput. Several annular folds of the skin —false joints—encircle the body, three in the anterior half, and one distinguishing the trunk from the foot. The latter consists of three well-marked joints rapidly diminishing, terminated by two forked acute toes which are rather short. ‘Two pyriform mucus- glands run through the foot from the toes. The branchial system is well displayed : 1 Eckstein figures two tentacular brushes of sete on the front, with a crimson eye-speck at the base of each. ; 26 THE ROTIFERA. a rather thick ribbon, slack, but scarcely convolute, passes down each side, apparently lost in (perhaps beneath) the lateral brain-sac, bearing sundry vibratile tags, and merging into a small contractile vesicle. The alimentary canal and the ovary were both amply sacculate in such specimens as I have examined. I first met with this fine species on the dichotomous leaves of the Water Crowfoot, growing in a sunken pan in my own garden near London, in the summer of 1849. It was vigorous and active, swimming rapidly through the water, with a headlong, pushing violence, or fixing itself slightly by its toes, and thrusting about its head in all directions. It seemed fierce and voracious; for, though I did not actually see it swallow food, it several times munched with apparent greediness the side of a large Motifer, returning to the attack, and seeming to bite ferociously. The Rotifer, if not materially injured, was thoroughly alarmed. I have since met with the species, but very rarely.—P.H.G.] Length, ,', inch. Habitat. Near London (P.H.G.); Sandhurst, Berks (Dr. Collins). N. tusa, Hhrenberg. (Pl. XVII. fig. 8.) Notommata tuba . i F Ehrenberg, Die Infus. 1838, p. 433, Taf. xlix. fig. 3. (SP. CH. Body trumpet-shaped; brain clear; a cervical eye; toes furcale, conical, minute. My right to mention this species rests on a pencil-sketch which I made from life, many years ago, and which I still possess, but without sufficient detail to warrant de- scription, and of which I have preserved no accompanying notes. In Dr. Collins’s Note- book, which is kindly entrusted to me, there is a pencil-drawing to which he has attached this name; but this also is unaccompanied by any note, except the date 1866. From Ehrenberg’s figs. I conjecture that its affinities are with Hydatina, the cervical eye notwithstanding.—P.H.G.] N. tacinutata, Lhrenberg. (Pl. XVII. fig. 9.) Notommata lacinulata . , é Ehrenberg, Die Infus. p. 428, Taf. li. fig. 4. [SP. CH. Small; body cylindrical, thick, broadly truncate ; brain clear; foot short; toes long; trophi forcipate; incus much developed, hemispheric; mallei very small. This tiny, sprightly atom is of pleasing form; vertically viewed, it is a very regular oval in outline, the head dilated, archedly truncate, and of a width, when the hemi- spheric auricles are out, equal to that of the body; while at the other end the acute divergent toes, set on a very short foot, make an elegant finish to the form, Laterally viewed, the diameter is nearly the same, the fore and hind extremities nearly perpen- dicular and nearly equal, the dorsal line arched, the ventral straight, the foot and toes set-on at the end of the latter. The mastax is very large and the trophi peculiar. The incus is remarkably developed, the fulcrum stout and long, the rami forming, when closed, a transparent hemisphere, “so as to resemble, when viewed obliquely from above, a globe of glass standing on a pedestal.” (See my mem. ‘On Mandue. Org.” in “ Phil. Trans.” 1855, p. 482, pl. xvii. figs. 82-84.) The tips of the rami are habitually projected in greater or less degree from the front, so that there is no buccal funnel proper. Behind the mastax there is a large dilated pale-red eye, seated near the middle of a moderate brain, which carries no opaque chalk-granules.! The alimentary canal is ample, usually filled with food of a rich yellow-brown hue, which adds much to the attractiveness of the animal. ’ Eckstein finds his usual two red specks at the ciliate front, in addition to the large red eye at the bottom of the brain; but he does not associate them here with tentacular seta. NOTOMMATAD Al. 27 I first found this species in various waters around London in 1849; and have been familiar with it ever since. Wherever filamentous sub-aquatic vegetation grows, it is sure to be abundant. A restless little creature, it ranges among the leaves with incessant activity, now pushing its way through some narrow aperture, using its toes as points of resistance ; now pausing to nibble among the decaying alge ; now scuttling off, by means of its ciliary paddles, to another quarter. The toes, when used as a rest, are often stretched asunder as wide as they will bear. In general a free rover through its tiny ocean, it yet occasionally, though rarely, anchors by the mucous excretion from its toes.!_ These moorings it cannot always loosen when it wishes again to leave port. I have been amused to see one swiftly pursuing its course, dragging after it, at some half dozen times its own length, a bit of floccose sediment attached by an invisible thread. It seemed as it were pursued by an eager persevering enemy through all its windings, which enemy at length proved to be nothing but a bit of inanimate dirt.—P.H.G.] Length, =}, inch; of toes alone, ys!;5 inch; of egg, 745 inch. Habitat. Hvery- where in still fresh waters of aquatic vegetation : abundant (P.H.G.; C.T.H.). N. conuaris (?), Hhrenberg. (Pl. XVI. fig. 6.) Notommata collaris F : 5 Ehrenberg, Die Infus. 1838, p. 428, Taf. lii. fig. 1. SP. CH. Body cylindrical, tapering to both extremities ; ciliated face very long and oblique, projecting far out from the ventral surface just below the mastax ; head with small evertile auricles; neck large and swollen; nervous ganglion tri-partite, semi-opaque at the free border ; tail distinct ; toes minute. This Lotiferon (probably Ehrenberg’s N. collaris) resembles Copeus Cerberus ; and, like it, might almost be placed either in the genus Copeus or Notommata. I have only seen one specimen, which from its size (two-thirds of that given by Ehrenberg) was, I think, a young one. It can at once be distinguished from Copeus Cerberus by its singular ciliated face (which, on a side view [fig. 6a], gives the head quite a triangular outline), and by its swollen neck. My impression, when I drew fig. 6, was that this swollen condition of the neck was due to the presence of two unusually large and clear gastric glands, which inclosed the mastax between them, on one side, and pushed out the surface of the body on the other. But on referring to Ehrenberg’s figure (loc. cit.), I found that he had drawn the gastrie glands as small round bodies, decidedly below the neck. Unfortunately I lost my specimen before I had an opportunity of revising my sketch. The front of the head carries two low ciliated projections, one above each auricle ; the auricles themselves are decidedly larger than those of Copews Cerberus. The nervous ganglion consists of three distinct parts: a broad upper portion filling up the head; a narrower truncate part, projecting downwards to the top of the mastax ; and a long flask-shaped body, the lower end of which, at times, reaches almost to the bottom of the mastax. There is a splendid crimson eye, and a very well developed vascular system. ‘The rest of the internal structure requires no notice. It is a sluggish creature, loving to creep among the algw; but at times it will pro- trude its auricles and swim off into the open, giving one, as it turns, a good view of the peaked gutter, in which the ciliated face projects in front of the mastax, just as in Copeus spicatus and C. labiatus. Although mine was but a young specimen, still it was a handsome Rotiferon; and a full-grown one of #5; inch (Ehr. loc. cit.) would certainly be one of the largest and most striking of the Notommate. I am indebted to Mr. Thomas Bolton for this rare animal. Length. My specimen, 7, inch (Ehrenberg’s, y', inch). Habitat. In water from Sutton Park (T.B.): rare. ' I once saw half a dozen of these lively creatures, all in a row, attached by their toes to a delicate green filament, and whirling round it like gymnasts on the horizontal bar.—C.T.H. 28 THE ROTIFERA. Genus COPEUS, Gosse. [GEN. CH. Usually of large size, ventricose behind the middle, furnished with organs of sense! in the lumbar regions ; brain usually threefold ; body tailed. The type of this natural group is, as already observed, Notommata copeus, of Prof. Ehrenberg, which I propose to honour with his own name, Copeus Hhrenbergi. As I have myself found several other species closely allied to this, yet quite distinct, in a very brief period, and in one locality, it is probable that future research may considerably augment their number. The feature which peculiarly marks the genus is the existence of organs, doubtless of some unknown sense, not only in the vicinity of the great brain (where their presence is quite normal), but in the lumbar region of the trunk, far from the brain, where it seems strange to find them, and where the form and conditions of the surrounding parts seem to preclude their advantageous exercise. This, however, is but the expression of our ignorance. In many cases there is some extraordinary development of the ciliary system, in the shape of wide expansions of the face, or remarkable forms of the auricles, lately described; and sometimes the tail takes unusual shape and size. The skin, in several cases, has the power of secreting a dense mucus, insoluble in water, so as to constitute a thick coherent mantle for the animal, in which extraneous matters are entangled; and the production and retention of this seem to be subject to the animal’s will. It is perhaps in harmony with this specialty of sense-development that the brain itself is generally of great size, and of complex form ; for there is often, in addition to the central sac, which is sometimes pyriform with a tubular stalk, a secondary sac on each side. The species are for the most part of large dimensions, heavy and unwieldy in motion, and vegetable feeders.—P.H.G. | C. LABIATUS, Gosse, sp. nov. (Pl. XVI. fig. 1.) Notommata centrura . 6 : Leydig, Ueb. d. Bau d. Rdderth. p. 33. Taf. iii. fig. 21. [SP. CH. Lumbar regions furnished on each side with a stout seta (apparently single) projecting horizontally ; tail pointed; chin projected into a long, horizontal, channelled, ciliated process, very versatile ; brain threefold. This noble species I at first thought to be the N. copews of Ehrenberg. Yet the dissimilar structure of the head presently showed that it is quite distinct.2_ There is no trace of the great lateral telegraph-like arms which project from the head in C. Hhren- bergii; what answer to the auricles being small ciliate channels, bent-over at their ends, into which the front is produced on each side. These cilia are continued along the frontal margin: while from the lower part of the face projects horizontally forward a very moveable lip in the form of a great fold of transparent flesh, of which the two sides, sloping outward, make a channel as long as the width of the head, deep at the base, but coming to a point, its edges, which fold over toward the hollow (see fig. 1a), being fringed with locomotive cilia. From the occiput projects, pointing outward and forward, a stout antenna, of outline swelling to about seven-eighths of its height, then diminishing with an angle, to a truncate end, whence issues a brush of divergent sete, evidently connected by internal nerve-threads with the brain beneath. The ciliation of the face reaches far below the lip on the ventral surface. The longitudinal muscles are very numerous and conspicuous. Immediately behind the front is a row of (at least) fowr oval translucent masses, which may be compared with the globose masses in the head of Hydatina _ 1 An account of these ‘‘sense-organs,”’ “‘antenne,”’ or “ tentacles,” in the whole Class, will be given at the end of Part VI.—C.T.H. 2 Dr. Leydig, who (loc. cit.) has well described and figured this species, assumes that it is the N. centrura of Ehrenberg. But so practised an observer could not have overlooked the great lip, if labiatus had indeed been before him. NOTOMMATAD-®E. 29 senta and Huchlanis deflexa; these appear to be quite independent of the great brain proper. This is here triple; the middle lobe is pear-shaped, depending considerably below the mastax, with a long slender neck, quite pellucid, having a great red eye seated near its mid-length ; on each side is a similar but shorter lobe. The trophi are of the pattern in N. awrita: each uncus is somewhat slender, and seems to comprise but two fingers; but, from the opacity of the parts, I am not certain. Under pressure, there seemed to be five, blade-shaped, and closely parallel. A very long cesophagus leads to a wide and ample alimentary canal, divided by a sensible constriction into stomach and intestine, even when there is no diminution in their common outline. But this condition I saw rather suddenly much altered; so that the constriction was made as manifest as if a cord had been drawn tightly round. Both stomach and intestine were, in all specimens that I have seen, moderately full of dark yellow-brown granular food, interspersed with orange-coloured oil-globules, brilliantly refractive, most thickly at the pyloric end. The alimentary canal, when moderately filled with food, has a very peculiar appearance, as if divided by constrictions, both transverse and longitudinal, into squares. This is not accidental, but characteristic, bemg seen in every example that has occurred to me, and distinguishing the species from all its congeners. A pair of ovate, colourless gastric glands are seated on the two shoulders of the stomach. The contractile vesicle is large; the branchiew take the form of two very long, and very slender bags, transparent, but much corrugated, rather than of convoluted cords. I counted three vibratile tags, which happened to be all on the same side: one level with the eye, one with the lumbar seta, and one intermediate. The ovary appeared normal. ‘The fusiform body ends in a well-marked tail, stiff, transparent, tapering to a point, but diminishing abruptly in the middle, forming a distinct shoulder there. Through it runs a pair of chain-like glands, resembling those in the toes, supposed to be mucous. A foot of two joints carries a pair of straight, short, conical acute toes. The manners of this striking creature were rather sluggish, though it moved and turned and twisted about restlessly. I did not see it swim. I had an interesting observation of the character of its food, and of its mode of feeding. The water was much stocked with the finer desmids and diatoms,—great Closteriums, Euastrums, Cosmariums, and the like. I caught my Copeus eating a great Epithemia turgida. He had evidently only just seized it with his protruded jaws, and had drawn one end of the desmid into his mouth, and was vigorously biting it. After a while, the frustule was pierced, as was seen by the cloud of dark granules that rushed down the mastax. All the contents were quickly sucked-in, till the shell was as empty and clear as a glass vessel ; to the manifest increase of the dark contents of the alimentary canal. Then it was contemptuously thrown away. Another had partly gnawed through a slender fila- ment of conferva, and had extracted, and was still extracting, the green granules from its interior, just at that part. Afterward I saw it devouring a small crescentic Closterium. This it ate up bodily ; and it occupied considerable time, even after the desmid was within the buccal funnel, and the end within its jaws. Thus it appears that this large species is a true vegetarian in diet. I have seen several more, all from a ditch in Sutton Park, Birmingham. All agree in these characteristic details. Each one has been quite clean, and totally devoid of any gelatinous covering.—P.H.G.] Length, ;'; inch; width, 4, inch. Hab:tat. Birmingham (T.B.). C. sprcatus, Hudson. (Pl. XVI. fig. 2.) Notommata spicata : Hudson, J. Roy. Micr. Soc. 2 Ser. vol. v. 1885, p- 612, pl. xii. fig. 5. (SP. CH. Lumbar regions furnished with tubules, setigerous at their extremities ; two occipital antenne ; brain threefold ; tail saccate. In this species we see two pairs of what we may call tentacles, of consimilar 30 THE ROTIFERA. structure : the one pair (the ordinary antenne) seated on the occiput, the other on the hinder part of the trunk, one on each side. Hach tentacle consists of a tubular column, which has a thickened extremity, whence issues, in the anterior pair, a brush of divergent sete; in the posterior, a single seta; all of great length and tenuity. The lumbar tubules are much more slender than the occipital, but are twice as long; and the increase to the terminal knob is much more gradual. The general form is sub-cylindrical, becoming more ventricose at the hinder part, then abruptly diminishing. But this form is subject to constant alteration, as the animal is ever lengthening or shortening, swelling one point, and contracting another. A very curious appearance is presented by the two sides at intervals. There is, near the middle of each side, a portion of the outline, which is now and then thrown into folds,—not constrictions of a rounded saceate body, as usual, but presenting the exact appearance of a single thin tissue, the edge of which is thrown into sharp, minute, and close-set wrinkles, like those of a frill of crimped muslin. The appearance is very fre- quent, seldom lasting more than a minute or two: not peculiar to one individual, but common and characteristic. I cannot explain it. The body is contracted into a true tail, which is of a thick sub-cubical form, corrugated with strong folds of the skin, like that of C. pachyurus, presently to be described, but smaller. Below this is a small foot, bearing a pair of furcate toes, short, taper, and drawn out to excessively slender points, often slightly incurved, the flexure varying in different examples. The frontal cilia ap- pear to be seated on slight eminences. The face projects into a channelled protrusile lip, whose edges are ciliated; agreeing both in shape and structure with the like organ in C. labiatus, but not nearly so large (figs. 2a, 2b). The brain is 3-lobed, composed of three pyriform ovate sacs; the outer two clear, the middle one shorter, and turbid or almost opaque, with a broad red eye lying transversely across its upper part, in shape like a shallow lens. The trophi are large and distinct, of the form seen in Notom. aurita. A long esophagus leads to an ample alimentary canal, on which are seated a pair of kidney-shaped gastric glands. In the specimen which I have delineated (and I have observed it in others), the alimentary canal formed a great bag, one side of which was smooth and expanded, a most delicate transparent tissue, enclosing many small diatoms and other algew; while the other half was thrown into close longitudinal wrinkles. Within it were four or five oil-globules of brilliant orange-hue, varying in size, the light refracted through which made very attractively beautiful objects, as the focus was ever and anon changed. The ovary takes the form of a long and slender band, full of clear embryonic vesicles, passing in a sigmoid curve from near the gastric glands to the bottom of the cavity. At its hinder extremity was an ephippial egg, covered with transparent spines, broad-based, much curved, much like the prickles of a rose, of whose development Dr. Hudson has given an interesting account (loc. cit.). Just above this was another smaller egg, maturing and already opaque. The undeveloped portion of the ovary is speckled all over with minute light-refracting dots. The branchie take the ordinary form of slender, somewhat twisted cords, probably tubular throughout, beginning apparently at the front face, by many attenuate ramified channels, with doubtless open ends, to receive the influent water for respiration; and terminating each on one side of a large contractile vesicle, occupying the hinder end of the visceral cavity. Hach branchia has attached to it by a slender stem a pear-shaped bag, which hangs free in the cavity, at about mid-body ; and, a little below this, an ovate enlargement, which is sessile by its whole side. The contractile vesicle takes a globose form when full; when it is seen to have a number of very minute clear glands (?) scattered over its surface. I found the period of filling, between one contraction and the next, to be just three minutes. At the point where the pear-shaped bag is given off, each branchial cord adheres firmly to the epithelial lining of the skin; but is free above and below that point. I searched carefully, but vainly, for any vibratile tags in the course of either branchia. But, in one I saw, in a very slender offshoot, close to the attachment of the pear-shaped bag, which yet was not a “tag,” a vibration exactly similar to that of a NOTOMMATAD/S. 31 ‘‘tag.’’ From each toe runs up a thread, which in the foot dilates into an ovate gland, studded with minute vacuoles. Probably these are mucous glands: but no mucus- strings were visible from the foot, nor any gelatinous envelope of the body, in all the specimens (nearly a score) that I have examined. The brush of each occipital tentacle (antenna) consists apparently of three, or at most four, sete ; each lumbar tentacle carries but a single seta. Through all, lines are seen running down from the set to the base. From the base of each lumbar tentacle the thread which descends from the seta is distinctly seen to pass for some distance up the visceral cavity toward the brain, till it can be no longer distinguished among the multitude of lines. On the other hand, the thread issuing from the base of each antenna may be traced to the very summit of the brain. This is, perhaps, the largest of all known Rotifera. Some among the Rhizota may exceed it in length, a great part of which is occupied by the foot of almost linear tenuity. But, bulk for bulk, Copeus spicatus far exceeds them all. It is a noble, as well as a very interesting, member of its class. Viewed on the stage of the microscope, we forget that we are contemplating a speck, such as a lady’s cambric needle might prickina sheet of paper, and are struck with what we are ready to call its gigantic dimensions. For, with a half-inch objective, it almost crosses the round field of view, and with a quarter, such as is needful to interpret the organization of the Rotifera, we are obliged to examine it piecemeal ; for a large portion of the creature is necessarily beyond our vision. Its great size, slow movement, and brilliant transparency make it a subject very favour- able for observation. Perhaps this is the finest addition made to our knowledge of the Rotifera since Ehrenberg’s magnum opus. And we owe our acquaintance with it to Dr. Hudson, who named, described, and figured it in the ‘“ Journ. Roy. Micr. Soe.’’ for May 1885. It was discovered by Mr. Bolton, who sent him specimens, as he has lately sent to me also, obtained from Sutton Park, Birmingham.—P.H.G.}! Length (moderately extended), 54, inch; width, ;}5 inch. Habitat. Birmingham: Coleshill (T.B.); Sandhurst (Dr. Collins). C. pacHyurus, Gosse, sp. nov. (Pl. XVI. fig. 4.) (SP. CH. Front furnished with a pair of long and thick auricles projectile and retractile ; lumbar regions with tubules, destitute of sete ; tail saccate. The general accuracy of Prof. Ehrenberg’s details, where he gives them, makes me distinguish this species from his N. copeus; though it comes very close to that fine species, perhaps even closer than does Dr. Hudson’s N. spicata, or any other. It is, in- deed, less than half the size of Copeus (= Ehrenbergit), my specimen measuring 7; inch in length, when moderately extended ; I could not be sure that the brain had more than one lobe; the lumbar tentacles are placed far back, as in spicatus, and differ in apparent structure from those of either; and finally the tail is neither a minute conical tubercle nor a long stiff pomt, but a wide sub-globose sac (as in spicatus, but far larger), whose walls are thrown into stiff sharp folds, as if composed of a firm leathery skin. Yet the general aspect is that of Hhrenbergii; the auricles have the same form and direction, and the same comparatively large dimensions. Ordinarily they are quite un- 1 A side view of this fine Rotiferon has been accidentally omitted from pl. xvi.; but will be given in pl. xxx. It shows that the two occipital antenne are connected by a transverse ridge crossing from the base of the one, to that of the other. My solitary specimen had a semi-transparent gelatinous covering, out of which peeped the ends of the four tentacles. The ephippial egg, when I first saw it, was quite smooth, and separated by a clear space from its outmost covering. I saw its prickles begin to grow, and watched them slowly stretching across to the outer shell. Two hours elapsed before they had accomplished the distance.—C.T.H. 82 THE ROTIPERA. suspected, being absolutely concealed within the rounded outline of the head ; but, at the will of the animal, are suddenly pushed out horizontally, by eversion of the skin, to a leneth more than half the diameter of the head. They then form oblique cones, which are truncate at their tips; but the skin there, which seems in some sort double, is at every instant drawn in a little, as if very sensitive. The outer upper corner of each is richly ciliated ; and the ciliary action, at this point of each, makes a strong vortex, into which floating atoms are drawn, and whirled round as in those of the Bdelloids. The auricles are often extruded when the animal is not swimming, but grubbing among the sediment ; and they do not sensibly augment the speed, then; butif extruded during the swimming, they do so notably. Each can be thrust out in varying degrees ; and very often one is out while the other remains concealed: they are manifestly very flexible. No antenna from the occiput is visible; and the tentacles on the lumbar regions are very minute tubules projecting through the internal skin, and con- nected with a visible basal area on the exterior of a vascular membrane which sur- rounds the abdominal viscera. I can discern, even with a high power, no set at the tips of these tubules: but possibly these may be retractile. Indeed, the tubes them- selves are not always apparent. After death, the ventral surface being in view, a thread was distinctly seen on each side proceeding from the base of the lumbar tentacle, dividing into two branches at about mid-length, and going up to the sides of the brain. Bach thread, both before and after the division, had a sensible diameter, and showed a double outline. No under lip breaks the uniform rotundity of the frontal outline. But, in a ventral view, when it was still and contracted in dying, I have observed an ovate line, as of a minute orifice, just within the edge (fig. 4b), which may possibly have marked the place where a lip had protruded. The general figure of the animal much resembles that of N. awrita; but is more variable, as if the integument were softer and more flexible. A momentary glance while it was turning left the impression that a segment would be as at fig. 4a; as if the ventral surface were dilated and flat. The skin was free from gelatinous envelope. A stout foot of three joints carries two toes of the blade-form, stout, of uniform width, somewhat long, straight, and pointed. Behind them, separated from them by the cloaca, and from the gibbosity of the trunk by a strong constriction, there is a large bladder-like inflation of the skin, thrown into strong folds or creases, which must be taken to represent the tail. It is colourless, and appears quite empty; it is constantly changing its outline, but ever falls into the same folds. It is slightly bilobed, and seems somewhat dilatable. This great fat ventricose tail is a conspicuous character, by which this species may in a moment be recognised. The internal economy is, in most examples, sufficiently clear. A three-fold brain is seen: the mid-lobe pear-shaped with a long slender neck, the bulb reaching far below the mastax; the side-lobes compara- tively short. I have seen the mid-lobe filled with granular matter, not quite opaque, but darkly turbid. A deep-red eye, large, oblong-square or ovate, is seated on the neck of the mid-lobe. An ample mastax, with normal trophi, nearly fills the breadth of the pectoral region; followed by a vast stomach, in most examples, densely filled with dark- brown conglobate rolls of food; sometimes with no glands visible, at others with two small glands, dark, with a large oil-globule within each, of deep orange hue, whose rich refraction of light has a very striking effect, like a pair of coloured carriage-lamps. The ovary often has a great egg, nearly mature. Lateral canals, one on each side, are more or less clearly discerned, on one of which I have seen one vibratile tag; but I have not been able to detect a contractile vesicle. In manner of life this, like its congeners, is dull and slothful, rolling stupidly and aimlessly about, and ever altering its form, but not much given to locomotion. Now and then, however, it seeks a new locality; and then it shoots away in a straight line, with considerable swiftness and grace, cleaving its path, with dilated front, through the water. Iwas so fortunate as to be present at the dinner of this species, as I had been at that of C. labiatus. Several large alge were strewn around, among them a Closterium, NOTOMMATAD Al. 33 dark green, very slender, nearly straight, and longer than the Copeus (perhaps C. line- atum). The animal attacked two of these in succession, taking hold transversely, yet not attempting access there. But feeling its way, it worked, very cleverly, and with manifest intelligence, till its jaws reached the tip. At this, then, they worked eagerly, drawing it in, so that it stretched out lengthwise from the head. No impression, how- ever, was made on the flinty frustule, and it was presently relinquished, to attack another, equally in vain. After some hours, I perceived that it was essaying food again; and again one of the same long Closteriwms, which now was drawn far down the buccal funnel; while the mastax in its usual position had already eaten a good deal of the desmid, chewing it away, as one would eat a radish. The great auricles (in this very example) were reluctantly and charily put out. They would not be suspected at other times. During several hours’ observation I saw them extruded only on one ocea- sion, when the creature was gliding through clear water. And then, it thrust out first one and then the other, timidly and tentatively, as it were, and drawing each back before it was nearly out; then again protruding it; till, by this time, some impediment was reached, and I saw neither any more. Such was yery much my experience of others also. The first specimen that I saw occurred in water sent me, in June, by Dr. Collins from his ‘‘ happy hunting-ground”’ at Sandhurst. But more recently Mr. Bolton has sent me examples from the prolific ditch in Sutton Park, near Birmingham, where it revels in company with labiatus aud spicatws.—P.H.G.] Length, 7, inch. Habitat. Pools and ditches where the larger Diatomacee@ abound. Sandhurst; Birmingham (P.H.G.). C. caupatus, Collins. (PL XVI. fig. 5.) (SP. CH. Form slender, swelling in the middle; auricles wanting ; one occipital antenna, and one lumbar tentacle; tail minute. In “Science Gossip ”’ for 1872, Dr. Collins described and figured this Notommata of singular facies. I had long desired to examine it, having had my curiosity excited, not only by the brief diagnosis of its discoverer, but by numerous pencilled sketches in his well-filled note-books, committed to me from time to time by lis courtesy. At length, by his kindness in sending me samples of water from the original habitat, I have been gratified by the sight of several specimens in healthy activity. It is a species much more abnormal in appearance than in structure: an appearance which depends on the seeming severance of the head from the body by a long interval. The head is large, somewhat square in outline, and, owing to the definition of the brain with its eye, and of the mastax, it catches the observation in a moment. Then follows a neck of unusual length; and though its thickness is scarcely less than usual, its extreme transparency and colourlessness render it hardly visible till focussed ; and it contains no organs, save on each side the twisted lateral canals, of such filmy mistiness as scarcely to be perceptible when searched for; and so there seems nothing at all, save the wsophagus, a tube of great subtleness and slenderness running through the middle of its entire length. We seem to see an oval abdomen filled with viscera, and a head tied to it at the end of a long string. The head carries at each frontal corner a small globe refractive of light, which I take to be an auricle, though I have not seen them retracted or pro- truded, nor are they manifestly ancillary to speed, being visible uniformly in the animal's twinings and crawlings. The frontal surface between these auricles bears vibratile sete, as well as ordinary locomotive cilia. A large well-developed brain occupies the whole width, and descends, sack-shaped, far down the occiput, bearing on its facial side a bril- liant crimson globular eye, and in its rear, supplying a nerve-thread to the sensitive seta which runs through an antennal tubule, projecting from the back of the head (figs. 5c, d). A mastax of ordinary form in the family has the bent mallei of some thickness. It is figured at 5b from some very good observations, though, from difficulties inseparable VOL. Il. D 3B4 THE ROTIFERA. from the circumstances, I dare not vouch for the minute details, particularly of the incus-rami. The respiratory organs, in the form of slender cords, loosely twisted together, but, as I presume, tubular, can be traced to the very front of the head; at least to the point on each side where the proximity of the brain to the integument allows them to be no longer discerned; and thence backward without interruption, till their ends ramify and are lost on the walls of the ample contractile vesicle that occupies the termination of the abdominal cavity. It was an operation of much delicacy, but with a }-in. obj. I think I satisfactorily followed the entire course described. In the ample abdomen the viscera are large. The alimentary canal is clearly separated into a stomach and an intestine. In all the individuals examined, neither of these held any visible food, but both were tinged with pale umber-brown. An ovary of embryonic ves_cles, and a great dark ripening ovum, were conspicuous in one. At the expansion of the long cesophagus into the stomach are the pair of ovate colourless glands, which possibly are biliary, and may impart the prevalent yellow-brown tinge to the digestive canal. ‘The dorsum, just before the point where it contracts into the foot, rises into an angular prominence ; which must be regarded as a true tail, because beneath and behind it is the common excrementary outlet, whether for matters urinary or feecal—the cloaca. The anterior side of the orifice is crowned with a bristled tubercle (fig. 5d), very closely resembling that projecting from the hind head. It seems a tubular wart with a thick- ened rim, bearing a rather short seta on the summit. From the base of this are discerned, clearly running down through the transparent tube, two fine lines, which probably are the optical expression of a nervous cord, bending forward to some sensible distance up the body, till lost behind the viscera. I searched (vainly) for some ganglion in the vicinity, with which this thread may communicate. But I rather presume that it runs through the body, and communicates with the great brain at the very front. It seemed to me that each of these tentacular warts, both that on the head and that on the tail, is susceptible of sensible elongation, and of occasional withdrawal, partial or perfect. The foot is slender and colourless, like the anterior parts, and is terminated by two minute and delicate toes; from which two long, club-shaped muscles pass forward nearly to the cloaca. The species was discovered by Dr. Collins in 1865, in a small pool near Sandhurst Military College, whence he has recently sent me a supply. There seemed here the exercise of a sense of companionship, at least in captivity. After some days this species became rather numerous in the bottle of water-moss, and I have had, perhaps, a dozen in my live-box at once, of various ages. I noticed, much too often to be merely fortuitous, that they were in the habit of associating in couples, two being generally in close contiguity, and now and then coming into actual contact; the one crawling, in their lithe embracing manner, over the foreparts of the other; separating, howeyer, immediately after. It was not sexual. In young individuals, not more than half as long as the adult, all the characters are developed; except the great length and almost inyisibility of the neck, which are not so manifest.—P.H.G.] Length, 3, inch. Habitat. Sandhurst, Berks (Collins); Dundee (P.H.G.). C. CERBERUS, Gosse, sp. Noy. (Pl. XVI. fig. 3.) Notonunata centrura. Gosse (nee Ehr.), Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 200. [SP. CH. Tentacles wholly wanting (or unobserved) ; auricles small; brain three- lobed ; tail a minute tubercle. ‘This species approaches the ordinary Notommate, in form and in the absence of those projected organs of sense which characterise the other species of this genus. Yet the general aspect, the sluggish manners, aud the three-lobed brain, seem to war- NOTOMMATAD 45. BS rant me in placing it in this genus. Indeed, when, five-and-thirty years ago, I first met with it, I concluded that it was identical with Ehrenberg’s N. centrura. But I have lately seen several more examples, which have convinced me that it is still an un- described species. The form is rudely cylindrical, with many irregular constrictions, and the abdominal regions somewhat swollen. The front is rondo-truncate, with a minute auricle on each side. These seem scarcely protrusile, though the oval space in which ciliary action is seen appears in each. The ciliated face is prone, and reaches far down; no lip appears. At the hinder extremity there is a distinct tail, small, saccate, almost amorphous, beneath which the cloaca opens, as I saw by the actual emptying of the rectum. A very short foot carries two minute, conical, pointed toes. The brain consists of three sacs, of which the central hangs low, being seen behind the mastax, and as usual forms a long tube at the origin, in which is the eye of lenticular form, and brilliant crimson hue. The lateral sacs are moderately short. All three are more or less occupied with opaque granular matter; but in the central sac this is generally (not always) so much diluted as to be pellucid. The central sac, too, is occasionally seen truncate at its lower end, exhibiting very distinctly at its margin the separate cells of which it is composed. The trophi are normal: the mallei apparently four-fingered. The alimentary canal is large, saccate, furnished above with small globose gastrie glands, and not sensibly divided ; its central longitudinal cavity may usually be traced, full of digesting food of a dark umber-hue, while the thick surrounding walls are tinged with the same. The vo- luminous ovary, forming a wide horseshoe across the ventral region, its horns directed backwards, is full of clear embryonic vesicles, and often carries a dark maturing egg which I have seen discharged. The branchial system has the usual form of a rather thick cord (probably tubular), not twisted, but hanging so loose as to be thrown into many curves, with at least three vibratile tags on each, and the usual contractile vesicle of moderate size occupying the hind mid-yentral region. Muscles, both longitudinal and transverse, agree with those that I long ago demonstrated in Not. awrita.! The whole head is usually tinted with buff, and the mastax-front with red-brown. My first example of this species was found in June 1850, in a phial dipped on Hamp- stead Heath three weeks before. The more recent were in the sediment of a phial sent me by the kindness of Dr. Collins, from the historic pool in Sandhurst Wood. The creature, like its congeners, is slow and deliberate in manners, burrowing and rooting in its floccose surroundings. Its motions are much like those of the water-bears ; in- deed, on first catching a glimpse of my subject among the half-hiding sediment, I have repeatedly been doubtful whether I was looking at a Tardigrade or one of these massive Notommatade.—P.H.G.] A specimen of Mr. Gosse’s Copeus Cerberus, which I found in some water from Sutton Park, Birmingham, enabled me on one occasion to obtain an excellent view of the mastax and trophi; for it every now and then slowly turned its head back, so as to bring its ciliated face up to the cover-glass, and thus to rotate the mastax, for me, with all its parts in their natural position. I could distinctly see the massive malleate trophi unusually thick and broad ; the short, wide, yet graduated teeth of each uncus opposing each other at the top of the mastax, like the fingers of the two hands brought just to touch at their tips. Immediately above them were two very prominent lips, like a parrot’s beak, and evidently of a much harder substance than the rest of the mastax : they were seated upon it, on each side of the opening between the buccal funnel and the teeth. These I saw repeatedly open and shut as food passed down the funnel to. the trophi. Length, ,\, inch. Habitat. Hampstead Heath; Sandhurst, Berks (P.H.G.). a ' Trans. Mier. Soc. Lond. vol. iii. p. 101, pl. xv. 86 THE ROTIFERA. Genus PROALES, Gosse. GEN. CH. Of moderate or small size; body generally cylindric, or larviform ; ciliated face more or less prone; brain clear ; auricles and tail wanting. This again is an extensive group, containing many species, some of them of familiar occurrence, often obscure, of indefinite character, and hard to be distinguished. Some are entozoically parasitic on other creatures. The vibratile cilia are disposed on a face, along that side of the head which is more or less in the ventral plane. Their bodies are usually lithe, soft, and versatile; their motions rapid and various. P. peciviens, Hhrenberg. (Pl. XVIII. fig. 6.) Votommata decipiens . : . Ehrenberg, Die Infus. 1838, p. 431, Taf. lii. fig. 6. $5 vermicularis ; 5 Dujardin, Hist. Nat. Zooph. p. 648, pl. xxi. fig. 7. [SP. CH. Body cylindric, slender, worm-like ; foot wndeveloped ; toes minute. This much resembles a dipterous larva; having a soft, flexuose, slender body, with a rounded front, and two minute, conical toes, without any sensible foot. A large, oc- cipital brain carries a red eye, distinct, though small; a erystalline lens is conspicuous, seated on, and partly imbedded in, the pigment-globule ; the latter much the larger. (See Duj. loc. cit.) Near the front are two clear colourless granules, usually distinct in the many examples that I have met with. These may be readily mistaken for eyes when the animal is in motion. A mastax with trophi of normal form leads by a very long and slender esophagus to a cylindric alimentary canal, with usual accompaniments. T first found this in 1849, in waters near London both north and south, Since then it has occurred repeatedly in various localities. When I saw my first example, it was spinning round on its long axis. After a while it became less impatient, but still very lively. It frequently bent itself up double, in the manner of a caterpillar, and occasion- ally shrank up into a wrinkled, shapeless ball, remaining thus awhile quiet. Gliding through the water by means of its rotatory cilia, its motion was not particularly rapid. Though I have called the trophi normal, there is, in the form of the rami, a manifest approach to these organs in Diglena.—P.H.G.] Length, ;4, to 4; inch. Habitat. Near London; Epping Forest ; Birmingham ; Stapleton Park, Yorkshire; Dundee (P.H.G.): pools: not common. ; P. revis, Ehrenberg. (Pl. XVIII. fig. 17.) Jotommata felis . : . Ehrenberg, Die Infus. p. 431, Taf. lii. fig. 7. [SP. CH. Body cylindric, slender ; a large decurved fleshy proboscis ; eye very large ; trophi Diglenoid ; foot stout ; toes slender, pointed. Of this little species, the slender trunk is strongly fluted longitudinally. The curious projection which Ehrenberg calls a horn, is a thick soft lobe of translucent flesh, which curves down before the head, perhaps a tentative organ, and recals what we see in some of the Diglene. So also do the pincer-shaped rami; and, as in that genus, they are capable of being rapidly and forcibly thrust forth, with a snapping action. The brain is broad, and descends far ; it bears on its round extremity an eye so large that it occupies fully half the diameter of the body. Yet it is seldom seen; being a lens seated transversely, and edgewise to the observer. The stomach too, with high lateral shoulders, usually densely filled, hinders the observation, not only of the eye, but of all NOTOMMATAD. 387 the viscera.'| Its manners are lively and restless; rarely swimming, but incessantly boring and pushing through the yellow sediment in which it chooses to dwell; and that so pertinaciously, that when it comes to the edge of a mass, it will not (or very rarely) go on into the clear, but turns back, and bores its path anew. If it does sail out for an instant, it presently stops short, turns tail, and hurries back to its cover. I have seen the pincer-jaws rapidly protruded almost to their full length. I have seen many speci- mens, in water and sediment from the ditch in Sutton Park, Birmingham, which Mr. Bolton has so successfully explored. The new Rotifera Plewrotrocha mustela lately described and figured by Mr. W. Milne (Trans. Phil. Soc. Glasgow,” 1885), is very like the present species. He has represented the male, which closely resembles the female, but is smaller, and devoid of digestive system. The memoir is of high value.—P.H.G.] Length. About y!, inch. Habitat. A ditch near Birmingham (P.H.G.); Glasgow (Mr. Milne). P. aippa, Ehrenberg. (Pl. XVIII. fig. 8.) Notommata gibba . : ° c Ehrenberg, Die Infius. 1838, p. 430, Taf. lii. fig. 4. (SP. CH. Body compressed; back much arched, deeply incised above the stout foot ; toes slender, pointed, slightly decurved. The fore parts are separated from the trunk by a marked infolding, as well as the foot; this latter constriction, when viewed sidewise, forms a deep sinus. The first example that I met with was in Noyember 1849, in a pond at Battersea Rise. I afterwards found other specimens. The front is prominent and round; over it pro- jects a semi-ovate plate apparently slightly bent downward, on each side of which is a fine seta. Perhaps the more natural place of this species would be in the (restricted) genus Notommata, near lacinulata. But the ciliated face is prone. The brain descends bag-like, into the occiput, and bears a wart-shaped red eye on its very end. The taper rectum terminates in a cloaca, in the deep posterior infolding. A minute contractile vesicle is in almost incessant contraction. The foot, with its curved toes, is often thrown forcibly back, in the manner of Rattulus. The animal is lively, actively swimming, and contracting strongly as it goes, and throwing the toes backward and forward.—P.H.G.] Length, ,1, to s1, inch. Habitat. Battersea; Stapleton, Yorkshire; my domestic aquarium (P.H.G.): rare. P. sorDIDA, Gosse, Sp. Nov. (Pl. XVIII. fig. 7.) [SP. CH. Body nearly cylindrical ; head broad, truncate ; foot very broad, with a depression through the median line ; toes minute, conical. This is a somewhat clumsy, ungraceful, unattractive species. The whole integument is flexible, and thrown into transverse folds, though seemingly stiff. The corona is broadly truncate, formed by numerous ill-defined globose masses, on which the cilia are grouped. The whole front is capable of little expansion or change, and the motion consequent, not very swift. The mastax is ample, of the Notommatous pattern ; behind which a brain, moderately developed, carries a red eye, on its side. The eye is often invisible ; then suddenly appears as a minute speck (or, as I once saw, two red specks, apparently in contact), or, often, as a well-defined considerable mass of rich colour. I 1 Herr Eckstein (Sied. wu. Koll. Zeits. 1883, p. 363, fig. 29) describes and figures a pair of minute dark-red points one on each side of the front, whence a brush of sete springs. These I have not seen but cannot doubt that they are of the nature of antenne, and that the red speck is imaginary. He describes the proper eye besides, and notices the distinct refracting lens, by which it is embraced. 38 THE ROTIFERA. have seen the saccate brain at its hinder end, densely opaque in a great ball, just as in N. aurita, while all the remainder was clear. In every other respect the specimen was a normal sordida. The most observable characteristic of this species, by which it may without fail be identified (for it is quite constant), is the condition of the foot. The hinder half of the trunk, viewed dorsally, insensibly diminishes to a width about one- third that of the widest part, where it is abruptly truncate; the hind half of this is separated by a slight fold, and appears to constitute the foot-proper. Yet there are no visible joints in it, and its outline, as I have said, simply continues the gradual tapering. Down the middle of this foot there runs what seems a shallow depression, crossed by two similarly depressed transverse lines, and the whole ends in two small conical toes. When once this peculiarity has been noticed, there is no mistaking it. I first found the species in a tube sent me by Mr. Hood from Dundee, and since then in water from Miss Saunders of Cheltenham, and abundantly from Woolston, sent by Miss Davies. Some of these last were hyaline, and more active.— P.H.G.] Length, ,;|,5 to 4, inch. Habitat. Many localities in England and Scotland: common in pools (P.H.G.). 7% ; P. TiaRipia, Gosse, sp. nov. (Pl. XVIII. fig. 10.) (SP. CH. Body cylindric or fusiform, curved in the manner of Rattulus ; foot and toes both long, and bent in a sigmoid curve. This animal, I do not doubt, has been confounded by observers, as it was by myself, with the N. tigris of Ehrenberg, but this latter I now relegate to another genus, in the Sub-order Loricarta. The present is certainly il-loricate, and its long ciliate face, almost absolutely prone, shows its affinities to be here, though it is certainly osculant with Rattulus. Its trophi, too, are symmetrical, and of the Notommatous pattern. The cilia of the face seem set on minute eminences; and there are longer set among them. The belly line bends upward and then downward to include the base of the deep foot, which again bends upward (i.e. backward) to the toes, and these bend downward at their tips. So that the whole line from the face to the toe-tips forms a double sigmoid curve of much elegance. In June 1885 I first became cognizant of this interesting form. It was haunting the decaying whorls of Nitella, in water from Woolston Pond, sent me by the kind courtesy of Miss Saunders. It has occurred also in other waters. It is an energetic animal, given to sudden and rapid changes of motion, shooting through the free water with great celerity, the toes stretching behind straight and parallel; now abruptly turning on itself to pursue another course, now arrested by a cloud of floccose, to dig into the decaying vegetation with apparent determination and vigorous perseverance. The digestive canal is almost invariably dark with granular food, of a deep rich-brown hue. A contractile vesicle is usually conspicuous. — P.H.G.] Length, ;}, inch. Habitat. South and Midland England; pools (P.H.G.): rare. / P. perromyzon, Lhrenberg. (Pl. XVIIL. fig. 9.) Notomimata petromyzon . 3 : ; Ehrenberg, Die Infus. p. 427, Taf. 1. fig. 7. [SP. CH. Body ovate ; foot long, stowt, and very distinct ; toes minute. The form is gibbous-ovate, truncate at each extremity, when contracted ; the head is rounded, pratrusile; the foot apparently of one joint, very large and long, but abruptly less in width than the truncate body whence it issues; the two toes are very minute cones. The character of the foot makes the species particularly easy of recognition. The sixaplicity of the trophi makes them very instructive. The incws-fulcrum is NOTOMMATAD A. 39 thin and blade-like, straight but slightly ineurved at the free end, deeply truncate above where the rami are jointed, which are long triangular blades arching backwards. The mallet are slender rods, each with a process, and an wneus of two fingers.! Ehrenberg describes the species as parasitic on the branching Bell-vorticels Hpistylis and Carchesium, among whose twigs it lays its eggs; and also in Volvox. I have seen it always free, though repeatedly in close association with both these Infusoria. I have been acquainted with it from many localities since 1850. It is lively in its motions ; yet frequently adhering to the glass, and moving by a feeble crawling ; it can, however, swim rapidly. Its contractions are almost perpetual, and very vigorous.—P.H.G.] Length, when extended, ;1,; inch. Habitat. Around London; Walthamstow ; Leamington Canal; Cheltenham; Woolston; Birmingham: pools and garden reser- voirs (P.H.G.). 2 P. parasira, Ehrenberg. (Pl. XVIII. fig. 11.) Notommata parasita. . c Ehrenberg, Die Infus. 1838, p. 426, Taf. 1. fig. 1. Hertwigia volvocicola . . é Plate, Jenaisch. Zeits. f. Natur. 1885, p. 26, figs. 7, 8. [SP. CH. Body cylindric or gibbous, rounded at each end ; foot and toes wanting. Parasitic in Volvox. To the characters just given may be added that the jaws are long, slender, protrusile, and asymmetric: the mallei being dissimilar in length and curvature; thus recalling the Rattulide. A brilliant crimson eye, wart-shaped, sits on the dorsal corner of a large occipital brain; from the front of which projects a club-shaped antenna, some- times drooping, sometimes erect. The prominent round head is clothed with fine cilia, and surrounded by a wreath of stronger vibration ; when this is retracted the margin is thrown into puckers. The habits of this inconspicuous species are curious; for it is parasitic within the spheres of Volvox globator. Examining this elegant creature, we may, even with a pocket-lens, discern which are tenanted, by a spot differing from the young clusters in form and colour. Such a spot proves to be the Proales, snugly ensconced within the globe, in whose spacious area it lives at ease, and swims to and fro like a goldfish in a glass vase. For the most part it affects the inner surface, engaged in devouring the green Monads that stud the gelatinous expanse, or else eating away the embryo clusters. Sometimes laid eges are present, with the Proales; sometimes eggs alone. The young seems always hatched in a Volvow, and, entering an embryo cluster, is expelled with it. Often they eat their way out, and swim atfreedom. Observing in a globe one large egg, I opened the globe with a needle, and freed the Proales, placing it in water, and adding several Volvoces, all untenanted. But it did not enter one, during several hours’ obser- vation. During this period it discharged, loose in the water, an ephippial egg, covered with prickles. I have seen a prickly egg and a smooth one, transparent, with eye and jaws visible, in the same sphere. One of the latter I saw hatched, the young just like the adult. The Volvox appears to suffer little from the depredations of its ungrateful guest. The Proales is lively and energetic in freedom. It glides wildly about, often in a zigzag course, turning from side to side, as it dashes rapidly along. Sometimes it rotates on its axis as it goes; or, becoming stationary, it turns on its blunt extremity, as ona pivot. Itis perpetually contracting and elongating, and throwing itself into angular folds and contortions.—P.H.G.] This is one of the partially loricated Rotifera. The soft front of the head, seen dor- sally, is truncate, and much like that of Notops hyptopus. The edge of the trunk, within which the head can be withdrawn, is chitinous, and scolloped in regular curves, just like the edge of a lorica. At the hind end of the trunk, and on the median line of the dorsal 1 See Phil. Trans. 1855, p. 432, pl. xvii. figs. 27-31. 40 THE ROTIFERA. surface, is a forked projecting pucker of the hardened skin, so greatly resembling the notch in the lorica of a Brachionus, that I thought at first that the structures were identical. Ehrenberg (Joc. cit.) says that the ereature has a minute, and slightly project- ing foot; which, as Mr. Gosse has stated above, it certainly has not: but it is clear, from Ehrenberg’s description and figure, that he has mistaken the forked pucker which I have just described for a pair of small toes; a mistake easily made when the dorsal surface is presented to the line of sight from a certain point of view. The animal’s dor- sal outlin® reminds one of Notops hyptopus ; which Rotiferon is also partially loricated. I have often seen one of these little creatures ineffectively nibbling at the gonidia of the Volvox which it inhabited ; but once I watched one bite its way into what was, I sup- pose, a softer place than usual ; and a moment after I saw a long stream of bright green globules course swiftly through the mastax, down the esophagus, and into the stomach.' Length, ;!, to ,}, imch. Habitat. Wherever Volvox is numerous: London, Birmingham, Leamington, Dundee (P.H.G.); Clifton (C.T.H.). Genus FURCULARIA, Ehrenberg. (GEN. CH. Body gencrally larviform, cylindrical, with a tendency to enlargement in the lumbar region ; usually compressed ; front conical, broad, and deep ; eye single, frontal, sometimes wanting ; ineus forcipate, much developed, protrusile; toes two fur- cate, usually conspicuous. It is not easy to attach to this genus such a definite character as shall be really use- ful to the student for identification and diagnosis. Ehrenberg is very vague. He gives but two distinctive points,—the frontal eye, and the forked toes. The latter is worth- less, as being indistinctive ; and the former is unfortunately not constant, or not always available. Eckstein’s character for the genus is really but the character of one species, inapplicable to others. Yet it is a good genus (as used by Ehrenberg, not by Dujardin), and easily recognized in almost all its members, by one who is personally familar with them. Possessing much resemblance to the species of the extensive genus Proales, the Furcularie have an aspect, as well as habits, of their own. Both aspect and habits are more easily detected than described. The front, more or less a low cone of wide base, in vertical aspect, with a minute but usually conspicuous crimson eye set at the very point, with no lateral developments—this is doubtless highly characteristic. So also are the toes, in general strongly marked, very active, and often thrown spasmodiecally backward, above the body-plane. There is one feature in their habits which is markedly prevalent: the predilection whieh many of them show for darkling retreats, and the tenacity with which they cling to them. No hare flees to cover more eagerly. Examples will be given in detail presently. The species are vivacious, energetic, restless, eager, predatory. The strongly deve- loped rami of the powerful incus, moved by proper muscles, are capable of protrusion from the face of the front, with a fierce snapping action, in which, however, they are rivalled by other kindred genera, such as Diglena and Distemma in particular. The recognized species are not numerous. Ehrenberg admitted four. To these I have added five others, including the F. marina of M. Dujardin (if, indeed, mine is identical with his); but one of Prof. Ehrenberg’s has not been yet met with m Britam. They are wide-spread, and are not very uncommon, in the sediment of pools and ditches. Two species which Ehrenberg placed in lis great genus Notommata, I prefer to place here.—P.H.G.] 1 Dr. Plate (Joc. cit.) has described P. parasita (Notommata parasita, Ehr.), male and female, as a new species under the name Hertwigia volvocicola, on account of its having no toes. Dr. Cohn gave an excellent figure of the male in Sieb. w. Koll. Zeits. 1858, but drew the female with two minute toes. NOTOMMATAD A. 41 ¥, vorricuna, Hhrenberg. (Bly XX tgs 15) Furcularia forficula . . Ehrenberg, Die Infus. 1838, p. 421, Taf. xviii. fig. 5. ” ” . 0 2 Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 199. A > 0 ‘i ‘ Lord, Micr. News, 1884, p. 235, fig. 27. [SP. CH. Body stout, straight, nearly cylindrical; broadest at the head, which comes to a frontal point, where is a single red eye ; toes two, furcate, blade-shaped, acute, decurved, the ventral edge of each notched with two strong teeth. The deep sickle-shaped toes, having their under-edges notched near the base, readily identify this.!| Its form is nearly cylindrical, slightly thicker in front; the back is sometimes gibbous, viewed laterally. The head forms a short regular cone, whose base is the width of the head, at the apex of which is placed the small but distinct red eye. The whole front appears set with cilia, which cause two vortices: a turbid occipital brain is visible, carrying the eye at its anterior extremity. In contaet with this as usual, is an ample sub-globose mastax, with characteristic trophi. A long csophagus leads to the alimentary canal, which has thick granular walls, and bears two large gastric glands. At times the dorsal portion of the stomach is inflated into a large clear bladder, which displaces the granular walls around it. As this often appears and vanishes rather suddenly, it has a singular effect. Towards the hinder part the granu- lation becomes less opaque; but whether there is any division between stomach and intestine has not been clearly seen. A small contractile vesicle les around the base of the foot, and I have sometimes been able to trace the lateral canals and vibratile tags. A small oblong or cord-like ovary generally occupies the venter, sometimes dilated into a maturing granulate ovum. Many longitudinal muscles are visible, but the contractions and contortions of the animal are so incessant as to render it almost impossible to define them. By these contortions the firm skin is thrown into various irregular angular folds. The foot seems composed of two joints, of which the basal is by much the stouter, each enclosing a gland. The curved broad blade-like toes bend downward at their sharp points; each is cut into a strong projecting sharp tooth at its base, and its foot joint immediately preceding has two teeth exactly similar. Ehrenberg alludes to this animal as very rare. I have been familiar with it for more than five-and-thirty years, and I consider it by no means uncommon. I used to meet with it in the waters around London, and have since found it in very many localities, often among conferva, and in the floccose sediment of ditches. In confinement it is often most restless, constantly swimming about with a swift gliding shooting motion, and throwing itself into frequent folds and twistings. The body is nearly colourless, but for the opacity of the granulate viscera, which appear white by reflected light. On repeated occasions I have observed, in this species, the curious habits already referred to of inhabiting tubes, for some unimaginable purpose, of its own ingenious manufacture. I cite the following note from my Journal, jotted down while under my eye. ‘‘A fine specimen I found tenanting a long curved passage, in the yellow-brown floecose from the ditch in Sutton Park. This was just wide enough to allow it to move freely, and to turn its soft flexible body, when needed. It was about twenty times the animal's length, outwardly undefined, being but a cavity formed in the irregular mass of accumulated floccose. Within this, semi-transparent in parts, the Furcularia was diligently pushing its way from end to end, turning back on itself the instant the end was reached, not showing its nose out in the clear for a moment, and returning on its course ; moving with considerable rapidity, never deviating and never resting. But after doing this a long while, perhaps an hour or two, it began to pause here and there, and to move ' Ehrenberg describes and figures a species, Distemma forficula, of which I know nothing more, with toes closely resembling the above. Only, to judge from his figs., the toes are recwrved instead of decurved, and the notching is on the dorsal instead of the ventral edge. 42 THE ROTIFERA. more slowly. I at last picked the sheltering material to pieces with needles in order to be quite sure of the species: for I had not yet had one satisfactory view of it at this time. Yet even then it kept obstinately under the floccose, refusing to come out into the open, éven when its tube was torn up.’’ On another occasion, lately, a striking illustration of the fierce appetite of this carnivorous creature occurred to me. One in the live-box was driving to and fro in its eager headlong way, when its course was suddenly arrested. A Nais worm had been wounded, probably by the pliers in taking up the milfoil from the phial, and a cloud of the pale flesh-granules had oozed, and was still oozing, out of its side. The Furcularia, aimlessly swimming, had come to the out- side of this cloud, and its whole manner was changed instantly. It darted at the mass, snapped and snapped again, turning hither and thither, but not leaving the vicinity. The sharp rapid momentary projections of the head and of the jaws showed how heartily it was enjoying its unexpected meal. This went on for some time; but I was called away, and was compelled to leave my hungry little friend at his dinner.—P.H.G. | Length, ;'; inch to +}, inch. Habitat. Around London, Dundee, Birmingham, 5 Hants, Devonshire, and elsewhere (P.H.G) : by no means rare. F. eracizis, Hhrenberg. (Pl. XIX. fig. 14.) Furcularia gracilis 9 : “ ¢ Ehrenberg, Die Infus. 1838, p. 421, Taf. xlviil. fig. 6. [SP. CH. Body slender, compressed, the ventral line making a prominent angle; front rounded; face oblique; toes slender, straight, acute. This well-marked little species is of slender form, as its name imports, nearly equal- sided, somewhat compressed, occasionally gibbous at the hind-back, the outline of the belly concave, with a salient angle about two-thirds from the head, whence it abruptly recedes to the short conical foot. The front is rather small, rounded; the face obliquely prone, ample, clothed throughout with cilia. The jomts of the foot are not readily separable; the toes, furcate, slender, acute rods, almost straight, are about one-fourth as long as the body, and are usually carried parallel. The eye is small, but conspicuous, of a vivid crimson, situate as usual in the middle of the very front, at the anterior extremity of the brain. A little wart-like projection is seen on the occiput, which is probably an antenna. The mastax is long and pear-shaped, contaiming a strongly forcipate incus, of which the fulerum is evanescent, with a pair of long incuryed mallei. The rami seem to reach over in a long descending pair of points, probably accessory to, but distinct from, the glassy rami themselves. The latter are frequently protruded from the oblique face, to bite the floceulent matter, adhering to the moss, and to seize atoms with a short snapping action. I obtained this species in some abundance, near London, in my early researches, among the stems and bracts of a submerged moss. Since that time, it has occurred in widely separated localities, never with any notable variation. Its manners are active, writhing nimbly along with the toes stretched out behind, but now and then, for an instant, widely expanded.—P.H.G.] Length, 5}, inch to y}, inch. Habitat. Pools, wide-spread; London; Stapleton Park, Yorkshire; Woolston ; Caversham; Cheltenham; Dundee; Oban (P.H.G.). F. cuca, Gosse. (Pl. XX. fig. 4.) Furcularia ceca . : ; ‘ Gosse, Ann. Nat. Hist. vol. viii. 1851. (SP. CH. Body cylindrical, the ventral line straight ; front rewnd ; head separated by a strong constriction; eye wanting or invisible; toes slender, slightly recurved, obtuse. NOTOMMATAD A. 43 This species is much like the preceding: yet it seems sufficiently distinct. The figure is truly cylindrical, with a hemispherical head, and a short conical foot, each divided-off by a strong fold. Both the folds are bounded body-wards by a distinct thick ned ring, the anterior by far the stronger; there is a third fainter transverse fold just behind the mastax. The face is prone; but its plane is curved, not flat as in gracilis. The great obtuse cone which forms the foot has but two separable joints, of which the hinder is notched behind, and carries two furcate slender rod-shaped toes, one- third the length of the body, very slightly recurved at the tips, which are rounded. This last character, which may seem unimportant, is, I think, constant. The whole visible head, in vertical aspect a perfect hemisphere, appears clothed with short cilia, which extend also over the prone face, as far as the great constriction. No eye was discernibie. The toes are commonly held in mutual contact, the tips often slightly crossed. The manners were much like those of the other smaller Furcularieg ; it both crawled and swam, but not swiftly. It was found in July 1850, in the sediment of a phial which had been dipped five days before, from Oldham’s Pond, Leamington. A few weeks afterward, I met with another in the same phial, which well sustained my judg- ment of the distinctness of the species; while it gave me a few additional details. It had an occipital brain, but again no trace of eye. The alimentary canal has a pair of minute gastric glands; it was traced clearly to the cloaca, which appeared on the dorsal surface of the foot as a minute notch. The csophagus, a long slender and somewhat sinuous duct, leads from the back of the mastax to the stomach. These two examples have furnished all the information that I possess of it.!—P.H.G.] Length of body, ;4, inch; of toes, ;45 inch; total, extended, ,}, inch. Habitat. Leamington (P.H.G.); Sandhurst (?) (Dr. Collins). F. eipsa, Hhrenberg. (Pl. XIX. fig. 13.) Furcularia gibba . : 5 c . Ehrenberg, Die Infus. 1838, p. 420, Taf. xlviii. fig. 3. [SP. CH. Body oblong, slightly compressed, convex on the back, flat on the belly ; the gibbosity of the back abruptly falling off steep to the foot; toes furcate, style- shaped, straight acute, nearly half the body-length. For more than thirty years I had assumed that this species was well known to me; when at length I discovered that what I had supposed F’. gibba was really a loricate form, with a cleft dorsum, presently to be introduced under the name of Diaschiza semiaperta. Lately, however, I have met with an animal precisely agreeing with Ehren- berg’s description and figure. Yet I judge it highly probable that other observers have, like myself, confounded the common Diaschiza with the rare Furcularia. As I have seen but a single example of the real Simon Pure, I can add nothing to the published descriptions, except what may be gathered from the figure.— P.H.G.] F. ENSIFERA, Gosse, sp. nov. (Pl. XX. fig. 3.) (SP. CH. Body gibbous; toes simple, blade-shaped, wider vertically than laterally ; foot-joints wanting ; eye wanting. I first observed this rather attractive species in July 1885, in water taken from one of my window jars, where aquatic mosses had been growing for several months. ‘The ' Except that Dr. Collins, in his Note-book kindly communicated to me, has pencil sketches of what he supposes to be this species, taken at Sandhurst, Berks. Its form, however, is much more gibbous behind than that of mine. 44 THE ROTIFERA. mosses originally came from one of the Scottish lochs, and the ancestors of these Rotifera may have been then introduced. But I constantly rinse out my live-boxes, after an examination, in one or other of my reservoirs; and as I have received samples of water, animals and plants, from many kind friends in various parts, it is impossible to trace the original habitat of any species which either of them may now contain. In form the present species much resembles ceca or gracilis; it is, however, larger than either, nearly, if not quite, equalling forficula in dimensions. The gibbosity of the back, its abrupt descent to the cloaca, and the peculiar mode of carrying the toes behind, more easily seen than described, are all characteristically Furcularian. A remarkable peculiarity, that strikes the eye at the first glance in the vertical aspect, is that the toes seem to be articulated direct to the trunk, without the interven- tion of the usual foot-joints. This is not an accidental malformation, but is evidently proper to the species, all the specimens being alike. The toes, too, are wide apart at their bases, the interval being sometimes straight, sometimes running up into an angle (fig. 8). They are in general carried nearly parallel; but they are often stretched so wide apart as to be horizontal, or, on the other hand, crossed. I could detect no eye, nor any brain, nor even turbidity, though I sought diligently. All the examples were brilliantly transparent, but most were tinged with a very delicate shade of canary- yellow, the stomach and intestine usually gorged with food of a warmer hue. The front and face are of a pale orange-tint. The manners of this species are exactly those of its fellows. In the live-box half-a- dozen congregated under a single leaf of the moss, neglecting other leaves, though there were plenty more, apparently as eligible; and there they kept restlessly moving to and fro, twining and twisting on themselves, swo more, beneath the translucent green leaf. The freedom and facility with which they turn round within their own length and breadth is remarkable. It is effected with marvellous rapidity, and with no change of place, but only of position. You are looking with a high power at the head or mastax— a twinkle, a dimness—and in an instant you see the toes in the very spot! The creature has turned itself quite round, and is off on its steps.—P.H.G.] Length, ,},, inch; of which the toes make about one-fourth. Habitat. The leaves of aquatic moss in a tank (P.H.G.). F. marina, Dyjardin. (Pl. XIX. fig. 15.) Furcularia marina 0 : 5 Dujardin, Hist. Nat. Zooph. 1841, p. 649, pl. 22, fig. 4. [SP. CH. Body long, cylindrical; toes blade-shaped, simple, decurved, pointed, minute ; eye wanting. Marine. The great length and uniform thickness of this species, truncate at each end, obliquely in front, transversely behind, distinguish it readily from its fellows. There is a lobu- late, pointed glandular brain in the occipital region, on which no eye-speck can be detected by either transmitted or reflected light. Behind this are some minute, seem- ingly isolated bodies, which may be connected with the branchial system. The points of the jaws are frequently pushed out from the oblique front to a considerable distance (fig. 15a), and retracted rapidly and repeatedly, with a snapping action. A minute protrusile antenna (?), ciliated at the tip, is seen behind the buccal funnel (fig. 15a). It was in August 1854 that I became acquainted with this interesting species, already made known by M. Dujardin in 1841. I had been keeping a small marine aquarium ever since February; but during a two months’ absence from home in the summer, most of the creatures had died, and were decomposed on my return. The water, how- ever, remained fairly pure; and I therefore merely removed a good deal of the decayed matter from the bottom, and restocked it, mainly with Actinig. On the sides of the tank, and in the sea-water, I found this pretty /urcularia by thousands, associated with NOTOMMATADA. 45 a species of Hwplotes, and a few of a Colurus. I have since found it repeatedly in sea- water from the Tay Estuary. It is active and sprightly in its manners, browsing among the floccose; frequently elongating and contracting its body, and occasionally swimming in the open water.—P.H.G.] Length, 34, toy}, inch. Habitat. A marine aquarium; tide-pools in the Firth of Tay (P.H.G.). I’, Bouront, Gosse, sp. nov. (Pl. XX. fig. 2.) [SP. CH. Front rondo-truncate ; body fusiform ; foot-joints small; toes conical, about half as long as the foot ; eye small. Lacustrine. This species I at first supposed to be Ehrenberg’s F’. Reinhardti, which has not yet occurred to British research; but, on mature consideration, there seem important differences, which warrant my raising this to specific rank. Reinhardti is stated to be ya Mch in length, which is not so large as F’. forficula and F’. gibba; whereas this is gz Inch in length, and so is a very giant among Furcularie. Then the foot in Reinhardti is half the length of the body: in Boltoni about one-fourth ; the toes in the former are minute, one-fifth to one-sixth the length of the foot: im the latter rather long and slender, full half the length of the whole foot and toes. Ehrenberg speaks of “the great eye’’ as an attractive feature in his species; but in this, the eye is, as usual, minute and inconspicuous. Lastly, his species is marine, living parasitically on the branching stems of the well-known polype, Laomedia geniculata ; whereas mine oc- curred in a pool in the heart of England. Thus I venture to pronounce it new; and honour it with the name of that energetic microscopist, Mr. Thomas Bolton, who sent it to me. It has evidently very close relation with #’. Reinhardti, as is shown by the general form, and especially the spindle-shaped trunk, and abruptly tapered foot. It is a true Furcularia, as to its trophi, of which I had a very favourable observation ; the mallet being slight and feeble, while the incus is strongly developed with wide, glassy, arched rami, produced into long decurved points. The front, in life, is probably conical, as usual; but in the condition in which alone I have seen the species, the cone was so low that its outline was nearly straight, with a minute but clear red eye-speck occupying the very centre of its edge. The mastax is of the usual large dimensions, followed by a slender cesophagus, an ample stomach with small oval glands, a separate intestine full of dark granulate food, an ovary with a great opaque maturing egg, and what I took for a contractile vesicle. The trunk is thickest at the lumbar region, and that whether viewed laterally or dorsally. Thence it diminishes rapidly to a width less than that of the head, and carries a foot of three joints, of which the first is contained within the trunk-walls, and the others are yery small and slender, followed by a pair of furcate toes, which are of a long conical shape, acute, and nearly as long as the three foot-joints together. The whole foot is sometimes thrown up towards the belly. I first became cognizant of this species in October 1885, a specimen having occurred in sediment collected from a ditch in Sutton Park (a locality most prolific in rotiferous and other microscopic life) by Mr. Bolton and sent to me. The animal was dead, but recently ; so that the form was little altered, and the organs were all 7m situ, and readily identified. I subsequently found a second rather smaller example in the same tube of water, also dead; which afforded me the advantage, always to be prized, of an additional study. A sight of the living animal is still a desideratum.—P.H.G.] Length, 7; inch to 2, inch. Habitat. A ditch near Birmingham (T.B.). 46 THE ROTIFERA. I’. micrnopus, Gosse, sp. noy. (PI. XIX. fig. 12.) [SP. CH. Foot inconspicuous ; toes minute, conical. No eye visible. This small species, known only by a single example, is much like F’. forficula in form, but the toes are very small in proportion, being cones whose length little exceeds the breadth of their base. The animal is clear and colourless; very soft and flexible ; constantly contracting and lengthening. The anterior parts are somewhat thick, eradually attenuating to the foot, where the width, both transverse and vertical, is less than half that of the head. An occasional glimpse of the side (fig. 12a) showed that the face was truncate, and obliquely prone; whereas the front viewed dorsally was obtusely conical in outline. But the extreme changeability of form, especially in the fore parts, and the flexibility, were notable. No brain could be defined, nor any trace of an eye. Though, according to Ehrenberg’s arrangement, this should be a Plewrotrocha, if the eye is really wanting, yet the whole habit and form of this creature showed its affinities to be with Furcularia. I found the specimen described in water sent me by Mr. Bolton in December 1884, obtained from a boggy ditch in Sutton Park.—-P.H.G.] Length, ,!, inch. Habitat. A ditch near Birmingham (P.H.G.). F. tonaiseta, Llrenberg. (Pl. XVIII. fig. 16.) Notommata longiseta . . . Ehrenberg, Die Infus. 1838, p. 482, Taf. lili. fig. 2. [SP. CH. Body cylindric, rownd at each end ; foot thick, one-jointed ; toes twice as long as the body, unequal. The cylindric body is slightly arched, but retains an uniform thickness. The whole rounded front is ciliate, with a semi-prone face. The toes, jointed on a thick cylindric foot, seem made of spun glass, thick at the base, but tapering to great tenuity, though not very acute. The right is about one-fourth longer than the left. The mastax and its trophi. in situ, closely resemble those of Furcularia gracilis ; but I have not resolved them satisfactorily. A great brain carries an opaque terminal mass at its point. The front, viewed dorsally, has the outline of a low cone, with a single minute red eye at the very point; and now and then I have seen pushed out what seemed minute lateral auricles ; yet with no perceptible acceleration of motion. ‘The contractile vesicle is very large. There is a prominent angle on the occiput, which may indicate a protrusile antenna; but I have not seen it exserted. I had this pleasing species in 1851, from a dyke near Stratford, and presently after- ward from Maidenhead. Recently it has occurred in water from Snaresbrook sent me by Mr. H. Davis, and from Woolston, by Miss Davies. It swims slowly, often turning to one side; occasionally throwing apart the long toes, and springing when alarmed, so as to fling the body more than its own length in an uncertain direction, the sound made by the toes striking the glass on such occasions being distinctly audible.—P.H.G.] Length, to tips of toes, ,; to y+, inch. Habitat. Pools in the southern half of England (P.H.G.). F. zquautis, Ehrenberg. (Pl. XVIII. fig. 15.) Notommata aqualis : . : Ehrenberg, Die Infus. 1838, p. 432, Taf, lin. fig. 3. (SP. CH. Indistinguishable from the preceding, save that the toes are equal. Though the resemblance between these two species is very close, Ehrenberg was NOTOMMATADE. 47 certainly right in distinguishing them. Quite accidentally I have had the two in sight at once, side by side, yet without the slightest mutual recognition, and thus had facilities for comparison. A¥qualis has the body longer and slenderer, more taper, where longiseta is gibbous, less divided into apparent joints by constriction, especially at the foot, besides the co-equality of the toes in this. Yet, on the other hand, the gibbosity of the former nearly disappears when extended in swimming, and then they are much alike. I first saw this species together with F’. longiseta, and both in some plenty, in water from Woolston, in September 1885. Though the species showed no association, their manners were exactly the same. The springs made by both and by Scaridiwm, with which they have apparent affinity, depend, doubtless, on the length and elasticity of the toes : and suggest a certain relation to the Triarthrade, and even to the order ScrrTopopA, in which, toes being wholly wanting, the same function is performed by special limbs, long, taper, and elastic.—P.H.G.] Total length, about ;}, inch. Habitat. Woolston (P.H.G.). Genus EOSPHORA, Hhrenberg. (GEN. CH. Body oblong; head dilated and furnished with protrusile auricles ; foot very distinct, with telescopic joints, and furcate toes ; eyes three, viz. one large, cer- vical, two minute, frontal. Of the four species which Ehrenberg includes under this genus I know but the one which he has not catalogued in its proper place, but which he subsequently mentioned under the head of Diglena aurita. His words are: ‘‘ Dr. Werneck sent me a drawing of a new Hosphora, very like the Diglena of Berlin. I found, soon after, in the Berlin animal, a pale red point on the opaque sac in the neck, which makes this an Hosphora, if it prove to be an eye”’ (“* Die Inf.” p. 444). Judging by this species, there is little to distinguish Hosphora from Notommata (proper), except the two minute frontal eyes ;! and this distinction is evanescent, when we remember in how many species of Notommata Herr Eckstein has seen frontal pig- ment-specks. Yet, looking at the form of the trophi, I consider it intermediate between Notommata and Diglena.—P.H.G.] E. aurira, Hhrenberg. (Pl. XVII. fig. 14.) Diglenaaurita . 9 : } Eosphora aurita : i *p c 3 : Gosse, Pop. Sci. Rev. 1863, vol. ii. p. 475, pl. xx. Ehrenberg, Die Infus. 1838, p. 444, Taf. lv. fig. 2. (SP. CH. Body cylindric ; head separated by a neck ; front slightly convex ; brain an opaque globe at the end of a long slender tube; trophi forcipate ; foot slender, cylindric ; toes slender, acute, furcate. This is an attractive species: its form is elegant and symmetrical, particularly when the auricles are everted above the neck; the slender foot and toes well finish the body behind ; and the prevalent depletion of the viscera with bright pellucid green food, add brilliancy of colour to the clear glassy vase. To the naturalist, too, it is specially interesting. Far down in the body is a transparent ball, filled with opaque matter, whence a slender tube extends right up the very front: this tube is more or less turbid with like matter. On the ball just where it contracts to the tube is a broad and thick ' The frontal specks Dr. Leydig denies to be eyes, in the species awrita ; but I have no hesitation in pronouncing them to be strictly analogous with what we call eyes throughout the class. Pp y y 48 THE ROTIFERA. lens of crimson pigment, and at the frontal end of the tube, one on each side of it, are two small crimson globules.’ All three are beautifully rich and distinct, even by trans- mitted light. It is indubitably Werneck’s Hosphora aurita. The jaws are quite of the Diglena type, but the mallei are stouter, as in Notommata: the points are often pro- truded. A curious feature is that the capacious stomach juts up in two long horns, as high as the top of the mastax, distinct from the gastric glands. An ovary and a con- tractile bladder, both ample, help to fill the cavity ; and the body terminates dorsally in a broad triangular tail, which projects far above the foot, with the cloaca between. On the occipital edge is a minute antennal tube and a bristled wart on each side of it. This triple arrangement is peculiar. The manners are usually sluggish.2—P.H.G.] Length, ;},; to >}, inch. Habitat. Greenwich Park; Hampstead Heath ; Birming- ham: pools; not rare (P.H.G.). Genus DIGLENA, Hhrenberg. (GEN. CH. Body swb-cylindric, but very versatile in outline, often swelling behind and tapering to the head ; eyes two, minute, situated near the edge of the front ; foot furcate ; trophi forcipate, generally very protrusile. This genus, while Notommatoid in form, has a certain aspect of vigour and intensity of function peculiar to it. Though one or two assigned species are massive, the majority are slender, lithe and energetic ; the taper and elongate anterior parts habitually thrown above the general line of progression, in the manner of some lepidopterous and dipterous larve, as if eagerly exploring. The form of the trophi, though on the Notommatous pattern, is very predaceous; and the sharp, formidably-armed rami of the incus can be, and frequently are, thrust far beyond the limits of the head, and forcibly snapped. The front, in most of the species, is furnished with a hooked proboscis. The furcate toes are, in general, long and sharp, sometimes sickle-shaped. Of the eight species included in the genus by Prof. Ehrenberg, lacustris, conura, and capitata have not been recognised in Britain; awrita is an Hosphora, and has been just described. To the remaining four, seven species are now added.—P.H.G. | D. cranvis, Ehrenberg. (Pl. XIX. fig. 6.) (SP. CH. Body massive, sub-cylindric ; head rounded, with a frontal proboscis ; face nearly prone; a tuberculiform tail; foot large, bulbous ; toes straight, parallel- edged, abruptly pointed. Of this imposing species my knowledge for many years was limited to a specimen which I found in September 1851, already dead, in a dyke at Maidenhead. ‘'The trophi were beautifully distinct. Their structure was nearly the same as in D. forcipata, but the bristle-like teeth that line each side of the incus were much more conspicuous, and apparently larger; arranged in double rows. In August 1885, examining an aquatic moss growing in a glass reservoir im my study, I found, first one, and then another, of the same species, alive and active. The agreement in detail with my dead original was exact. ‘Two very minute eyes, nearly close together, are at the front, whence pro- jects a small hooked proboscis; and below this the ciliate face is very prone. The ' Eckstein says that these are connected with the great cervical eye by nerye-threads. 2 Hyferth (On the Lowest Forms of Life, 1878) says that Triophthalmus of Ehrenberg is but the young condition of Hosphora; and that, eyen in the egg, are seen two dark specks, near the eye, which subsequently disappear. But Eckstein (Sieb. wu. Kill. 1883) holds this conclusion doubtful, till the entire development from the egg has been watched. He confronts the points of consimilarity with those of dissimilarity in two instructive tables. 1. Copeus labiatus la. * * 2. Copeus spicatus 2a, 2b. ,, ; 3. Copeus Cerberus . Ba. 5 P 4. Copeus pachyurus ee oR on Copeus candatus . ao aon * Us s ” OH s ” . Notommata collaris (?) PLATE XVI. dorsal view . edges of lip . dorsal view . side views of head dorsal view . side view dorsal view . F transverse section : < head, showing buccal orifice dorsal view . side view 5 mastax and trophi occipital antenna hind dorsal tentacle dorsal view . side view THER2QQaQangqn 1 7 - i 7 v on i 7 von MN - ae } a - - 7 : 7 t 7 : 7 4 = 7 " > " . ; ql! 7 a7 i 7 . : . 7 a : 7 u la an ah 7 : =. 1 aa Dy 7 Pl XVI i im : ye 1. Notommata brachyota . la. 7 “i 1b. en » 2. Notommata saccigera ” ” 3. Notommata ansata 3a. ” ” 4. Notommata tripus 4a. ny Re 4D. x) % 4c. BS on 5. Notommata pilarius 5a. ” ” 5b. ” ” 6. Notommata aurita 6a. ” ” 6b. 3 5 7. Notommata cyrtopus Ta. ” ” 7b. 3 ” 8. Notommata tuba . 9. Notommata lacinulata . 9a, Rs “0 9b. ” ” 9c. ” ” 10. Hosphora aurita 10a. 1 3 x 5 11. Taphrocampa Saundersiz lla. A ms 110. ” "mo 12. Taphrocampa annulosa. 12a. + ay 126. oA a 12¢. a ae 12d. rr ” 12e. "9 “5 13. Albertia intrusor 13a. ” ” Tso a 14. Albertia naiadis PLATE XVII. dorsal view. side view . ; 5 end of brain, with eye; side view dorsal view . side view dorsal view. side view dorsal view. 5 : side view (smaller scale) head, showing auricles trophi . dorsal view . side view transverse section dorsal view. side view . ‘ ; , central lobe of brain, with eye dorsal view . side view trophi . dorsal view. dorsal view . side view G trophi, ventral view trophi, side view dorsal view. side view dorsal view. side view | transverse section dorsal view. side view . transverse section trophi, side view . trophi, ventral view tail (var.) ventral view side view . ; trophi, ventral view side view . . (after Mr. E. C. Bousfiel AARDARMRAMAAARARAAAHAVARAAAAARAAARAAADBARAAA|ADH a) ed fo mp. Janhar big, Te 7 P wr § steed a we ~ LW UA if 4 >| = or] i r "4 i i a a | af 4 wy | ‘ N ; ry Sa) ; a 0 1 4 p { a (4 f 1 , } i Pe of fal t j 1. Notommata forcipata la. p es 1b. ” ” 2. Notommata naias . 2a. a " 2b. 55 aes ; 3. Pleurotrocha constricta. 3a. 1) ” 3b. "9 3c. oy 5) 4. Pleurotrocha leptura da. 5 4 5. Pleurotrocha gibba 5d. ” ” 6. Proales decipiens . 6a. ” ” 7. Proales sordida WG; alOs 55 of Te. 8. Proales gibba 9, Proales petromyzon 9a. ” ” 9b. ” ” 9e. o 9d. A 10. Proales tigridia L0G) G5 ‘3 11. Proales parasita Ila. ,; A : 12. Distemma labiatum 12a. ” ” 13. Distemma Collinsii 14. Triophthalmus dorsualis (?) . 14a. ” ” 15. Furcularia equalis 15a. ” ” 16. Furcularia longiseta 16a. eo Ay 17. Proales felis . a (7 en A IRN Sp i . PLATE XVIII. dorsal view. side view toes . ventral view head; dorsal view mastax and trophi dorsal view. side view head; ventral view foot and toes dorsal view. side view dorsal view . side view dorsal view. side view dorsal view. side views . trophi . side view ventral view , side view ; extended . side view; contracted head, side view; enlarged . eye . : dorsal view. side view side view mastax and trophi dorsal view. side view side view . dorsal view. side view . dorsal view. side view dorsal view. side view dorsal view . side view trophi . RARADAAAONAWAAMAAADH|H|AAM MQ QQ M DAQAAAAQAAADA| as , VLA; TRIOPATHALM US (2)3FURCULARIA. J of A mis CH ‘UROTRO ig P LE [PATA 2°N NATAS. 3.P a 7 A P.H.Cosse ad viv. de L.GIBBA.6 PR DECIPIENS. 7; PR.SORDIDA. 8.PR.GIBBA. 9.PR 412D LABIATUM.13. D:COLLINSL 14T.DORSUALIS.15 FA QUALIS.16.P.LONGISETA.1 . a -PETROMYZO. Ay 5. 4 EN FORO - _ re oa «| i a a : a NS iT 0.PR.TIGRIDIA.11.PR.PARASI 1 > 1. Distemma raptor le. m1 > ld, > ” le. if + 2. Diglena forcipata 2a. iD » 2b. 2c. 5 Re 8. Diglena biraphis Ba. cn “r 4. Diglena circinator 4a. Dr - 4b. D ” 5. Diglena clastopis ” 6. Diglena grandis . 7. Diglena gibber 8. Diglena caudata 9. Diglena giraffa 9a. ” ” . 10. Diglena catellina 10a. ,, 75 11. Diglena permollis 12. Fureularia micropus . 12a, A a 13. Furcularia gibba 13a. 13D. ~ 3 18c¢. - re 14, Fureularia gracilis 14a. A 6 15. Fureularia marina l5a. ‘ be 15d. PLATE XIX. dorsal view side view trophi foot and toes. ; contracted; dorsal view Pr side view . dorsal view side view trophi, expanded trophi, shut dorsal view side view dorsal view side view 5 ‘ fore parts, in contraction dorsal view side view dorsal view side view side view dorsal view side view P head, dorsal view . dorsal view side view dorsal view dorsal view side view side view mastax and trophi, obliquely ventral view trophi, expanded trophi, shut . dorsal view side view side view protruded trophi, and antenna trophi AAD AANAAAM QBODMWAANMWARMAARDAADQMARAARMARQAA I-Zl SITIOWHSd O10 I YNITIALV9 910 Of VAAVHIO OIA 6 V.IVANVS DIT 8 ¥19 ‘910'S YOLVNIOUID S10 + SIHAVHIE JIGS VIVdIDNOd SITS WOLdVa'SIC I ot SOd0uoIN. pe 2 RIAA! VNGIDIG ‘VNATLISIG *“VWItVvVinvda v4 ‘YNIUVA A SI SITIVE9 Avi VERIO s Wadd DIC Z STONVHD‘DITS SidO.l ‘i dua qaeuury 1. Fureularia forficula . ; la. BS a G 6 1b. ” ” 2. Fureularia Boltoni . ‘ 2a. - A A 6 3. Fureularia ensifera . 3a. “A 5 A > 4. Fureularia ceca . 4a, - A 5. Mastigocerca bicornis. 5a. aa .. : 5b. - ieee 6. Mastigocerca stylata . Ga. of 6b. os x ; 7. Mastigocerca carinata 8. Mastigocerca elongata 9. Mastigocerea rattus 9a. Ps _ 4 P 10. Mastigocerca lophoessa . 10a. Pe 11. Mastigocerea scipio 12. Mastigocerca macera . 13. Rattulus tigris 13a. x 1b, 18¢. Le : 14, Rattulus cimolius 14a. 5 . . : 144, 14e. i : f 15. Rattulus sejunctipes lia. ,, as 16. Rattulus calyptus 17. Rattulus helminthoides lia. ,, * 18, 18a. Ccelopus porcellus 18d. © 33 18¢. ” ” 18d. 7 ” 19. Coelopus tennior . 19a. 4 33 5 20. Caelopus minutus 20a. ,, , ‘ 21, Coelopus brachyurus . 0 22. Ceelopus cavia . 7 : PLATE XX. dorsal view . 5 ; side view 5 ; : : toe 5 9 3 Q dorsal view . 5 : : : side view : : dorsal view . , : . , side view 5 dorsal view . , ; : side view 4 ; : dorsal view . side view : : , : muscles side view P ; mastax and trophi muscles side view : ; : 5 insertion of toe side view dorsal view side view side view empty lorica . side view Z side view; dead . : ‘ ; side view ? mastax and trophi foot and toes dorsal view side view : mastax and trophi dorsal view side view 5 : : side view A % obliquely ventral view side view side views . front of lorica : . , transverse muscles; and toes, apart toes, one within the other dorsal view . 0 side view 5 dorsal view side view r side view , 5 9 side view RARRRARAMARARARARAAAARARARAARARARARAARRARARARARBRAAAAD PH.Gosse,ad viv del a uss nT 2sd ART Wworyrsey -isut 1 « TUS. al 2 LONGATA.9 MRA va) te GQ — Qo Fe a & = = “ ee x i wy 2 NOTOMMATAD®. 49 brain has a turbid yellowish appearance, at times clearly defined. The alimentary canal is very large, darkly granulate, composed of many sacs ; and a slender rectum clearly opens into a cloaca below the tubercular tail. Convoluted lateral canals run down cach side ; but no contractile vesicle could be discerned. The manners are sluggish; it twists and wriggles much, with little change of place. It is a fine large species, not devoid of elegance when extended ; but it often contracts into very uncouth shapes.—P.H.G.] Length, .); inch. Habitat. Maidenhead; an aquarium at Torquay (P.H.G.): rare. D. GIBBER, (osse, sp. nov. (Pl. XIX. fig. 7.) [SP. CH. Body encased mm a transparent leathery sheath, hunch-backed ; face prone ; frontal proboscis small ; toes long, decurved. In sediment from one of my window-reservoirs, I found this large Diglena. About the size of D. grandis, it much resembles that fine species in general appearance. Its form is that of a cylinder, flattened along the belly ; the entire soft parts are encased in what we might call a lorica, only that it is manifestly flexible: a difference, perhaps, merely in degree. This sheath, of a glassy transparency, is almost unchangeable in shape; yet it has marked creases here and there, which are permanent, serving for needful flexibility. At what might be called the shoulders, it rises to a conspicuous conical hump, diminishing thence by a gradual slope to the hinder parts. The internal organs do not rise above the cylindrical body-wall, leaving thus an ample cavity within the sheath all down the back; quite empty, save that a very delicate conglobate gland, attached by a thread to the hinder extremity, works up and down within it, by the con- tractions and contortions of the animal. What seemed the trochal front was, through the inclination of the head, nearly on the level of, and continuous with, the ventral sur- face, and was covered with vibratile cilia. Behind, the body-sheath is cut off obliquely, with a well-marked edge, for the emission of a stout foot, which carries two long curved blade-like toes, often thrown widely apart. On each toe, at about one-fourth of its length, there is an abrupt decrease of diameter on its superior edge, with the appearance of a joint; and a delicate line crosses each near its point. This individual appears to have been subjected to the remarkable accident of the protrusion of the entire mastax, with all its accessories, from the frontal face, so that it was totally unable to retract it. Whether this was the result of over-eagerness in feed- ing, producing unguarded muscular exertion, or of violence from some of its predatory foes, I cannot guess. I could discern no mark of any pinch on the body. But there was a great extruded mass of flesh, amorphous and motionless, yet bearing a manifest resemblance in outline to a mastax : while in an occasional glance that I could get at its front, I saw what looked exceedingly like a long ineus and a hooked malleus on each side, though only the bottoms of these organs could be shaped, and that very vaguely. Besides, there was not a trace of mastax to be seen within the head, for I searched carefully for it; the protruded mass was just where it would be, if such a misfortune had occurred; there was a conspicuous constriction behind the mass, evidently pre- venting retraction; while the mass was apparently of definite and unyielding shape, containing hard and lengthened organs. ‘he frontal disk, both above the mass and also to a small extent below it, was covered with cilia in rapid, but feeble vibration ; no whorls were produced in the surrounding floccose ; no swimming or crawling pro- gress was made by the animal; though it constantly contorted its body, and threw about its toes. Its vital power was manifestly stricken, and even the movements gradually grew feebler and feebler. I had not detected the slightest motion within the (supposed) mastax ; its nerves had been probably paralysed at once. But fragments of the floceose sediment kept on adhering to the exposed parts, as if these were glutinous; and this was more manifest at first than after some time. From the summit of the front a minute finger-like proboscis descends. —P.H.G.] VOL. Il. 0 50 THE ROTIFERA. Length. Of head and body, ,4,5 inch; of toes, 45 inch ; total length, about 7, inch ; vertical height at hunch, about g}5 inch. Habitat. An aquarium (P.H.G.). D. rorcrpata, Ehrenberg. (Pl. XIX. fig. 2.) Diglena forcipata a - 4 Ehrenberg, Die Infus. 1838, p. 443, Taf. lv. fig. 1. [SP. CH. Body cylindric, rather stout, obtuse at each end; face long, prone ; trophi typically forcipate ; toes scythe-shaped. This is one of the imposing species; stout, though more larva-like than either of the foregoing. The integument is again firm and thick, and forms tranverse folds, which are constant. The bluntly-tapered head carries the usual decurved fleshy proboscis, whence the ciliated face descends in the ventral plane to a length about one-third that of the body. A turbid brain descends far down the occiput, and bears two minute eyes on the very frontal edge. The mastax and jaws show a fine development of the form normal in this genus,! and perhaps they could nowhere be studied with greater advantage. The digestive apparatus differs little from that of D. grandis, or other species, but there is here no projection above the cloaca. The foot is large and bulbous, severed from the body by one of the strong folds; it bears two toes, which are stout, shaped like the blade of a pocket-knife or scythe. A large contractile vesicle occupies the lower abdomen, which appeared strangely divided into two by a strong constriction. Small vibratile tags were seen on attenuate threads running down each side. I made acquaintance with this species, crowding the edges of a jar of water dipped from the ‘‘ Black Sea’ at Wandsworth, in January 1850. It was active, but little given to locomotion. Its numerous cilia are in constant agitation, and appear pale blue by reflected light ; while the minute ruby-like eyes sparkle on the colourless body, the turbid parts of which are like whitish clouds. What I have called the proboscis may possibly be a broad lip, for it is visible only from the side. The wide spread of the toes is characteristic.2—P.H.G.} Length, J, to 7; inch. Habitat. Domestic aquaria near London, and Torquay (P.H.G.) ; Sandhurst, Berks (Collins). D. crrcinator, Cosse, sp. nov. (Pl. XIX. fig. 4.) (SP. CH. Body slender at each end, gibbous in the middle; proboscis acute ; mastax moderate; toes slender, strongly incurved. The fore parts are slender and nearly cylindrical (but flattened on the oral surface), swelling somewhat suddenly to a great ovate body, gibbous on the back, but flat on the belly ; and as suddenly diminishing behind toa rather thick and short foot, which carries a pair of toes, each one a very regular quadrant of a circle in outline, broad at the base, running off to a very fine point. These toes are decuryed, and also incurved towards each other, like the legs of a pair of calliper-compasses; and often thrown widely apart. The skin is very flexible, and, as the animal is every moment lengthening and contracting, and throwing itself into the most varied contortions, makes many irregular folds; yet the form delineated always recurs, and is evidently characteristic. The under surface has a remarkable projection (fig. 4a), pointing obliquely backward, more or less conspicuous, visible sometimes on each side in the dorsal aspect (fig. 4). This seems the limit of the ciliated face. The very front is furnished with a hook, which is capable of being thrown forward, as if hinged or jointed; and apparently sidewise also, for it is occasionally glimpsed for an instant, at either side of the head. ‘This process is not a bent finger, but a regularly curved hook, hard and sharp-pointed. After a while 1 They are described and figured in my Mem. ‘‘ On the Mand. Org.” (Phil. Tr. 1856) 435, figs. 50, 51. 2 The animal described and figured by Mr. J. E. Lord (Microsc. News, 1884, p. 146, figs. 23a, b, c) is, I have little doubt, the present species. NOTOMMATAD. 51 the slender fore parts were retracted, and then from the gibbous body was seen project- ing a curious little puckered bundle of transparent flesh and skin, as shown at fig. 4). This species I first found in the sediment of one of my indoor tanks among decaying conferva and milfoil: this was in June 1885. Afterwards it occurred again in a tube sent from Dundee by Mr. Hood. All the features were exactly the same as before; but this was more impatiently restless. I thought I saw a pair of frontal eyes, but I could not be quite positive. In a brief quiescence I made a careful study of the trophi, whose points are in contact with the very skin of the front.—P.H.G.] Length, ;1, inch. Habitat. An aquarium at Torquay; Dundee (P.H.G.). D. GIRArra, Gosse, sp. nov. (Pl. XIX. fig. 9.) (SP. CH. Body slender, necked; eyes distinct, frontal, protuberant; toes slender, straight. This form, having some resemblance to D. circinator, differs from it, not only in the more marked neck, but in the toes being quite straight instead of circularly curved. For, though this may seem an unimportant character, I think the form of the toes will be found to present remarkable constancy in the same species. In circinator I could not be certain of eyes, but in this species they are well-marked, though minute, of dark hue, situate on the very frout of the head, so close to the skin as to be prominent as tiny black warts on the surface. The head is small, and its connection with the body is by a sort of neck which can be greatly lengthened and attenuated, as the animal makes its frequent explorations through the free water in all directions, feeling about, very much as an earthworm does in the air. For this the skin is very flexible and versatile. The abdomen is tumid; but not so abruptly gibbous as in circinator. The foot is taper, and the toes moderately long, straight in eyery direction, not blade- shaped, but regularly diminished to great slenderness, and very fine points. There is no tail. Beneath the eyes the front forms a well-marked proboscis, which takes the shape of a decurved hook. At times this appears of equal thickness throughout, and blunt, or even truncate ; then it is distinctly seen in the same individual much length- ened, and tapering to a fine point. Can the terminal part be protrusile ? The ciliated face is quite prone, and appears to run far back on the ventral surface, where a chin-like prominence indicates the end of a ciliated furrow. (See Diglena forcipata, fig. 2a.) The skin, though flexible, seems very strong; it is continually thrown into folds by the unceasing contortions and contractions of the animal; it looks leathery, but is perfectly colourless and brilliantly transparent. It is a lively, vigorous, attractive creature ; pushing among the sediment, occasionally swimming with a smooth gliding motion. I found another specimen in the same water, exactly agreeing with the above. It had the odd habit of forcibly contracting the foot, and throwing back the toes, as far as the tapering outline of the body would allow; and then protruding the foot with a jerk, bringing the toes at the instant to aright-angle with each other, and therefore horizontal ; immediately repeating the curious action; and so for fifty times together. When swimming glidingly, it will suddenly quicken its pace an instant, and make a sensible snap, as if it seized something ; and this again and again ; though my eye could detect no atom in the clear water.—P.H.G.] Length, ;}5 inch. Habitat. Woolston (P.H.G.): rare. D. caupata, Hhrenberg. (Pl. XIX. fig. 8.) Diglena caudata . . . Ehrenberg, Die Infus. p. 445, Taf. lv. fig. 6. [SP. CH. Body cylindric, long, slender ; front broadly truncate, with two frontal colourless eyes; foot short, very thick, with two long straight slender toes. It is excessively versatile and variable in form, constantly contracting into inde- E 2 a2 THE ROTIFERA. seribable shapes (of which fig. 8b may serve as an example), with various sharp folds and augles. Yet it may be said to have a characteristic form, which is sub-parallel-sided viewed dorsally ; but which, viewed laterally, is narrow for the anterior third, where it rises abruptly to nearly double the height. This is generally maintained to the end of the trunk, where it descends with even a sharper angle to give emission to a thick foot, carrying two long, straight, slender, acute toes. The front is unusually wide and truncate, viewed dorsally ; but laterally, it is seen to project into the usual fleshy hook, which is probably sensitive, and used to collect and test food. The ciliated face is almost prone; behind this is an ample mastax with jaws of the. normal pincer-form. The viscera present nothing noteworthy. The whole animal is of crystalline clearness ; and is devoid of colour, so far as I have seen. The eyes, too, if eyes they are, are two colourless globules of considerable size and of somewhat irregular outline, placed wider apart than in Ehrenberg’s figure, at the very front. The toes are long, tapering regularly to produced acute points, but slender throughout and quite straight, whereby they differ from those of clastopis. They are frequently thrown forward suddenly to more than a right-angle. (See fig. 8 and Ehrenberg’s fig. 4.) The lumbar fold of skin is often strong and sharp ; but there is no projection really answering to a tail; and the specific name is a misnomer. [examined two specimens in September 1885, from water which had stood on my table about four weeks, originally from Woolston Pond.—P.H.G.] Length. About ,+, inch. Habitat. Woolston (P.H.G.); Sandhurst (Collins). D. PERMOLLIS, Gosse, sp. nov. (Pl. XIX. fig. 11.) [SP. CH. Body extremely soft and versatile in form, swollen in the middle, broad and truncate in front, tapering behind to a thick and long foot ; toes two furcate, slen- der, acute. I am conscious that the above is an unsatisfactory diagnosis of what I am sure is a distinct form. In a tube dipped from a fresh-water loch by Mr. Hood, containing a few leaves of milfoil thickly studded with Rhizota, I found a Notommatoid creature, cer- tainly new to me, and apparently undescribed. Its most salient character was its exces- sive softness, as if it had no skin at all, but were a lump of mere jelly, yet intensely active and restless, swelling and contracting, lengthening and shortening, twisting and infold- ing, without the slightest intermission, for more than two days while under observation. All this made it quite unlike any other Rotiferon I had ever met with. The slender toes, at the end of a rather large foot, are very mobile, ever thrown about to their ut- most, or suddenly brought point to point with a snap; in this specimen they had the remarkable peculiarity of what looked like a minute terminal joint, like a separate claw, which, however, was not apparent in other examples. The front is widely truncate, composed of many globose transparent cells ; from the midst of which projects the usual soft triangular proboscis. The ciliated face below this is prone, whence frequently the trophi,—an incus with circularly forcipate rami, worked by long mallei,—are protruded with energetic snaps and snatches. Below the mastax is a vast alimentary canal, con- sisting of nucleate cells; an ovary of embryonic vesicles occupying the yenter. I could not detect any eye-spots; but a rather short brain filled the occiput. I subsequently obtained other examples from the same quarter. In one was a large contractile vesicle which I saw discharged, but I could not time its period. The cor- ners of the front, when rotating, have almost the appearance of auricles. —P.H.G.] Length. About 3, inch. Habitat. A pool near Dundee (P.H.G.) D. cuastopis, Gosse, sp. nov. (Pl. XIX. fig. 5.) (SP. CH. Body cylindric, long, slender; front rounded, without visible hook ; foot long, slender, with two long decurved toes. NOTOMMATAD A. 53 Tam not quite clear whether I ought to name this form. But, assuming that the cluster of unequal-sized and irregular-shaped red specks, resembling the fragments of crushed rubies, at the very front of the head, represents two frontal eyes, I place it in this genus, especially as the trophi appear to agree with those of the slenderer Diglene, and there is much similarity to them in general contour and conformation. Its shape is long, thin, and nearly parallel-sided, viewed dorsally (fig. 5), abruptly narrowed to a very slender foot, and long, thin, acute, decurved toes. Laterally (fig. 5a), the lumbar region is gibbous without any marked fold. ‘The eyes, resembling broken fragments, as said, are placed at the very front; and are conspicuous, even in the swift shootings of the animal. The front descends to a blunt angle, which may be the anterior point of a prone ciliated face. I could discern no fleshy hook. I did not detect the brain; but behind the mastax were two opaque globules, which seemed not to be eyes, but were possibly chalk-masses, smaller, and more shapely, than usual. A very long alimentary canal reached far down the cavity, well filled with food of various tints, accumulated in many dark nodules, which imparted to the animal in its movements a very peculiar spotted appearance. Most of the internal structure is as yet undefined. This is one sample of the very rich harvest of species that I reaped out of a small bottle procured for me from Sandhurst Wood pool, by Dr. Collins, in June 1855. Though I had the specimen under my eye for an hour or more, I could scarcely, in all that time, find it still long enough to permit me to turn to the paper, in order to delineate it; and if I did, I was almost sure to lose it out of the field, to find it again with diffi- culty. It is swift and headlong in its course, shooting through the free water rather than swimming, and only now and then entering a cloud of floccose sediment, to push, with persevering violence, a way through it. Only this single example has been subjected to examination.—P.H.G.] Length, ;}; inch. Habitat. Sandhurst, Berks (P.H.G.). D. cateniina, Hhrenberg. (Pl. XIX. fig. 10.) Diglena catellina ; - : Ehrenberg, Die Infus. 1838, p. 444, Taf. ly. fig. 3. [SP. CH. Body cylindric, short, abruptly truncate at each end ; toes short, straight acute, projected from the ventral side, at a right-angle to the body-axis. This plump, sturdy little creature oceurred among my earliest researches in the summer of 1849. It is a true Diglena, yet is very dissimilar to its fellows, replacing their long, lithe slenderness by a short thick body, having strong skin-folds, often quite abruptly truncate before and behind. Now and then, indeed, a bluff rounded head is pushed out, carrying two eye-points at its front, and a ciliated face, hardly prone. From the broad square stern, a small foot projects at the lower margin, and two small, slender, acute toes, pointing downward, serve the creature for support and for locomo- tion. The internal organs are little noteworthy. There is a large occipital brain, and an enormous mastax, of which the jaws are normal. Ehrenberg describes this tiny species as both marine and lacustrine. I have found many specimens from tide-pools in the Tay estuary, collected by Mr. Hood.—P.H.G.] Length, 5}, to ;}; inch. Habitat. A garden near London; a pond at Snavesbrook (P.H.G.); Sandhurst (Dr. Collins); marine tide-pools in the Firth of Tay (P.H.G.). DIG@LENA (?) BIRAPHIS, Gosse. (Pl. XIX. fig. 3:) Diglena (2) biraphis - 3 c Gosse, Ann. Nat. Hist. vol. viii. 1851, p. 200. [SP. CH. Body oblong, the head and abdomen gently swelling ; toes long, slender, straight, and perfectly even in thickness ; eyes placed close together frontally ; jaws 54 THE ROTIFERA. protrusile ; alimentary canal very large, projected behind and above the mastaa, always filled with green matter. This is an animal of no inconsiderable size, which has the technical characters of Diglena, but has little affinity with that genus, in structure or manners. My first ac- quaintance with it was in October 1849. A filamentous plant, growing in a pan sunk in iy own garden, was thickly covered with a floccose matter, inhabited by numbers of Stentor polymorphus. Among them were specimens of this Diglena (?). In January 1851, I again found it in the same water, and on a subsequent occasion; but I have never met with it since. The form is gracefully swelling and vase-like, not at all resembling a Diglena in appearance ; it has much the aspect of being loricate, but it is not. Two eyes are placed at the extreme front ; small, so close together as to be readily mistaken for one, brilliantly crimson. The transparent mastax, in situ, shows a pair of incurved strong pincers, whose approaching tips are two-toothed. These can be extended from the front for half their length, and seem to be a formidable instrument for seizing prey. These are, no doubt, the rami of an incus. What appears remarkable is that a great saccular lobe of the stomach runs up behind the mastax into the occiput, and divides into two lobules. The whole alimentary canal, with these lobes, was, in every example, uniformly filled with round green granules, the exact similarity of which to the component granules of the Stentors and the Loxodes, which abounded in the same water (together with various species of Huglena), suggested that the normal food of the Rotiferon may consist of the juices of these Polygastrica, especially as its formidable forceps seems to indicate car- niyorous propensities. The long straight rod-like toes are now and then turned up, so as to incline over the back; occasionally their tips are crossed.—P.H.G.] Length, ;}, inch. Habitat. A garden-pan near London (P.H.G.): rare. Genus DISTEMMA, Ehrenberg. (GEN. CH. Body more or less cylindric, long, slender before, swollen behind, ver- satile ; two cervical eyes ; front furnished with a fleshy proboscis ; toes two, furcate. This somewhat obscure genus Ehrenberg constitutes on four species. These, how- ever, must be reduced to two: for D. setigeruwm clearly belongs to the family Rattulide ; and D. marinum is one of the Loricata. The others I have not met with. But I enumerate three species, apparently undescribed, which seem to come into the genus. In aspect and manners they closely resemble Diglena, especially in their long, lithe, versatile forms, generally swollen behind; in the presence of soft tentacular appendages to the front; in the forcipate form and protrusile character of their trophi; and in their fierce raptorial habits. The species inhabit the sea and fresh waters.—P.H.G.] D. Raptor, Grosse, sp. nov. (Pl. XIX. fig. 1.) [SP. CH. Body long, gibbous behind, very changeable ; front with a long projectile lip ; foot short; toes small, slender, decurved. Marine. The lithe flexible form is usually lengthened, slender in the middle, becoming high behind, its outline descending in an abrupt curve to the very small foot. This is armed with two toes, whose thickness tapers abruptly at the middle (fig. 1c). It is near D. forcipatum, but is distinguished by this peculiarity of the toes, and by their curvature, And it is marine. The head is rounded, the front produced into three fleshy ciliate points, and a conical projection on each side, The central point is probably the tip of a curious fleshy process, which is now and then rapidly pushed out and in (figs. 1, 1a), quite straight, thus differing from the proboscis of Diglena. The lateral projections, when this NOTOMMATAD Ai, 55 lip is retracted, close against each other, as in Dinocharis. The median line of the dorsum makes a sharp roof-like angle, especially at the lumbar part, but does not rise to a ridge. Eyes are sometimes clear and distinct, one on each side of the mastax, wide apart, highly refractile, very pale red, but well defined ; but in some specimens they are quite invisible. The trophi consist of an incus, with ram? broad and circularly forcipate, on which work slender bowed madllei (fig. 1b). The mastax is often retracted below the middle of the body; then the animal will suddenly elongate, and the mastax will be driven forward and backward, rapidly and far, the rami snapping fiercely. This snap- ping snatching action is very observable. Sometimes the mastax is, fully half or more, protruded from the front, and this again and again in rapid succession, the jaws giving a short snap at each time. It is incessantly restless, sudden and rapid in its contrac- tions and turnings, yet not very locomotive, remaining long anchored to the glass by the toe-tips, swaying to and fro, much like a Monostyla, often stretching the toes apart. I owe my acquaintance with this interesting form to Mr. John Hood, of Dundee, who, lately, at my request, searched for marine Rotifera. He presently sent me con- tributions of sea-water, from the estuary of the Tay, in which I found many species, Among the stems of a conferva this new Distemma was pushing and snatching. It seems tenacious of life. The individual first observed lived in a live-box, con- taining a thin pellicle of water, for parts of three days, during which other Rotifera, its associates, had one by one succumbed. Perhaps from hunger, this specimen roamed incessantly through the clear water, snapping at every atom, now and then seizing a small diatom, and drawing it into the buceal funnel, to reject it instantly. The jaws were protruded and retracted every moment with lightning-like rapidity. Nowand then a tiny cloud of floccose would be dragged in and chewed eagerly, then forcibly ejected. The force and energy displayed by so small an atom was remarkable. The sight seems to have a very small range. This one seized and devoured many Monads and even large Protozoa; but it seemed to have no power of discerning them till they were close to its head; then the action was prompt enough. The highest expression of animal life that I have observed among Rotifera is this little obscure Distemma. As a fowl picks up minute atoms of food from the earth and pebbles and rubbish with which it is mingled, showing sight, observation, discrimination, selection, will, so does this Distemma manifestly snap up its food-atoms, often invisible to our eyes, selecting them! with rapid precision from other surrounding atoms. The jaws are thrust out and withdrawn, as I have said, with a quickness which we cannot follow, and with stroke succeeding stroke, quite as rapidly as a hen’s beak picks its morsels, and evidently takes something at each. The way in which it pounces upon animacules that we can discern, and the energetic viyour with which it seizes them, are admirable, and quite unparalleled among Rotifera, so far as my experience goes; and there is hardly a species described in this work that has not come under my observa- tion. If we could descend to his level, and form a personal acquaintance with him, I am sure we should find this Distenuma a person of great decision of character.—P.H.G.]. Length, (as in figs 1, la) ;4, inch. Habitat. Tay-mouth: tide-pools (J.H.). D. co~ninsn, Gosse, sp. noy. (Pl. XVIII. fig. 13.) [SP. CH. Body cylindric, long ; head large; foot stowt; toes two, furcate, long, slender, unnotched, acute. Lacustrine. This species is known to me only by a drawing in Dr. Collins’s Note-book. It is re- presented with a long body, a head of increased diameter, a stout foot, and two toes, ' «The power of choice is the distinctive peculiarity of a mental being.” ‘All activities that are indicative of choice [except reflex actions] are indicative of consciousness. Whereyer we see a living organism apparently exerting intentional choice, we may infer that it is conscious choice; and there- fore that the organism has a mind,”—Romanes, Ment. Evol. in Anim. pp. 47, 17. 56 THE ROTIFERA. which are thick, decurved at the tips, and of a length equal to one third of the whole animal when extended. The pencil-sketch has not many details of organisation. The only note which the observer has added is the following :—‘‘ It has the power of drawing-in the first joint of the foot into the interior of the body; and has a peculiar manner of separating the pair of curved toes.’”—P.H.G.] Length. Unrecorded. Habitat. Sandhurst, Berks (Dr. Collins). D. (2) LABIATUM, Gosse, sp. Nov. (Pl. XVIII. fig. 12.) [SP. CH. Slender, long, gibbous ; front furnished with a protrusile lip; foot long, with two minute furcate, virgate toes. Beyond what the mere outline suggests, as conveyed in the figures, I can give little information concerning this species. With much doubt I place it in the present genus ; and that only on the possibility that two obscure spots, dimly seen in the neck, may have been eyes. They may have represented the trophi. In fact my knowledge of this form rests on a single brief observation. I was examining an aquatic moss, which Dr. Collins procured for me in June 1885, when this little creature glided out. I saw ina moment it was new to me, but my attention was already occupied. There were in that live-box, at that instant, three or four Rotifera unknown to me; as many papers were before me, on which I was labouring to reproduce the portrait of each, feature by feature, as I could catch it. Here was one more. It was a complete embarras des richesses. What could Ido? I hastily threw in the outlines here given, careful to secure correct- ness in what was produced, but deferring minute examination in the hope of seeing it again ; while I pursued the study of those already in hand. The present subject, how- ever, found speedy concealment among the moss, and I could find it no more; nor has it ever reappeared. The form, particularly in the lateral aspect, recalls the owtré shape of Notommata caudata, with its long neck, elevated back, and slender foot ; but the re- semblance is only superficial. Its chief peculiarities are—(1) a slender parallel-sided, squarely-truncate proboscis or lip, projecting medially from the front, which is seen in the side view to be somewhat low in position ; it seemed retractile to some extent; (2) a long, slender, and tapering foot-joint, furnished with a furcate pair of toes, very minute, of equal thickness throughout, obtuse ; like tiny pegs. T can find nothing in Ehrenberg with which satisfactorily to identify it.—P.H.G.] Length. About 1, inch. Habitat. Sandhurst, Berks (P.H.G.). [N.B.—In Dr. Collins’s Note-book are pencil-sketches of an evidently large animal, which may possibly be the Triophthalmus dorsualis of Ehrenberg. I have carefully copied the sketches (Pl. xviii. figs. 14, 14a); but the details are not sufficient for dia- enosis ; and there are no descriptive notes. I have not myself met with anything like it. —P.H.G.] CE AG Paes lets Nc eae PLOIMA CHORLG ATA), How much weariness has there been in the human race during the last fifty years, because the human race cannot stop politically where it was, and, finding no rest, is pushed to a strange future that the wisest look forward to gravely, as certainly very dark, and probably very danger- ous! Meanwhile have the bees suffered any political uneasiness? have they doubted the use of royalty, or begrudged the cost of their Queen ? Have those industrious republicans, the ants, gone about uneasily seeking after a sovereign? Has the eagle grown weary of his isolation, and sought strength in the practice of socialism? Has the dog become too enlightened to endure any longer his position as man’s humble friend, and contemplated a canine union for mutual protection against masters ? No! the great principles of these existences are superior to change ; and that which man is perpetually seeking, a political order in perfect harmony with his condition, the brute has inherited with his instincts. P.G. Hamerton. Chapters on Animals, Presumption is our natural and original disease. Man withdraws and separates himself from the crowd of other creatures ; cuts out the shares of the animals, his fellows and companions; and distributes to them portions of faculties and force, as himself thinks fit. How does he know, by the strength of his understanding, the secret and internal motions of animals ?—MonrTalankE. CHAPTER X. Sub-Order Lortcava. Integument stiffened to a wholly, or partially, inclosing shell ; foot various. Family XI. RATTULID AQ. [Body cylindric or fusiform, smooth, without plice or angles ; contained in a lorica closed all round, but open at each end, often ridged; trophi long, asymmetric ; eye single, cervical. Generally subject to abnormal conditions. This family comes first in the Loricate sub-order, because the loricate structure is in varied condition; for, whereas in some species it is indubitable, in others, which yet can- not be severed from these, the integument is still thin, flexible, and membranous. Ehrenberg, indeed, while he assigned M. carinata to the Loricata, removed his genus Monocerca far away to Il-loricata. Yet that carinata and rattus are congeneric cannot be doubted by anyone who knows both; bicoriis certainly goes with the latter. The sausage-shaped species have many family affinities with these; though subdivisible inter se. The peculiar form of trophi represented in figs, 60-62 of my Memoir ‘On the Mandue, Organs” runs with little variation through all. The most curious peculiarity in the family is its tendency to asymmetry, which appears in many organs. In the mastax the right malleus always differs from the left; when there is an elevated ridge on the dorsum, it is apt to be bent over on one side, and, instead of running straight down the middle, to pass slantwise from right to left ; when two antenne are present they are unequal. ‘The toes, sometimes normal, are often reduced to a single style, with minute sub-styles grouped around its base. In other cases they are modified in a most unprecedented manner, described under the genus Celopus. On the whole, it is a group of very peculiar interest, both to the scient and to the intelligent seeker for amusement.—P.H.G.] Genus MASTIGOCERCA, Ehrenberg. [GEN. CH. Body fusiform or irregularly thick, not lunate ; toe a single style, with accessory stylets at its base ; lorica often furnished with a thin dorsal ridge. The terminal style is by no means a tail, but a true toe, however modified. The homology of the sub-styles is not clear. The surface of the body is usually smooth and polished, often elegantly tapered; nor does the thin elevated carina of the dorsum materially interfere with this elegance, which the long taper toe admirably finishes. This organ, though inflexible throughout, is capable of rapid and sudden motions, being bent right and left, and whisked to and fro with great agility. The mastax is usually pear-shaped and very long, but the esophagus, a sinuate duct, leads from it almost at its very summit occipitally, just where the mallei work upon the ineus. Thus the great length of the mastax does not intrench on the needful length of the stomach, since this viscus begins far forward. The muscles, in many species, especially the transverse series, have been well resolved. Muciparous glands are richly supplied. Surprise is often felt that Rotifera with but a single style should be able to maintain so firm a hold upon 60 THE ROTIFERA. glass as to resist the force with which the surrounding water is carried up into a pipette by the pressure of the atmosphere. It is doubtless by the adhesive power of the clear glue secreted and poured out by the oblong foot-glands. In Mastigocerca this may often be seen running down the outside of the toe, its production seemingly subject to the animal’s will. When first put into the live-box, it is commonly poured forth abundantly, so as to accumulate around the point, and to drag in a thick glairy stream behind it. I have seen it surround the terminal half of the spine to a thickness four times as great as that of the spine itself. Or it will run from the base downward, like a thick spiral cord. Sometimes it is not perceptible. The male has not been detected in the family. —P.H.G.] M. cantata, Ehrenberg. (Pl. XX. fig. 7.) Mastigocerca carinata . - 2 Ehrenberg, Die Infus. 1838, p. 460, Taf. lvii. fig. 7. (SP. CH. Body long-oval ; lorica ridged ; ridge high, arched, reaching to middle of body ; toe straight, equal in length to body-and-head ; sub-styles very minute. The height of the dorsal ridge is very characteristic in this familiar species, rising, in the midst of its length, to fully half of the vertical thickness (7.e. from back to breast) of the body. Its cessation, too, just beyond the middle of the back, gives a peculiar humped outline to the forepart, viewed laterally. The belly-line is about equally curved with that of the back. The ridge, as already observed, is not set-on straight down the dorsal centre, but on a line that slants considerably to the left, while in its elevation it leans over to the right. It is manifestly hollow along its base, for the viscera may often be seen extending into it for a little way. It is marked on its basal part, through its length, with close-set corrugations. The front is rounded, with many minute eminences, on which the cilia, which make two distinct vortices, are set; they increase in size and height to the occiput, where an antenna projects, capable of being erected or inclined. A long occipital brain carries a rather large bright-red eye, set like a wart at its interior lower angle. The mastax, a pear-shaped bag, is enormous, reaching, from the front, half the body-length. It contains an incus with a slender straight fulcrum, the rami of which are obsolescent and the alule very large, and two bent mallei, unequal in size and form. There is a very small contractile vesicle, whose period is shorter than I have observed in any other Rotiferon, twenty-five times a minute. The distension of the viscera conceals the branchial vessels, but I have seen one vibratile tag. The foot consists of an ovate bulb, to which is jointed the toe as a slender spine in the midst of two or three bract-like accessory styles, one of which is slightly longer than the others, distinctly moveable. The toe moves in all directions except backwards. —P.H.G.] Length. Of lorica, +}, inch; of toe, ~}; inch; depth to summit of ridge, »4,5 inch, Habitat. Pools; generally distributed: common. M. LopHoessa, Gosse, sp. nov. (Pl. XX. fig. 10.) [SP. CH. Body long-oval; dorsal ridge reaching to the foot, nearly uniform im height ; toe straight, two-thirds as long as body ; sub-styles one-third of toe-length. This I think a well-defined species. The ridge attains nearly to as great a height as in carinata, and is continued to the base of the foot. Its outline runs in several arches, and descends rather abruptly at the end. It is marked with faint radiating corrugations. The principal toe is a straight slender style, gradually tapering to a fine point, as in carinata, but not quite so long in proportion ; and the accessory styles, of which I could discern two, are of unequal length, the longer equalling fully one-third of the principal ; whereas in carinata it is not more than about one-eighth, by very careful micrometri¢ measurement. The mastax and jaws seemed much shorter than usual, but of the common RATTULIDA. 61 form. I did not discern any eye, but do not doubt its presence in life. None of the viscera showed any peculiarity. This species I met with at the beginning of October 1885, among sediment furnished me by Mr. Bolton. It was just dead; but afforded me a good observation. A week or two later, the empty lorica of another example occurred froin the same ditch ; and, a little afterwards, in water from Bracebridge Pool, still from Mr. Bolton, I found it yet again. And since, from Mr. Hood. The characters were constant in all.—P.H.G.} Length, ,1, to 2, inch; lorica, ;1; inch; depth at middle of ridge, ;§, inch. Habitat. Birmingham; Dundee. Pools: rare (P.H.G.). M. scipio, Gosse, sp. nov. (Pl. XX. fig. 11.) [SP. CH. Body sub-cylindrical, slightly larger in front, thick and round behind ; the front of the lorica set with three spines ; a long low ridge considerably on the right side; toe half the length of the lorica; sub-styles one-fourth the length of the toe. Greatest width about one-eighth of total length. This and the following two species have much in common; yet are distinguished by details of form and structure. The general outline differs in each, as shown in the figures. The particulars detailed in the technical Spec. char. of each, though minute, seem trustworthy. What appears distinctive of the present is that the front edge of the lorica, otherwise smoothly truncate, carries three projecting spines, one occipital and two lateral, each of which runs down the outside of the lorica for a short distance as a sharp ridge. There is thus a certain resemblance to M. bicornis. The general outline is that of a stout straight stick, thickened slightly near the head, with both ends rounded abruptly. At the extremity a very low ridge is seen, which runs up, considerably to the right of the medial dorsal line, almost imperceptibly at length, to the very front. The foot, which is short and bulbous, is contained within the rounded end of the trunk, but carries, attached to it by a very facile joint, a toe in the form of a slender spine, about two-fifths as long as the lorica. The spie, as in carinata, is not quite straight; it bears at its base a short supplementary style on each side, which moves on the basal joint with its own motions. Each is about one-fourth as long as the toe. The mastax is of immense size, occupying much more than half the body-length ; the trophi are often pushed to the very front. Vibrating cilia are disposed on minute eminences, of which the central one is continually lengthened and shortened. An ample brain runs down the occipital region, bearing a conspicuous crimson eye on ils extreme point. I saw no protruded antenna. Very characteristic (in all the specimens observed) was a long clear blank space, wide at the foot-point, and tapering to near the mid-venter: probably a contractile vesicle; only that I could never see it contract. The whole animal is transparent and colourless. I first saw this species in the summer of 1885, on an aquatic moss, growing in one of my window tanks. I subsequently saw other specimens ; one in particular, glued fast to a filament by the toe, illustrating the abundance and tenacity of this excretion, which, evidently, is not always under the control of the animal, so that, if usually it is a con- venience, it may become a snare. This individual was not quite dead, yet the turbid matter of the head was already forced out, together with many oil-globules.—P.H.G.]. Length. With the toe, ;1, inch. Habitat. On water-moss in pools (P.H.G.). 00 M. MAcerRA, Goss, sp. nov. (Pl. XX. fig. 12.) [SP. CH. Body fusiform, thickest behind the middle; lorica smooth-edged in front ; without visible ridge ; toe half the length of the lorica ; sub-styles one-fourth the length of the toe. 62 THE ROTIFERA, I can give little information about this species, which yet seems distinct. I have seen but a single example, and that was moribund, if not actually dead. I met with it in June 1885, in water from Woolston Pond, Hants, courteously supplied by Miss Davies. Spontaneous motion had not ceased, particularly in the toe-spines, and the structure of the abdominal viscera was still perfect; yet all the foreparts were one mass of dissolving flesh and air-bubbles, protruding from the front and spreading around. An eye-spot could be detected in the mass; but of the trophi not a trace. The form recalls IZ. rattus ; but greatly produced in length, and without discernible carina. I hesitate whether it should not be placed in the genus Calopus ; for it appears to have two unequal toe-spines, the smaller fitting beneath the other, and about one- fourth of its length. But the longer is straight, the shorter curved. So that, in defect of fuller observation, I assume that the shorter is but one of the supplementary styles common in this family ; though I could detect other minuter spinelets at the base. The specimen I unfortunately neglected to measure ; but the total length to the toe- point was, approximately, ;}5 imch.—P.H.G.] Habitat. Woolston (P.H.G.). M. ELONGATA, Gosse, sp. Nov. (Pl. XX. fig. 8.) (SP. CH. Body nearly cylindric, slightly larger before than behind ; lorica smooth- edged in front; ridge long, low, medial; toe as long as the lorica; sub-styles one- twentieth the length of the toe. This seems a very distinct species. Its smooth, hyaline, arched lorica, with a widely truncate front edge, quite smooth, but tapering in a graceful curve to the hinder end, where a small tubular orifice, also abruptly truncate, allows emission of the foot; is very distinctive from the preceding two species, to which, however, its remarkable length allies it. It is nearer to MW. carinata than they; yet sufficiently remcte from this by conspicuous characters ; in particular, by the dorsal ridge, which is low throughout, and, as I believe, medial. The greatest depth of the lorica (viz. just behind the front edge) is just one-fourth of its length. This front edge, destitute of points, is apparently attenuated to thin membrane, thrown into minute transverse folds, inverted and everted with the motions of the head-mass. The foot is of one minute joint, exterior to the loriea. It bears one toe, a spine of great length and slenderness, almost quite straight, nearly uniform in thickness to the fine pomt. Its length about equals that of the lorica. Two accessory styles, very minute, are appressed to its base. ‘The mastax is ample, and, as in I. carinata, haying two mallei, unequal and dissimilar. I owe my acquaintance with this charming species to Mr. Hood of Dundee, whose keen eye had already detected its specific distinctness. He sent me, in November 1885, water from one of the pools near Dundee, containing a number of living specimens. They are sprightly and active, swimming elegantly through the clear water, with a smooth but swift gliding movement.—P.H.G.] Length. Total, ,4; inch; of toe, y1¢ inch ; of sub-styles, yyy inch; depth of lorica, 3}, inch. Habitat. Loch near Dundee (J.H.) ; Birmingham (P.H.G.): not rare. M. rartrus, Lhrenberg. (Pl. XX. fig. 9.) Monocerca rattus “ ; . Ehrenberg, Die Infus. 1838, p. 422, Taf. xlviii. fig. 7. [SP. CH. Body ovate, truncate in front, pointed behind ; ridge reaching to two- thirds, evenly arched ; toe longer than body-and-head together ; sub-styles, very minute. The lorica is elegantly ovate, subtruncate before, where a thick head protrudes, with a rounded front, on which numerous pimples are beset with bristle-like cilia, making RATTULIDA. 63 a single vortex. Behind the head is a strong transverse fold, seen in retraction, but obliterated in extension ; close to which projects horizontally backward a long antenna. The whole structure bears a very close resemblance to that of M. carinata, from which, however, it is distinguishable at a glance. The mastax and trophi are on the same pattern; but the right malleus is even still further reduced, only a slight vestige of it remaining. The dorsal ridge is evident but very low, with an outline regularly and ele- gantly curved. The foot is small and short; the toe nearly straight, long, slender, acute, closely embraced at its very base by several very short sub-styles. A copious secretion of mucus is often seen running down like a cord, from the base, whose viscosity is attested by the force with which the tip is moored to the glass. This very elegant and sprightly animal is well named, for its resemblance to a rat is at once manifest, both in form and movement. It moves nimbly about among the vegetation, now nibbling, now turning short, now scudding hither and thither by little starts, whisking its long tail (toe) about in all directions. It swims gracefully and rapidly, revolving often on its axis. The periodic evacuations of its small contractile vesicle are thirteen in a minute. The species is often found in company of the finer De- snudee, and from the alimentary canal being commonly distended with matter of a rich golden-brown hue, I conjecture that some of these may form its ordinary food. In the discharge of freces, I have noticed such a quick closing contraction of the rectum at the point where the intestine merges into it (yet without constriction of the whole tube) as suggests a sphincter there: and the distinction between the coloured contents of the intestine and the perfect clearness of the rectum is well defined. —P.H.G.] Length. Of body and head, ;1, inch; of toe, y+, inch; total, .,. Habitat. Pools, widely dispersed, not uncommon (P.H.G.). M. srcornis, Hhrenberg. (Pl. XX. fig. 5.) Monocerca bicornis : A - Ehrenberg, Die Infus. 1838, p. 423, Taf. xlviii. fig. 8. [SP. CH. Body fusiform-ovate, with long thick head armed with two projecting unequal spines ; lorica not ridged ; toe two-thirds as long as body-and-head, with a bulbous base, and no sub-styles. The integument is truly a lorica, though more flexible than usual. It is truncate at the neck, whence a thick cylindrical head protrudes, the anterior half of which can contract by bringing the sides together in strong puckers. With much resemblance to both. rattws and carinata, there is a marked difference in aspect, from the greater development of this head, and from the unequal spines which project over it; of which the left is medial, much the longer, and decurved. The absence, too, of any dorsal ridge is noteworthy. The toe is slightly swollen at its base, but I cannot detect any sub- styles, though Ehrenberg speaks of them; it is slightly recurved. The right malleus has here quite disappeared. The brain is of unusual length, even descending below the long mastax, and the eye, of moderate size and a pale-red hue, is seated near tts middle. There are small gastric glands at the base of the stomach, and two similar vesicles attached to the rectal end of the intestine. The contractile vesicle’s periods are three in a minute. In other points there seems little to distinguish the species from its fellows. There are, however, two antenne, also unequal, which project, side by side, beneath the chief frontal spine. I have seen an egg matured in the ovary, remarkable for its small size: perhaps male. (Cf. Monoc. valga, Ehy.) In ponds and lakes around London, I met with this species and the preceding, six- and-thirty years ago; I have occasionally found both since, the present the rarer. Yet I have had this multiply in a phial; so numerous and so large, as to be visible to the naked eye. They glide slowly about, sometimes hanging to the glass, or playing around 64 THE ROTIFERA. the floccose attached to growing Nitella. It forms a charming object under reflected sunlight. The body is colourless, and sparkling as a vase of glass, as are some of the viscera. An advanced egg is conspicuously white; and so is the head of the mastax ; the eye comes out like a ruby; the stomach, full of food, is richly brown, or perhaps grass-green; and the rotating front is enveloped in a cloud of pale cobalt blue. Like its neighbours, it is lively in movement.—P.H.G.] Length. Of body, ;},5 inch; of toe, y1,5 inch; total, ,; inch. Habitat. Pools near London ; Birmingham (P.H.G.). M. styLaTa, Gosse. (Pl. XX. fig. 6.) Monocerca stylata 5 > 3 Gosse, Ann. and Mag. Nat. Hist. Sept. 1851, p. 199. [SP. CH. Body irregularly oval; head short ; lorica flexible, puckered in contrac- tion, not ridged; toe less than half as long as body-and-head, simple, with no sub- styles. In several respects this nimble little species resembles the preceding; the lorica (even more flexible and skin-like) opens wide in front to emit the head, and closes with many folds or puckers, converging toa blunt point. The form is more irregular than in any other species, being plump and gibbous ; the skin, which is so flexible as scarcely to be called a lorica, is often drawn in, or protruded in angles, which vary the shape. The foot-bulb is enormous, usually inclosed within the body ; to this is jointed the toe, a taper acute spine, nearly straight, without a swollen base, and without sub-styles. The brain is thick and moderately long, carrying a large eye on the middle of its dorsal surface, protuberant as a wart. No antenna has been observed. The protruded head is short, set with cilia, strong and bristle-like, around the margin. The jaws have the asymmetric character already noticed; the one malleus is very long and simply bowed. As in bicornis, there is a long distinct rectum, to which are attached two globular cca, larger than the gastric glands above. There is a small contractile vesicle. The cloaca is marked by a depression. Under strong lateral pressure, a very complicated system of muscular bands is seen (6b), mostly transverse, but many irregularly diagonal. I copied them with great care. I first obtained this species from a garden reservoir near London, in 1850. Its minuteness and its figure, its short foot and great red eye, may cause it to be mistaken for an Anuwr@a, which it resembles in its swift, headlong, obliquely-revolving motion. Specimens in a phial may be detected with a pocket lens, rapidly urging their way, senerally in a perpendicular direction, upwards or downwards, always with this revolv- ing action. When alarmed, they suddenly increase their speed, shooting across the field of view with such a fleetness that it is difficult to keep them in sight.—P.H.G.] Length. Of body, »!, inch; including toe, ;1, inch. Habitat. South London; Hampstead Heath ; Stapleton Park, Yorkshire; Birmingham (P.H.G.). Genus RATTULUS, Ehrenberg. [GEN. CH. Body cylindric, curved ; lorica smooth, (usually) without a ridge ; toes two, decurved, symmetric. 3 The Notommata tigris of Ehrenberg, with its rounded body, thickest before, its general curvature, and its two coequal toes, continuing the curve of the body, may be considered the type of this genus, which manifestly, however, forms a connecting huk with the Notommatade, through Proales tigridia. The genus is a very natural one, inseparable, notwithstanding some diversities, with a common facies readily apparent to the skilled observer.—P.H.G.] RATTULIDA. =r) or R. tiers, Miiller. (Pl. XX. fig. 18.) Notommata tigris ’ ’ v Ehrenberg, Die Infus. 1838, p. 431, pl. lili. fig. 1. [SP. CH. Body suwbcylindric, largest in front ; foot thick ; toes two, stylate, long ; sub-styles fwo pairs, very short ; brain clear. The lorica, though subcylindric, a tube open at both ends, and bent, is wider in front, where a great thick head is protruded, which is invested in an inflexible shelly coat, running off both frontally and mentally into hard sharp points. The face between bears rotatory cilia set on minute eminences. Ehrenberg says ‘“ the outer skin appears somewhat firm’’; and I have met with the empty dead shell, as evidently chitinous as that of an Huchlanis. The whole animal is rounded, not only as a tube is round, but the outline of the back is the segment of a circle, a form which is unchanged with all the animal’s motions. The foot appears to consist of one or two thick joints, and carries, besides the two toes, which are long taper styles, evenly decurved, sub-styles one on each side of each toe (fig. 135), usually close appressed and minute. In death the toes are bent up under the belly; but in life they are usually carried straight behind, quite parallel, or often thrown upward, without, however, changing the downward curvature of their points. The ample mastax (fig. 13a) is pear-shaped: the mallei straight, unequally de- veloped. The large brain carries a clear pale-red wart-like eye, on its point. The stomach is usually full of dark-brown food, coarsely granular. Some points in Herr Eckstein’s description of Diurella tigris make me doubtful whether his species and mine are identical. Mine I have had repeated opportunities of studying, both alive and dead.—P.H.G.] Length, ,3, inch, of which the toes are ;}, inch. Habitat. Sandhurst, Berks; Woolston, Hants: rare (P.H.G.). R. HELMINTHODES, Gosse, sp. nov. (BID eRe figs U7.) (SP. CH. Body very slender, especially in front, the width less than one-fifth of the length ; toes without accessory styles at the base ; brain clear. This obscure species approaches near to Ff. tigris in form, and also in the slender- ness and comparative length of the toes. It is, however, much more elongated (even when all allowance is made for the protrusion of the parts in death) ; and the anterior half is the slenderer, whereas in tigris it is the thicker. The lorica, if I am not mis- taken, has a long low dorsal ridge, beginning insensibly near the mid-length, and end- ing abruptly in an oblique angle (fig. 17) just above the foot. The short, stout, bulbous foot carries two long fureate toes, which are simple styles, very slender, tapering to fine points, decurved, closely resembling those of f. tigris. Yet I was not able to separate any accessory styles at the base of each, such as are seen in that species. Something was there ; if styles, very short and close appressed, but it seemed rather a swelling of the basal part of each toe. Jt was only a dead lorica that came under my observation ; from which the head-mass was extruded by decomposition, as an amorphous turbid cloud. Yet the mastax and its jaws of the normal form were still distinct, and the stomach and ovary were scarcely changed. I could not satisfactorily define a contractile vesicle, nor branchial tubes. The toes were turned up close to the belly. The lorica occurred in a tube sent me at the beginning of November 1885, by Mr. Bolton, of water from Blackroot Pool, near Birmingham, in which Asplancha priodonta had swarmed, all now dead.—P.H.G.] Length. To tips of toes, ,}, inch; of toes, 44, inch; width (and depth) of body, sy inch. Habitat. A pool near Birmingham (P.H.G.). VOL. II. EF 66 THE ROTIFERA. R. crmonius, Gosse, sp. nov. (Pl. XX. fig. 14.) (SP. CH. Body arched, parallel-sided ; skin flexible; brain opaque; toes short, blade-like, decwrved ; no sub-styles. The brain, descending far into the occiput, is furnished at the end with a large and opaque chalk-mass. This I have signified in the specific name, from «moda = chalk. Its component cells are very distinct at the lower margin, which is sub-truncate. When the fore-parts are retracted forcibly, as is frequently the case, the conspicuous chalk- mass will sometimes reach to two-thirds of the entire length, displacing the viscera. A pair of small auricles are occasionally thrust out (fig. 14), without any sensible augmentation of speed, while the animal pushes through sediment. I have looked in vain for an eye, though it may have been concealed by the opaque cells. The tro- phi (figs. 140, c) exhibit the virgate pattern common in the family. The toes are short compared with those of tigris, decurved ; set side by side, and widely expanded (fig. 14). This seems a quite distinct little species, there being no other with which it can be confounded, on examination. The specimen described was in the bottle with which Dr. Collins favoured me in June 1885. Its movements were by no means rapid, but persevering, forcing its way incessantly through the leaves of water-moss and sedimentary floceose. I have lately found a second in water from Mr, Bolton.—P.H.G.] Length, ,}, inch. Habitat. Sandhurst, Berks; Kingswood Pool, Birmingham (P.H.G.). R. CALYPTUS, Gosse, sp. nov. (Pl. XX. fig. 16.) [SP. CH. Body and toes as 2m cimolius ; brain clear ; face furnished with pendent veil-like lobes of flesh. Marine. This has much resemblance to R. cimolius, but it is larger, and the brain-sac is clear, not opaque. No eye has been visible: the toes are of like dimensions, pattern, and de- curvation. A remarkable peculiarity is that in the front a thick and broad veil of trans- parent flesh hangs down, apparently bilobed, meeting another great lobe of like appearance from below. The function of these lobes I do not know. The body is cylindric, with no visible dorsal ridge. The mastax and trophi conspicuous, but ill-defined. An ample brain descends with a point into the occiput, with neither chalk-deposits, nor eye. A long and slender cesophagus leads to an ample alimentary canal. The ovary occupies the ventral region of the cavity; and a moderate contractile vesicle is behind all. A single example of this charming little Rattulus I found in October 1885, with many other species of Rotifera, in sea-water, procured for me by Mr. Hood from the tide-pools of the Firth of Tay. In manners it was sluggish, contracting and lengthening itself with uniform persistence without changing its place. It was of hyaline transparency and colourlessness.—P.H.G.] Length, ;}, inch. Habitat. Tide-pools on the Scottish coast (P.H.G.). R. SEJUNOTIPES, Gosse, sp. NOV. (Pl. XX. fig. 15.) [SP. CH. Body projecting much above and behind the foot; toes two, coequal, slender, decurved, set side by side, wide apart. Of this remarkable species Dr. F, Collins has made several graphic sketches in his Note-book. It is of the unaris form, stout, plump, and curved; the foot consists of a great basal bulb, wholly internal, and a second joint, thick and short, to which are arti- culated two toes; these are acute slender styles, so curved as to continue the outline of the body, mutually equal, set on the same plane, but (which is most unusual) wide apart. RATTULIDA. 67 The hinder body is ventricose, greatly overhanging the foot. There is a great aggregation of minute air-(or oil-)globules in the dorsal cavity. The trophi I supply conjecturally. Dr. Collins has added to his figures the following note: ‘‘ Head very large ; rotatory organ compound ; a large eye ; peculiar ganglionic mass or brain lying on dorsal surface. Two toes, which it sometimes crosses; peculiar from being very wide apart, and de- curved, as the toe of Rattulus lunaris. Found in a pool near Wellington Military College, Berks.” —P.H.G.] Length. Unrecorded. Habitat. As above. Genus C@LOPUS, Gosse. [GEN. CH. Body cylindrical, curved ; foot bulbous, inclosed ; toes, one broad plate with another laid upon it, in a different plane. A very remarkable deviation from normal structure is found in the species thus asso- ciated. Instead of two toes, consimilar and coequal, placed side by side right and left, like the legs of a man; here are two toes very unequal, hollow triangular plates of like shape, but of diverse dimensions, the smaller lying within the hollow of the larger. To use a homely comparison, let us suppose the bowl of a tablespoon, broadly truncate at the top and drawn out to a long point; then the bowl of a teaspoon of exactly the same shape, laid smoothly in its hollow; the two separately articulated to the foot-bulb, so as to be capable of independent motion to a slight extent. These organs are so anomalous that it is hard to describe them as ‘‘ toes.” If it could be proved that the cloaca opens between them, we might say without hesitation that the larger and upper represents a true tail, the smaller and lower a stylate toe. But I have no knowledge on this point ; which could be settled only by a rare accident,—the observ- ing of the act of evacuation at the moment when the animal was viewed laterally. In general figure and organization, there is so close an agreement with the former two genera, that the family affinity is indubitable. Several species I am able to asso- ciate as manifesting this structure: and, what is very curious, I have found it exhibited by a member of a remote genus,—one of the Coluri (q. v. infra). It is possible that Ehrenberg’s Rattulus lunaris may represent my C. porcellus. But the absence of any detailed diagnosis, in his text, leaves it doubtful; while his assigning of two eyes to his species is against the identification. The Diwrella rattulus, Hyf., described and figured by Herr Eckstein, may possibly be the same thing. The delicate lines that are drawn through the middle of the toe, in his engraving, may be either the inner edges of two normal toes, or the outer edges of a single superposed toe; and the closest examination does not determine this. If the former, it is a species of my genus Rattulus; if the latter, a Celopus. His text also is ambiguous. ‘‘ Two toes, long, much bent bellyward, and slender,” seem to point to Rattulus ; while ‘‘ at their base they do not stand close side by side, but lie with their points one on the other,” appear to indicate the peculiarity of Calopus, ill-understood.—P.H.G.] C. PoRCELLUS, Gosse. (Pl. XX. fig. 18.) Monocerca porcellus . 5 ‘ Gosse, Ann. and Mag. Nat. Hist. Sept. 1851. [SP. CH. Body cylindric, short and plump ; lorica ridged ; head with two pro- jecting spines ; the longer toe equal in length to the depth of the body. This neat, plump little creature always reminds me of a fat young pig. The general form may be compared to that of a well-filled sausage, a little bent, as sausages often are, and the varying shades of brown colour produced by the distended stomach and F2 68 THE ROTIFERA. ovary, add to the resemblance. The large head is bent downward; the brow and the chin project each in a sharp spine, between which the front is capable of a slight protru- sion, ciliated, and furmished with a tubular antenna. Viewed dorsally, the front is ever and anon closed by the rapid approach of two triangular pieces from the sides, which recede immediately (ef. Dinocharis, &c.). The movement has no connection with the mastax. When the animal is confined by pressure, not sufficient to hurt it, it protrudes the jaws ; and besides this a sort of veil is thrust forward, very thin and membranous, seemingly stretched between the frontal and mental points, and from an intermediate point (fig. 18>). The action, though frequent, is momentary, and the withdrawal is complete. The lorica terminates anteriorly by a strong transverse fold, at its full width, whence the mobile head is emitted, of much less apparent diameter. The difference, how- ever, is mainly owing to a rather high dorsal ridge, which rises abruptly from the fold, and continues nearly equal in height to three-fourths of the body’s length ; or even, in some cases, to the whole.! The basal joint of the foot is a round transparent bulb of great size, almost wholly enclosed within the body-walls. It must not be confounded with the contractile vesicle, which is much smaller, and lies upon it. ‘To this foot-bulb is so articulated as to allow very free vertical motion the remarkable form of toe which has been just described. It is usually bent forward toward the belly, but can be thrown out behind, particularly in swimming. The trophi resemble those of Mastigocerca: the fulerum of the incus a long slender rod with the back elevated into a thin ridge; no trace of rami can be discerned, but their pendent divergent alulee, which are unequal. The whole mastax is covered with fine transverse lines. A wide and long brain, of the normal form and position, carries near its middle a great deep crimson eye. On killing one by sudden pressure, the branchial vessels were severed from their connection with the contractile vesicle, and forced out, displaying some details of their structure. They ap- peared as a single tubule on each side, striate in parts with cross lines; towards their hinder parts are seen a number of transverse branchlets, whose ends have been torn off, suggesting not one but many communications with the contractile vesicle. There are also very minute structures attached at intervals to them, one near the head, resembling a twig of several leaves. These I cannot explain. With this very attractive little creature I have been familiar since October 1849, when I met with it at Clapton, near London. It has occurred in many localities since. Its manners are sprightly and elegant. It is perpetually in motion, threading its way through the tangled conferva wires, and swimming across the open spaces, with a rapid eliding movement, turning on its long axis as it goes, The clear viscera, resembling bladders of various shapes and sizes, some filled with richly-coloured food or feces, others granulate, or occupied with embryonic globules, all interspersed with orange- coloured fat-bubbles, and all seen through the transparent skin, have a most charming effect, as the animal thus revolves. It frequently arrests its roving course to examine the plants, and now and then to nibble at them, when the mastaxis brought to the very front, and the jaws themselves are seen projecting from the head, and eagerly biting. Sometimes it swims round and round, in a circle of which the curved outline of the back forms an are.—P.H.G.] Length, ;1, inch, of which the double toe forms about one-fifth. Habitat. Pools and lakes: widespread through Middle and South England (P.H.G.). C. TENUIOR, Gosse, sp. nov. (Pl. XX. fig. 19.) (SP. CH. Body cylindric, decurved, slender ; lorica withowt sensible ridge; head defended by two or three projecting points ; toe with two sub-styles. ' Tam almost sure that the ridge is inclined ; its edge bending over towards the right. I have seen it distinctly wrinkled along the base, as seen in MW. carinata.—P.H.G. RATTULID. 69 This species has manifest affinity with porcellus; but it is much slenderer, and its proportions are different. The width of the body to its length (exclusive of the foot) is as 1: 4; whereasin porcellus it is as 1:2). The toe is here beset with a short sub-style on each side (as in Mastigocerca); whereas in porcellus I can see no trace of these. The lorica, moreover, is not elevated into any sensible dorsal ridge. In all other re- spects it appears to agree with the preceding, except in being somewhat longer. The species first occurred to my notice in water from Woolston Pond, sent me in September by the courtesy of Miss Davies. Several examples occurred, but all dead. A few days later I found it alive in water sent by Mr. Bolton from Birmingham, as well as another dead.—P.H.G.] Length, ;}, to +}; inch; depth, ,}, tog}, inch. Habitat. Weedy pools. Wool- ston: Sutton Park and Coleshill, Birmingham (P.H.G.). C. BRACHYURUS, Gosse. (Pl. XX. fig. 21.) Monocerca brachyura : 5 5 Gosse, Amn. and Mag. Nat. Hist. Sept. 1851. (SP. CH. Body cylindric, short, plump, decurved ; lorica not ridged ; head without spines ; toe-length less than the depth of the body. This species I described in 1851 from a single example taken on Hampstead Heath. It died before I had completed my observations; but I have since seen it on repeated occasions, from various localities, though always scaree. With much resemblance to C. porcellus, it is notably smaller; there is no trace of ridge; the twofold toe, though exactly similar, is proportionally shorter; the front is obtusely truncate, seen dorsally and laterally, and is destitute of projecting spmes. When viewed endwise (as on many occasions), the transverse outline appears quite circular, so far as the back and sides are concerned. A long depending brain carries a great red eye at its tip. The singular appearance of a second eye in the breast, mentioned in my original diagnosis, occurred in no other specimen; it must have been illusory, though unaccountable. The viscera agree with those of porcellus ; the contractile vesicle very large. The toes are almost always thrust up under the belly. In manners this varies much from its lively predecessor, for though constantly in motion it is singularly slow and sluggish, creeping to and fro on the leaves of the milfoil, nibbling ever as it goes.—P.H.G.] Length (without toe), ;4 inch; toe, -),inch; total,,}, inch. Habitat. Hampstead Heath ; Sandhurst; Woolston; Caversham (P.H.G.): pools: rare. C. CAVIA, Gosse, sp. nov. (Pl. XX. fig. 22.) [SP. CH. Body elevated and globose, very protuberant behind the foot; lorica without ridge or frontal spines. In the summer of 1885 Mr. Henry Davis kindly collected water for me near Snares- brook in Epping Forest. Among other treasures found therein I met with this pretty little creature, which at first I was inclined to identify with C. brachyurus. It differs from it i form, however; the great elevation of its hinder quarters, and particularly the development of its buttock into a great plump breech, gives it the aspect of a squatting mouse or guinea-pig, and makes the double curved toe proceed (in appearance) from a notch in the belly, far forward. The mastax agrees with that of its congeners, of moderate size; but the brain is very large, and so is the eye at its point. The stomach was ample, filled with yellow food. Face truncate, slightly prone. The little thing was rather swift at first, but not wild.—P.H.G.] Length (without toe), z1,; inch. Habitat. Epping Forest (P.H.G.). 70 THK ROTIFERA. [I suspect the Distemma setigerwm of Ehrenberg to belong to thisgenus. He himself alludes to the liability of confounding it with Rattulus, as well as to the difficulty of resolving the very slender toe, which, at first sight, seems single ; and to his inability to see any proper foot-joint. Yet he assigns to the species two eyes; which does not accord with any true species of Celopus known to me.—P.H.G.] Ca@Lopus (?) minutus, Gosse, sp. nov. (Pl. XX. fig. 20.) [SP. CH. Two eyes, wide apart; mastax and rotating cilia (apparently) wanting ; body rotund, nuinute. Little as I know of this tiny animal, enough is manifest to show that itis one of much physiological interest. Though for convenience of reference, and because of certain conspicuous resemblances, I place it with the C@lopods, it must be considered a species incerte sedis. The general figure, plump and round, recalls C. porcellus and cavia, and so do the short, curved foot, thick at its base and tapering to a sharp point, and its manner of articulation. Yet, whether the structure of this member is that peculiar to Calopus,—a secondary spine lodged within the inferior concavity of the principal,—I cannot certainly affirm. I strove hard to determine this point, but could not obtain absolute certitude. It appeared single and indivisible. But it is at the anterior extremity that the chief anomalies of the little creature are found. Two cervical eyes are seen, tiny globelets, brilliant and distinct, set wide apart, close within the outline on either side, in a dorsal aspect (fig. 20). I could find no trace of mastax or trophi, in general so largely developed and so conspicuous in this family ; but instead of it what seemed a simple slender duct or tube, formed by the union of two short branches which communicate with the front, and open into a great sacculate stomach ; as if the esophagus had been continued upward,—the mastax being atrophied, —to the very front, or rather merged into the buccal funnel. Again, with the closest scrutiny I could detect no cilia nor any ciliary action. Only a solitary example has occurred to my observation, from the Black Loch, near Dundee. It was alive but inert, and to a certain extent glued fast to the glass by an excretion from the foot.—P.H.G.] Length, ,1 inch. Habitat. Black Loch, near Dundee (P.H.G). Family XII. DINOCHARIDA. Lorica entire, vase-shaped, or depressed ; sometimes facetted, often spinous ; head distinct, with a chitinous covering ; foot and toes often greatly developed; trophi symmetrical. Of the three genera, which together form the Dinocharide, two, viz. Dinocharis and Scaridiwm, resemble each other in the great length of the foot and toes, and in their conspicuous condyles. Both these genera are also completely loricated ; but whereas in Scaridium the chitinous euticle is thin, somewhat flexible, smooth, and transparent, in Dinocharis it attains a greater development than in any other genus of the Rotifera. For, not only is the trunk completely enclosed in a dense lorica shagreened with little knobs, ornamented with ridged facets, or bristling with spines, but the head and foot also are similarly protected, and the lorica stretches down even to the base of the toes. The third genus, Stephanops, resembles the first two in having a chitinous covering for the head, and in bearing stiff spines, which are not organs of locomotion, on various parts of the trunk; but its skin can hardly be termed a lorica, and its foot, though well-jointed and often spinous, is never immoderately long. ‘The head-gear in the DINOCHARID. vu three gencra is also very different, and Stephanops has two eyes remote from the mastax, while Dinocharis and Scaridiwm have but one, closely applied to it. In all, however, the trophi are symmetrical, the family differing widely in this respect from the Rattulide. Genus DINOCHARIS, Ehrenberg. GEN. CH. Lorica vase-shaped, dense, shagreened ; facetted, and with projecting plates, or armed dorsally with spines ; head retractile within a chitinous cap ; eye single, apparently attached to the mastax ; foot and toes very long, the former bearing spines. Two of the species of this genus, viz. D. pocillum and D. tetractis, resemble each other very closely ; the main difference being that the former has, on the last joint of the foot, a small spine between the two toes. But the third species, D. Collinsit, is strikingly unlike the other two, in several respects. Their lorice are vase-shaped, facetted and spineless; whereas its lorica is quadrangular, much depressed, free from facets, but notched round its edge and bearing long dorsal spines. The head-coverings are also unlike. Those of the first two species consist each of quadrantal pieces that can be brought close together so as to enclose completely the withdrawn corona; but in the latter species the head is protected on the dorsal surface by a notched shelly hood, and is uncovered on the ventral surface. D. pocittum, Ehrenberg. (REO teen) Dinocharis pocillum F y . Ehrenberg, Die Infus., 1838, p. 472, Taf. lix. fig. 1. af 0 5 : 7 Grenacher, Sieb. wu. Koll. Zeits. Bd. xix. 1869, p. 497. SP. CH. Lorica vase-shaped, sub-cylindrical, facetted, without spines ; foot and toes very long, and together nearly twice the length of the trunk ; spurs curved ; a short spine between the toes. The vase-shaped lorica of this species has a flat portion with scalloped edges down the centre of its dorsal surface ; anda similar, but somewhat protuberant, portion on the ventral surface. These two plates are connected by stippled concave surfaces, which pass from a dorsal scallop to a ventral one and meet each other in stout transverse ridges, which are very prominent in a side view; and, when the creature is viewed directly in front, so as to obtain transverse views of the trunk, it is evident that the lorica, as shown in the elegant figure 1c, is produced on either side into delicate wing- like plates at right-angles to its surface. The head is protected by a complete cap, con- sisting of two pieces, which can fit together closely so as to conceal the corona, or fall back on each side into a fold in the neck in order to permit the head to protrude. The loricated foot, which is as long as the trunk, has three joints; on the last of which are two slender toes, decurved, bent outwards, and as long as the foot itself. Between the toes is a short chitinous spine. The first joint bears two stout spurs, usually about as long as the joint that bears them, but occasionally more than double the length. The front is rounded and set with small cilia: it is difficult to say what is the exact structure of the corona, or the arrangement of the ciliary wreath. There are a large mastax with sub-malleate trophi; two conical gastric glands; a broad cylindrical stomach ; short intestine; moderate ovary; and very large contractile vesicle. This latter lies athwart the body when distended, and in that condition fills up more than one- third of the body-cavity: its time is four minutes. The lateral canals can be readily seen on the ventral surface, but I detected only one vibratile tag. There is a large crimson eye on the under surface of the nervous ganglion, which overlies the mastax so that the eye seems attached to this latter. Dr. Grenacher (loc. cit.) has seen two lateral rocket-headed antenne on each side of the lower third of the dorsal surface. This is an elegant and curious creature. With its toes well apart like a pair of com 72 THE ROTIFERA. passes, and its foot either thrown into one long curve or oddly bent zigzag fashion, it grubs among the sediment of the live-box ; and sometimes it glides gently away by the action of the coronal wreath, with its long toes trailing gracefully behind it, just like Scaridiwm eudactylotum. Length, J, inch. Habitat. Clear ponds and ditches, Hampstead Heath; Kew Gardens; Woolston (P.H.G.); Clifton, Birmingham (C.T.H.) : not very common. D. terractis, Ehrenberg. (Pl. XXI. fig. 2.) Dinocharis tetractis 5 . . Ehrenberg, Die Infus. 1838, p. 473, Taf. lix. fig. 2. SP. CH. Lorica vase-shaped, narrowing to the hind extremity, facetted, without spines ; foot and toes very long, together more than twice the length of the trunk ; spurs curved ; no spine between the toes. This species is extremely like D. pocillum, differing from it chiefly in having no spine between the toes on the last joint of the foot. The trunk viewed dorsally has a some- what triangular outline, the apex of the triangle being towards the foot, and is shorter in proportion to the foot and toes than it is in the former species. Mr. Gosse has ob- served in this species that the lorica runs off at the hind end into three, thin, transparent, and radiating plates, of which one is dorsal; and that this latter is not continued so far forward as the lateral plates, so that a transverse section shows no trace of the dorsal radiating one, but rather a slight depression between two gibbous swellings. This is well shown in fig. 1c, a transverse section through D. pocillwm. Mr. Gosse has also seen many specimens of D. ¢etractis, in which the spurs on the penultimate joint were more or less deteriorated; so that in some they were reduced to short tubercles, or even effaced altogether. These latter specimens were precisely Ehrenberg’s D. pauper, which can no longer, therefore, be entitled to rank as a species. Length. Up to ,; inch (P-H.G.). Habitat Clear ponds and ditches throughout England and Scotland (P.H.G.; C.T.H.): common. D. conuinsu, Gosse. (Pl. XXI. fig. 3.) Polychetus subquadratus (2). E 5 Perty, Z. Kenntn. kl. Leb. 1852, p. 45. Taf. 1. fig. 6a. Dinocharis Collinsti . . F ; . Gosse, Intell. Observer, vol. x. 1866, p. 269. Polychetus spinulosus js 5 A Archer, Quart. J. Micr. Sci. vol. viii, 1868, p. 72. SP. CH. Lorica depressed, sub-quadrangular, with serrated edges and eight dorsal spines ; spurs straight ; foot and toes short, together as long as the trunk. Though this Rotiferon is clearly a Dinocharis, it is a very singular one. The foot is short, the toes small, the lorica depressed, and a chitinous dorsal hood protects the head. The lorica is somewhat rectangular in shape, but broader in front than behind, with its fore corners rounded off, and its lateral edges serrated. At each hind corner a sharp spine projects, while six others rise from the dorsal surface. There is an outer pair attached to the shoulders, pointing down the back; and an inner pair, slightly decurved at the tips, rising from the central highest point of the lorica, and pointing diagonally outwards and upwards. A third pair, sharp and straight, rises from the hind end of the lorica, one on each side of the foot, and pointing outwards and upwards; while the first joint of the foot itself carries a pair of sharp chitinous spurs. The lorica is closed, much arched dorsally, highest in front, and flat on the ventral surface. The dense lorica, which is stippled in the central region, makes it difficult to define the internal structure ; but Mr. Gosse, from whose Memoir (loc. cit.) this account is taken, succeeded in ob- serving a globose mastax, ample alimentary canal, and rich ruby eye. DINOCHARIDA. 73 This Dinocharis was discovered by Dr. F. Collins in 1866, in a small pool in a wood near Sandhurst. Dr. Collins sent it to Mr. Gosse, who figured and described it (loc. cit.) in 1867. Dr. Max. Perty’s Polychetus subquadratus may possibly, but not probably, be the same creature ; if so, it is most inaccurately drawn and described. Mr. Archer's Polychetus spinulosus is undoubtedly D, Collinsiw. Mr. Gosse says of its habits that ‘it is rarely still, rooting among the sediment or swimming with a smooth gliding motion of no great speed. If I may judge of its be- haviour in freedom from what is seen while under our notice, it seems to be a specially bottom-frequenting form.”’ Length, ;3; inch. Habitat. Sandhurst, Berks (Dr. F. Collins); Clifton (Mr. Brayley) ; Carrig and Callery districts, Ireland (Mr. T. Archer) ; Dundee (P.H.G.): rare. Genus SCARIDIUM, Ehrenberg. GEN. CH. Lorica vase-shaped and compressed ; or pear-shaped and depressed in front; very thin, transparent, smooth, without spines or projecting plates ; head with a chitinous cuticle, except in front; eye single, really or apparently attached to the mastax ; foot without spurs ; toes very long. In the genus Scaridiwm the foot and toes (especially the latter) are remarkable for their great length, for the distinct condyles, which give them such free action, and for the powerful striated muscles, which enable the animal to jerk its long toes widely apart, and to strike the water violently with its foot, so as to make it an effective organ of locomotion. In both species the lorica is a transparent, thin, stiff skin, which ap- pears to be continued over the foot; but its shape in the two species is very different : for, while the lorica of S. longicaudum recalls that of Dinocharis pocillum, the lorica of S. eudactylotwm somewhat resembles in general outline that of a Brachionus. In each species the eye appears to be attached to the mastax, instead of to the nervous ganglion ; this would be a very unusual arrangement, but it is possible that the appearance is due to the nervous ganglion’s being closely applied to the mastax, and more than usually transparent.!. The habits of the two creatures are similar. They swim quietly for a time, trailing the foot and toes behind them in an elegant curve; and then, with a sudden leap, they dart off into a new course. 8. Lonaicaupum, Hhrenberg. (Pl. XXI. fig. 5.) Scaridium longicaudum - ° > Ehrenberg, Die Infus. 1838, p. 440, Taf. liv. fig. 1. ” ” 5 ° . 5 Gosse, Phil. Trans. 1856, pl. xvii. figs. 64, 65, [SP. CH. Body compressed ; front truncate; eye adherent to mastax ; body, foot, and toes of about coequal length. The most remarkable peculiarity of this species is the anomalous character of the eye,—a large flattened capsule, with crimson pigment not quite filling it, permanently attached to the surface of the mastax, and apparently not connected, as usual, with the occipital brain, which, however, presses upon it from above and behind. The trophi, too, are very abnormal. (See my Mem., loc. cit.) The animal, with its long unwieldy foot and toes, reminds us, not less by its movements than by its form, of Dinocharis. It is active, swimming with unequal, not very swift, action, with little movement of the foot and toes. It has the habit of making sudden springs, using, apparently, for this purpose, the fore parts, not the toes.—P.H.G.] * I suspect this to be the case in S. ewdactylotwm ; but in S. longicaudum Mr, Gosse is confident that the eye is inseparably seated on the mastax. 74 THE ROTIFERA. Length, inch. Habitat. Stratford; Maidenhead; Cheltenham; Birmingham ; Starmont Loch, Dundee (P.H.G.); pools and dykes: rare. §. EUDACTYLOTUM, Gosse, sp. noy. (Pl. XXI. fig. 4.) SP. CH. Lorieca pear-shaped, depressed and narrowed in front ; toes as long as all the rest of the animal. [S. eudactylotwm was discovered in September 1881 in a small loch in Perthshire, by Mr. Hood, who sent me a tube of the water. This I found well peopled with this charming species. It is much more globose than longicaudwm, and much more trans- lucent, looking like an oval bubble of clear glass. The head is small, formed of several ciliated eminences. Among the turbid clouds, which are probably brain-matter, there are one or two oval spots, which refract the light strongly ; but I cannot interpret them. As a small red eye always moves to and fro with the movements of the mastax, I con- clude that they are organically united as in longicaudwm. The incus and mallei are much more normal than in that species. The manubria, however, are tripartite, and the middle joint is largely and somewhat irregularly looped. The apparatus is un- usually minute, obscure, and difficult. The mastax is distinctly three-lobed. There are a long csophagus, wide stomach, intestine, and small ovary with nucleated ovarian vesicles. In one example was a small maturing egg. The longitudinal muscles are numerous, and unusually conspicuous, owing to the brilliant trans- parency. But the most remarkable feature is the foot of three articulations, with strongly marked condyles, and a pair of furcate toes of excessive length and tenuity. They are usually straight, but are sometimes a little curved outward at their tips. It is graceful and elegant in its motions. I have never seen one resting, but invariably swim- ming with a smooth even gliding, not at all rapid, often varied by a sudden spring or skip to one side, like its fellow S. longicawdwm. The toes are very flexible, and highly elastic ; sometimes when the animal suddenly turns, I have seen the toes bent almost double, but recovering their straightnessin a moment. That the integument is a proper lorica, closed and vase-like, is undeniable; yet it is so thin and flexible that the head retracted every instant carries with it the in-turned delicate front edge, which is again everted. At the moment of eversion I have repeatedly seen what I believe to be an an- tennal seta of exceeding tenuity ; but certainly no tubule or pimple.— P.H.G.] The lorica is tolerably flat on the ventral surface, but on the dorsal is distinctly gibbous behind and depressed in front. Like that of Brachionus, it deepens down to the hinder third of its length, and then suddenly drops with two abrupt curves. Viewed dorsally (fig. 4), it can be seen that a central portion of the lower third is arched above the general surface, and kept so bent by transverse muscular fibres. The head on the ven- tral surface is scooped into a hollow above the buccal funnel, and the corona bears two hemispherical ciliated prominences. On the long esophagus, at a little distance from the stomach, are two small stalked glands (fig. 4a) similar to those in Pterodina and other Rotifera. The gastric glands are of unusual size and form. They are Y-shaped (fig. 4), and each has its stem attached to the top of the stomach, and its outer branch continued up to, and round, the inner dorsal surface of the lorica, to which it is attached. Each inner branch hangs down, pointing inwards, towards the ventral surface, to which it is probably tied by a fine fibre. These glands are distinctly, though delicately, spotted with nuclei. The vascular system is best seen from the ventral surface (fig. 4b), where the lateral canals, surrounded by wide ribbons of delicate floccose matter, seem to adhere to a considerable portion of the lorica, keeping chiefly toward the sides. The contractile vesicle (fig. 4b) looks asif it consisted of an oval central chamber, surrounded by several smaller : an appearance probably due to the muscular fibres crossing it in a somewhat regular pattern. It is rather large, and a side view (fig. 4a) shows that it lies by itself at the hind end of the inner ventral surface, while the rest of the viscera DINOCHARIDA. 75 follow the arch of the dorsal. I detected four vibratile tags (fig. 4b) on each side: one near the top of the lorica one about the middle, and two on a plexus of tubes lower down. The muscles that pass down the foot to move it and the toes are very conspicuous and are coarsely striated ; and the condyles of the toes (fig. 4c) are remark- able. The nervous ganglion (figs. 4, 4d) is so extremely transparent, that in can hardly be detected except by a chain of dark spots round its lower edge, which betray its pres- ence when it moves. It is very long, cylindrical, with a rounded free end, and lies across the mastax and eye (fig. 4d). It may possibly be attached to both. Two rocket- headed antenne can be seen, one on each side of the dorsal surface (fig. 4), and about one-third of its length from its base. I am indebted to Mr. J. Hood for the numerous specimens of this beautiful creature which enabled me to make drawings of it from various points of view, and to supplement the details given by Mr. Gosse. Length, ;, inch. Habitat. Pools near Blairgowrie (J.H.): very rare. Genus STEPHANOPS, Ehrenberg. (Lorica cylindrical or pyriform, entire ; head bearing a permanent, wide, circular shield ; toe (or toes) often surmounted by a toe-like tail. The species which constitute this well-marked group are in general easily recognized by the beautful glassy shield which protects the head, and which, seen dorsally, in- stantly recalls the ring of glory which surrounds the heads of sacred persons in medieval pictures. This differs from the frontal hood in the Coluride, by being non-retractile, and having no motion apart from the whole head. Several of the species have spines affixed to the lorica or to the foot. The foot is habitually exserted, composed of joints which are stout, long, and distinct.—P.H.G.] 8. LAMELLARIS, Hhrenberg. (Pl. XXI. fig. 7.) Stephanops lamellaris . - é Ehrenberg, Die Infus. 1838, p. 478, Taf. lix. fig. 13. [SP. CH. Lorica pyriform, having a narrow neck, and slightly prolonged behind into three sub-parallel slender acute spines ; foot furnished with a toc-like spine. The form is swollen and vase-like, with a marked everted rim or neck, within which the whole head has a slight motion, surmounted by its lovely round glory-shield, which equals the lorica in breadth. Under its shelter is seen the conical front with its rotat- ing cilia, its oblique points, and its two ruby eyes, very wide apart. Below the rim or neck the trophi are conspicuous, formed on the pattern seen in Huchlanis. The viscera are normal, including an ample transversely-ovate contractile vesicle. The hind part of the lorica is deeply truncate, and the three spines are limited to the dorsal end. The foot consists of three joints, long, and strongly marked, of which the last (save the toes) carries a very slender spine seated on a tubercle on its dorsal side, not quite so long as the two toes. The foot joints are permeated with two long chain-like glands.—P.H.G.] Length, ;i, inch. Habitat. A garden tub (P.H.G.): rather scarce. 8. muticus, Hhrenberg. (Pl. XXI. fig. 6.) Stephanops muticus : cS : Ehrenberg, Die Infus. 1838, p. 479, Taf. lix. fig. 14. (SP. CH. Lorica cylindric, having a distinct thick neck, and prolonged behind into a spoon-like shield, which is unarmed, as is also the foot. What I identify with Ehrenberg’s muticus agrees better with his description and figures than with Eckstein’s. Can the latter have made his drawing from two indivi- 76 THE ROTIFERA. duals, lamellaris and muticus, which he supposed one and the same? I confess I have had suspicions that these are but one species. I have had specimens in my live-box of what seemed lamellaris, with the three caudal spines clear enough; yet in a few minutes I could find only specimens of muticus, with no spines at all to be discerned, to my great bewilderment. It seemed as if the spines could at will disappear, but I cannot conjecture how. This has happened repeatedly. Except the greater development of the neck, there is little else to discriminate the two.—P.H.G.] Length, 1, inch. Habitat. Fresh waters around London; an aquarium at Tor- quay (P.H.G.): scarce. S. UNISETATUS, Collins. (Pl. XXI. fig. 8.) Stephanops uniseta ° . - Collins, Science Gossip, 1872, p. 11, figs. 9a, b. (SP. CH. Lorica ovate, its hinder end without points, but bearing a dorsal spine, very slender, straight, as long as the body ; foot with a slender tail and two toes. The discoverer of this interesting form has furnished me with a number of examples from its original habitat: all inhabiting the leaves of a subaquatic moss. In the ‘‘ Jour. Roy. Mier. Soc.” 1885, Dr. Hudson has suggested the identity of Mr. Lord’s species! with this; but I think its thick fore-parts, the curvature of its spine, and several other pecu- liarities, indicate their diversity. If so, we have five dorsal-spined species. The spine here is so attenuate that it may well be called a seta, According to my observations, it vibrates with the tremulous motions of the body, but has no proper separate motion. Its base is attached to a shelly knob, level with the bottom of the mastax ; it is quite straight, and its point reaches the tips of the toes. The hind edge of the lorica is truncate and unarmed, as in muticus. There are two slender pointed toes, and a minute spinous tail at right-angles from their base. The species affects concealment, but occasionally comes out to swim with a smooth gliding motion in the open interspaces ; often subject to a momentary vibration through- out.—P.H.G.] Length, ,},, toy}, inch. Habitat. Sandhurst (Collins ; P.H.G.): not rare. S. cHLENA, Gosse, sp. nov. (Pl. XXI. fig. 9.) [SP. CH. Lorica cylindric, forming a semicircular occipital shield, without any constriction ; toe single. Ehrenberg’s S. cirratus (not yet recognized with us) appears to lead to this, the sides being straight without any neck. The face is oblique, wider than any other part, beset with irregular fleshy lobes, with a retractile lobe forming a kind of chin. A great sac- like brain carries one minute eye, very difficult to be seen. The lorica, without any diminution in width, ends behind in three points, and resembles a short cloak reaching to the loins. From this descends a thick and long foot, whose penultimate joint carries an acute spine at a right-angle, which is a proper tail; thence a stout taper pointed toe, along whose middle a line may be dimly seen, suggesting two toes soldered into one. The rectum may be traced to a cloaca between the tail and the toe. Its manners are those of its fellows. In swimming, its movements, already rapid, are accelerated now and then by sudden starts, probably predatory.—P.H.G.] Length, ;1, to}, inch. Habitat. Sandhurst: Woolston (P.H.G.)?; pools : rare. 1 Micr. News, vol. iv. 1884, p. 146, fig. 24. The figure of this Stephanops has one dorsal spine, and one short spine, or tail, sloping upwards, just above the toes. 2 There are differences in form and size between the Sandhurst and the Woolston specimens, so considerable that possibly these may be distinct species : the former much larger, more slender, the front not sensibly lobular ; the whole animal yellow-tinged.—P.H.G. DINOCHARID 4%. Ligh Mr. J. G. Tatem (‘‘ Quart. Journ. Mier. Sci.’ vol. vii. 1867, p. 252, with figs.) described and figured a Stephanops (S. longispinatus) with one long dorsal spine, no posterior spines; and two short straight spines (one on each side) on both the first and second joints of the foot. Mr. T. Bolton (in 1884) published among his fly-leaves a Stephanops (S. bifurcus) with one long dorsal spine, and one short posterior spine slanting backwards and upwards, from the end of the lorica; both spines on the median line, and none on the foot. Mr. J. Hood in the same year sent me a drawing of yet another species (8. armatus) with one long dorsal spine, and two short posterior spines, one on each side of the end of the lorica slanting slightly upwards and outwards, and somewhat convex to the lorica. This species also had no spines on the foot. Mr. Hood’s figure is given in pl. xii. of the ‘‘ Journ. Roy. Micr. Soc.” 1885. Family XIII, SALPINADA. [Body more or less completely inclosed in a firm lorica, which is open at each end, and divided down the back by a fissure whose sides are united by membrane ; two furcate toes always exposed. We come now to forms which are indubitably and manifestly loricate, the integument permeated by a peculiar chemical principle known as chitine, which imparts hardness and stiffness to it without diminishing its transparency. This substance is unaffected by alkalis, which immediately destroy all the flesh and membranous parts: a fact which is often useful to the scient, as by the addition of a minute drop of caustic potash to the cell containing a specimen to be examined, he can in an instant obtain the external form unchanged, generally clear and bright, with all the internal organs, that had marred distinct vision, dissolved away. The animals we have now to consider are clothed in a coat-of-mail (Jorica) more or less complete, of which the edges are sharply marked. Thus they display an evident analogy with the shelled MOLLUSCA, and one more close with the EnromostrRaca, with which, in its bivalve tribe Ostracoda, the present family may be advantageously compared. The lorica here consists of two lateral segments of an ovoid box, open in front and behind, for the emission of the head and the foot, the two edges parallel and approximate along the dorsal line, and either widely open along the belly, as in Diaschiza, or united and soldered into one there, as in Salpina and Diplax. The front is composed of ciliated prominences, not protected by an arching hood; the foot is provided with two furcate toes.—P.H.G.] Genus DIASCHIZA, Gosse, gen. nov. [GEN. CH. Body compressed ; the dorsal half of the trunk inclosed in a carapace, which ts split medially ; one eye present, usually cervical; trophi virgate, not distin- guishable from those of Furcularia; toes long, blade-like, furcate. This well-marked group, now consisting of seven species, was wholly unsuspected a few months ago. One after another has occurred to my own observation, within the past year, and I strongly suspect that other species will yet be discovered. The genus forms a very striking link of connection between the Loricate and II-loricate sub-orders, as will be shown, more in detail, under the remarkable species D. semiaperta.—P.H.G.] D. vauGa, Gosse, sp. nov. (Pl. XXII. fig. 12.) (SP. CH. Lorica decurved ; eye occipital, small ; toes long, slender, much decurved. Among filaments of Myriophyllwm, growing in an aquarium, very thickly beset with various Diatomacee, &c., appeared in March 1885 an active, restless, little creature, 78 THE ROTIFERA. which, at first, I thought one of the common forms of the minuter Notommate or Furcularig. But I presently perceived that it had peculiarities of structure, which were quite unfamiliar to me. Its figure is nearly that of a cylinder, somewhat bowed down- ward at each end, and a little arched along the dorsal line. A small truncate foot carries two slender toes, about two-thirds as long as the body, much decurved, so as to form a segment of one-fourth of a circle; these are usually carried wide apart. A large brain bears a red eye-point considerably anterior to its extremity, visible only at intervals ; in subsequent specimens, however, sufficiently conspicuous. The whole form and manners of this animal indicate its affinity with species which are il-loricate. The situation, dimensions, and structure of the manducatory apparatus are indistinguishable from those of Notomm. lacinulata ; yet the dorsal parts are inclosed in a semi-cylindrical shell of transparent chitine, reaching about half-way down each side, with a straight edge; and cleft throughout the dorsal line, into two parallel halves, moderately separated (reminding us of a Salpina, or still more of my Diplax conupressa), reaching to the end of the body, where each terminates in a point slightly over-arching. Anteriorly this bifid carapace terminates transversely at what may be called the neck, allowing the soft tissues of the head to be partially retracted for an instant, when the lateral angles of the lorica are seen as two unchanged blunt points. It is remarkable that, in a lateral view, the very front itself appears as if the integument were so stiffened with chitine as to project both above and below in slightly obtuse points (fig. 12a). I soon after found two individuals among conferva in a ditch at Coffin’s Well, near Torquay; and still later in waters from many widespread localities. I find little varia- tion in them. ‘The dorsal cleft is shallow, but always visible when the animal turns.— PoE Gi MA Length. Of body, 31,5 inch ; of toes, +4, inch; total, ,4, inch. Habitat. Torquay ; Woolston ; Sandhurst ; Birmingham ; Cheltenham ; Oban (P.H.G.): not rare. D. pxiaua, Gosse, sp. nov. (Pl. XXII. fig. 18.) (SP. CH. Minute; lorica flexible, constantly thrown into folds; eye cervical ; toes thick at their base, less than one fourth of total length. On one or two occasions I had met with this little species in water sent me by Miss Saunders, from a window tank in her residence at Cheltenham. I had marked differences between it and D. valga, but yet set it down as that species, waiting for further light. More than five months afterwards, I was examining some of the pale impalpable floccose alga that grows thickly around the filaments of certain pond-weeds, originally from Dundee, but which had been several weeks on my table, when I saw this little thing in some number, and perceived that its peculiarities entitle it to specific rank. Though valga is a small species, this is not half its size ; its proportions, too, are different. It is much plumper and more gibbous behind; the toes, instead of slender rods uniform in thickness, are long cones, tapering to acute points ,and only one-third of the length of the head and body. The investing integument is evidently very flexible, every contraction and every turn throwing it into strong folds. Yet, thin as it is, it is a true lorica, reaching half- way down each side, as in valga, and displaying the dorsal fissure quite distinetly, as one views it from behind; when it is seen to be very shallow. No other poms in its economy eer noteworthy. —P.H.G.] Length, 5}, to z4, inch; toes alone, +31, to y;459 inch; lorica, ;}, inch. Habitat. Algwe in fresh-water aquaria (P.H.G.): rare. SALPINADAS. 79 D. Hoop, Gosse, sp. nov. (Pl. XXII. fig. 15.) [SP. CH. Body gibbous and ventricose behind ; dorsal cleft narrow, parallel-sided ; eye cervical; toes rather short, blade-shaped, acute, decurved, one-fifth of total length. This little species comes near to D. valga, but is considerably larger, and more swollen in the posterior half of the body, whether viewed dorsally or laterally. The toes afford the most obvious discrimination between them. In both, each toe is a segment of a circle : in valga it is a slender rod of about equal thickness throughout its length, which is nearly equal to that of the lorica. In Hoodii it is shaped in one aspect like a carving- knife, in another like the half of the moon when three days old. As I have observed the forms of the toes in Rotifera generally to be very constant, I am disposed to rely much on them in specific diagnosis. Only one individual occurred ; and of this my observations were imperfect. I found it in the pale floccose alga, which invests aquatic plants near Dundee. In memory of this origin I honour the little Diaschiza with my respected correspondent’s name. A few weeks after this, I was so fortunate as to find another example, in water sent me by Mr. Bolton, from Blackroot Pond, near Birmingham. In the former specimen I had not perceived any eye ; but in this it was very conspicuous, of large size, and of some- what pale rose-red hue, though brilliant, resembling D. peta in colour, but in a less marked degree. It is cervical, occupying the extremity of an ample brain.—P.H.G.] Length. Not measured, but about one and a half that of D. valga. Habitat. Loch near Dundee ; pool near Birmingham (P.H.G.): rare. D. pmra, Gosse, sp. nov. (Pl. XXII. fig. 11.) [SP. CH. Body thick, widest in front; lorica with the dorsal cleft very narrow, its edges parallel and ridged ; eye cervical, very large, pale ; toes blade-like, recurved. In June 1885, soon after I had discovered D. valga, a little water was sent me by Miss Saunders, from Woolston, in which were a good many specimens of that species, some much smaller than I have described. In the same water, however, I found one much larger, which proved a second species of the same genus. Again was I deceived into the supposition that I was dealing with a Notommata, or a Furcularia, such as F. gibba, till I caught sight of the cleft down the back; and particularly, when, as the creature turned, I for a moment saw it from behind, and looked up along the furrow. The lorica seems again to be a mere carapace, reaching no more than half-way down the sides, and cleft in a straight line along the back. It has an elevated ridge through- out; so that the cleft forms a furrow between the low walls; and these are much closer together than in D. valga, so that the furrow is very narrow. The dorsal posterior terminations do not run off into curved points, but make nearly right-angles. I judge the lorica to be very thin and flexible. The toes are slender, pointed blades, somewhat recurved, often carried parallel when the animal glides forward. The mastax is large, and seems formed quite on the pattern seen in Fwrcularia. Behind this is an ample brain, carrying at its sacculate extremity a very large globose eye, of extremely pale, transparent, carneous hue; this species differing thus from the former, in the position, size, and colour of the eye,—itself a well-marked and conspicuous distinction. The digestive canal is divided into stomach and intestine, both which are large and saccu- late ; and there is a contractile vesicle. The forepart of the abdominal viscera was, in this example, delicately tinged of a salmon-colour. At the cloaca, asif a minute portion of the intestine, there was protruded a little clear globose vesicle; perhaps accidental. This species is in manners restless and recluse, seeking its food and shelter under 80 THE ROTIFERA. the skins of decaying algw, and other aquatic plants. It seems reluctant to swim in the open water; but yet can glide along, smoothly and swiftly, when it pleases. Three months had nearly passed, and I had met with no second example of this beautiful species, though examples of valga and semiaperta had been numerous. But then, in water from the same fruitful pond at Woolston, a specimen occurred, which seemed the counterpart of peta, except that the great brain was destitute, so far as I could discern, of the pink eye, which had been the most conspicuous distinction of the species. Presently, however, another appeared; and here the whole occiput was instantly seen to be radiant with the soft, rose-red tint; the eye, in fact, or at least its pigment, occupying, just as in my first example, the whole lower part of the ample cerebral sac. Hence I infer that the rosy hue, normally pale, may sometimes become so dilute as to be practically undiscernible.—P.H.G.] Length, ;}, inch. Habitat. Woolston Pond; Sandhurst, Berks: rare (P.H.G.). D. SEMIAPERTA, Gosse, sp. nov. (Pl. XXII. fig. 10.) [SP. CH. Body compressed, highest behind ; lorica with the dorsal cleft closed in front, gaping behind, the ventral edges apparently approximate ; eye frontal ; toes long, slender, recurved. In describing Furcularia gibba (supra, ii. 43) I have spoken of the resemblance borne to that species by the present, a resemblance which extends to other species. D. semiaperta bears much likeness to D. peta, but is still larger ; it is, too, higher behind, and the brain has no pink colour. There is, indeed, a well-defined oval eye, of deep red hue, but of moderate size, and situate near the front (fig. 10b). The brain is large, descending far down the back of the neck, quite clear, and strongly defined in outline. The locomotive cilia appear set on minute eminences over the whole rounded front, making no wheels, but visible as a simple frmge. The trophi are unusually large (fig. 10d'). The lorica, though split all down the back, has the edges of the fissure in contact at first, so that only the hinder half is open, and this but narrowly. In a succession of fair views that I had of one which was dying, looking down the back from the front of the head, not only was the gape of the lorica well seen to be but partial, but it evidently appeared that the cleft part was not elevated into a ridge, as it is in other species. The lorica-halves appear even to approach along the belly, as they do along the back. But I am not certain of this. Hach division terminates behind in an obtuse, slightly-decurved point (fig. 10), often obliterate. One individual of this species had two globose bladders protruding from the cloaca, as I have described in D. peta. It may indicate a prevalent form of disease in the genus. In one specimen was a large dark egg, nearly matured. Another had the alimentary canal greatly distended, and of a greyish-blue hue, an unusual colour in Rotifera ; but the mystery was explained by the fact that a colony of the Blue Stentor (S. ceruleus) was established on the same sprig of water-moss; and it became evident where the Diaschiza had obtained its dinner.—P.H.G.] Length. Total, 3, to jj, inch. Habitat. Cheltenham; Woolston, numerous ; Birmingham ; Stormont Loch, Scotland (P.H.G.): pools, rather common. 1 This drawing was made from a protracted and excellent observation of a recently dead specimen, completed without any reference to my published figs. (Phil. Trans. 1886). Yet it is seen how exactly the details agree with those figs. (35-40), and especially with 39 and 40 of the Memoir. In examining many dead specimens of D. semiaperta, I have obtained accurately the appearance of fig. 37 ; the long produced, decurved points of the incus explaining what had seemed so inexplicable im situ. Iam, however, almost sure that these arching points proceed from the fulcrum between the rami, and are not prolongations of the wide glassy rami themselves. SALPINAD AL. 81 D. TENUIOR, Gosse, sp. nov. (Pl. XXII. fig. 14.) [SP. CH. Body swb-cylindrical; dorsal cleft of lorica wide throughout; toes thick, nearly straight, obtusely pointed. Here is a species which bears a relation to Fureularia gracilis,’ similar to that which D. semiaperta bears to F’. gibba. In September, 1885, while I was examining water, sent me by the courtesy of Miss Davies from Woolston Pond, my attention was arrested by first one and presently another, of what appeared indubitable /’. gracilis. Each was either half-concealed, as it burrowed in the floccose matter, or in swift motion as it glided through the clear water; so that, while I could recognize the form and general character as accurately agreeing with drawings which I had carefully made of that species, many years before (except that these were of rather stouter build), I could get no opportunity of testing the condition of the back. Presently, however, I was so fortunate as to catch sight of the integument of a dead specimen of the same, perfect in form, but empty and transparent, the mastax 7m sitw. By imparting currents to the water in the live-box, while the object was under my eye, I could turn it into various positions ; among others, one in which I could look along the line of the back. It was distinetly double-ridged, and rather wide-cleft. The gap is of nearly uniform width from the occipital edge of the lorica to the hinder edge just over the foot. I have said that the form was stouter than of F’. gracilis; it appeared stouter now than in the two living restless examples that had first attracted my attention. But I reflected that the dead lorica would naturally be broader than in life, because, the tezgumentary membrane of the venter haying been ruptured by decay, the elasticity of the dorsal shields would naturally cause their lateral expansion. Circumstances prevented my further study of the two living specimens; and I can give no further information of the anatomy than what was to be learned from the dead body.? The features, however, that were visible were, from the very stillness of death, definable with precision. The toes, in particular, are diverse from those of any other Inown species, being not sensibly recurved nor decurved, but straight, or nearly, not blade-shaped, but round, rather thick, abruptly brought to a point.—P.H.G.] Length. About ;4, inch. Habitat. Woolston Pond; Dundee (P.H.G.): rare. Genus DIPLAX, Gosse. (Ann. Nat. Hist. 2 Ser. vol. viii. Sept. 1851, p. 201.) [GEN. CH. As Salpina, but the eye is wanting, and the lorica is destitute of spines in front and rear ; foot and toes long and slender. The two species of this genus I found both in the same water, Oldham’s Pond, Leamington, and both on one day, July 13, 1850. Of the first, only one specimen occurred ; the second was numerous. With a single exception of the latter, I have never again met with either. They both approach very close to Salpina, but the absence of spines is notable, and the toes are proportionally more attenuate and longer. The head is seated in a flexible tube, cleft at the occiput, which is capable of entire involution within the lorica. It seems an approach to the persistent neck-tube of Dinocharis, to which genus the present is allied by the condyles of the foot, and by the length and slenderness of the toes. —P.H.G.] ‘ I strongly suspect that Herr Eckstein’s delineation of F’. gracilis (Sieb, uw. Koll. 1883, pl. xxvi. fig. 43) has actually been drawn from a specimen of Diasch. tenwior. * Recently (March 1886) I have found it, in an aquatic moss sent me by Mr. Hood. It was very restless, but I saw that the trophi, viewed dorsally, were on the pattern of Notommata lacinulata.— P.H.G. VOL. II. G 82 THE ROTIFERA. D. compressa, Gosse. (Pl. XXII. fig. 8.) Diplax compressa . 6 Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. Sept. 1851, p. 201. [SP. CH. Body much compressed ; lateral outline of lorica nearly a parallelogram. The lorica consists of two trapezoidal plates, of which the ventral is the longest side, connected together a little within the dorsal edges, so as to leave a double ridge. The plates are bowed outward, laterally, and seem to be conjoined below. The whole lorica may be rudely compared to a cell made by two spoon-bowls soldered edge to edge. The transparent dorsal ridges can approach and recede, and are probably connected merely by elastic skin. The whole frontal region is occupied by the brain, which descends sac- like into the occiput, but shows no trace of eye. The mastax is small, and the trophi obscure. A digestive canal, very wide at its origin, almost opaque from granulation, diminishes, with no apparent constriction, direct to the cloaca in a straight course. The ovary was normal, and I saw an ample contractile vesicle of sluggish action. No lateral vessels were traced, but one vibratile tag was seen. Along the line which, in the lateral view (fig. 8), indicates the bottom of the dorsal cleft, there are seen three oval scars, possibly insertions of muscles for closing the valves. The foot consists of three lengthened joints, two of which are decidedly condyliform (as in Dinocharis), habitually protruded; it carries two divergent toes, straight, rod-like, acute. The manners of the single specimen found were much like those of Salpina, but it swam more, rarely resting on its toes. It was found among the sediment in the phial, after several days’ keeping.—P.H.G.] Length. Of lorica, ~}, inch; total, when rotating, y+, inch. Habitat. Leamington (P.H.G.): rare. D. TRiGoNA, Gosse. (Pl. XXII. fig. 9.) Diplax trigona 5 . . Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. Sept. 1851, p. 201. [SP. CH. Body triangular in section ; lateral outline of lorica ovate. There is much resemblance between this and the preceding; but the ventral side is flat, and about equal to each of the lateral sides; and the longitudinal outline of the back forms one third of a circle. The pectoral edge, which in D. compressa is but slightly notched, is in ¢rigona indented with a broad and deep sinus (fig. 9). The neck-tube which incloses the head is only so far retractile, that, when its sides are brought together, they protrude between the lorica-edges, in form of a thin fold (fig. 9a). The frontal cilia are strong and bristle-like, grouped on prominences; behind which a very small brain-sac descends, with no visible eye. The trophi, of the common Salpina pattern, and the internal structure generally, are as in the preceding ; almost always obscured by a vast aggregation of air-bubbles. A thick tortuous vessel runs down each side. The toes are very slender, straight rods, in some examples much longer than here figured. The surface of the lorica is delicately punctured.—P.H.G. | Length. Of lorica, +4, inch; total, ,4, inch. Habitat. Leamington; Stratford (P.H.G.): rare. Genus SALPINA, Elrenberg. (GEN. CH. Lorica an oblong box, furnished with spines, but widely open at each end, split down the back; head and foot protrusile ; toes furcate, long, straight ; trophi sub-malleate ; eye single, cervical. A homely illustration of this common and well-marked genus may be obtained by supposing a Notommata or Diglena of long straight toes inclosed in a transparent shell. This shell, the lorica, may be compared to a pillow-case, open at the two ends, with one SALPINADA. 83 long side (the dorsal) unsewn, whose edges remain approximate, yet separate.! Both ends run off into projecting points, which are grouped into four series, occipital and pectoral in front, lumbar and alvine behind; and these terms may be convenient for definition. The head can be retracted wholly within the lorica; but the foot only partially, and the toes never. These are moderately long, blade-shaped, acute, straight, divergent. The eye is usually conspicuous, single, rather large, placed on the occipital end of an ample brain. The mastax is large, globose, the mallei and incus well- developed, the former many-fingered. A bristle-bearing antenna is protruded between the occipital spines.—P.H.G.] S. mucronata, Ehrenberg. (Pl. XXII. fig. 1.) Salpina nuucronata < : ; Ehrenberg, Die Infws. 1838, p. 469, Taf. lviii. fig. 4. [SP. CH. Occipital spines two, procurved ; pectoral two, wide apart, separated by a deep sinus ; lumbar single, short ; alvine two, recurved, separated by a wide and deep sinus ; dorsal parts of the lorica minutely stippled. The lorica is somewhat three-sided, the back arched, and doubly ridged, with a narrow but deep furrow ; the sides gracefully swelling ; the belly nearly flat. The two occipital spines, antler-like, are bent forward and slightly approximate at their points, with a deep sinus between their bases. From the two edges of this sinus spring the two dorsal carine, arching to the middle in an elegant curve, and meeting in the conical lumbar spine. The two pectoral spines are short and nearly lateral, as are the two alvine ; both pairs are mutually severed by a broad and deep excavation of the ventral surface of the lorica, while a similar sinus, less deep, bounds each of these pairs on the right and left. The flat ventral surface bulges out abruptly to form the pectoral spines. The head is very large, and is composed of many globose lobes, each of which carries a group of rotating cilia. An ample brain carries a small horizontal antenna, and a large cervical crimson eye. The trophi are frequently seen to protrude obliquely from the front, to nibble the floccose matters on which the animal feeds, which are, I think, exclusively vege- table. The alimentary canal, large and very sacculate, following ashort cesophagus, carries two ovate clear glands, and leads (apparently without division) to the cloaca. In an experiment, it readily received carmine. An ovary often shews embryonic vesicles ; and sometimes a great maturing egg adds to the size and to the beauty of the animal. The lorica is elastic; in looking up along the cleft I have distinctly seen the ridges approach and recede, sometimes nearly closmg up and then gaping widely. The latter is coin- cident with retraction of the head-parts, and at the same time some of the viscera are forced up between the ridges, considerably above the level of their basal line (fig. 1). Though active, it does not swim much. It chiefly courses up and down among the roots of the duckweed, which it affects, examining each in detail. It is not very sensitive to alarm, caring little for taps or jars upon the instrument. The toes are often expanded and closed. It is nearly colourless.—P.H.G.] Mr. KH. C. Bousfield has seen a male Salpina attached by its penis to a female which was probably S. mucronata. It seemed to him that the male organ pierced the ventral surface of the foot at the base of the first joint. This appearance was doubtless due to the male’s adhering externally by the broad end of the retroverted penis. Dr. Plate 2 says that the male of Hydatina senta pierces the female, anywhere, with its penis. He admits that he has never seen the organ within the female’s body, and that he never could find any aperture after the apparent penetration; but suggests that the cilia of * The dorsal fissure is not of fixed width, but variable at the will of the animal. An example (not quite mature) of S. brevispina, which was sitting quite still, end-on, so as to give me an excellent sight, had its dorsal cleft rather wide open; while I looked at it, it deliberately closed up the sides to mutual contact. * Jenaisch. Zeits. f. Natur. 1885, p. 37. 84 THE ROTIFERA. the penis make very minute punctures in the skin, and that the rod-like spermatozoa find their way through these. Such hypothesis scarcely requires serious notice; but I may mention that Mr. Brightwell, Mr. Gosse, Mr. Hood, and myself have all seen coitus take place, in various Rotifera, at the cloaca. Length. About ,}, inch; lorica, ;4; inch. Habitat. Weedy pools; duckweed ; around London (P.H.G.); Sandhurst, Berks (Dr. Collins). 8. sprnicErA, Ehrenberg. (G2R MOE Rais 4) Salpina spinigera : : Ehrenberg, Die Infus. 1838, p. 470, Taf. lviii. fig. 5. [SP.CH. Occipital and pectoral spines scarcely diverse from the preceding ; lumbar a long, slender, acute spine, slightly recurved; alvine pair slightly divergent and decurved ; sinuses separating the occipital from the pectoral, and the lumbar from the alvine, with straight bottoms. The species of this genus are so consimilar that little more is needful than an enumeration of the points of technical difference. These will be better discerned from the figures than from verbal description. Though minute, they are constant, and I think, therefore, specific. The most marked, here, is the production of the lumbar point into a true spine in which the ridges meet, and which takes a direction different from their outline. The sides have oblique corrugations; and the general surface is coarsely stippled in various degrees. The eye is large and pale red. It is certainly a rare form; yet I have met with it on various occasions.—P.H.G.]. Length. Of lorica, 4, inch. Habitat. Pools at Battersea Rise; Hampstead Heath ; Leamington ; on Ceratophyllwm (P.H.G.). 8. BREVIsPINA, Ehrenberg. (Pl. XXIL. fig. 4.) Salpina brevispina : ° - Ehrenberg, Die Infus. 1838, p. 470, Taf. lviii. fig. 8. [SP CH. Occipital spines wholly wanting; pectoral pair short and straight ; lumbar and alvine as in mucronata. The total lack of the pair of occipital spines to the lorica is a clear distinction of this species, the anterior extremities of the dorsal carine not sensibly projecting beyond the level of its truncate front, which, however, is not quite a straight line. The dorsal arch, and the lumbar joint which terminates it, are nearly as in mucronata, only the point is much shorter, and the sinus between it and each alvine spine is circular. The surface is delicately stippled or covered with impressed dots. The ventral plane of the lorica has not that abrupt bulging, which marks both the preceding species ; the dorsal is more strongly arched than in either. This species is sufficiently common in the fine-leafed aquatic vegetation of ponds and ditches. Its manners are precisely such as have been recently described. I do not know how to distinguish between this and the S. redwnca of the same author.—P.H.G.] Length. About +4, inch. Habitat. Lakes and pools: very common (P.H.G.). §. MACRACANTHA, Gosse, sp. nov. (Pl. XXII. fig. 6.) (SP. CH. Occipital spines wanting ; pectoral pair short, straight ; lumbar spine and alvine pair long, straight; the latter much longer than the former; the anterior and posterior ends of the ventral side of the lorica deeply excised ; lorica-surface not stippled. The lorica of this fine species is ventricose ; the dorsal cleft is widely gaping. The lumbar union of the carine forms a true spine comparatively long and slender, yet is SALPINADZ. 85 much exceeded by the stout straight and long alvines. For many years I knew it only by a single dead specimen found in a pool at Maidenhead in September 1851. But recently (March, 1885) I met with a healthy example on Myriophyllwm in one of my re- servoirs at Torquay, which enabled me to complete my diagnosis and delineation. The great head is sub-lobate, beset with brushes of cilia, stout in the middle, becom- ing more slender on all sides. A great occipital brain carries a very large and brilliant red eye, and a rounded antennal lobe, bearing a few sete. The great mastax, when feeding, is protruded through the mental sinus. The abdominal viscera are normal, except that the gastric glands seem wanting; and there appear to be two contractile vesicles, into which the two lateral canals open by a trumpet-shaped mouth. The manners were similar to those of other Salpine, nibbling eagerly and persever- ingly, as it crept, thevegetable surface of the milfoil, with its protruded trophi. After it had remained in energy for several hours, I killed it, by mingling with the water in the live-box a minute drop of sol. caust. pot., whereby all the soft parts were instantly dissolved. There remained, however, uninjured, 1, the great red eye, which, in one aspect, had a quadrate form: 2, the two toes: 3, the whole mandueatory apparatus. A few minute air-bubbles were scattered through the visceral cavity. I could now discern that the surface of the lorica is not at all scabrous, by which (as well as by the other peculiarities already adduced) it may well be distinguished from Khren- berg’s S. ventralis, to which it yet approximates.—P.H.G.] Length. Of lorica, J; inch; breadth and depth, each 5},; length of toes, 545. Habitat. Maidenhead; Torquay (P.H.G.). S. EUSTALA, Gosse, sp. nov. (Pl. XXII. fig. 5.) [SP. CH. Occipital spines wanting ; pectoral pair short, incurved ; lumbar spine conical, short, arched ; alvine pair very long, stout, and incurved ; dorsal cleft narrow, of equal width. The lorica is gracefully ventricose, the back and sides being much arched, the belly slightly. The great alvine spines strike attention, as a conspicuous feature in all aspects ; they being long, thick at their bases, and incurved to the points, which are obtuse and approach each other. The lumbar spine is the united termination of the two dorsal ridges; it is only half the length of the alvines, conical and sharp-pointed, slightly arched on the dorsal edge. The dorsal cleft, narrow and of equal width throughout, reaches to the very front edge, which then is nearly horizontal on each side, but on reaching the pectoral side, after a deep sinus, rises to a short sharp spine. The whole surface of the lorica, ventral as well as dorsal, appears stippled or punctured with minute sunken dots. But, in some examples, this is hardly perceptible; while, in others, it is coarse and conspicuous. The head, viewed laterally, is about as deep as the body; the front is made up of an intricate series of eminences (carefully delineated in fig. 5a); one large lobe, toward the mentwm, is crowned with-stout and long cilia, which curve forward uniformly when in vigorous motion; other lobes carry much finer, shorter, and straighter cilia. There is a thick, obtuse, antennal lobe, bearing a brush of fine sete near, but not at, its extremity; and, within its walls, are seen curves and lines connected interiorly with a great descending brain, near the point of which is a round red eye. The internal structure is, in general, normal. But what appears peculiar is that there are (if I have not greatly erred) two coequal and consimilar contractile bladders symmetrically placed, large and conspicuous, each of which receives the dilated end of a lateral vessel.! And this does not seem to be a series of twisted cords, but a long slender sac, dilated here and there, where globular vacuoles are seen within. ' These vesicles were exactly alike, each subtrigonal, seated (optically) on each side of the circular orifice.for the outlet of the foot. Hach was evidently the terminus of the respiratory apparatus of its side, which, a rather wide ribbon or bag of clear tissue, containing several vacuoles, opens by a trumpet- 86 THE ROTIFERA. This large and handsome species, one of the finest of the Salpine, I was at first in- clined to identify with S. redunca of Ehr.; but it is more than double the size of that species, and the great development of its alvine spines sufficiently distinguishes it. It may be regarded as bearing the same relation to redunca as S. macracantha bears to ventralis. Ihave seen several examples; one from the Lake at The Grove, Stanmore, the residence of my esteemed relative, Mrs. George Brightwen.—P.H.G.] Length, J, inch; horizontal width, ;1,; inch; depth, 3}, inch. Habitat. Wool- ston; Stanmore (P.H.G.): rare. S. suLcATA, Gosse, sp. nov. (BLSeXOoS hee 7) [SP. CH. Occipital spines two, slightly procurved ; pectoral two, straight, acute ; lumbar single, short, with a widened base; alvines longer, straight ; dorsal cleft very wide, with outcurved edges. The lorica is of the usual outline, but somewhat wide, both in the vertical and lateral aspects. Of the anterior spines the pectoral are the shorter and straight, the occipital incurved. In the rear, the alvine pair the longer, and recurved; the lumbar short, straight, acute, with an abruptly widened cuneate base. From this lumbar point two dorsal ridges run up, curving outward to the occipital spines (figs. 7, 7), in- closing a shallow depression, which appears covered with only membranous integument. The lorica, on the ventral surface, is quite continuous and evenly rounded. I had some protracted and satisfactory sights of the creature in various positions, particularly from a point directly in the rear, and at different angles, by which I distinctly saw the dorsal furrow. One of these views is carefully delineated at fig. 7). I know this form only from a single specimen just dead (but with the soft parts not yet decayed), which occurred, Sept 14, 1885, in water from Woolston Pond, sent me just a month before. It seems to be undescribed, yet well-marked by its broad dorsal furrow, widening forward. It has no relationship with Ehrenberg’s S. bicarinata, from which, however (to judge by his figures,—for of diagnosis he gives none), it is sufficiently distinct. It is a small but interesting form.—P.H.G.] Length. Of lorica, without toes, ;}, inch; transverse width, ;}; inch. Habitat. Woolston (P.H.G.): rare. [I am indebted for my knowledge of a very distinct species, S. matica, to Dr. Collins’s Note-book of pencilled sketches, minute but carefully executed. I have enlarged his figures (Pl. xxii. fig. 3). He has added no note to this form; but his delineations were made from specimens procured from a secluded pool near Sandhurst Military College, in December 1866. He identifies the species with S. mutica of Herr Perty. From these it appears that the lorica does not vary much from the normal form (as in S. brevispina, for instance); save that the front is straightly truncate, without any spines, that the dorsal fissure is narrow and shallow throughout, and that it slightly widens behind, where its edges terminate in two very slightly prominent lumbar points: alvines seem wholly wanting. This species looks toward the genus Diplaz, as sulcata looks toward Diplois, yet both appear to be true Salpine.—P.H.G.] Genus DIPLOIS, Gosse, gen. nov. [GEN. CH. Lorica, more or less depressed, ovate in outline; formed of two sub- equal plates, united by elastic membrane; the dorsal plate arched, ridged, and split down the middle ; the ventral flat ; toes straight, furcate ; eye single, cervical. shaped expansion, into the upper obtuse point of the bladder. (See the description of the preceding specics.) SALPINADAE. 87 Of the two noble species for which this genus is constituted, the general form and aspect suggest their location in the next family, while the technical characters fix them here. At the first glance at their elegant forms, like ample oval plates of the clearest glass, evidently broader than deep, we hesitate not instantly to pronounce them normal Huchlanes ; but a moment’s observation reveals a fissure through the back, so charac- teristic of the Salpinade. The aflinity between Diplois propatula and Salpina sulcata is very close. The internal organization, so far as observed, agrees with that of Huchlanis. It is possible that the H. bicarinata of Herr Perty and the H#. Weissti of Dr. Leydig may belong to this genus ; but I have seen no diagnosis, or figure, of either.—P.1.G.| D. propaTuLa, Gosse, sp. nov. (Pl. XXIV. fig. 2.) [SP. CH. Dorsal cleft wide before, closed behind ; ventral plate considerably less in outline, furnished with three spines behind ; toes very long, of uniform thickness. This species is broadly ovate, sometimes nearly circular, in outline, the dorsal plate strongly arched, and medially ridged ; the ridge cleft so widely that the lorica is oblit- erated at its front in a vertical view, forming an acute point at each side. Hach side of the fissure, from the lateral point, approaches the other in a graceful curve, till, at the hind-back, they unite at an acute angle. The posterior margin of the plate extends beyond this, forming the uninterrupted segment of a circle. The ventral plate is of similar outline, but very much smaller, and quite flat. It ends behind in three acute spines, of which the laterals diverge and the middle one projects from the general level. The foot, of strongly marked articulations, is protruded between the plates ; the toes, of great length and tenuity, are straight, of uniform thickness throughout, with blunt points. No setz have been detected on the foot-joints. The internal organization pre- sents nothing distinctive, so far as it has been observed.! The interspace between the lorica-plates is considerable ; and this, together with the great width of the dorsal cleft, produces a curious effect, as the animal twists about, making the triple character of the lorica, with its points and angles, very apparent. This distinct and imposing form has but recently come under my personal observa- tion. But it is figured by Dr. F. Collins in his Note-book, from specimens obtained twenty years ago near Sandhurst Mil. Coll. Figs. 2 and 2a are carefully copied from his pencil sketches.2_ On two separate occasions I have found the species, at each time in water sent from the original pool, which thus is its only recognised habitat. Its motions are elegant and lively, and its appearance most attractive.—P.H.G.] Length. Fully extended, about =; inch. Habitat. Pool at Sandhurst, Berks (Dr. Collins ; P.H.G.): rare. D. Davizsim, Gosse, sp. nov. (Pl. XXIV. fig. 3.) [SP. CH. Dorsal cleft narrow, parallel-sided, open throughout ; ventral plate nearly equal, with no posterior spines ; toes blade-shaped. This species occurred in water dipped from Miller's Pond, Woolston, The lorica is decidedly triquetrous, the dorsal plate rising with sides slightly bulging, to what would ' Tt will be observed, however, that while in my own figure (2a) the gastric glands are of the ordinary form, Dr. C. has represented a pair of large pyriform sacs, each containing a vacuole, with long and slender ducts which lead from (or into) the cesophagus. These suggest the remarkable structure found in Pterodina, to which I refer the reader. ? The toes are here represented as out-curved; whereas, in the living examples I have seen, these organs were quite straight. Dr. Collins is a very accurate observer, and the lengtb and curvature of the toes (“slightly curved”’) are distinctly mentioned in his MS. notes. In his transverse section, moreover, the lorica-plates are much eloser together than I have seen them. Possibly, in both these particulars, there is some individual variation. 88 THE ROTIFERA. be a sharp medial line, but that it is split throuchout, and so forms a narrow furrow with low walls. Though the fisswre can be distinctly traced to the occipital edge of the lorica, I am not quite sure that the ridge, or wall, begins to rise above the dorsum-level quite so early ; perhaps not till the middle of the length, and then gradually. ‘The two strong sharp points at the hinder end of the dorsum, so conspicuous in many aspects of the living animal, are but the optical expression of the ends of the dorsal ridges seen vertically. The ventral plate is sensibly less in outline than the dorsal: it is ovate with the pectoral edge truncate ; flat, thin, and glassy; at each extremity it becomes delicately membranous. The foot consists of three distinct joints, long, and regularly diminish- ing; they are habitually extruded between the plates, perhaps in a sinus of the ventral ; but Iam not sure of this. The toes are moderately long, slender, blade-shaped, being (very slightly) dilated beyond the middle, and then rather abruptly pointed. No set are visible. The condition of the dorsal cleft is not invariable. Sometimes it is seen to extend not more than half-way up from the tip: or eyen to be closed nearly to the points, expanding there rather suddenly. Possibly the lorica is elastic, and subject to the animal’s will; for I have certainly seen the fissure wide throughout. The hyaline transparency of the whole, while it enhances the beauty of the creature, increases the difficulty of discerning all particulars of its structure, even those that are external ; especially as, from the incessant movements and changes of axis in swimming, it is almost impossible to focus any one part in any one position. The front consists of a number of low prominences, each rising to an obtuse cone, and each crowned with a row of vibrating cilia. The mastax, an oblate sphere, presents nothing noteworthy; the brain descends sac- like behind it, with a round deep-red eye near the middle of its internal side, distinctly crowned with a refracting lens. The stomach and intestine, not separable, occupy a large space in the body-cavity, usually filled with contents of an uniform rich deep-brown hue. ‘This greatly adds to the animal’s beauty, as it constantly roves up and down the narrow cells made by the crossing filamentous leaves of Myriophyllwm in the live-box. In general form and appearance this species very closely resembles the larger Hu- chlanes, which all its manners and actions perfectly represent, and do not in the least remind one of a Salpina. It is a fine addition to our Rotiferous fauna. Since it appears new, I honour it with the name of Miss Davies, of Woolston, Hants: a lady who has long made the Rotifera her special study, and to whose courtesy I am indebted for my first knowledge of the species. Specimens have come under my observation, not only from the extreme south of England, but, on repeated occasions, from Scotland. It is, however, rare.—P.H.G.] Length. Extended, 4 inch. Habitat. Woolston; Dundee (P.H.G.). Family XIV. EKUCHLANIDA. Lorica of two dissimilar plates, one dorsal, one ventral, wnited so as to form two confluent cavities, of which the wpper is much the larger ; foot jointed, furcate. Genus EUCHLANIS, Hhrenberg. GEN. CH. Dorsal plate with the medial portion arched ; ventral plate nearly flat, usually with a flange on either side ; eye single, just above the mastax. There are no more beautiful or perplexing Rotifera than those contained in the genus Huchlanis. Their large size and brilliantly transparent lorice render them most attract- ive objects for dark-field illumination ; and it is by this method of exhibiting them that the true structure of their lorice can be best determined. The animal must have room enough to swim at its ease, and there must be a few bits of alge for it to creep on. Then, as it turns while swimming, or as it works its way over and round the weeds, the creature will display all the beauties of its glassy armour; which, invisible at one moment, will flash out at another in broad plates and unsuspected surfaces. EUCHLANIDA. 89 To get a clear notion of the form of the lorica,! suppose that the shell of a tortoise has its flat base split longitudinally down the middle ; and then that half of each part, on either side of the split, is bent down at right-angles to the flat base. Further suppose that a second flat oval plate, smaller than the base, is cemented to the free edges of the bent-down parts, and the resulting form will closely resemble the lorica of an Huchlanis. It is obvious that a small box will thus be formed below the true base of the tortoise- shell, and that its cavity will be continuous with that of the shell, and that its bottom will project on either side as a flange. Moreover, on the outside of this box, on either side of it, will be a long furrow, bounded by the oval plate above, the flange below, and by the side of the box. In the actual lorica of Huchlanis the portion corresponding to the small box, below the true shell, contains a considerable portion of the viscera ; while the furrow (when the animal is viewed sidewise) often presents the edges of the two bounding planes so as to look merely like two parallel limes running from front to rear. If we further suppose that the altered tortoise-shell, with its attached second plate, is made of glass, and that it is held up so as to have the lower plate fully exposed to view, it is clear that we shall see three sets of edges. First the outside edge of the proper base of the shell ; secondly, within the first and parallel to it, the smaller oval edge of the lower attached plate; and thirdly, within this latter oval, the edges of the bent portions to which the lower oval plate is attached, and which connect the upper oval plate to the lower one. All these lines can be plainly seen in the ventral surface of E. dilatata (Pl. xxiii. fig. 5); where a is the edge of the dorsal plate, b is the edge of the ventral plate, and c the edge of the connecting portion at right-angles to both. The position of the inner two of these three lines varies greatly with the different species, according to the relative sizes of the upper and lower flat plates ; and so does the distance between these plates, and consequently the breadth of the longitudinal side furrows. These differences are great helps in distinguishing the species, which have been much confounded. Another assistance is the presence or absence of a sharp notch (Pl. xxiii. fig. 2b) in the occipital dorsal surface of the lorica. In some species there is no such notch, but a wide gap (PI. xxiii. fig. 5a), and the dorsal portion of the lorica near the head is membranous ; so that it has no constant outline when the head is retracted. . Mr. Gosse is of opinion that his two species, H. deflera and E. pyriformis, as well as a third lately discovered by him, haye no ventral plate, but have a ventral membrane instead of it. On this account, as well as on account of a peculiarity in the structure of their rami, he would separate them from Huchlanis as a new genus, under the name Dapidia. As, however, we do not agree on the first of these two points, we have thought it better to leave the creatures, for the present, with their names unaltered. Ehrenberg has made use of delicate sete, which are sometimes found on the foot, in order to separate the species; but neither Mr. Gosse nor myself thinks this a cha- racter that can be trusted. For the sete are difficult to be seen, are liable to injury, and are certainly not constant in their presence in the same species. The internal structure of the various species is so closely alike that a description of it in one species will very nearly serve for that in any other. KE. tyra, Hudson, sp. nov. (Pl. XXIII. fig. 1.) SP. CH. Lorica long, narrow, oval, depressed ; transverse section a low circular segment; dorsal occipital edge membranous; hind dorsal edge without a notch ; ventral plate with a very narrow flange, of wavy outline, elliptical and broadest at the hind end ; sete absent. ! Ehrenberg quite misunderstood the lorica of Huchlanis, which he imagined to be open down the ventral surface between the two inner lines c,c (pl. xxiii. fig. 5). This mistake, and the omission to draw or account for the line b, b, has led to endless confusion in determining the species. Dr. Cohn, however (in Sieb. wu. K6ll. Zeits. ix. 1858, p. 289), fully explained the error about the lines c, c¢; but missed the flange of the ventral plate with its edges 0, b. 90 _ THE ROTIFERA. I found this large and beautiful new Huchlanis, in June 1885, in water sent to me by Mr. Thos. Bolton, from Sutton Park, Birmingham. It can be easily recognized by its long oval dorsal plate, which has not a trace of a notch behind, and by the curiously rounded end of the flange of its ventral plate, which, unlike that of any other Huchlanis, is widest at the hind end, and elliptical there in outline. As in EZ. dilatata and E. macrura, the dorsal plate is membranous near the head. The creature is very trans- parent, and it has a way of jerking its toes apart and then keeping them open, which is very characteristic. It has unusually large foot-glands, and shows the adhesive nature of their secretion by slowly twirling round, first on one toe and then on the other, for several minutes at a time. From the ventral surface it is easy to see the structure of the corona. It is truncate, and gouged out, as it were, above the buccal orifice, some- what in the fashion of Hydatina senta (Pl. xiv. fig. 1c). A fringe of small cilia surrounds its outer and inner edges, and on the face of the corona itself are curves of larger cilia, whose ground plan is shown in black lines in Pl. C. fig. 10. Two papille rise from the same surface, very visible on a dorsal view, which seem to be tubular, but in which I have never detected anything like a tactile organ. Dr. Plate! figures the similar organs in H. dilatata with a triradiate passage down their length. He says that they are covered with a very delicate membrane, and suggests that they serve for respiration. The trophi are sub-malleate with five teeth in each uncus. The stomach is tied on either side by muscles, which are attached to the border of the lorica at one end and to the middle of the alimentary canal at the other. From these latter points muscular fibres pass diagonally upwards along the surface of the stomach, and by their perpetual contractions throw it into ever-varying folds ; while at the same time the lateral muscles twitch the stomach from one side to the other. Yellow oil-globules, often prettily arranged in quincunx fashion, are imbedded in the thick stomach-walls; and in the intestine, which is usually most obvious, the furious motion of its lining cilia can be seen with ease. The gastrie glands are curiously lobed on the ventral side (fig. 1a) and contain large nucleated cells. The foot-glands are very long, club-shaped, and bent oyer almost to the edge of the lorica; they are continued down the short three-jointed foot, and end in each toe in what appear to be three very delicate, adhering, quill-shaped vessels (fig. 1b), with their pointed ends near the toe’s extremity. The toes are two short, stout, sword-like blades; and, so far as I could see, without sete. The vascular system is conspicuous. Two intertwined lateral canals, hanging in bold loops just on a level with the mastax, and at the summits of the foot-glands, run down each side of the lorica to a large and normally placed contractile vesicle. I have seen four vibratile tags on each side: one close to the head, one at the upper loop, another at the lower, and one midway between them; doubtless there is a fifth. The ovary is a large cushion-like mass stretching across the venter with unusually large germs: fig. 1a shows a maturing ovum. The nervous ganglion (fig. 1) is very large, with nearly parallel sides, a scalloped front edge, and a rounded hind end, which is distinctly cellular. It stretches far below the mastax, in front of which, on its inner surface, it bears a dark- red eye. ‘Two small setigerous pimples rise from the corona behind the tubular papille mentioned above. On the neck is another setigerous eminence, the dorsal antenna. I have not succeeded in finding any dorso-lateral antenne. There are two pairs of longitudinal muscles for withdrawing the head, which are plainly striated ; the rest of the muscular system is very similar to that already described (i. p. 8) in Brachionus rubens. Length, ;!, inch. Habitat. A pond in Sutton Park (C.T.H.): rare. KE. pinatata, Hhrenberg. (Pl. XXIII. fig. 5-) Euchlanis dilatata 5 : e Ehrenberg, Die Infus. 1838, p. 463, Taf. lviil. fig. 2. 7 3 : ; . : Cohn, Sieb. w. Kill. Zeits. ix. 1858, p. 289, Taf. xiii. fig. 4. ’ Jenaisch. Zeits. f. Natur. 1885, Taf. ii. fig. 18. EUCHLANIDA. 91 Euchlanis dilatata 3 A é Moxon, Trans. Linn. Soc. vol. xxiv. 1864, p. 459, with figs. Eckstein, Sieb. wu. Koll. Zeits. xxxix. 1883, p. 385, fig. 33. ” ” SP. CH. Lorica a broad oval; dorsal plate depressed in front, arched behind ; transverse section (through the highest point) a low circular segment ; dorsal occipital edge with a broad gap, joined to the head by a membrane; hind dorsal edge notched ; ventral plate flat with a broad flange of oval outline; trophi with five teeth in each uncus. This species, like that which precedes and that which follows it, has no occipital notch in the dorsal plate, but has a broad gap (fig. 5a), which is only visible when the head is completely withdrawn. The edge of the gap is united to the head by a softer continuation of the lorica, which effectually obliterates the gap when the head is protruded. The lorica, though depressed, slopes upwards a little to a point not far from the top of a posterior notch in it, and then drops abruptly as if pinched in on either side of the notch. The ventral plate is nearly as wide as the dorsal, and a ventral view shows the edge of its flange running parallel to the edge of the dorsal plate just within it. A side view shows the two edges as two parallel lines near together, and drawn along the animal's side from end toend. Ehrenberg says that there are no sete on the foot, but both Dr. Moxon and Herr Eckstein draw a pair of pedal sete, and I have met with specimens bearing sete in no other respect differing from those that lacked them. Dr. Colin (loc. cit.) gives a full description of the male. It is a reduced copy of the female with a sperm-sac and penis taking the place of the alimentary canal and mastax, which as usual are entirely wanting, Dr. Cohn has seen the wand-like spermatozoa ‘‘ swarming ’’ in the sperm-sac. Length. Female, ;',, male, j!; inch. Habitat. Clear ponds and ditches: common. I. macrura, Hhrenberg. (Pl, XXIII. fig. 6.) Euchlanis macrura ° C é Ehrenberg, Die Infus. 1838, p. 463, Taf. lviii. fig. 1. SP. CH. “ Closely resembling E. dilatata; lorica a narrower oval ; toes somewhat longer; trophi with seven teeth in each uncus ; a pair of recurved sete on the foot.” I have met with an Huchlanis, whose figure is given in fig. 6, which had all the above characteristics given by Ehrenberg, but I doubt whether #. macrura is a good species, as none of the corresponding characters seem constant in H. dilatata, except the number of teeth in each uncus; and, unfortunately, I found several specimens, of what I should otherwise have termed HZ. macrura. with only five teeth in each uncus. Length. About 7, inch. Habitat. Clear ponds and ditches : not uncommon. E. rriquptra, Lhrenberg. (Pl. XXIII. fig. 4.) Euchlanis triquetra 5 6 5 Ehrenberg, Die Infus. 1838, p. 461, Taf. lvii. fig. 8. 37 Ah) 5 c = C Hudson, Mon. Micr. J. viii. 1872, p. 97, pl. xxviii. SP. CH. Lorica oval, with a high flat median plate at right-angles to the dorsal surface ; transverse section (through the highest point) triangular ; dorsal occipital edge notched ; hind dorsal edge notched ; ventral plate concave, and (with its flange) two-thirds of the width of the dorsal plate ; trophi with five teeth in each uncus. This most beautiful species is often to be found among the confervoid growth on the walls of old ponds. Its lorica rises in a high thin plate, and is not unlike a delicate glass dish-cover set over an inverted glass dish somewhat narrower than itself. The vertical plate, that thus rises like a crest from the dorsal surface, is very flexible and elastic, and can be easily bent aside by the compressorium without injury. The ventral plate is curyed downwards all round its edge, so that the lateral furrow between the two plates is wide; and, as shown in fig. 40, its flange stretches barely half-way across the base of 92 THE ROTIFERA. the dorsal plate. The outline of the dorsal portion of the lorica, when seen directly from the front or rear (fig. 4c), is triangular; the section, so obtained, having a base just twice its height. There is a well-marked occipital notch (fig. 4b) in the dorsal plate, through which a short, stout, dorsal antenna usually protrudes. Dr. Grenacher has detected two dorso-lateral antenne close together ‘‘lying near the crest of the lorica.”’ Ehrenberg says that there are no sete on the foot; but I have never failed to find two when using dark-field illumination. The rest of the structure requires no further notice, as it is a tolerably close repetition of that of H. lyra. This is one of the choicest of microscopic objects, when shown in a dark field; especially when it is quietly gliding over and round a few tangled alge. Its strange armour is now invisible, and now blazes out as it catches the light; while the ruby eye, the daintily-tinted stomach studded with glittering drops on canary-coloured quiltings, the ruddy intestine softened by the tremor of its ceaseless cilia, and the restless head crowned with an ever-varying halo of flashing setex, form a picture that once seen can never be forgotten. : There is a variety of EF. triquetra, with a lower vertical plate, which I have met with now and then; and which, on several occasions appeared to have but one long seta on the foot. Possibly this is Leydig’s HL. wniseta (Pl. xxii. fig. 3). Length. Up to 4; inch. Habitat. Clear ponds and ditches: not uncommon. E. DEFLEXA, Gosse. (BI) XO figs) Buchlanis deflexa - c = Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 200. (SP. CH. Outline of lorica ovate ; ventral gape wide, equal, with deep walls ; toes broad, blade-shaped ; lateral horns of ineus straight. This is a large and very beautiful species. It is not to be distinguished at first sight from a true Euchlanis, but the carapace, which is highly arched, turns in at the lateral edges, and after proceeding for a space horizontally, ¢.e. across the ventral surface, is bent down at a right-angle to a considerable width and then terminates, as if we might suppose the ventral plate to have been originally flat and continuous ; then to have been slit down the middle, and each side to have been bent down at a line midway between the slit and the outer margin. Thus the abdominal cavity is enlarged, and the viscera are protected only by the common integument which is stretched across from edge to edge. This being flexible, a variation of contained space is allowed, for development of eggs, for distension of the alimentary canal, &c., which, in Huchlanis, is obtained by the flexibility of the skin that connects the two plates. The lorica is almost circular behind, where a very minute central notch admits the two sides to overlap in the slightest pos- sible degree. The foot issues, of course, from the ventral hiatus; it bears two toes, which are thin, flat, and wider in the middle part. The penultimate joint of the foot proper has on its dorsal side a curved projection, which arches over a deep excavation. It carries two pairs of long sete, one or both of which are sometimes wanting. ach toe has a cor- rugated mucus-gland (?) running through it. The broad head is composed of many (ten 2) transparent globate lobes; the front is divided into several pairs of lobes, which carry bundles of cilia. The three strong lines which (with the front) form a square, reaching behind the mastax, are puzzling, but I believe they represent the wide, clear brain. The sacculate stomach is enormous, with two gastric glands; and two glands, beside, are attached to the mastax: there is a small, distinct intestine in which the epi- thelial cilia may occasionally be seen; a great ovary, with embryonic vesicles, and sometimes one (or more) dark ovum maturing. The branchial tubules, two or more, contorted and very loosely twisted, carrying four vibratile tags on each side, open by two distinct mouths on each side, into an ample contractile vesicle, just before the cloaca, whose periods are very irregular, even in the same individual: now emptying once in two minutes, then several times per minute. Many muscles are seen, some indubitably EUCHLANID A. 93 striate. An eye-spot which appears to be unconnected with the brain, is situate nearer the pectoral than the dorsal side. I found this species in 1849 in ponds around London, and have seen it often since. It has sometimes occurred so large that even with the naked eye I have had no difficulty in distinguishing the head from the foot.—P.H.G.] I once found among a number of specimens of H. deflexa a perfectly empty loriea, belonging to this species, and fortunately standing up vertically, so that it twmed round and round on its pointed end, as on a pivot (Pl. xxiv. fig. 1c). I was thus enabled to see with the utmost distinctness that it was closed everywhere except a large opening in front, where the head had protruded, and a small one behind, that had given a passage to the foot. The ventral plate (fig. 1c; v), as I term it—the ventral membrane as Mr. Gosse considers it—had no flange, but seemed to me quite as stout and stiff as (not to say stiffer than) the other ventral parts of the lorica. Whatever it was, whether chitinous plate or membrane, it had remained with the rest of the lorica while the softer tissues of the animal had disappeared. Length, ,, to 4 inch; breadth, 335 inch. Habitat. Pools and lakes (P.H.G.: C.T.H.) : widespread. KE. PYRIFORMIS, Gosse. (Pl. XXIII. fig. 2.) Euchlanis pyriformis . . . o . Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 200. (SP. CH. Outline of lorica constricted in the middle ; ventral gape narrow, widest in front, with shallow walls ; toes narrow, rod-shaped ; lateral horns of ineus over- curved, The peculiar narrowing of the edge which gives to this species a pear-shaped outline is caused by the edge of the upper plate being curved right under on each side, this edge being formed by two surfaces thinned off to great tenuity, so as practically to become but one layer at some distance from the edge. The under sides then proceed inwards till they nearly meet, when they are bent downwards into shallow walls, just as in FZ. deflexa, which recede from either to form projecting lateral points at the front; while behind they merge into a shallow groove and small sinus, at the end of the upper plate. Along this the foot is extruded, which usually has two sete, a prominence and notch, as in the preceding, and two long toes, quite straight, slender, of equal width, except that they are abruptly pointed. The brain and whole internal organization scarcely differ from those just described ; but the four slender horns that stand up from the sides of the incus are curiously bent over outwardly in the form of hooks. The eye is small, as in the preceding. In both species the beauty is much enhanced by a line of minute corrugations, running parallel with, and a little within, the margin of the lorica, like the ‘‘ milling”’ around the edge of a new coin. Muscles in much pyro- fusion, longitudinal, transverse, and oblique, are to be defined in this very fine species. I obtained it first at Battersea Rise, only the day before my discovery of HL. deflexa. Few specimens occurred, and it has always been a rarity with me. It swims with swiftness and grace; is of sprightly manners; is beautiful and attractive, and being large and brilliantly transparent, is well suited for study —P.H.G.] The transverse section (fig. 2a), was obtained by viewing the animal, which I haye drawn in fig. 2, directly in front; it is taken through the turned-in portions of the dorsal plate. It shows that at these spots, the flange of the ventral plate (according to my interpretation of the lorica), almost touches the dorsal edge. These curiously bent portions varied somewhat in different specimens; but all my examples had four sete on the foot. The hind portion of the nervous ganglion was darker, denser, and more obviously cellular than the fore-part, from which it was separated by a wavy outline. Its front edge was also scalloped like that of H. lyra. Length. Up to =, inch; of lorica, A, inch; of toes, 3; inch. Habitat. Or.a- mental waters (P.H.G.); garden pond, Clifton (C.T.H.): rare. 94 THE ROTIFERA. Family XV. CATHYPNADA. [Body inclosed in a lorica, open at cach end, of two plates ; the dorsal more or less elevated ; the ventral nearly flat, the two divided by a deep lateral longitudinal sulcus, covered with flexible membrane ; toes two, or one, always exposed. This is a well-marked, easily recognised, and compactly coherent group, the two divisions of the lorica, and their connection, readily identifying its members, notwith- standing the diversity in toes. The appearance, viewed from behind, reminds one of a pair of bellows, if we only imagine the upper board arched instead of flat; the leathers representing the lateral sulci. The toes, in two of the genera, are two, furcate; in the others there is but a single toe: yet the form, position, and use of these organs are so exactly identical, and yet so peculiar, that the genera cannot be dissociated. An ample brain, descending into the occiput, carries a single eye, usually conspicuous. The trophi are large, the mallei much more developed than the incus, vireate. All the genera are marked by a common habit, which is not found elsewhere. One will rest on the tip of its toe (or toes), and having bent down the whole body, remain motionless, and as if asleep, for a long interval, the whole fore-parts retracted. Then it will seem to awake, and languidly swing round the body, first to the one side, and then to the other, without letting go its moorings, and without protruding its head; and then, perhaps, go to sleep again. Or it may rouse itself into activity, and begin to grope away among the floccose, or glide deliberately off, soon coming again to anchor. Vive species were known to Ehrenberg, who placed the two with fureate toes in the genus Huchlanis, with which, however, they have no close affinity.—P.H.G.] Genus CATHYPNA, Gosse, gen. nov. [GEN. CH. Lorica swb-circular horizontally, usually much arched vertically ; lateral inangulation wide and deep ; toes two, furcate. The characters by which the species of this genus are distinguished are sometimes minute, and even obscure, yet constant; the shape assumed by the toes, and especially by the extreme points of these organs, demanding attention. In one group they are narrow, parallel-sided, like a carpenter’s rule; in another, much widened in the middle, with the sides curving to the point: the former I call rod-shaped, the latter blade-shaped. The former, too, do not taper gradually to the tip, but are abruptly narrowed with a right-angle, so as to make a sensible shoulder, whence the point descends as a marked claw. And this may be only on one edge, or on both edges ; the toe being one-shouldered or two-shouldered.—P.H.G.] C. tuna, Hhrenberg. (Pl. XXIV. fig. 4.) Euchlanis luna 2 ‘ Ehrenberg, Die Infus. 1838, p. 462, Taf. lvii., fig. 10. [SP. CH. Dorsal and ventral plates of lorica swb-cqual, occipital edge crescentic ; toes rod-shaped, two-fifths as long as lorica, clawed ; the claw one-shouldered, one-fifth as long as toe. The lorica, broadly ovate in horizontal outline, ending in front by a crescentic exca- vation, and in rear by a small sinus between two points, and the toes, very narrow, parallel-edged, generally carried in contact, with short, sharp claw-tips, may easily serve to identify this common species. The dorsal and ventral plates are of nearly the same form and curvature; high and deep behind, they come into contact in front, at least at the lateral edges, which project in two acute points. During the long retractations of the fore-parts, the lorica may be considered shut by this contact. When activity is resumed, the plates separate, and a broad head protrudes, the front of which is truncate, CATHYPNADA. 95 with two equidistant incisions, at each of which appears a bristle (fig. 4). The rotating cilia are set along the edge. A mastax of very ample dimensions, with a pair of long mallei, but rather small incus, is always conspicuous. Behind this the occipital brain carries an eye, usually large and brilliant. A great saccate stomach, without sensible cesophagus, with large gastric glands, and followed by a separate intestine, passes obliquely across the dorsal region; and the ovary, as usual, occupies the ventral.! In the adult, the surface of the lorica is smooth, and the whole animal is transparent and colourless. Though individuals swim actively now and then, yet the habitual slugeishness and inertia of the species cannot fail to attract attention. As described, it will balance itself, by the hour, on its united toe-tips, with an occasional lazy swaying to and fro; or even loosen this feeble hold, and ailow its body to sprawl away at right-angles to the food-surface, free in the water, the foot being bent up to the belly.—P.H.G.] Length. Total, 3; inch; of lorica, y4, inch. Habitat. Fresh waters (P.H.G.): common everywhere. C. nusticuLA, Gosse, sp. nov. (Pl. XXIV. fig. 6.) [SP. CH. Lorica regularly ovate, with the frontal opening very narrow; dorsal surface coarsely tesselated ; ventral plate nearly flat ; toes blade-shaped. This fine species is very hyaline, notwithstanding that the broadly-oval and arched surface is cut into facets. These are not very regular, nor very distinctly marked, having the appearance of folds in leathery skin. They appear to be limited to the carapace. This is turned-in along each side, with a sharp lateral angle meeting the edge of the ventral plate, similarly turned-in, as is clearly seen when the creature is viewed from behind (fig. 6). The union is doubtless completed by a flexible and extensible membrane. The head is included between firm plates, which, seen vertically (fig. 6), appear as two lateral projecting points, between which the front, of many conical lobes that carry vibratile cilia, works to and fro. The brain and its lozenge-shaped eye are normal; and so are the great trophi, the stomach with trigonal gastric glands and distinct intestine, and the ovary. A contractile vesicle is sometimes conspicuous, but no details of the respiratory nor of the muscular systems have been defined. A rather thick and short foot, rounded laterally, bears the two toes, which are articulated with round condyles. They are moderately thick blades of fusiform outline, when seen laterally, thinner towards the base, and rather bluntly pointed. I first met with this form, in July 1885, in the sediment of water in which aquatic weeds had beén sent from the north of London. Subsequently other examples occurred, in water from Caversham and Woolston, and from near Dundee, in December. The earlier specimens were even more clumsy and sluggish than ordinary, moving waywardly from side to side, as if not quite under control, adhering all the while by the toes. Hence I called it rwsticula. This, when too late, I would have changed; for some were much more attractive, transparently beautiful, with the eye large and of a lovely rose-pink hue, and so sprightly in manners as to be worthy of a more courtly designa- tion. In these, too, the digestive canal was distended with food of a clear rich orange- brown hue. These were Woolston specimens. Scottish examples bred freely and in- creased in my phials.—P.H.G.] Length, ;35 inch. Habitat. Pools throughout England and Scotland (P.H.G.) : common. ‘ In one example the ovary was fastened, by two threads with swollen enlargements, to each side of the lorica, near the middle; and the gastric glands were also tied to the same points (fig. 4). Long threads (muscular ?) with like enlargements were scen to pass from the foot-bulb to near the same points, if not higher. 96 THE ROTIFERA. C. suLcATA, Gosse, sp. nov. (Pl. XXIV. fig. 5.) [SP. CH. Lorica broadly ovate, much elevated ; anterior edges straight ; ventral plate much smaller in outline than dorsal, both strongly fluted ; toes blade-shaped. The general form and appearance of this species may cause it to be easily confounded with luna, especially when viewed from the side. The arched carapace comes to a sharp edge all round, bending far-in abruptly; then bending outward again with a like angle, and coming to a like edge, to form the ventral plate. This, when seen sidewise (fig. 5a), seems to be of the same dimensions as the dorsal; but when seen direct from below it is much less all round (fig. 5c), except in front, where the pectoral edge is parallel with the occipital, both being transversely straight, but bounded, as usual, by two small lateral points. Both surfaces are coarsely and deeply fluted; the incised lines of the dorsal passing round and beyond the inbent edge. The bulbous foot projects slightly through an excavation in the dorsal plate’s thickness: it is kidney-shaped; in its hollow the toes are articulated. The lorica is, by the graying of its surface, rendered so opaque that the internal organs are not easily defined. There is, however, a small but conspicuous crimson eye in the occiput, and, by inference, a brain. The mastax is so large that, when the head is withdrawn, it occupies fully one-third of the visible area, at the middle of the lorica. Below this appears the ample stomach, dark with digesting food, and (in the condition just named) pushed far up above the mastax on either side. This well-marked species I obtained in a number of examples, both alive and dead, haunting aquatic moss, in water sent me by Dr. Collins from his historie pool at Sand- hurst. For awhile I thought I had got hold of the Huchl. lynceus of Ehrenberg, but examination of his text and figures forbade the identification. It is of the usual manners. It often swims smoothly and swiftly, continuing the exercise for long periods without rest, the toes usually carried behind, in mutual contact; yet at intervals anchoring, re- tracting the head and foot, and assuming still repose, broken, now and then, to sway wildly in all directions, on its glued toes, as on a pivot, more HL. lune.—P.H.G.] Length. Extended, 4, inch; of lorica, 3}, inch; of toes, -}, mch; width of lorica, aziz inch. Habitat. Pool at Sandhurst, Berks (P.H.G.): uncommon. Genus DISTYLA, Eckstein. [GEN. CH. Lorica of the form of a long ellipse, open and membranous before, closed behind, depressed, higher before than behind ; lateral inangulation feeble ; toes two ; “ selvage-like thickenings of the lorica around the foot.” Herr Eckstein has described and figured two species of this genus, whose toes bear the same relation to each other as those of C. luna and rusticula. The genus is closely linked with the preceding; yet the lengthened and flattened form, the habitual protrusion of the head, and the more constant activity of the species distinguish it. Only one of Herr Eckstein’s species has occurred with us, but I add (doubtfully) another.—P.H.G.] D. Gissensis, Eckstein. (Pl. XXIV. fig. 8.) Distyla Gissensis ' c 0 Eckstein, Sieb. uw. Koll. Zeits. xxxix, 1883, p. 383, pl. xxvii. [SP. CH. Lorica round behind, broadly truncate in front, with short lateral points ; toes rod-shaped, thick, obscurely two-shouldered, claws small ; brain simple. The outline is that of a narrow ellipse abruptly cut-off a little before the middle, so _ that the lorica, at its truncate front edge, is scarcely diminished in width. It becomes, Dinocharis pocillum ” ” ” Dinocharis tetractis ” ” ” ” ” ” ” ” Dinocharis Collinsii ” ” ” Scaridium eudactylotum ” Scaridium longicaudum ” ” ” ” ” ” ” ” ” ” ” ” Stephanops muticus ” ” Stephanops lamellaris ” ” Stephanops unisetatus ” ” Stephanops chlena ” ” PLATE XXI. dorsal view side view ventral view . transverse section . variety ; foot. trophi . dorsal view side view transverse section . head; eap closed head; cap open dorsal view, the armatu re omitted dorsal view, showing spines . ; side view transverse section. dorsal view side view ventral view . junction of foot and toes mastax and brain . mastax, trophi, and eye dorsal view side view head, showing mastax, t dorsal view side view dorsal view side view dorsal view side view dorsal view side view rophi, and eye . RMAMRARRARHAAAHHEHHeaggenagngotHHAy ad ae, . NYTHD iS 6 SALIVLSSINA I9 @ SIHVTITUNVTIS 4°SNOLLAW Ls ‘9 °*NNCAVIIONOT 39'S “WNIOTALOVGNTIS F HSNITION dT &¢ SILIVELIL a 2 wnT1l00d at "SAZONVHAUALS ‘AQICIVIS ‘STUVHIONIG ean oat! caren itd “eee 7 7 aod OF} 'ey7 07) SPIT uOSPR} PLATE XXII. 1. Salpina mucronata . dorsal view . é ¢ la. [ 5 . side view . 0 1b. % os . lorica, oblique view . 2. Salpina spinigera . . dorsal view . . 3 : 2a. AS * : . sideview . A : F 2b. i 53 A . transverse section, dorsal half 3. Salpima mutica. . dorsal view . 6 : 6 3a. - mA F . side view . A ‘ 4. Salpina brevispina . sideview . 5 j : da. A * ; . lorica, dorsal view 5 4b. an a 5 . lorica, side view . 5 5 5. Salpina eustala . . dorsal view . : 5a. a a ;: . side view . 9 0 6. Salpina macracantha . dorsal view . : a : 6a. a x . side view . 5 A a 6b. 3 . . trophi, side view . ‘ : 7. Salpina suleata . . dorsal view . : 0 Ta. 3 : i . side view . 3 5 : 7b. A Re 3: . rearview . : : : 8. Diplax compressa . . sideview . ¢ ; 3 8a. ss af G . dorsal view . 0 5 8b. rf 3 7 . transverse section ; 9. Diplaxtrigona . . dorsal view . 0 : C 9a. A 3 : . side view . A : : 9b. 5 1 5 . transverse section 10. Diaschiza semiaperta . side view . 4 . : 10a. 55 % . lorica, dorsal view , ‘ 10b. 7 . . head and eye 5 10e. Pa - . trophi . ; 5 . 11. Diaschiza peta . . side view . : 6 lla. 7 . : . dorsal view . : 12. Diaschiza valga_ . . dorsal view . : ; 12a. - : . side view . : 13. Diaschiza exigua . . dorsal view . : 13a. :5 5) : . side view . ; . 14. Diaschiza tennior . . dorsal view . c 14a. 5 oe . side view . j : yi 15. Diaschiza Hoodii . . dorsal view . 5 : : 15a. y Hh 6 . side view . 5 A < GD AA DA AA AAA RAARRARMBARARARAARAARARARARARARADRA > a ‘I1G00H VIC I HOMMNGL VIC PT VNOIXS vidcr * = Fs iY A Vid Zi VL¥d VICI! VIMAdIVINAS VIC Ol VNODIMI did 6-VSSAYAWNO) dd 8 VIVITOS BZ WOYNS 9 VIVISONIS S YNIUSIAZHES F YIILNNS © VHSSINIdS S ¢ VIVNONIAW'S I 4 *VZIHOISVId 'XWIdI@ *YNId [oP AIA PE e860 HJ PLATE XXIII. 1. Euchlanis lyra . 0 . dorsal view H la. 6 0 0 . ventral view . H 10. aA ay Ay 5 . foot, and contained econ H 2. Euchlanis pyriformis . . ventral view . H 2a. A H A . transverse section . H 2b. os a . . front-edges of lorica H 3. Enuchlanis uniseta (?). . side view p 5 9 5 H 4. Euchlanis triquetra . - dorsal view H 4a. - 5 A . side view H 4b. Fe x é . ventral view of jorien H 4c. Re p ; . transverse section . H 5. Euchlanis dilatata . . ventral view: a, edge of Gora plate; b, edge of the flange of ventral plate; c, edge of the portion connecting the dorsal and ventral plates, and at right-angles to both . H 5a. AY 7 0 . dorsal front-edge of lorica H 5b. : . ventral front-edge of lorica . 1st 6. Euehlaria macrura . . dorsal view H ie GNI a+ VLESINN Fe SINUOAIMAd 22 VAT TI YUNUIVAN T9 VIVIVIIC 2S VEL "SINVIHIIAGA ep AA Pe uospnH LD Euchlanis deflexa Diplois propatula ” ” Diplois Daviesize ” ” Cathypna luna. ” ” ” ” ” . Cathypna suleata ” ” . Cathypna rusticula . ” ” Distyla flexilis . ” ” . Distyla Gissensis ” ” PLATE XXIV. ventral view. dorsal view side view . . 6 6 empty lorica, ventral view dorsal view side view . dorsal view side view . transverse section hind end of lorica, dorsal view . trophi ; 5 4 9 dorsal view, head extended dorsal view, head retracted side view, head retracted . rear view . dorsal view é 5 side view, head retracted . side view, head extended . lorica, ventral view . edge of lorica dorsal view side view . rear view . dorsal view side view . dorsal view side view . RAARARRRAARAMDAARAARAARAAMRADRHAADA _ a > = _ _ : >“ _ 7 > a Pm - ; as a > _ 7 ~ i = r - oy. 4 . - 1 a 7s : 7 - ae 7 a 7 a - ae - 2 7 m _ ee = - ra —_ — _ ‘ . 7 ’ - _ , « “6 ' -_ -_ _ I SISNASSID SIG 8 SITIXA1A SIC 2 10 ‘¢-WI1E Tz “¥INDIISON 39 VIVITINS IS VNATO + WISZIAVG did "VIALSIC@ ‘WYNdJABLVO! SIOIdI a SIN “MUst pet me pA pr esso4y fg ee ay qru pe vespuy y9 3] Sty \) @ \ & ys od ay -z Y ‘ ; < ti e . /\ <} ) 1. Monostyla cornuta . la. ” ” : 1b. ” ” 2. Monostyla lunaris 2a, 2b. 5, 93 2c. ” 5 3. Monostyla poadridentata 4. Monostyla bulla . da. " oh : 4b. H : 4c, : 5. Monostyla Lordii 6. Metopidia lepadella 6a. ” ° 6b. i H 7. Metopidia triptera Ta. - 5 7b. . 5 : 8. Metopidia oxysternon 8a. 9 ” 8d. 5 ” 8e. ” ” 8d. 7 ” Se. ” ” Sf. 7 x 8q. 3 ” 8h. or ” 9. Metopidia acuminata Sa. ” ” 9b. a 9c. “7 A 10. Metopidia shomboide S 10a. ry) ” 10b. £ 3 11. Metopidia solidus lla. > 11b. m » 1le. ” 3 1ld. as = lle. ” ” : uf. * : : 12. Colurus dactylotus . 12a. op a : 13. Colurus pedatus ¢ 13a. ” ” PLATE XXV. dorsal view . : . ; 4 side view : b : 3 5 transverse section . ; : : dorsal view . 2 3 5 4 side view . , : . P rear view a 5 r ; . dorsal view dorsal view . : side view ‘ : ; ; 3 year view front of lorica dorsal view dorsal view side view 5 7 ‘ transverse section ° . 5 dorsal view side view front view ‘ ventral view . 3 5 0 6 side view 5 : lorica; ventral view lorica; dorsal view transverse section head; side view trophi . : pectoral notch of forest hind end of ventral plate, shaves the foot dorsal view . : , ‘ ; side view 3 % lorica; ventral view transverse section . dorsal view . : M ‘ F side view : ; transverse section < dorsal view : : ventral view, head retracted. side view rear view - front of lorica : , : < hind end of lorica. stomach : : dorsal view . : * p f side view side view : ; foot and toes orifice for ‘aay (ony (oS Tey DS G2 G2) 42 G> > G> C2 > Go G2 re A ~ MQAD|AADWHD|AX “ ¥ * ALLY G29 Cl SQLOULIVG'D Zl SAGIIOS W Il SICIOSMOHY WOT VIVNIN NOY W'6 NONNSLSAXO WQS dIdUW 2 ¥TIACVds1W 3 NCUCTN Ss VITNENY VIVINGZCINCYNO We STHUYNN'1 WZ "SMU 100'VIALSONONW VINNUOTW I ror Am oF oeser Ld CATHYPNAD. 97 however, very thin and flexible, so as to be subject to much inversion in retraction. The head, very freely extruded, is thick and large, a truncate cone, with a slight auricle at each lateral angle, and a central bladder-like lobe, which is retractile. The whole head, which is very mobile, projects between two pointed shelly shields. In death, the head being abnormally extruded, these appear as stout oval (or lozenge- shaped) shields, quite separate from the lorica. The foot, of one apparent joint, is bulbous and kidney-shaped ; to it are jointed the toes, which are much stouter and shorter than in Cathypna luna, They terminate in similar small acute claws, but the shoulders are less sharply angular. It is very thin, viewed laterally (fig. 8a). The dorsal plate comes down to a blunt edge on each side, with feeble duplication; the hinder ventral parts, inclosed in membrane, being small, and much overlapped by the clear thin edge of the lorica. A very favourable sight of one, as it deliberately turned- up endwise (so slowly, indeed, that I could carefully focus it as it moved), showed that the ventral plate is co-extensive with the dorsal; but is very thin at the edge, sloping upward toward the middle half; this forms a downward arch to contain the viscera. Herr Eckstein describes the brain in D. Ludwigii, as divided into three long sacs, like as in Copeus centrurus and C. Cerberus. In the present species there seems to be a broad base rather abruptly diminished in width, bnt forming only one sac, which carries a great crimson ovate eye, at its very point. I have received the species rather plentifully in water from Mr. Hood; and more sparsely from Mr. Bolton: the former averagmg much larger size. Its manners are much more sprightly than those of Cathypna. I have also found it (with lorica very flexible and expansible) in spring, in a domestic aquarium of my own, which had re- mained unchanged for more than a year.—P.H.G.] Length, ;}5 to y}5 inch; width, 545 to s}, inch. Habitat. Bracebridge Pool, Birmingham: rare. Starmont Loch, Dundee: abundant (P.H.G.). D. ruExinis, Gosse, sp. nov. (Pl. XXIV. fig. 7.) [SP. CH. Lorica narrow, nearly parallel-sided, corrugated, flexible, plicate. I am not by any means sure that this is entitled to specific rank; nor, if it is, whether it ought to be placed in the genus Distyla. It may be but the immature con- dition of some other species, such as C. sulcata. Yet the condition, at birth, of the lorica of MW. cornuta, appears to forbid the conclusion that flexibility and corrugation are marks of immaturity in this family. A lorica is evidently present, soft and flexible, covered with irregular wrinkles; marked also with a series of longitudinal folds, scarcely amounting to flutings. The eye is large, rectangular, bright rose-red, seated on the inner side of the brain, close to its point. The other organs are normal. Its manners are lively, often wild, searching the edges and surfaces of the water- moss which it haunts, and often creeping within them. It sometimes anchors by its toes, and appears to go to sleep, just like its brothers and cousins.—P.H.G.] Length. Hxpanded, 3} inch. Habitat. Sandhurst, Berks (P.H.G.): rare. Genus MONOSTYLA, Ehrenberg. (GEN. CH. As Cathypna, but that there is only a single toe. This group, consisting of numerous species, is so exactly the counterpart of Cathypna, except for the toe, that one can scarcely avoid the conclusion that this is, structurally, of slight importance. The details of the form, the habits (as the use of the toe as a pivot, and the frequent and long-continued inertia), and even the specific variations in the shape of the toe, all are so accurately the reflection of what has been described as to VOL. Il. H 98 THE ROTIFERA. suggest that Cathypna is Monostyla with the toe cleft through the middle, or that Monostyla is Cathypna with its two parallel toes soldered into one.—P.H.G.] M. tunanis, Ehrenberg. (Pl. XXYV. fig. 2.) Monostyla lunaris C A 6 : Ehrenberg, Die Infus. 1838, p. 460, Taf. Ivii., fig. 6. [SP. CH. Lorica broadly ovate, the dorsal plate round and greatly elevated, the ventral nearly flat ; both in front projected into wide, triangular, flattened points, be- tween which the edge is deeply excavate; toe straight, rod-shaped ; claw protruded between two slender spines. The gibbous lorica descends abruptly before it is produced into the wide clear triangular lobes in front. And there seems no noticeable difference in outline, either of the lobes or of the intervening sinus, between the dorsal and the ventral plates. For, in retraction, these are very firmly appressed, with a common outline; so that no change of position, and no focusing, makes the eye cognizant of more than a single, somewhat thickened, crescentic line. The general figure is so elevated that it is more than half a sphere, if we neglect the inangulation of the lateral sulcus, which, in this species, is not deep. The foot-bulb appears to lie in a hollow of the ventral plate; it is wide and kidney-shaped behind, where the straight-edged, rod-like toe is articulated. This terminates in a slender acute claw, not with a rectangular shoulder; but with a pair of fine points, between which the claw is, as it were, imbedded. Herr Eek- stein describes certain appearances, which he interprets of the thickened lorica- structure, for strengthening the foot against the violent strains endured as the animal throws itself to and fro. He also depicts certain pale-red specks and excessively fine lines, going upwards from the claw, which he would connect with the nervous system, as well as with the mucous glands. ‘The rotatory organ is simple, but almost retired, so that only a slight elevation with a single seta projects out of the lorica. When it is extended, we discern two great lobes, which overlap the lorica-edge on each side, over- reaching each other dorsally, but ventrally running off into the buccal orifice’ (Ibid.). A specimen in my possession, anchored by the toe to the glass of the live-box, threw itself vigorously into all possible positions, for twenty-four hours, without once removing ;! all that time, so far as observed, active in this special way, but close shut-up. The movements, indeed, though constant, were not incessant, but very forceful, spasmodic, and sudden. In general the animal is clear and colourless: of this specimen, the whole body was stained of a yellow-brown hue, like sherry wine, so deep, while yet clear, that no definition of viscera was possible. Yet the red eye was now and then defined, and, under direct sunlight, came out very rich, and of a deep crimson hue. The great tri- angular lobes of the lorica, being very thin, were quite colourless and glass-like.— P.H.G.] Length. When extended, ;1 to 3}, inch. Habitat. Woolston; Sandhurst ; Thames, near Reading ; Snaresbrook (P.H.G.): mostly in pools: not uncommon. 7 7~ ~ M. cornuta, Ehrenberg. (Pl. XXYV. fig. 1.) Monostyla cornuta 6 2 : 4 Ehrenberg, Die Infus. 1858, p. 459, Taf. lvii. fig. 4. [SP. CH. Lorica ovate, moderately depressed, the front shallowly incurved ; toe somewhat blade-shaped, the claw without a distinct shoulder. This species is very much like WM. lunaris, so as, when retracted, scarcely to be dis- tinguished from it except that the anterior dorsal edge of the lorica is slightly less incurved. It is smaller, and rather more oval in outline; in the act of extruding the ' During the latter part of the time, however, it became yery sluggish, and less willing to move and jerk about. DL CATHYPNADA. 99 frontal disk, and when it is extruded, there is an appearance of two lateral, slender, incurved horns, and between them two spots which look like a pair of ill-defined eyes; neither of which we see in lunaris. But these are not what they seem: the horns are the optical effect of the somewhat thickened and stiffened edges of the extruded head-mass, which, in the process of contracting and expanding, incline to each other, resembling conical knobs; and the spots are only the summits of certain fleshy eminences, which bear vibratile cilia. There is a true eye-spot of large size and crescent form, and of pale-red hue, seated on the inner side of the brain-mass, that hangs behind the mastax. The ventral plate has its pectoral margin quite straight; it is considerably less than the dorsal along each side, while commensurate with it behind. There is a square hollow in it for the reception of the foot-bulb, which is somewhat kidney-shaped. The toe, viewed vertically, is more blade- than rod-shaped, for the outer margins bulge outward in a greater or less degree, the widest part generally (but not invariably) near the point. This point has often the semblance of a claw; but this is illusory, for there is no true angled shoulder. The trophi are of the normal form, but of unusual length. It is a very common species, and from its sluggish habits, combined with its minuteness, the observer is apt to pass it by with contemptuous neglect.—P.H.G.] Length. Of lorica, 4,5 inch; total, extended, ;3, inch. Habitat. Still waters (P.H.G.): common everywhere. ¢ 7 . M. Bubba, Gosse. (Pl. XXV. fig. 4.) Monostyla bulla 5 - a Gosse, Ann. Nat. Hist. 2 Ser. vol. viii., 1851, p. 200. [SP. CH. Lorica a pointed oval ; dorsal and ventral plates both gibbous, and nearly co-equal ; toe rod-shaped in vertical aspect, with a two-shouldered claw, but decurved and gradually tapering in lateral aspect. This species I found in a small pool on Hampstead Heath, in August 1850, and, soon after, in the lake of Richmond Park, abundant. Lately it has occurred in water from Woolston, and from Caversham. ‘The yellow hue is not, as I first supposed, in- variable. Some are quite colourless, except for the digesting food. The great rotundity of the ventral plate ; the regular decurvation of the tapered toe; and the deep narrow sinus in both the occipital and the pectoral fronts of the lorica,—these are the true dis- tinctions. The oval outline is so acute in front that the sinuses are bounded only by two obtuse points. The gibbous dorsum ends behind with an oblique retrocession, showing laterally a great rounded foot-bulb. The head projects in two receding lobes, ciliated on their inner surfaces, just as in cornwta. The mallei are certainly two-fingered. The animal burrows among Chare, Conferve, &e.—P.H.G.] Length. Expanded, ;}, inch; of lorica, y4; inch. Habitat. Pools (P.H.G.). M. Lorpit, Gosse, sp. nov. (Pl. XXYV. fig. 5.) [SP. CH. Dorsal plate of lorica tesselate, its hinder end excavate, the excavation forming three sides of a square ; toe rod-shaped ; claw shouldered. This is a rare species, bearing much the same relation as Cathypna rusticula does— each to its congeners. Indeed, they are so much alike as to be easily confounded till the foot is seen to be two-toed in that case, one-toed in this. It in general resembles M. cornuta, but is much more transparent. The single toe is more slender in propor- tion to its length, and much longer in proportion to the whole animal; it is a straight parallel-sided rod, with a minute acute claw apparently forming a separate joint. If this is the case, we should perhaps consider this joint as itself the toe, and the long rod as the penultimate joint of the foot. The shoulder is double, viewed vertically, but single and much rounded, viewed laterally. The outlines of the toe, however viewed, are always a little uneven ; suggesting that the surface is irregularly pitted. The lorica H 2 100 THE ROTIFERA. is ovate, not so pyriform as in cornuta. The edges of the upper and lower plates come closer together; for the anterior two-thirds the edge of the dorsal plate is about level with that of the ventral, but much exceeds it in length. The dorsal is straightly truncate behind, with the margin on each side, following the ovate outline and descending much farther, so as to form two points. The dorsal surface is somewhat coarsely tesselated, like that of Cathypna rusticula, but with the pattern slightly different (Pl. XXIV., fig. 6). The whole surface appears as if irregularly crumpled, interfering with distinct definition in spite of the transparency. The head is a low truncate cone, produced into a number of slight frontal eminences, on which the locomotive cilia are arranged in tufts or bundles. These do not appear to create sensible vortices in the surrounding water. This species is, I conjecture, the fig. 22 of Mr. J. E. Lord (‘‘ Microsc. News,’’ June 1884, page 146), as MW. cornuta is his fig. 21. I therefore distinguish it with his name. I have met with it myself, on rare oceasions recently, among decaying vegetation in the water of Woolston Pond, and abundantly in water kindly sent me by Miss Saunders. Length, 53, toy}, inch. Habitat. Woolston; Newbury ; Dundee (P.H.G.): rare. There is a form,—of which Iam almost inclined to make a separate species,—in general like Lordii, but remarkable for the excessive length and slenderness of the toe, which almost equals the length of the lorica. It may be but an extreme var. of the present form. Yet the lorica seems to lack the square excavation behind, and to be more pyri- form in outline, running off in front into broader lobes, as in lunaris. This I have found in water sent me by Mr. Bolton from Sutton Park.—P.H.G.] M. quapripentata, Hhrenberg. (Pl. XXV. fig. 3.) Monostyla quadridentata 3 5 a Ehrenberg, Die Infus. 1838, p. 459, Taf. lvii., fig. 5. (SP. CH. Lorica nearly circular, greatly depressed, especially behind ; front deeply cleft, with two horn-like spines decurved and expanding at their tips. The horns well distinguish this form. During retraction these are drawn together, and made eyen to cross each other (fig. c). Besides these, and outside them, the dorsal plate projects into a broad-based triangular point on each side; while the pectoral margin forms a flexible membrane, very deeply cleft in the middle, and further deepened at will. The hind part is exceedingly flattened, merging into the foot, of which the last joint is cubical, with a central notch. Here is articulated the toe, rod-shaped, but that the outline of each side, instead of being straight, is strongly waved: an appearance which may possibly indicate the waves of a tenacious mucus. At one-fifth from the tip a double shoulder, rounded rather than rectangular, leaves the usual acute claw. The head protrudes (fig. b), much as described in cornuta. Of the trophi, the mallei (fig. d) are remarkable for a conspicuous horn projecting upward from each angle. The gastric glands are large; there is a large separate intestine, and also an ample contractile vesicle. Several examples have occurred to my observation. In one I was witness to a curious phenomenon. A large shelled Infusory, Arcella vulgaris, was within the Monostyla, though how it had managed to force its way in, I cannot imagine, for it almost filled the cavity of the lorica. Its fleshy processes were protruding in front, and, by the death of the Arcella, unable, I suppose, after it had devoured its host, to get out, these processes gradually lengthened inordinately. It was a curious sight.—P.H.G.]} Length, 1, to , inch; of lorica, y4, to 745 inch. Habitat. Barking ; Stratford ; Maidenhead; Hampstead (P.H.G.); among duckweed, in pools and ditches: rare. COLURID. 101 Family XVI. COLURIDA. [Body inclosed in a lorica, usually of firm consistence, variously compressed or de- pressed, open at both ends, closed dorsally, usually open or wanting ventrally ; head surmounted by a chitinous arched plate or hood; toes two, rarely one, always exposed. The arching hood over the front, looking, in a lateral view, like a thin hook, movable, and so distinguished from the ‘“ glory-crown ”’ of Stephanops, always conspicuous, is the most notable mark of this family, in which I propose to unite the mostly flat Metopidie with the high-backed Colwri. As no subdivision above species exists in nature, but all (as Genera, Families, Orders, and Classes) are arbitrary collocations, made simply to facilitate the study of the species, which alone is natural history; it follows that the more constant, and the more obvious, the characters on which we found our Divisions, the better. Hence I would not choose the form of the trophi, the presence or position of the eye-specks, or the distribution of the cilia, for distinction—if I could get others ; because all these are found, in practice, so very difficult to determine. The existence of eyes in some Coluri and Metopidie, for instance, is so very uncertain and indetermin- able, that I incline to agree with Dujardin in rejecting some of Khrenberg’s genera. The distinction between Lepadella, Metopidia, and Squamella, is more than doubtful; while in Metopidia and Colurus, individuals of indubitably the same species are found, some displaying eye-specks, and others in which no search detects them.—P.H.G.] Genus COLURUS, Ehrenberg. [GEN. CH. Body swdglobose, more or less compressed ; lorica of two lateral plates, open in front, united on the back, gaping behind, and (in general) wholly so up the belly ; frontal hood in form of a hook, not retractile ; foot permanently extruded, of distinct joints, terminated by two furcate toes. A very familiar group, of minute dimensions, agreeable form, and sprightly action, the Coluri give the impression of being, while sub-cireular in lateral outline, very thin in transverse diameter. This, however, is an illusion, arising from their being most frequently presented to the eye in the lateral aspect. When we do catch a glance at one in turning or swimming, we see that the body is moderately broad, ventricose, and even globose in the middle. The lorica consists of two glassy shells, each a segment of a hollow sphere, which are, normally, soldered edge to edge, at the fore-back, and begin to gape at the loins, the cleft then passing round behind, usually widening for emission of a stout foot, and passing up the belly to the front, by which time it has generally become as wide as the body itself. So constructed it may be imagined to be highly expansile, and in fact we observe that its width is constantly increasing and diminishing. The fore edges of the two plates, in the retraction of the head, are appressed so close as to seem but one lamina ; but separate for the protrusion of the head with its rotating cilia. The hood, a decurved plate, often broad but sometimes narrow, of hyaline delicacy, is not retractile, but is seen when the lorica is shut up, resembling a semi-crescentic hook. The foot consists of three strongly marked joints bearing straight, acute, slender toes, often thrown wide apart, but, in some cases, so uniformly adherent that it is difficult to see whether they are two or one. The whole foot is often stretched behind ; but much more commonly it is projected forward under the belly, through the ventral gape. The presence, the position, and even the number of eyes, seem subject to much variation. Most of the known species are lacustrine in habit, but some are exclusively marine. It is a characteristic habit of the species of the genus, particularly of C. obtusus, to elevate themselves to the utmost on the toe-poimt as on a pivot, and then awkwardly tumble over, as if they had not power to maintain their balance. The Monostyle per- form in somewhat similar style, but though their posturings and gyrations are wild, they seem to have better control over them. 102 THE ROTIFERA. In general, the species cannot be discriminated, while in life and activity, without extreme difficulty ; their differences are so very slight, their dimensions so minute, and their restlessness so incessant.—P.H.G.] C. preFrLexus, Ehrenberg. (Pl. XXVL. fig. 1.) Colurus deflexus C : . Ehrenberg, Die Infus. 1838, p. 476, Taf. lix. fig. 9. [SP. CH. Lorica, viewed dorsally, broadly ovate, bluntly pointed before, produced behind into two acute spines, separated by a wide, deep sinus: viewed laterally, the outline is the quadrant of an oval: the venter cleft from end to end ; foot robust, with two short, slender, acute toes. If I rightly identify the species, there is little difference of aspect between this and bicuspidatus. In this the posterior spines are said to point slightly below, in the other slightly above, the horizontal line. Yet as this depends on the angle at which the animal is viewed, which is every instant varying, the distinction is evanescent, and, I fear, worthless. Yet, on careful study, this, which is by much the more robust species, is seen to have the two halves of the lorica severed all round, except in the middle of the back. The fore edges of these halves, deeply truncate, but a little out-curved, are firmly pressed together in retraction ; and the effect of this appression, when seen from above, is the dividing line of the blunt cone, which is seen minutely opening and closing every moment. A muscle-band passes, in relaxed curves, from the front of each of the appressed sides to the surfaces of the retracted organs seen in a confused heap far down, evidently for the purpose of pulling out the trochal apparatus when required. A large pale crimson eye seated on an ample brain-sac; a mastax of the Huchla- nidan pattern; a cylindrical stomach succeeded by a wide intestine; an ovary often containing a nearly developed egg ; and a small contractile vesicle ; are usually seen. But in the middle of the back, just under the lorica, are two curious organs, each apparently an agglomeration of minute, clear vesicles, perhaps of air, perhaps of oil, observed long ago by Ehrenberg. He declared them inexplicable ; and I cannot supply the explanation. When, after a self-inflicted imprisonment, it may be of hours, the Colwrus opens its closed cheek-plates, a trochal mass of conglobate lobes, fringed with wreaths of cilia, is thrust out, by whose vibration the creature smoothly but rapidly shoots away. The frontal hooked-plate, which, even in the inert state, has been discernible by the delicate, thin, curved line of its edge, moves to and fro, and under very favourable circumstances we may see that its inferior surface is fringed with vibratile cilia. I judge it to be an organ of touch; Herr Eckstein’s opinion to the contrary notwithstanding.—P.H.G.] Length. Of lorica, 5}, inch; from hook to toes, ;45 inch. Habitat. Ponds and ditches ; quite common (P.H.G.). C. Bicusripatus, Ehrenberg. (Pl. XXVI. fig. 2.) Colurus bicuspidatus 5 6 Ehrenberg, Die Infus. 1838, p. 476, Taf. lix. fig. 7. [SP. CH. Almost exactly those of C. deflexus, except that the lorica is not cleft either dorsally or ventrally ; but only excavate behind, slightly on the dorsal, deeply on the ventral side. I have seen only a few examples of this form, all from Sutton Park, Birmingham. It is, I presume, Ehrenberg’s bicuspidatus, his figures showing a lorica undivided beneath. In examples long under examination, I became quite certain that neither the dorsum nor the venter was cleft ; but a narrow sinus, reaching to more than one-third of the lorica in length was excavated up the flat ventral plate, and a very slight one out of the dorsal end. Through this orifice the foot is thrust, of rapidly diminishing joints, COLURID A. 103 and what appears a single, slender, acute toe. At least I could not, with close watching, detect any sign of its division. In the dorsal view the frontal hood (fig. 2) appears not as the segment of a sphere, but somewhat indented in front. It ever moves backward and forward, as protruded and retracted. The venter appears quite flat, the semi-globose dorsal plate rismg abruptly from it with a sharp angle. In one, as it turned slowly, I saw distinctly the form. If we suppose one-third of an egg to be removed longitudinally, and replaced by a flat plate, we shall gain a fair idea of the general outline. This is certainly an uncommon form. My acquaintance with it is limited to a very few examples, obtained from Woolston Pond, and Sutton Park, Birmingham. Its manners are peculiar. It swims constantly, never resting to grope, as other species do, but sail- ing deviously and deliberately about; now and then quickening its pace; almost con- stantly with the venter at the glass of the cell; so that whereas I obtained plenty of ventral views, I got few dorsal, and scarcely one good lateral.—P.H.G.]} Length. Extended, 51, inch; transverse width ,}5. Habitat. Woolston; Birming- ham (P.H.G.); very rare. C. uncinatus, Ehrenberg. Colurus uncinatus : ‘ : Ehrenberg, Die Infus. 1838, p. 475, Taf. lix. fig. 6. [SP. CH. Lorica, viewed dorsally, broadly ovate, truncate before, produced behind into two short spines: viewed laterally, the owtline is rondo-triangular, high in the muddle of the back, the posterior spines short, blunt, and abruptly set-on ; venter widely cleft throughout; toes two, short, slender, acute. Lacustrine. The lorica is turgid, the back not ridged but smoothly rounded; its ventral gape parallel-edged, the edges apparently bent downward (as in Huchlanis deflexa), making an angle with the swell of the sides, the anterior portion lengthened into a short tubular neck. The hook is narrow and spoon-shaped. The internal structure is obscure, partly from its sphericity; yet the mastax, stomach, intestine and cloaca, the ovary and the contractile vesicle, can be defined. It is usually of minute dimensions, and, though widely spread, rather rare. I have known it since 1849.—P.H.G.] Length. Lorica, from z4, to »}, inch. Habitat. Clapton; Battersea; Bath ; (P.H.G.). C. oprusus, Gossé, sp. nov. (Pl. XXVI. fig. 3.) [SP. CH. Lorica ovate in all aspects, the posterior ends rounded without any points, ventrally cleft throughout, gradually expanding for the foot-orifice, the fissure reach- ing round to the back, both before and behind ; foot small, with two nunute slender, ex- panding toes. Lacustrine. This little unrecognised species, which I find not uncommon, is clearly marked by the blunt ends of the lorica. The lateral plates are separate for above three-fourths of their cirewnference, being soldered together with a sharp suture, only in the very middle of the back, and generally much compressed. The foot and toes together are about one- third as long as the lorica; the toes, like sets for tenuity, with no shoulder, are often separate, The internal economy is normal ; including the common bubbles in the back ; two colourless refractile globules have been seen on the brain, which may be eyes. Its manners are sluggish, swimming laboriously, with jerks.—P.H.G.] Length. Without foot, =}, to z+; inch. Habitat. Near London; Woolston; Lea- mington ; Dundee (P.H.G.): not uncommon. 104 THE ROTIFERA. C. caupatus, Hhrenberg. (Pl. XXVL. fic. 6.) Colurus caudatus G 0 : 6 Ehrenberg, Die Infus. 1838, p. 476, Taf. lix. fig. 8. (SP. CH. Lorica, zn dorsal aspect, pear-shaped, widest behind ; dorsal hind sinus shallow, between very short terminal points, not at all produced ; ventral cleft close, abruptly becoming a semi-circular foot-orifice ; toes slender, frequently expanded ; foot and toes three-fourths as long as lorica; eyes two. Lacustrine. There are several species which may, almost equally well, serve as the caudatus ot Ehrenberg, to distinguish which requires minute examination. The above characters are carefully noted from many observations, and need not be repeated. The free expan- sion of the long toes, unusual in this group, is noteworthy. The frontal hook is normal, and I have repeatedly seen two eyes just beneath it. On the ventral surface the abrupt expansion of the fissure from a linear cleft to a broad round opening for the emission of the wide basal foot-joint, should be noticed.—P.H.G.] Length. Total 53, inch. Habitat. Birmingham; Woolston (P.H.G.) : weedy pools. C. AMBLYTELUS, Gosse, sp. nov. = (BID Sexevily aig: (bs) (SP. CH. Lorica, in dorsal aspect, broadly ovate, the hind ends rounded, without projecting points ; ventral cleft gaping, widening before and behind ; toe single, long, with a medial depression ; foot and toe two-thirds as long as lorica ; eyes cervical. Marine. This species also may be very readily confounded with C. caudatus, but the cha- racters above given, though minute, seem to distinguish it satisfactorily and constantly. The lorica is arched, so that its dorsal outline forms about one-fourth of a circle, split at its occipital end, and also for a little way above the foot; the two lateral extremities being rounded. When the animal in its turnings shows the ventral side, even though slightly, we seem to see sharp points to the lorica; but this is an illusion, for the points are but the ends of the curved plates seen edgewise ; another turn, and they at once become again obtuse. On the ventral surface, which is nearly flat, the edges of the two plates are either wide apart or very closely approach each other, or may even overlap, but recede on each side of the foot, so as to leave the orifice nearly circular. The single long slender toe, running off to a fine point, has a medial mark throughout, as in those Metopidia, &e., which keep the toes ordinarily appressed; but I have never seen a separation, and the most delicate focusing with high powers fails to divide the fine point. The usual hood is displayed. The mastax and its trophi are normal. The brain, large and turbid but undefined, occupies the occiput ; and two minute red eyes, rather close together, are situate on it cervically. The other interior organs are as ordinary. One oil-globule (sometimes two) occupies in general the middle of the back, and is conspicuous. This species seems exclusively marine. . I have found it somewhat numerous among algee, collected by Mr. Hood from tide-pools at low-water at Taymouth, near Dundee, and also in Torbay. It is tery restless, ever roaming, yet mainly affecting the conferva, at which it nibbles constantly ; when swimming it shoots along with smooth rapidity. The form is plump and round, the blunt corners low-descending ; the body hyaline and colourless, the taper toe stretching far behind.1\—P.H.G.] ‘Tam very confident that other species of this long-toed group exist, in both our fresh and salt waters. But though I have some drawings and notes, I have not as yet materials sufficient for satis- factory diagnosis.—P.H.G. COLURID&. 105 Length. From hood to ends of lorica, 545 can foot and toe, s}5 inch; total, 1,5 inch. Habitat. Marine pools at low tide (P.H.G.). C. DAcTYLoTUS, Gosse, sp. nov. (Pl. XXV. fig. 12.) [SP. CH. Lorica wide in front, shallowly tubular behind, without points ; foot very short but wide ; toes thick, large, and curved. Marine. A somewhat thickset form. The lorica is ovate, viewed dorsally, with a broad an- terior gape, out of which what seems another shelly valve projects, connected by an involute joint with the lorica (as seen in fig. 12a), a sort of hood, protecting the ciliate front and answering to the usual hooked plate, but of very different form. The front consists of several fleshy eminences (fig. 12) bearing vibratile cilia. The lorica ends behind in a short truncate tube, through which the foot finds exit. This is exceedingly short and inconspicuous, though broad; the toes are fureate, thick at their base, blunt-pointed, and slightly decurved, when seen laterally (fig. 12a). I have seen but a single example, in sea-water from tide-pools near Taymouth.— PAE Gell Length, ;4; inch. Habitat. Marine pools (P.H.G.). C. PEDATUS, Gosse, sp. nov. (Pl. XXV. fig. 18.) [SP. CH. Lorica cleft behind, ending in two square points ; foot stout, long ; toes minute, straight. Marine. Two examples of this little insignificant species occurred in water sent by Mr. Hood, from the Tay Firth marine pools. They were both in the same live-box as C. dactylotus. The thick foot-joints and the very small toes forming a small cone, when closely appressed as they usually are, will distinguish the species from all others. It is somewhat less than its congener just named. I detected nothing in it worthy of record besides.—P.H.G.] Length. About}, inch. Habitat. Marine tide-pools; rare (P.H.G.). C. c@LoPinus, Gosse, sp. nov. (Pl. XXVI. fig. 4.) (SP. CH. Toe very long and slender, consisting of a narrow plate laid within a similar, but wider plate, and closely appressed to it. Marine. In the form of the toe we have here an example, quite unique in this genus, of the structure which characterises the genus, hence named Calopus, in the Rattulide. The toe consists first of an extremely long, tapering, hollow, thin plate of transparent chitine, such as would be presented by the bowl of a glass spoon, if drawn out to excessive length and tenuity. Then suppose a similar plate of glass, but narrower throughout, to be laid in the hollow of the former, fitted exactly to it, and reaching its taper point far before the other. What is the relation of the one spine to the other, and of both to the body; what their functions, what their movements, separately or conjointly, I know not. I have met with but one example, and that a dead and nearly empty lorica. The occurrence of such is often of great value. It is true that it may give little or no information of the internal structure, and, of course, none of manners. But of the external form and its appendages, composed of undissolved chitine, we can often obtain views of beautiful clearness, given with a minute precision that we can seldom hope for from a living animal. For the object is perfectly still, and remains so as long as we choose, while it is generally feasible to make it revolve in various directions by producing mechanical 106 THE ROTIFERA. currents in the water, and so to examine its appearance in other aspects. Thus was this creature delineated, and I vouch for its: accuracy so far as the details are given. The loriea seems (I can say no more) to be widely severed on the ventral aspect, and to end in rectangular points behind. The frontal hook appears normal.—P.H.G.] Length, to tip of spine, ;}4 inch; of which the spine is about one-fourth. Habitat. Among confervee in tide-pools in the Firth of Tay (P.H.G.); rare. Genus METOPIDIA, Lhrenberg. [GEN. CH. Lorica usually depressed, entire, with an opening at each end for the emission of the head and foot; frontal hood in form of a hook ; foot and toes as in Colurus ; eyes usually two. For reasons already given I include in this genus, not only the species so named by Ehrenberg, but also his genera Lepadella and Squamella ; thus agreeing in principle with Dujardin (‘‘ Infus.” p. 682) while I cannot accept his details. They seem to fall into the same natural family as Colwrus; for though the prevailing plate-like form seems at first sight to differ greatly from the compressed Colwri, yet this form is not invariable, M. oxysternum and M. triptera presenting notable exceptions ; while in the arched frontal hook there is a remarkably conspicuous feature in common. Some of the species are among the most familiar of Rotifera.—P.H.G.] M. LepapeLua, Hhrenberg. (Pl. XXYV. fig. 6.) Metopidia lepadella : . 5 Ehrenberg, Die Infus. 1838, p. 477, pl. lix. fig 10. [SP. CH. Lorica oval, much depressed, evenly rounded above ; its ventral plate shorter behind than the dorsal, and slightly excavate. That Ehrenberg’s Lepadella ovalis, Squamella bractea and S. oblonga, and Metopidia lepadella are but species of one genus, I cannot doubt, and even the specific differences between them are very evanescent. The number, and even the visibility, of the eye-specks vary in individuals, and cannot be trusted for diagnosis. The present is a common form in most fresh waters. The lorica in its dorsal outline, both longitudinal and transverse, is a segment of a circle, and the ventral is straight. Seen from above it is oval, pointed at both ends, and yet truncate; the ventral plate round behind, and so considerably shorter, and slightly emarginate for the emission of the foot. The frontal hood agrees with that in Colwrus, slightly protrusile, and is used for raking the rubbish among which it feeds. The ciliate face is almost prone, and the trophi can be brought to its surface. I think I have seen the male; a minute creature, in form a very long cone, tapering to a point, with two slender toes; in front, quite truncate, with a sharp horn projecting from its forehead. No organization was visible within, save two conspicuous clear vesicles, side by side in the middle of the body, not at all like oil-globules, being irregularly oblong: nor accidental, being found in each of a large number of individuals, seen at different times. A pair of fine lines ran far down the two sides of the body, and in the hinder part was a large angular web of thin yellowish tissue. Else the whole seemed structureless and of hyaline clearness. It contracted into a shorter oval figure.—P.H.G.] Length. Of lorica, 54, inch. Habitat. Fresh waters everywhere (P.H.G.). M. souipus, Gosse. (Pl. XXV. fig. 11.) Metopidia solidus : 5 O a Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 201. [SP. CH. Lorica nearly circular, depressed, with a low rounded ridge above ; ventral plate commensurate with the dorsal behind, but deeply excavate ; dorsal having a submarginal line of corrugation. COLURIDA. 107 This charming species, though in technical characters very similar to the preceding, is yet readily distinguished when once it is known. It is very much rarer, averages nearly twice its size, while its outline, in retraction, far more nearly approaches a circle. This, with its crystalline brilliance, recalls the lovely Pterodine, of which it is no wnworthy rival ; and its resemblance to them is much augmented by a delicate line of corrugations, which run round just within the margin, like the ‘‘ milling” within a shilling. It was this feature that suggested the specific name, and no allusion to the adjective solidus. The arch of the lorica is much lower than in lepadella, especially towards the edge, while down the middle there runs a very low, rounded ridge. The fore and hind exea- vations are nearly as in lepadella. Besides the frontal hood, there is another clear disk which appears to protect the rotating cilia, and a transparent bulb is placed on each side of this, within each of which is seen a minute red eye, so that these organs are widely separated. Some curious facts connected with digestion were illustrated by mixing a little car- mine with the water. Particles were readily imbibed, and soon appeared as a red cloud in the fore part of the stomach. Presently this pellet passed into the upbent viscus at the bottom, which I supposed the intestine ; and a second pellet, swallowed at the same instant, took the vacated place. After an hour, the whole alimentary canal had assumed the appearance of fig. 11f, the supposed intestine being only a lobe or pocket of the stomach. The pellet No. 1 now moved rapidly down to the cloacal extremity of the twofold viscus, but, instead of being discharged, it swiftly passed up (as between the dotted lines) to its first position at the base of the stomach; then returned to the cloacal end, and quickly again mounted ; repeating these movements several times, till at length it coalesced with the second pellet. All the while the whole interiors of both chambers were full of an incessant quivering from the action of epithelial cilia. From all this, it really seems as if something analogous to rumination occurred in these minute creatures. The gastric glands and the lateral canals are very abnormal ; and the con- tractile vesicle is sometimes ample, sometimes totally wanting.—P.H.G.] Length, ,1,, inch. Habitat. Walthamstow; Leamington; Birmingham; Woolston ; Dundee (P.H.G.). M. acuminata, Hhrenberg. (Pl. XXV. fig. 9.) Metopidia acuminata 3 5 5 Ehrenberg, Die Infus. p. 477, Taf. lix. fig. 11. [SP. CH. Lorica ovate, ending behind in an acute point ; occipitally deeply notched between projecting spines ; the edges very thin. Besides the above peculiarities there is little to mark this obscure little species, which yet is amply distinct. When seen sidewise it has much likeness to a Colurus, save that its form is flatter; and the deeurved frontal hood is more conspicuous. It is an eager and persevering feeder, raking with its hood-edge among the floccose.—P.H.G.] Length. Of lorica, 31, to 31, inch. Habitat. North London; Leamington; Sand- hurst (P.H.G.); very scarce. M. OXYSTERNUM, Gosse. (Pl. XXY. fig. 8.) Metopidia orysternon 5 . 3 Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 201. (SP. CH. Lorica an ovate bow of tesselated surface ; with a thin ridge running down the dorsum ; venter with a similar medial ridge terminating abruptly in mid-length. This is a very curious form. It is a depressed rhomboid-oval, with a rather high and thin arched ridge running down the back from the bottom of a deep frontal smus. The ventral surface is also ridged as far as the mid-length, where the ridge ends, like the sternum of a bird. ‘Then the surface is deeply excavated, and again projects, forming a prominent sheath for the emission of the foot. The whole lorica is cut into facets, as 108 THE ROTIFERA. in Notews and in many Anwre@e@, and all minutely shagreened. The head is deep, form- ing three lobes, all ciliated. In retraction the two sides of the lorica close on each other, leaving within a large clear space, exactly as in many Colwri, to which a further resemblance is borne by the position and direction of the foot and toes ; the former in- clined forward, and the latter bent abruptly backward. A rather small brain carries an eye as large as half the mastax (possibly two suffused, since in some specimens two are observed), pale but rich, transparent rose-red. In rotating a narrow, parallel-sided, truncate lip is seen thrust out in front, as in V/. triptera. The trophi are on the plan common in the Huchlanide, and neighbouring families. I first obtained the species in an ornamental water near London in 1849; recently in a ditch at Coffinswell, near Torquay, and in water from the Black Loch, Dundee, in company with Gcistes Stygis and Gi. brachiatus. It is of lively manners.—P.H.G.] Length, ;1, inch. Habitat. London; South Devon; Dundee (P.H.G.): rare. M. RHOMBOIDES, Gosse, sp. nov. (Pl. XXV. fig. 10.) [SP. CH. Lorica rhomboid-ovate in outline ; dorsal surface tectiform, lower behind, ending in an obtuse point ; ventral surface jlat. This seems to come between orysternum and triptera. The cescphagus is long, and often thrown into curves. The gastrie glands are peculiar, being placed at the ends of two long threads, probably tubular, which are seated on the corners of the stomach, the slobular glands themselves being affixed to the lining of the lorica.—P.H.G.] Length, ;4, inch. Habitat. North London (P.H.G.): very rare. M. triptera, Hhrenberg. (Pl. XXV. fig. 7.) Metopidia triptera . 0 . ° Ehrenberg, Die Infus. 1838, p. 478, Taf. lix. fig. 12. (SP. CH. Lorica nearly circular, as viewed dorsally, dilated into three wide, but thin, wings, one dorsal and two lateral. The aspect of this tiny living jewel, viewed dorsally, is almost exactly that of WM. lepadella, and so it is if viewed sidewise. But an instant turn, or a slight change of level, and the broad planes come into view, with an effect that surprises. Hach of these is, speaking loosely, a semi-oval, formed of two thin glassy plates, soldered into one for about half their width, then diverging to constitute, with the like structure of the vertical plate, a sub-cylindrical sheath, in which the organs and viscera are inclosed. The foot finds its exit by a sinus excavated out of the lower part of the cylinder, whose fore end is truncate for the extrusion of the head. This is surmounted by a broad chitinous hood descending in front to a sharp edge (as usual hook-like in lateral perspective), quite distinct from the tripterous lorica, within which its base is slightly retractile. It is con- spicuous in all aspects. From above, the ciliate front, with its minute crimson eyes, one at each extreme lateral joint, is clearly discerned through its transparency. It is a most exquisite little creature, of crystal brilliance, and sprightly in manner, without being swift. It swims little, but serapes and pokes in the parasitic floccose. Here, as it turns and twists deviously about, we see constantly changing aspects of the three shining planes, whose surfaces and edges are ever crossing each other, all visible through each other, from their perfect translucency. Thus, though the difficulty of resolving the organic details of the active atom is augmented rather tantalisingly, one cannot but be charmed by the beauty and variety displayed. I have seen one, slowly gliding in a straight line, go on revolving on its axis, bringing the six surfaces into view in quick succession, with a striking effect. On another occasion one came sidling up to a noble Huchlanis. The contrast, and yet the resemblance, was curious; the one could have Jain comfortably within the ample mastax of the other.—P.H.G.] Length, ,}, inch. Habitat. Sandhurst (Collins) ; Woolston; Dundee (P.H.G.): rare. COLURIDA. 109 M. practEa, Hhrenberg. Squamella bractea : 5 0 Ehrenberg, Die Infus. p. 480, Taf. lix. fig. 16. (SP. CH. Lorica oval, much depressed, its front deeply excavated especially on the pectoral side ; dorsal plate ending behind in two minute projections ; ventral deeply excavate ; eyes four. The differences perceptible between this and lepadella are exceedingly small; the four minute eyes, set in square, are very rarely discerned ; but I have seen them. One deposited an ephippial egg, clothed with very long spines, while under my observation. Perl Grel| Length. Of lorica, ,1,, inch. Habitat. Pools and infusions ; common (P.H.G.). Genus MONURA, Ehrenberg. (GEN. CH. As Colurus, but the toe is a simple style. It is mainly in deference to the great Prussian zoologist, that I retain the generic distinction between this and the preceding group. With the recollection that in C. leptus I can discern no trace of a medial depression in the toe, that in C. amblytelus there is the depression, which I have never seen separated, that in C. caudatus there is the de- pression apparently as inseparable, which, yet, on occasion, palpably opens and expands ; to build a genus exclusively on this condition of the toe is most precarious.—P.H.G.] M. coxurus, Hhrenberg. (Pl. XXVI. fig. 7.) Monura colurus 6 6 F C Ehrenberg, Die Infus. 1838, p. 474, Taf. lix. fig. 4. [SP. CH. Lorica ovate, much compressed, highest at the front, with the hind ends rounded ; eyes two, approximate. Marine. Viewed vertically this animal has the form of a mussel, gaping widely all along the venter and around each extremity, with no sensible change of outline for the emission of the foot, and hinged only along the middle of the dorsum. In a lateral view the lorica forms the half of a very long ellipse, flattened ventrally, obtuse behind, thence gradually rising till it is highest at the front, whence it descends in a bold curve to rejoin the belly side. Thus the outline is markedly different from that which is charac- teristic of Colurus, though the difference depends on minute peculiarities. The round anteriors of the valves are, often and long, firmly appressed (fig. 7a), the whole head and viscera being far withdrawn, and a wide hyaline space left, within whose edge a very delicate corrugation marks the line of mutual contact. At intervals the valves part, and a head is protruded, armed with long and coarse cilia, and over- arched by a conspicuous frontal hood. This has the unusual appearance of a wide veil of exceeding tenuity, strengthened by an acute taper hook of chitine running through its medial line. Under the base of this organ are seen two brilliant crimson eyes, moderately near each other. Slight indications of a manducatory apparatus are seen, and occasionally the globose form of the mastax ; but all so evanescent as to defy defi- nition. A large sacculate stomach, divided by constriction from a still ampler intestine ; an ovary and a small contractile vesicle, with the cloaca at the dorsal base of the foot, are all normal. The foot itself is prominent, moderately thick, of three long, well- marked joints ; the toe, a single, long, acute style, thick at base, and suddenly diminish- ing in its dorsal outline, has the remarkable peculiarity of being as flexible and elastic as whalebone. The extruded foot and toe are two-thirds as long as the lorica. I first met with this species, congregating in great numbers around my marine 110 THE ROTIFERA. aquarium, in September 1854, Its manners agreed with those of the larger Coluri, shutting itself within its valves, and that so stubbornly, as to die rather than open them. Lately I have received specimens from Mr. Hood, found in marine tide-pools in the Firth of Tay; and have taken many in Torbay. Length. Of lorica, 51, inch ; of foot and toe, 4, inch; total extended, 5}, to 51, inch. Habitat. Marine pools in Forfarshire and Devonshire; domestic aquarium (P.H.G.). Very recently specimens of what I suppose M. dulcis, Khr., have been sent me, from fresh water, by Mr. Lord of Rawtenstall. The lorica is acute, instead of obtuse, behind.—P.H.G.] Genus MYTILIA, Gosse, gen. nov. [GEN. CH. Body ovate ; lorieca as in Colurus, but the head and neck habitually protruded, as well as the whole foot ; no frontal hook.—P.H.G.] M. TAvina, Gosse, sp. nov. (Pl. XXVI. fig. 8.) [SP. CH. Eyes two, frontal, wide apart. Marine. The lorica is essentially similar to that of Colwrus (though the facies of the animal is quite different), being a shell of two lateral valves, ike that of a mussel, unbroken on the dorsum, descending on each side, and open all along the venter. Behind they are patent, where the thick foot emerges ; but their edges approach, or even overlap, as in Pierodina, at the pectoral front. A massive head, and an equally thick, distinct neck, both about equal to that part of the trunk that adjoins them, are normally projected from the lorica, and not, as in Colurws, concealed between the valves. As there is, moreover, no trace of the hood, or hooked plate, that shields the face in kindred forms, the difference of aspect is very marked, and one of the Iloricate forms is involuntarily suggested.! This is augmented by the circumstances, that the foot is long and thick, especially at its base, that it tapers tere gradually from the thickness of the trunk, and that it is habitually carried in the line of the body. Whereas, in Colwruws and Monura, it is much smaller than the visible body, is usually projected at a sensible angle, and appears to come out between the ventral edges of the valves. The lorica, too, is of much less depth in proportion to its length; for, whereas, in Colwrus the depth to the length may be about 2: 3, in Mytilia it is about 2:5. It is obliquely truncate at the hind margin, the lateral edges diverging thence till they meet at the pectus. The body, which is arched on the dorsum, diminishes along the lumbar line, and forms a minute conical projection, representing a true tail, behind which the cloaca opens, whence the foot proceeds, in a similar ratio of diminution and in the same line, for a considerable length, terminating in two stout pointed toes, often jerked widely apart. Each is per- meated by the usual mucus-gland, long, thick, and clavate. The imternal structure is with difficulty defined. The extreme restlessness of the creature, combined with its minuteness, renders an examination during life almost impossible ; and, after death, the outlines of the delicate organs become blurred, and soon obliterated. I believe I have perceived, on repeated occasions, and in many specimens, two minute eye specks at the front, rather wide apart. The mastax is comparatively large, and the trophi normal (as in fig. 8c). But the whole interior is almost opaque from granulation, and so, very difficult to penetrate. It is a pretty little creature, sprightly and attractive, with much in its manners and ways that reminds us of its kindred Coluri, one of which, C. amblytelus, is its constant ' T cannot avoid a lurking suspicion that under Ehrenberg’s figure of Distenma marinum may have lain Mytilia tavina, notwithstanding discrepancies. COLURID. 111 associate. The species is another of the discoveries of Mr. Hood, of Dundee. He finds it in sea-water, and has sent me many specimens in vigorous health.—P.H.G.] Length, ,4, toy, inch; width and depth equal, about ;4, inch. Habitat. Tide- pools at the mouth of the River Tay (J.H.); and in Torbay (P.H.G.). Genus COCHLEARE, Gosse, gen. noy. [GEN. CH. Lorica not half the length ; foot long, annulate ; toes two, furcate. The two species which I include in this genus are minute and inconspicuous, but peculiar. The lorica is quite a subordinate feature, the parts behind this greatly deve- loped into what appears.a very stout and long foot, of many annulose joints, terminated by two minute toes, on which the creature usually elevates itself, and turns as ona pivot. Both the species are lacustrine.—P.H.G. ] C. STAPHYLINUS, Grosse, sp. nov. (Pl. XXVI. fig. 9.) [SP. CH. Lorica hemispheric. The integument is wrinkled irregularly, and scarcely firm enough to be called a lorica. It is nearly circular in outline, arched dorsally, and flat ventrally, abruptly attenuated to the stout and long foot of four distinct joimts, ending in what looks like two acute toes soldered together, frequently turned up in a threatening manner, Eyes and internal organs dim and uncertainly discerned. I have found but one specimen, in a dyke near Stratford, in 1851.—P.H.G.] Length, ,}, inch; width, 345 inch (P.H.G.). C. TURBO, Gosse, sp. nov. (Pl. XXVI. fig. 10.) (SP. CH. Lorica three-sided. The form of the loriea may not be constant, yet the facies of this differed so much from that of the preceding, that, until we have more knowledge, it is well to treat them as distinct. The flexible lorica is nearly parallel-edged, but rises to a dorsal angle, like a roof; yet each of the sloping lateral surfaces consists of two planes, very slightly in- clined to each other. The head appears as if it had a broad hood like that of Stephanops chlena, but flexible, for sometimes a lobe of it flaps inward. The front is formed of two half-cones, ciliated on their inner faces, which approach and recede at will, making two vortices. A large occipital brain bears a red eye near its pot, The toes are dis- tinctly furcate.—P.H.G.] Length, ;1, inch; width, ,4, inch. Habitat. Black Loch, near Dundee (P.H.G.). Family XVII. PTERODINADA. Lorica entire, various; corona and ciliary wreath those of the Philodinade ; trophi malleo-ramate ; foot wholly retraciile, transversely wrinkled, jointless, toeless, ending in a ciliated cup ;—or foot absent. This is a singular group of Rotifera. Unlike all other loricate free-swimmers, Piero- dinad@ possess a corona of a Bdelloidic, and trophi and foot of a Rhizotie type. The corona is that of Philodinade, the trophi are those of Melicerta, while the foot (when present) would be very like that of Gcistes serpentinus, but for its extremity. The two genera of which the family consists differ in the shape of the lorica, and in the foot. 112 THE ROTIFERA. In Pterodina the lorica consists of two delicately thin, and nearly flat plates, soldered together at their edges; in Pompholyx it is continuous, flask-shaped, and without edges. In the former the ventral plate is perforated for the emission of a long, wrinkled, toeless foot ; the latter is footless. Genus PTERODINA, Ehrenberg. GEN. CH. Lorica entire, greatly depressed, of two oval, but nearly circular plates soldered together at their edges ; foot wholly retractile, transversely wrinkled, jointless, toeless, ending in a ciliated cup. The species of this genus differ from each other chiefly in the flexibility, shape and adorning of the lorica. In all, the corona consists of two circular lobes, whose ciliary wreaths, seen from above, present as perfect an appearance of two revolving wheels as in Plhulodina or Rotifer. The cylindrical foot is encircled by deep constrictions, which cease abruptly at some distance from its free end, and is remarkable not only from its being the foot of a fixed Rotiferon, but also from its ending in a richly-ciliated hemi- spherical cup. There are, too, some other points common to all the species, that deserve notice. The salivary (?) glands on the wsophagus are very numerous, and the gastric glands are of unusual length and shape. They are attached to the junction of the cesophagus and stomach by long tapering stalks; and, crossing the lorica transversely, are fastened to the dorsal surface by their broad ends. Between these attached ends of the gastric glands, and the lowest portion of the head, lie curiously-scalloped folia- tions (of a delicately blue-tinted substance) of which it is difficult to say whether they are continuous with the gastric glands, or are expansions of the lobed masses investing the base of the head, or are something analogous to the floccose ribbons which in so many Rotifera surround the lateral canals. They are very conspicuous in P. patina, but only faintly visible in P. valvata; and the upper portions of the lateral canals, with the attached vibratile tags, lie across them.! The contractile vesicle appears to be absent. The longitudinal muscles are coarsely striated, and the two eyes are distinct, colourless, transparent spheres resting on ruby pigment. I failed to find any dorsal antenna, but the dorso-lateral antenne lie with their rocket-shaped heads close to the surface of the lorica near its edge at about one-third of the semi-circumference from the top. P. parina, Ehrenberg. (Pl. XXVI. fig. 11.) Pterodina patina . 4 Ehrenberg, Die Infus. 1838, p. 517, Taf. Ixiv. fig. 4. an : Eckstein, Sieb. u. Koll. Zeits. xxxix. 1883, p. 401, Taf. xxvii. fig. 59. SP. CH. Lorica inflexible, nearly circular, stippled just within the edge, especially on its upper third ; bosses absent from the lorica; gastric glands with broad, lobed ends. Lateral foliations very conspicuous. This is the common species; but, though no rarity, Miller has rightly described it as ‘‘ Animalculum crystallinum, splendore nulli secundum ’’; for it is a lovely crea- ture. ‘The dorsal and ventral plates are pressed close together into a glassy shield of marvellous thinness. The former is more or less roughened round the edge; and, about the level of the mastax, this roughening spreads inwards to some distance. Occasionally, too, I have met with specimens in which there were faint traces of bosses, at irregular intervals, within the edge; but usually these are absent. A side view enables one to see that the ventral plate bulges out along the longitudinal axis, so as to form half of a hollow cone, whose broad end is forward, and whose point lies on the ventral surface at ' Mr. Gosse differs from me concerning the use of the “gastric glands’’; the presence of the vibratile tags; the structure of the foliations; and, generally, concerning the Branchial System in Pterodina. His account of this structure will be found in the Appendix. PTERODINAD A. 118 a distance of about one-third of the axis from the edge of the lorica. From the broad front opening the head protrudes; and here the cone is slit down a little, and the flaps rounded off, to give the head a freer passage. When the head is withdrawn, the flaps are drawn by muscles close together, up to the under side of the dorsal plate. Just below the pointed end of the conical hollow, there is a circular opening in the ventral plate, through which the foot can be protruded or withdrawn. The gastric glands are very conspicuous. They are unusually long pear-shaped bodies, stretching from the top of the stomach at right-angles to the animal’s length, and having their broad heads fastened to the inner lining of the lorica. Round these points of attachment spread out wide foliations of a filmy substance, curiously and deeply scalloped, and passing upwards towards the head, and outwards nearly to the edge of the shield. It is not easy to see either the lateral canals or the vibratile tags, as they are often obscured by other organs. Lately, however, I succeeded in holding a P. patina firmly down in a clean drop of water, without hurting it; and, as its head moved backwards and forwards, I could see one of the thick, striped, longitudinal muscles bend aside, and permit a view of two vibratile tags, as well as of the lateral canals to which they adhered. The former lay about midway between the gastric gland and the bottom of the head; while the latter sloped upwards and inwards, towards the funnel in which the head moved, and were cut off abruptly below by the edge of the gastric gland, at about its middle point: I could see no trace of a contractile vesicle. Two pear-shaped glands are attached by long stalks to the esophagus just below the mastax, and lower down is a cluster of similar glands crowding round the spot where the csophagus enters the stomach. The stomach and intestine lie usually side-by-side, and distinctly separate. The latter no doubt discharges through a cloaca at the root of the foot, on its dorsal side, just where it issues from the circular opening in the ventral plate.! ’ Length. Of lorica,;};inch. Habitat. Clear ponds and ditches: tolerably common. P. vauvata, Hudson. (Pl. XXVI. fig. 13.) Pterodina valvata . . r . Hudson, Mon. Micr. J. vol. y. 1871, p. 25, pl. Ixxii. SP. CH. Loriea capable of being folded down on each side, nearly circular, smooth ; bosses studding the edge at regular distances; gastric glands very long, club-shaped, with rounded ends. Lateral foliations inconspicuous. I found P. valvata at Abbot’s Pond, near Clifton, in the summer of 1871. It was in great abundance, and in company with P. patina; and in captivity it increased so amazingly, that the glass sides of my aquarium were frosted with the adhering Rotifera. The lorica is remarkably transparent, and is ornamented within its edge with ten bosses, which add greatly to its beauty. When the two species are present together, the differ- ence between them is recognized at a glance; for, delicate as P. patina is, P. valvata far surpasses it in filmy transparency. While watching some of the new Pterodine, I was surprised to see one of them sailing by with its lorica folded down (fig. 13a) like the flaps of a Pembroke table : 2 its outline was so altered that it scarcely seemed the same animal. This curious infolding of the lorica is due to the contraction of two con- spicuous transverse muscles, which do not necessarily act together ; as a friend, who was watching with me, saw some specimens with only one side folded at a time. The gastric glands have not such broad heads as those in patina, and are altogether ' Herr Eckstein (loc. cit.) says that the foot is not an organ of prehension, but is the intestine, the ciliated cup being the cloaca. He does not, however, state that he has ever seen the f@ces discharged through the foot; and, indeed, such a statement would seem incredible. Mr. Gosse, however, has witnessed the fecal discharge, and says: ‘ As well as I could see, it takes place at the upper side of the orifice through which the foot protrudes, projected in a strong current, and not immediately diffused.” * [As a rule the folding of the valves is somewhat rarely performed. I have observed, probably, hundreds at various times, and I think I haye not seen half-a-dozen folded.—P.H.G.] VOL. Il. I 114 THE ROTIFERA. narrower. The foliations are so slight as to permit the lateral antenne with their nerve-threads to be easily seen. Their rocket-shaped extremities lie close to the lorica, not far from its edge, and between the first and second bosses on either side: they are therefore, in an unusually forward position. The lateral canals can also be traced, in many conyolutions, from the lower part of the head, to the point where they are abruptly cut off by the gastric glands. In young specimens, in which the ovary is a small, transverse, pyriform sac, and so does not obscure the view, they are seen again below the gastric glands on either side of the stomach; and, passing behind it, appear to end below it on either side, in small pear-shaped expansions. I could never find any contractile vesicle; but, under favourable conditions, I have seen three pairs of vibratile tags: one a little above the heads of the gastric glands, one on a level with the middle of the stomach, and one not far from the pear-shaped sacs in which the lateral canals seem to end. Length. Lorica, +}, inch. Habitat. Abbot’s Pond, Clifton (C.T.H.): not common. Abundant near Torquay (P.H.G.). I met once with an empty lorica (Pl. XXVI. fig. 17) which I suppose to be that of Ehrenberg’s P. elliptica. It came from a pond in Sutton Park, Birmingham. P. mucronata, Gosse, sp. noy. (Pl. XXVI. fig. 15.) (SP. CH. Lorica usually circular; dorsal plate furnished with an acute mucro projecting from its front. Lacustrine. In April 1885, associated with P. patina and P. valvata, which were swarming in one of my window reservoirs, I first met with this very pretty form. It never became very numerous ; but, in the course of a few weeks, during which I was paying special attention to the genus, I met with more than thirty examples. The thought occurred that it might be the young condition of one of its larger fellow-species ; and, if so, valvata would be the more probable. Yet I have found the young of valvata no larger than mucronata, but with no trace of the mucro: and I have seen a nearly mature egg in mucronata, which, though not conclusive, augments the probability of adult condition. On the other hand, slight unevenness of frontal outline is not rarely discernible in adult specimens of both the larger species. The matter is still swb judice ; but for the present mucronata seems worthy of specific rank. The lorica has not only the intra-marginal granulation of its fellows, which gives them so elegant a resemblance to a new silver coin, but is shagreened or studded with close-set rugosities over the entire surface of the dorsal plate, so delicate, however, that the hyaline transparency is not interrupted. What I consider the branchial organs are small; the efferent lobe, answering to the pyriform (gastric gland), is generally inconspicuous, and the afferent tubes are clustered in form of a cone around the base of the sub-horizontal muscle. I have not satisfactorily observed the existence of eyes. The pair of diagonal muscles is unusually well-developed. The lorica has about two- thirds of the diameter of valvata.—P.H.G.] Length. About ;4) inch. Habitat. A domestic aquarium (P.H.G.): rare. P. cryprata, Hhrenberg. (Pl. XXVI. fig. 14.) Pterodina clypeata . F A Ehrenberg, Die Infus. 1838, p. 518, Taf. Ixiv. fig. 6. [SP. CH. Loriea elliptical, truncate at each end; coronal disks widely separated. Marine. I first formed acquaintance with this attractive species in July 1850, in sea-water from the Essex coast; and lately it has been sent me in abundance by Mr. Hood from PTERODINAD A. 115 the Firth of Tay. I have been able to preserve it in health for many weeks in phials of sea-water. Its ovate outline well distinguishes it from lacustrine forms; and this out- line is subject to some variation by the action of a stout transverse muscle-band across the venter, drawing together the two sides ; the medial length of the ventral plate being membranous and flexible, and the pectoral edge being cleft and overlapping. It is well suited for illustrating the branchial system. The plexus of the anastomosing afferent tubes is wide and particularly clear, and seems to be distributed on all sides of the great funnel. And the union of these can be readily traced into a large sac, which (placed on the ventral surface) presently bends dorsum-wards into a great pyriform vessel (as in P. valvata) on each side, and so pours its deoxygenated water by a slender duct into the cesophagus. The abdominal viscera are rather small. The long and flexible foot appears to be furnished with a central piston which protrudes and retracts its ciliated end ; this is endowed with considerable power of adhesion.—P.H.G.] Length. Head and foot extended, ,4, inch. Width, 5}, inch. Habitat. Among confervee in tide-pools ; mouth of the Naze, and of the Tay (P.H.G.): not rare. P. rruNcATA, Gosse, sp. nov. (Pl. XXVI. fig. 16.) Pterodina elliptica : A C Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 203. [SP. CH. Lorica ovate, somewhat pointed behind, the occipital edge abruptly trun- cate and slightly notched, the pectoral widely cleft. Lacustrine. I know this from a single specimen only, which I took in the autumn of 1850, in the expanse of water locally known as the Black Sea, at Wandsworth. My study of it is imperfect ; for though it rotated freely, I was called away before my observation had proceeded far, and when I returned it was retracted and soon died. The eyes are small, remote, and almost colourless. The extrusile foot, the trophi, the digestive apparatus, the pair of diagonal muscles, and (so far as seen) the plexus of branchial tubules on each side, were all generally normal.—P.H.G.] Length. Of lorica, ;} inch. Habitat. A lake near London (P.H.G.): very rare. Genus POMPHOLYX, Gosse. (GEN. CH. Lorica entire, bottle-like ; foot wanting; two frontal eyes; corona double behind, united before ; eggs attached after extrusion. Lacustrine. Two species, so far as we know, compose this genus; both small, obscure, and rarely seen. The one was found by myself in 1850; the other by Mr. Bolton in 1884.—P.H.G.] P. cOMPLANATA, Gosse. (Pl. XXVIIL. fig. 1.) Pompholyx complanata c 5 Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 203. [SP. CH. Lorica two-sided, nearly circular, with rounded edges ; occipital edge obtusely pointed, pectoral edge notched. The form is that of a round flat scent-bottle. The corona is composed of two disks, resembling those of a Bdelloid, but united in front, with a deep occipital sulcus, wherein an antenna protrudes. The eyes are placed one on each side of this sulcus, large, globular, ruby-red, and highly refractile. The jaws and alimentary canal seem of the Pterodina pattern, but the minuteness of the animal precludes definite observation. The cloaca appears at the end of the lorica, as a round orifice, with a slightly raised edge around it. Yet the great size of the egg suggests either that this orifice must be expansible, or that there must be a separate duct. In manners it resembles the Pterodine ; but it revolves as it goes like the Anurze. r2 116 THE ROTIFERA. It is somewhat slow of motion. The medial line of the venter is a salient angle; and this has a curious effect as the creature revolves.—P.H.G.] Length. Of lorica, +5 inch. Habitat. Pond at Lower Clapton (P.H.G.). P. suncata, Hudson. (Pl. XXVII. fig. 2.) Pompholyx sulcata < . Hudson, J. Roy. Micr. Soc. 1885, p. 613, pl. xii. figs. 7, 8. SP. CH. Lorica entire, divided into four convex lobes, by fowr longitudinal furrows. The lorica of this species is very unlike that of Mr. Gosse’s P. complanata. In the latter the dorsal and ventral surfaces are so compressed that they are slightly concave, while in the former both these surfaces are sharply convex, and so are the connecting lateral surfaces. A transverse section, consequently, consists of four segments of circles, as shown in fig. 2b. It is easy to obtain this view, as well as a good sight of the corona with its two wheels and red eyes, for the animal is fond of swimming upright close to the coyer-glass, or of exploring the bottom of the live-box, head downwards. I had little opportunity for studying the creature, but I noticed that the lorica had an aperture in its lower, pointed, and somewhat curved extremity. I am indebted to Mr. Bolton for this pretty little Rotiferon, which he discovered in company with Conochilus dossuarius in the summer of 1884. [A curious habit which this genus has in common with Brachionus is that of carrying the eggs, after they are successively discharged, until the young burst the shell. These are nearly circular (absolutely so as often presented to the eye), very large in propor- tion to the animal, each connected by a highly elastic thread to the hindmost part of the lorica, between its two terminal points. This thread can be lengthened or shortened at the will of the animal, and this in a surprising manner ; for by very careful observa- tion I perceived that, in elongating, the slender elastic thread was actually projected, the egg of course being inert, and nothing pulling or even touching it. And to a surprising extent; for I have seen the thread to equal in length the longer diameter of the egg. The front edge of the lorica rises to a rounded projection dorsally, and two of less eleyation laterally; these latter appear to be separated by a shallow sinus pectorally. The mastax is small, the trophi formed on the pattern seen in Pterodina, an incus with small fulcrum and quadrantiform rami, and with obsolescent mallei. I have seen re- traction of the anterior parts to such an extent that the foot of the incus was very nearly at the bottom of the visceral cavity.—P.H.G.] Length, =}, inch. Habitat. Near Birmingham (T.B.): rare. Family XVIII. BRACHIONIDA. [Lorica box-like, open at each end, generally armed with anterior and posterior spines ; foot long, excessively flexible, wholly retractile, wrinkled, ending in two toes. Genus BRACHIONUS, Ehrenberg. GEN. CH. Lorica without elevated ridges, gibbous both dorsally and ventrally ; foot very flexible, wniformly wrinkled, without articulation, toes very small. Lacustrine and marine. This genus contains Rotifera mostly of large size and of showy appearance, being inclosed in glassy shells of regular outline, adorned with symmetrical projections, and always presenting a broad surface to observation. They have been favourites with observers from the dawn of microscopy; and they are still. Fortunately most of the species are common and easily accessible. The form of the foot is peculiar; it is a long BRACHIONID. 117 and thick muscular tube, very transparent, covered with minute and close wrinkles, full of muscles, which admit of rapid protrusion and retraction, and of motion in all direc- tions, with amazing flexibility (so that I have actually seen it tied in what, for the moment, looked like a knot!). The toes,—so small and apparently feeble,—have con- siderable power of grasping. They are sometimes used as a pivot on which the animal revolves. The mutual relations of the sexes are very distinct ; as I have shown in detail in my Memoir ‘On the Dicecious Character &e.” (Phil. Trans. 1856). The female carries the excluded eggs attached to her body till they are hatched. The distinction of the species rests mainly on the number, dimensions, and relations of the spines. Yet recent observations on B. pala throw doubt on the validity of such characters.—P.H.G.] B. pata, Ehrenberg. (Pl. XXVII. fig. 8; and Pl. XXVIII. fig. 3.) Brachionus pala . n 0 6 Ehrenberg, Die Infus. 1838, p. 511, Taf. Ixiii. fig. 1. on amphiceros n p 7 Die Infus. 1838, p. 511, Taf. lxiii. fig. 2. ” polyacanthus . ° Cohn, Sieb, u. Koll. Zeits. Bd, xii, 1863, Taf. xxii. fig. 4. “A amphiceros : ; Plate, Jenatsch. Zeits. f. Natur. 1885, p. 65, Taf. ii. figs. 22-24. SP. CH. Lorica thin, smooth, transparent ; with four, long, sharp, occipital spines. B. pala has a colourless, smooth and transparent lorica, armed with four long spines in front, but unarmed and rounded off behind. The lorica is flexible, and generally dragged-in a little on either side, round the attachments of the long dorsal muscles. The opening for the foot is a mere slit, through a pap-like protuberance at the end of the lorica; and its sides can be brought close together when the foot is withdrawn. The animal’s internal organization is very like that of B. rwbens, which has already been so fully described in Chapter I. that, beyond a reference to Pl. A, vol. i., and Pl. XXVII. fig. 3, only a few points require notice. The mastax is very large ; and so are the trans- parent vesicles which are seated on it on the ventral side, and may possibly be salivary glands. By transmitted light they show only two curved lines (their outer bounding walls) rising from the mastax to the head. The gastric glands are stalked, as in B. rubens, but the stalks are generally hidden behind the broad triangular ends of the glands.! The vascular system is very conspicuous, and the five tags on each side can be readily found. I once obtained an admirable view of the top of a vibratile tag, which was pointing up the microscope. It was not at all like that of Huchlanis dilatata given by Dr. Plate, and taken from the same point of view. Dr. Plate figures the summit of the tag as an oval with pointed ends. I found that of the lowest tag of B. pala to be a thin straight edge, like that of a chisel. If there be an aperture there, it must be extremely narrow. As the animal moved, the tag turned too, so as to present also the two charac- teristic appearances given in Pl. XIII. fig. 3d. Along with the undoubted specimens of B. pala were a good many of what appeared to be Ehrenberg’s B. amphiceros, with two short thorn-like spines on the lumbar regions, and two others still smaller, one on each pap-like protuberance by the foot (fig. 8c). Ehrenberg says that B. amphiceros differs from B. pala in its smaller size, in having no coronal styles, in having four sharp posterior spines on the lorica, in lacking side muscles in front, and in having four vibratile tags instead of three. Moreover he says that he could not find a dorsal antenna. Now I carefully examined these speci- mens with four posterior spines, and found them to be of the same size as B. pala, with styles on the corona, with side muscles in front, and possessing a large dorsal antenna. In fact they were the exact counterparts of pala. I may add, too, that both those which had, and those which had not posterior spines, showed, under favourable circumstances, five vibratile tags on each side. Nor is this all: for I found some specimens with two ' The lower ends of these glands are tied to threads, which are attached to the lorica just above the heads of the lateral antenne, and at their other extremities to the stomach. Mr. Gosse discovered and drew this arrangement, as well as the lateral antennw themselves, in 1850. 118 THE ROTIFERA. lumbar spines but none on the foot-paps (fig. 8d), and others with spines on the foot- paps but none on the lumbar regions (fig. 8¢); and, in all, the size and structure were the same. From this I conclude that Ehrenberg’s B. amphiceros is only a variety of B. pala. [As is also, I have little doubt, my B. don (‘‘ Ann. and Mag. N. H.” Sept. 1851.—P.H.G.] The lateral, or lumbar-spines are very variable, and occasionally reach an extravagant length, as shown in Pl. XXVIII. fig. 38, where they are nearly as long as the body of the lorica. In this specimen the spines were hollow nearly to their ends, and were, in fact, true prolongations of the body-cavity. They were, too, as flexible as the lorica, so that they could be brought all four together at the tips, or even crossed. Length. Lorica,~; inch. Habitat. Ponds and ditches: common. B. porcas, Gosse. (Pl. XXVIII. fig. 4.) Brachionus dorcas 5 . : Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 203. 9 ” 5 . : » Phil. Trans. 1857, pl. xv. figs. 15-19. [SP. CH. As B. pala; but the occipital spines longer and more slender; and the antlers curved forward ; pectoral edge undulate, with a central notch. This, too, may possibly prove only a variety of pala; but the appearance of the antlers struck me as unique ; particularly the elegant sinuous curvature, like that of the horns of the Gazelle Antelopes, which suggested the specific name. I had ample opportunities of studying it in both sexes, and in all ages, from Forest-school Pond at Walthamstow, in 1850; but I have not met with it since. The figures, in which I have delineated its anatomy in detail, will render much description needless. I could find no contractile vesicle in any specimen, but distinctly traced the lateral canals of each side to a common termination at the cloaca. An excellent sight of one of the vibratile tags, endwise, showed these organs to be attached by a very minute papilla, and to be flattened on two opposite sides (as at fig. 4d). The parent carries her eggs after exclusion.— P.H.G.] Length. Of lorica, 3, inch; width, ,; inch. Habitat. Walthamstow (P.H.G.): rare. B. urcgeouaris, Ehrenberg. (Pl. XXVIL. fig. 6.) Brachionus urceolaris . : S Ehrenberg, Die Infus. 1838, p. 512, Taf. Ixiii. fig. 3. (SP. CH. Lorica with six straight occipital spines and a deep sinus in the middle ; the pectoral edge rising slightly to the middle, whichis slightly excavate : orifice for the foot bounded by two papille. We have now species whose front is armed with six spines, usually low, but variable in height. In the present each spine is the origin of a shelly ridge, which runs for some distance down the lorica. Viewed dorsally, its outline is that of an elegant rounded cup; but, laterally, the occipital spines, and the gibbous dorsum descending below the flatter venter, destroy the resemblance. A round, or sub-square, orifice gives emission to the very agile wrinkled foot, as rapidly retracted. The lorica is somewhat scabrous. The internal organization is that common to the genus. The lateral canals begin at the highest point of the head-funnel, at the bases of the lateral spines. They pass down into close contact with the gastric glands, each of which is of great size and of retort- shape,’ and each canal has at that contact a dilatation into an oblique plexus. Before it reaches its end, it is tied to the lorica, and makes an abrupt angle, to join the con- tractile vesicle at the very neck of its discharge. Females carry, attached to the base of the foot, many small eggs which produce males, or few large eggs which produce females. (Phil. Trans. 1856, pl. xv. figs. 3-5 ; * In one specimen the gastric glands evidently merged into the substance of the lateral canals. BRACHIONIDA. 119 where the species is named rubens.) The eye consists of three cells of ruby crimson, from the edges of each of which, under sunlight, brillant reflection is seen.—P.H.G.]. Length. Of lorica, ,!, inch; total, foot and head extruded, ;\; inch. Width yj, inch. Habitat. Ponds and ornamental waters near London; Birmingham (P.H.G.): rather uncommon. B. RuBENS, Hhrenberg, (Pl. XXVIL., fig. 5; and Pl. A.) Brachionus rubens = 7 Ehrenberg, Die Infus. 1838, p, 513, Taf. Ixiii. fig. 4. [SP. CH. Nearly as the preceding, but the occipital spines have the form of saw- teeth, sloping inward ; and of the pectoral edge the central elevation is more marked. Thave strong doubts whether B. wrcecolaris and B. rubens are specifically distinct. Very different individuals may, indeed, readily be presented ; but a series do certainly run into each other. Considering them for the present as distinct, I refer to the figs. on Plate A, and its explanation, in which it has been selected for illustration as typically representing the organization of the whole class. In examples which we may call more characteristically vubens, we may see the gastric glands in a very peculiar condition ; each consisting of two sacs, quite distinct, each separated by a long duct, and the mner one leading by a duct to the esophagus, while the outer is manifestly united with the lateral canal. Then the canals themselves form several distended sacs with necks, just before they enter the contractile vesicle, which is here unusually small, for the genus.—P.H.G.] Length and Habitat. As the preceding. B. Miurert, Ehrenberg. (Pl. XXVII. fig. 7; and Pl. XXX. fig. 8.) Brachionus Miillert . 4 C Ehrenberg, Die Infus. 1838, p. 513, Taf. Ixiii. fig. 5. y hepatotomus« : Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 203. [SP. CH. The occipital spines reduced to low saw-teeth, much wider than high, with their outer edges sinuate; the pectoral line nearly straight, notched into round lobes. Marine. This is a very fine, elegant, and attractive species; and its marine habitat at once distinguishes it. I obtained it on the Essex coast six-and-thirty years ago; and recently Mr. Hood has sent it to me in abundance from tide-pools in the Firth of Tay, and Mr. Brightwell from Norfolk. It is a good traveller and lives long in small phials. I have had it in abundance in my own marine aquarium. Each gastric gland is a great sac divided nearly to its base, so as to appear two; and these vary greatly in shape and in relative size. They are very distinctly connected with the lateral canals. Both male and female eggs are carried, and males are pro- duced in abundance. The middle of the body in this sex is occupied by the spermatic sac, a great pyriform vessel connected by a bottle-like neck with the head-mass. On pressure this sac is seen to be full of bodies having a vermicular motion; and, on the pressure being continued, it bursts, freeing about thirty spermatozoa of unusual size, each being s}, inch long, a slender body merging into a long whip-like tail which maintains a quivering undulatory motion for several minutes after exclusion.—P.H.G.] Some fine specimens sent to me by Mr. J. Hood enabled me to make a drawing of the ventral aspect of this Brachionus (Pl. XXX. fig. 8), and to add a few notes to the above. The transparent vesicles which embrace the buccal funnel, and, resting on the mastax, reach up to the head, are here unusually large and conspicuous. The lateral antenne can le readily seen protruding the tips of their heads from a dent in the lorica on either side just below the gastric glands: they are here, as is often the case, attached also to the floccose investment of the lateral canals, and their nerve-threads are obyious. 120 THE ROTIFERA. On the dorsal surface it is easy to bring into view the four bases of the muscles which work the foot; and which show as four spots nearly in a line crossing the lorica where it first begins to lessen in width. Length. Lorica, y}, inch; width,,}, inch. Habitat. Sea-water. Essex and Norfolk coasts; Firth of Tay (P.H.G.; C.T.H.): common. B. Baxert, Hhrenberg. (Pl. XX VII. fig. 8.) Brachionus Bakert 5 G 3 Ehrenberg, Die Infus. 1838, p. 514, pl. Ixiv. fig. 1. oA rr : ; Gosse, Phil. Trans. 1857, pl. xv. figs. 11, 12. (SP. CH. Occipital spines six, the intermediate pair almost obliterate ; the pectoral line nearly level, wundulate ; behind two large lateral spines, and two smaller bounding the orifice for the foot. Lacustrine. This species has been dedicated to an early English microscopist; and it is both named and figured in Adams’s great work on the Microscope, published just a century ago. It is a common species, and from its elegant form and ample breadth very attrac- tive. Individuals differ much in the length, stoutness, and direction of the spines; the hind lateral pair being sometimes bent inward. The ventral surface is marked with minute granules, which are arranged in a pattern of some regularity. The gastric glands are again large, retort-shaped, with long necks, and are in contact, if not in union, with the lateral canals, which open into a small contractile vesicle at its cloacal end.— PEE G3 Length. Of lorica, ,!; inch: width, ;4;. Habitat. Fresh waters around London, and widely spread (P.H.G.) : rather common. B. ANGULARIS, Gosse. (Pl. XXVII. fig. 4; and Pl. XXX. fig. 9.) Brachionus angularis . 5 : Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 203. ” ” . ; 2 » Phil. Trans. 1857, pl. xv. figs. 13, 14. (SP. CH. Occipital spines reduced to slight undulations, with a slight (usually) rounded sinus in the middie; pectoral edge nearly straight; hind extremity with two short, blunt processes ; outline more or less angular. The figure, jutting out into blunt angles, though characteristic, is not absolutely invariable ; for I have seen a specimen whose dorsal outline was as regular as that of urceolaris. I first found it in the pond at Walthamstow in 1849; then in the orna- mental water at Kensington Palace; and on many occasions since; often associated with B. pala. The parent carries both male and female eggs to the hatching. The male I have described and figured elsewhere. I haye seen the sexual coitus. The internal structure presents nothing notable. Itis of lively, restless manners.—P.H.G.] The highly-arched dorsal surface of the lorica is not only facetted (as I have shown in Pl. XXX. fig. 9) but is carved out into curious hollows that are well seen in Pl. XXVIL. figs. 4, 4a, which drawings I made from an empty lorica of unusual beauty. The ventral plate is quite overlapped by the dorsal, which hangs down all round it; so that the ventral surface, taken as a whole, is concave, although its middle portion is convex. Nothing is easier than to clip the creature gently by its sides, so as to be able to look into the ventral hollow ; and then, with dark-field illumination, and the binocular, the true shape of this curious lorica can be seen at a glance. A side view shows also the very stout, wide-based dorsal antenna ; which, as usual, plays in the hollow between the occipital spines. The lateral antennw are well worth notice. The tip of each rocket-shaped head lies at an aperture in the lorica (Pl. XXX. fig. 9) which has, raised round it, a small chitinous ring ; through which the brush of setz can be seen to protrude BRACHIONIDA. 121 (Pl. XXX. fig. 9a). This is a little advance on the structure in Notews quadricornis, in which Rotiferon two distinct circular perforations, with smooth edges slightly raised above the general level of the lorica, give passage to the antennal brushes. Length. Of lorica, 3}, inch. Habitat. Near London ; Birmingham ; Dundee (P.H.G.) ; Clifton (C.T.H.); pools of fresh water: not uncommon. Genus NOTEUS. GEN. CH. Lorica facetted, and covered with raised points ; gibbous dorsally, flat ventrally ; foot obscurely jointed ; toes moderately long ; eyes wanting. N. QUADRICORNIS. (Pl. XXVIII. fig. 5.) Noteus quadricornis 0 . é Ehrenberg, Die Infus. 1838, p. 503, Taf. Ixii. fig. 1. 5 9 é é Leydig, Ueb. d. Bau d. Rdderth. 1854, p. 53, fig. 41. " “1 + a : Eckstein, Sieb. wu. KGll, Zeits. Bd. xxxix. 1883, p. 394. a a ‘ 5 Plate, Jenaisch. Zeits. f. Natur. Bd. xix. 1885, p. 65. The lorica of this handsome creature, the sole species of the genus, consists of two saucer-like plates; the dorsal one convex, facetted, and stippled; the ventral concave all round the edge but bulging in the middle, stippled and not tesselated. The front of the ventral plate is a concave circular segment with a minutely serrated edge, and the front of the dorsal plate has a similar, but unserrated, edge, with its outline broken by two projecting strips of the lorica which curve gradually over the head. At the hind end, the lorica is armed with two long, and nearly straight spines, widely separated by a straight edge set with a row of minute dots. The passage for the foot is a deep funnel-shaped cavity at the bottom of the ventral surface, covered by a loose flexible skin attached to its lower, inner edge, and also to the foot. The head is something like a broad and very thick basin. Seen from above, it shows the sides as circular lobes, con- nected on the dorsal side by an arched ridge. Its central hollow is small, and is laid open on the ventral surface bya V-shaped gap. The edges of the gap bear stout cilia, and there is a fan of similar cilia on the centre of the arched ridge connecting the circular lobes. On each side of the corona, apparently on the edges of the circular lobes, is a pimple bearing one or two styles. The rest of the corona is edged with ordinary cilia. The foot has three feeble false joints, and two rather long and sharp toes, which have the usual power of adhering to glass; though the two dusky objects running down its whole length are, I think, muscles for moving the toes, and not secreting glands. The mastax has a high position, and the trophi are weak examples of the sub-malleate type. The gastric glands are of unusual size and shape. They spread out like fans up into the extreme front corners of the lorica, and appear to be thin and delicately corrugated. They are joined to the apex of the stomach by long ducts. Just below the mastax there are small pear-shaped, and probably glandular, bodies attached by their stalks to the w@sophagus. The contractile vesicle is large, and the lateral canals and vibratile tags are very conspicuous; the canals edging the lorica all round down to the base of each hind spine. In the individual shown in fig. 4, a narrow ovary had one ovum beginning to form near its smaller end; and below this ovum lay, in wrinkles, the empty pointed end of the ovisac. The side muscles for mov- ing the head, a pair on each side, are unusually stout and obvious; the others are much as in Brachionus. A small heart-shaped nervous ganglion, with its broad end down- wards, lies on the occiput between the frontal horns ; and, seated on it, sloping down- wards, is the conical sheath of the short dorsal antenna, whose tip just emerges at the base of the gap in the lorica between the horns. Dr. Plate (loc. cit.) has seen two 122 THE ROTIFERA. lateral antenne protruding from small orifices on the dorsal surface of the lorica: one on each side, between the edge and the five-sided facets on the centre of the back.? This is a bottom-haunting creature; and, in my experience, not a very common one. When captured it betrays its presence by its slow gliding motion, trailing foot, and white lorica: a whiteness due to the minute dots of chitine with which it is frosted. Happily the lorica is very thin, so that it is easy to see the viscera, in spite of the ridges, facets, and frosting. Length. Of lorica, 2, inch. Habitat. Ponds and ditches, near London, (P.H.G.); Clifton (Mr. Brayley ; C.T.H.); Birmingham (Mr. Bolton junior): not very common. Family XIX. ANURHADA. [Lorica box-like, broadly open in front, behind open only by a narrow slit; usually armed with spines, or clastic sete ; foot wholly wanting. The genus Anurea of Ehrenberg, already extensive, and now augmented by many new species, ought to constitute a distinct family, very different in form, structure and habit from the Brachionide; and including several genera. The body is inclosed in a compact box-like lorica, open in front and rear. They have no foot, and therefore are incessant swimmers, never resting. The trophi differ from those of the Brachionide in that the manuwbria, though usually clubbed, never take the expanded semi-circular shape. The cilia, too, are not set around a two-flapped corona, but on three large eminences, each of which terminates in a globose lobe, crowned with stout sete. One eye is conspicuous, cervical. They are both marine and lacustrine.—P.H.G.] Genus ANURZA, Gosse, nec Ehrenberg. [GEN. CH. Lorica an oblong box, open widely in front, narrowly in rear; dorsal surface usually tesselated; the occipital edge always, the anal sometimes, furnished with spines ; the egg after extrusion is carried atiached to the lorica. Lacustrine.—P.H.G.] A. cuRvIcorNIs, Ehrenberg. (Pl. XXIX. fig. 9.) Anurea curvicornis . = ° Ehrenberg, Die Infus. 1838, p. 505, Taf. Ixii. fig. 5. (SP. CH. Loriea oblong, rounded behind, tesselated, armed with six occipital spines, of which the middle pair are procurved ; no spines behind. Of the tesselations, the medial row alone is perfect, of five facets; the posterior three are hexagons, the next square, the foremost an incomplete hexagon. From the lateral angles other ridges proceed laterally, forming other polygons, which are usually evanescent. Of the spines, the central pair (antlers) are strong, and curved forward, sometimes mutually approaching, sometimes receding. The lateral pairs are short, straight and pointed. From the outmost pair descends a prominent ridge on each side, making a sharp lateral edge to the lorica (fig. 9a). The eye is very large and brightly conspicuous; the mastax is a wide oblate spheroid, with mallei and incus well developed. A wide sacculate stomach follows, crowned with normal gastric glands, and descending with no distinct constriction to the hind end of the lorica, where there is a small orifice, through which I have seen the rectum protruded for a short distance, and then retracted. There is an ample contractile vesicle. The three main lobes of the rotatory organ are large and prominent when in action, each bearing a great round fleshy papilla, besides a smaller one on each side; each carries a divergent fan or brush of stout sete. The 1 I missed these in the living animal, but, afterwards, found the apertures (fig. 5a, a’) easily in an empty lorica, in the spots mentioned by Dr. Plate. ANURAADA. 123 cilia produce vortices, but not wheels. A curved tubular antenna, with terminal bristles, issues from the sinus between the antlers. This pretty species occurred by myriads in one of my garden pans near London in the autumn of 1849; and I met with it again in the watering pond on Hampstead Heath; but I have no record of it since. A great Bursaria, as well as Asplanchne, feeds voraciously upon it. It swims giddily, to and fro, with some swiftness.—P.H.G.]} Length, ,}, inch. Habitat. Near London; Birmingham (P.H.G.): not rare. A. HYPELASMA, Gosse. (Pl. XXIX. fig. 6.) Anuraa fissa . 5 . 5 Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 202. [SP. CH. Lorica withowt spines, consisting of two plates, the dorsal arched, the ventral flat, commensurate ; and widely cleft through its medial line. When I obtained this species, in 1850, I could not satisfactorily determine the character of its ventral plate; but subsequently, on many occasions, and with great precision, I saw that it is a thin flat plate, of the full width, apparently connected with the dorsal only by membrane. It is, moreover, divided down the middle by a fissure of varying width ; I have even seen the pectoral edges of the fissure overlapping. These peculiarities, combined with the straight transverse occipital edge, might almost entitle this species to generic separation. The egg is (proportionally) of vast size, nearly half as large as the whole animal; and not symmetrical, for, from the side at one end, projects a nipple, by which it remains attached to the parent. One I saw hatched. The young escaped at the part where the pedicle was, head foremost, rotating freely. It was exactly like the parent, and fully three-fourths of its size. There is evidently an anal orifice, whence frequently protrudes a very delicate membrane (doubtless the rectum), with its end expanded and recurved (fig. 6). When the rotating front is retracted, there are seen two shelly lobes rising from within the lorica, which approach to contact, and thus protect the head (fig. 6a). The internal structure is normal. Some specimens were thickly infested with a minute Infusorium (Colaciwm ?).—P.H.G.] Length, ,}, inch. Habitat. Near London; Leamington; Stapleton Park, York- shire; Dundee; Torquay (P.H.G.): rather common, A. TEcTA, Gosse. (Pl. XXIX. fig. 10.) Anuraa tecta . 5 0 ° ° Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 202. [SP. CH. Nearly as curvicornis, but more pointed ; and the tesselations are larger, and arranged on each side of a mesial dorsal ridge, which gives to the back the form of a vaulted roof. Of this pretty little species I have slight record. The arrangement of its facets suffi- ciently distinguishes it. It is high and nearly circular in transverse section. One that I saw carried a large ege-shell.—P.H.G.]} Length, 5}, inch. Habitat. Near London; Birmingham (P.H.G.): rare. A. acuLEeata, Ehrenberg. (Pl. XXIX. fig. 4.) Anurea aculeata . “ : : Ehrenberg, Die Infus. p. 508, Taf. Ixii. fig. 14. y brevispina. - 5 5 Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 202. [SP. CH. Lorica oblong-square in outline, slightly arched dorsally, flat, or concave, ventrally ; the normal occipital spines six, of which the antlers are procurved ; each of 124 THE ROTIFERA. the two posterior angles produced into a slender straight spine of varying length ; sur- face minutely punctated, and hexagonally tesselated. The form of this very abundant species exactly resembles, whether viewed from the back or side, that of a wicker hand-barrow familiar in some parts of the country. When the empty lorica is seen, it is a beautiful microscopic object. The rotating head, and whole internal organization agree with those common to the genus. It swims rather swiftly, in a peculiar style, continually revolving, both on the long and the trans- verse axis, throwing perpetual somersaults. Its irregular plunging and rolling strongly remind me of the motion of a ship in a heavy sea. My A. brevispina (loc. cit.) (Pl. XXIX. fig. 5) is, I feel assured, only a var. of this species, with the spines degenerate, and the puncturing nearly evanescent. Ehrenberg’s A. testudo and A. valga will, I think, fall into the same category.—P.H.G.] Length (including spines), y+; inch; width, ;45 inch. Habitat. Pools and lakes (P.H.G.): very common. A. COCHLEARIS, Gosse. (Pl. XXIX. fig. 7.) Anurea cochlearis . 5 : o Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 202. [SP. CH. Lorica spoon-shaped, ending behind in a straight slender spine ; the back ridged and tesselate, as in A. tecta. This bears the same relation to A. stipitata, Ehr., as A. tecta bears to A. curvi- cornis; differing from stipitata by the roof-like back, and the mesial division of the facets, which latter (as shown in Ehrenberg’s figures) are decidedly of the hexagon pattern. The outline, too, of stipitata is that of a broad, or even triangular shovel ; whereas that of cochlearis is decidedly spoon-shaped, broadly ovate. It is delicately punctate or stippled. The protrusile front is very ample; a great chin of two fleshy lobes is seen sidewise, besides the lateral and frontal lobes. The eye is manifestly on a lens, which sparkles in focusing, like a gem, but pale in hue. An egg of enormous pro- portions is carried before the caudal spine, reaching nearly to the chin. The spine varies much in length, from a mere tubercle to equal length with the lorica-body. The species is not uncommon in clear waters, often associated with Asplanchna, of which it forms a common article of food. I have taken an Asp. priodonta with an An. cochlearis in its stomach, which, after an hour or two, was ejected, and instantly swam about, as lively, and apparently as wninjured as ever !—P.H.G.] Length (including spines), ;}5 to 735 inch. Habitat. Clear ponds and lakes (PAE Gai: common. A. serrunata, Ehrenberg. (Pl. XXIX. fig. 8.) Anurea serrulata . O - 5 Ehrenberg, Die Infus. 1838, p. 508, Taf. Ixii. fig. 13. [SP. CH. Lorica oblong-square, much as the shorter-spined forms of A. aculeata ; dorsally tesselate with hexagons, except that the hind row of facets are two great poly- gons mesially divided ; ridges serrate ; both surfaces punctate. The most prominent character of this species is its extreme roughness, the edges of all the facet-divisions, and the back of every spine being jagged with minute round excavations, which stud every part of the surface. I have counted about seventy punctures in one facet. This roughness varies in degree. The antlers are often greatly developed in stoutness, length, and curvature: the hind spines are sometimes nearly obliterate. The pectoral edge makes two arches (each with an intra-marginal line) with a notch between them. The viscera sometimes protrude in a globose form beyond the end of the lorica: I think this is when the contractile vesicle is filling. The frontal lobes take the form of three short cylinders, each with its fan, of vibratile sete ; each of ANURMADA. 125 the lateral pair projects from the midst of a much thicker cylinder. There are two square antenne. The eye is large, sparkling in sunlight, and refractile.—P.H.G. | Length, ;!,inch. Habitat. Near London; Birmingham; Dundee (P.H.G.): common. Genus NOTHOLCA, Gosse, gen. nov. [GEN. CH. Lorica ovate, truncate and six-spined in front, sometimes produced behind ; of two spoon-like plates united laterally ; no hind spines ; dorsal surface marked longitudinally with alternate ridges and furrows ; expelled egg not wswally carried. Lacustrine and marine. The genus thus indicated may include the species biremis, striata, inermis (young ?), acuminata, and foliacea (2) of Ehrenberg, together with others, which appear to be hitherto undescribed.—P.H.G. | N. acuminata, Hhrenberg. (Pl. XXIX. fig. 3.) Anur@a acuminata - - 5 Ehrenberg, Die Infus. 1838, p. 506, Taf. Ixii. fig. 9. (SP. CH. Lorica produced behind into a long truncate point, spoon-shaped ; ven- tral plate concave, one-third shorter than the dorsal. The form is very elegant. Of the frontal spines the antlers are nearly straight, the laterals moderately long, the intermediaries very short. From their six points, and from their five interspaces, run strongly marked lines throughout the lorica, of which the former are elevated, the latter depressed angularly. The junction of the ventral plate is about one-third from the point where the cloaca opens. Here two muscle-threads are affixed, connected with the rectum, which they draw down. An ample contractile vesicle receives on each side a conspicuous branchial duct, which in some parts is slender, in others much expanded and corrugated, including many vacuoles, and carrying two vibratile tags each. A remarkable structure is seen in apparent connection with these organs, which recalls the pyriform sacs seen in Pterodina. The esophagus is long, and attached to it on each side is a small vessel which seems the ordinary gastric gland. But somewhat behind these are seen a pair of sacs, connected with the stomach on each side, and each giving off two threads, by one of which it is fastened to the liming mem- brane of the lorica, while the other runs down for some distance parallel with, and close beside, the tortuous vessel (branchia ?), and is then attached to the interior, where two remarkable shelly bosses are seen. The stomach itself is tied to the lorica by threads, which are probably museular.—P.H.G.}. Length, ,!; inch. Habitat. Ornamental waters near London (P.H.G.): very rare. N. tonaispina, Kellicott. (Pl. XXVIIL. fig. 6.) Anurea longispina . : . = Kellicott, Amer. J. Micr. iv. 1879, p. 20, with fig. ” ” . : : ; (Abstracted) J. Roy. Micr. Soc. ii. 1879, p. 157, with fig. aS ay > 5 3 . Levick, Midland Naturalist, ii. 1879, p. 241, 1 pl. - spinosa. 6 7 5 Imhoff, Zool. Anzeig. Sept. 1883, No. 147, with fig. SP. CH. Lorica greatly produced behind so as toresemble a frontal spine ; dorsal and ventral plates commensurate ; of the six occipital spines the central pair consists of one very long curved spine, and of one aborted straight spine; the lateral pair, of two long, and curved ; and the remaining pair, of two short, and straight ; the ventral plate has a movable flap with a straight pectoral edge. Notholea longispina does not readily lend itself to any theory on the cause of an 126 THE ROTIFERA. animal's form; as it is hard to see how its extravagantly long spines can be of much service to it. They evidently forbid its approach to the conferve and floating rubbish that are the favourite haunts of its class, under penalty of being probably anchored for life to the same spot; and they can scarcely serve as floats, for the animal is a heavy swimmer, as if overburdened with these great projections, and is usually found four or five feet below the surface. Neither can they be very serviceable as weapons of defence, for even the fry of a gudgeon would soon learn to snap it sidewise. At any rate it isa most interesting form, and though rare and impatient of captivity it is easily managed in the compressorium, as it can be firmly yet lightly held by its long curved spines without injury. The lorica is triangular in outline, the dorsal surface convex both lengthwise and across, the ventral slightly concave and rather more sharply curved as it approaches the hind end. Six spines spring from the anterior edge of the lorica. Two are lateral, and are continuations of thickened ridges running part way down the edges where the dorsal and ventral surfaces meet. They are equal in size, taper to a point, and curve first outward and then upwards and inwards. Then, on either side of the median dorsal line is a strikingly unmatched pair. One, the largest of all the six, is stout at the base, tapering to a point, and curved first downwards and then upwards, with a graceful sweep. The other is an abortive looking spine, of uniform thickness, about one-fifth of the length of its partner. In the gap between these two lies the dorsal antenna ; and, as this antenna is exactly on the median line, it follows that the longest spine is not in the middle of the lorica (as it has been hitherto drawn '), but slightly on one side of it. There is yet another pair of spines, of equal length, considerably shorter than the lateral spines, and lying one on each side between the dorsal and lateral pairs. The hind end of the lorica flows off into yet another tapering spine curving downward and then upward, like the longest; and, with it and the body, presenting on a side view an elegant sigmoid curve. At the top of the ventral surface the lorica has a square flap, which can move, as on a hinge, to permit the head to come out, and which closes over it, when it is with- drawn. There is also a slit, like a trap-door at the hind end of the ventral surface, through which the cloaca is emptied. All the front spines are rough, but the hind spine is smooth. The corona has a thick dorsal wall crowned with ciliated eminences, and surrounding a deep cavity leading to the buccal orifice. This cavity is thrown open on the ventral surface by a scalloped V-shaped slit; avd is guarded at each side on the top by two teat-shaped protuberances armed with stout vibrating styles. All the edge of the corona is ciliated, and so are the edges of the ventral slit, at the bottom of which hes the buceal orifice. The mastax with its sub-malleate trophi is close to the buccal orifice. There is a distinct esophagus bearing two stalked glands below the mastax, and a cluster of rather larger glands just above the stomach. The gastric glands, stomach and intes- tine require no notice. A contractile vesicle lies just below the latter, close to the cloaca ; the lateral canals and vibratile tags are conspicuous. The muscular system is like that of B. rubens (i. p. 8); and it is curious to see how, owing to the flexibility of the loriea, the longitudinal muscles can draw together all the frontal spines. As these are really continuations of stout chitinous ridges in the lorica itself, the approaching spines, with the flexible lorica folding up between them, look exactly like a closing umbrella. My specimens died before I had seen the nervous ganglion; but there is a dorsal antenna, protruding between the longest and the abortive spine when the head is expanded, and pulled in when the head is withdrawn. The adult had a single red eye, at the lowest part of the occiput, near the dorsal surface. Mr. Levick says that many of the first specimens that he found had two eyes; and that he thinks these animals were young ones. It would be very curious should it prove to be the case that two eyes in the young approach with age, and coalesce in the adult; especially as Brachiont 1 Dr. Kellicott, Mr. Levick, and Dr. Imhoff, all place the largest frontal spine exactly on the median line of the lorica, and half-way between two small spines ; I am satisfied that this is a mistake. Dr. Imhoft’s figure shows four small frontal spines besides the three long ones: this also is wrong; there are only three, the abortive spine and a pair. ANURZAD. 127 have an eye which has every appearance of being a coalesced pair. The extruded egg is carried on the ventral surface just above the hind spine. Dr. Kellicott discovered this fine Anwr@a in Niagara water at Buffalo, and soon after Mr. Levick found it in Olton reservoir. I am indebted both to Mr. Levick and Mr. Dunlop for many living specimens, and to Mr. Levick also for several mounted. Length. Total, 4, inch; of longest spine, ;1, inch. Habitat. Buffalo, U.S. (Dr. D. 8. Kellicott) ; Birmingham (Mr. J. Levick) ; Greenock (Mr. M. F. Dunlop). N. THALASSIA, Gosse, sp. nov. (Pl. XXIX. fig. 2.) (SP. CH. The two lorica-plates commensurate ; dorsal arched, long-ovate in out- line ; ventral, with pectoral edge straight. Marine. The antlers and lateral spines are moderate, nearly straight and sub-equal: the intermediate pair mere tubercles. The pectoral edge has no conspicuous unevenness. The lorica is scarcely changeable in outline, as if it were stiff and unyielding. Yet the shelly substance merges so insensibly into thin and evanescent membrane at the hind end (where a very delicate membrane, like a truncate tail [rectwm ?] is protruded), that we cannot determine the point of transition. The form and lobes of the front, and the array of fan-like sete; the brain and great eye; the mastax and jaws; and the abdominal organization, do not notably vary from what we see in Anurea. The broad protrusile and retractile membrane at the cloaca excretes mucus for temporary anchorage. One which I saw foreing its way through thick clusters of diatoms, emerged with several of them glued to its rear, which were then detached with some difficulty. In free swimming it is headlong and rapid, and very restless. In one example the intestinal canal was full of the frustules of diatoms. It is exclusively marine —P.H.G. } Length, ;}, inch. Habitat. Tide-pools in the Firth of Tay (P.H.G.) : common. N. scAapHA, Gosse, sp. nov. (Pl. XXIX. fig. 1.) [SP. CH. Lorica nearly as broad as long ; dorsal plate greatly exceeding the ventral in width ; pectoral edge sinuate. Marine. ; : The transverse outline is highly rounded, resembling the half of an ege-shell, far within the margins of which a flat (ventral) plate is fixed across the cavity, leaving wide overhanging edges. The lorica is very flexible, so that, when the fore-parts are forcibly retracted, the dorsal outline suddenly appears perfectly circular, except at its spinous front edge, and then bears much resemblance to that of a Brachionus. The cloacal orifice is a very short and thin fissure at the extremity, and does not extend sensibly up each side. In swiftly swimming, the wide but thin wing-like expansions of the dorsal plate are very conspicuous by their glassy clearness, and by their peculiar form, especially when seen end-wise ; and this gives a very distinct aspect to the species, which is more than usually attractive. When alarmed it suddenly retracts with a snap; and if it happens to be presented sidewise at the moment, the frontal spines close with the sinuous pectoral edge, so as to cross and interlace. I saw one eagerly feasting on an Actinophrys, and watched it for half-an-hour. At first the frontal cilia worked energetically at it, gradu- ally drawing it into the open front of the lorica, and holding it there. But the jaws were not applied to it; and it seemed as if the ciliary action alone were drawing off invisible gelatinous juices into the buccal funnel. Yet, when at length the Notholca relinquished its hold, the prey seemed uninjured. The species has been sent me by Mr. Hood, associated with the preceding, in sea-water from the estuary of the Tay. - P.H.G.] Length, ;}, inch. Habitat. Firth of Tay (J.H.). 128 THE ROTIFERA. Genus ERETMIA, Gosse. [GEN. CH. Lorica neither tesselated nor ridged ; destitute of spines proper, but furnished with long attenuate rigid bristles. This seems to be a natural group, containing numerous species. They appear to be destitute of the spines common to Anurea, pointed extensions of the lorica itself; for the slender appendages are quite different in form, and probably in function.—P.H.G.] EK. PENTATHRIX, Gosse, sp. nov. (Pl. XXIX. fig. 12.) (SP. CH. Five long bristles projected from the lorica ; one dorsal and two from each side: no frontal or posterior spines. This species I know only from a single dead and empty lorica which I found in the sediment of water, dipped in June, from a pool at Sandhurst, Berks, by Dr. Collins. The lorica is ovate, truncate in front, with no spines of the ordinary pattern, but bearing attached to the medial line of the dorsum a long stiff seta, or attenuate spine, the base of which is deep but very thin, the depth gradually diminishing. From the sides, about two-thirds down, spring a pair of similar bristles of less basal depth; and, at a short distance from the round extremity of the lorica, another pair. All radiate from the surface of the lorica, and are consimilar in length and tenuity. No trace of the mternal organs was left. This has evident affinities with the A. biremis of Ehrenberg, which he describes from a single specimen obtained in the Baltic Sea. That species, however, has four frontal spines.—P.H.G. | Length, unrecorded. Habitat. Pool near Sandhurst Mil. Coll. (P.H.G.): very rare. Ki. CUBEUTES, Gosse, sp. nov. (Pl. XXIX. fig. 11.) [SP. CH. Lorica bag-like, round behind, truncate before; with a diverging seta from the dorsum and one from the venter ; four straight spinous processes from the rounded end ; the whole surface cut into cubical tesserae. This minute and very curious form I place in the genus Hretmia, though the body processes seem rather spines than set. I have found it, but only as a dead lorica, on two separate occasions, and in water from widely distant localities; but Mr. Hood has since found it living, and sent me a good drawing of it, which well agrees with my own. All were in autumn and winter of 1885-86. The lorica edge is not spined, but notched. Yet the notches are but the intervals between the tessere of the front row, of which three are seen beside the lateral two. For the entire surface of the lorica is marked with two series of depressions, those of each series parallel to each other, but the two series crossing each other at right angles (or nearly); so as to leave a multitude of square tessere, or cubical knobs,—like dice set corner-wise :—a form of surface quite unique, so far as I know. I was, indeed, dis- posed to think it an Arcelline Infusory of the genus Diflugium, till I received Mr. Hood's report, which showed it a true Anuread. He describes the rotatory front as bearing the normal three great ciliate lobes. The large red eye I had myself seen.—P.H.G.] Length (including spines), 31, inch (P.H.G.); 5}, inch (Hood). Habitat. Birming- ham (P.H.G.); Black Loch, Dundee (Hood): rare. @EVAPA ER, Xa RARARAR ARR Rn SCIRTOPODA. Cetera de genere hoe mirande multa videmus, Que violare fidem quasi sensibus omnia querunt: Nequidquam; quoniam pars horum maxima fallit Propter opinatus animi quos addimus ipsei Pro visis ut sint, que non sunt sensibus visa. Nam nihil egrius est quam res secernere apertas Ab dubiis, animus quas ab se protinus addit. Lucretius, De Rerum Natura, Lib. iv. 1. 464, The life of the brute has commonly one immense compensation in its favour; the perfection of the individual existence is so rarely sacrificed to the prosperity of the race. It is not necessary, in order that one hippopotanims should cut his food conveniently, that another hippopotamus should lead an unhealthy existence like a Sheffield grinder; nor does the comfort of any bird’s nest require that another bird should slowly poison itself in preparing acetates of copper, sulphurets of mercury, or oxides of lead. The pride and beauty of a brute are never based upon the enduring misery of another brute. The wild drake’s plumage, splendid as it is, suggests no painful thought of consumptive weavers, of ill-paid lace- makers, of harassed over-worked milliners: and the most sensitive of us may enjoy the sight of it without painful thoughts; for it is God’s free gift, causing no heart-burning of envy, no care nor anxiety of any kind, —P. G. Hamerton, Chapters on Animals. We are then in a world of spirits, as well as in a world of sense; and we hold communion with it, and take part in it, though we are not con- scious of doing so. If this seems strange to anyone, let him reflect that we are undeniably taking part in a third world, which we do indeed see, but about which we do not know more than about the Angelic hosts ;—the world of brute animals. Can anything be more marvellous or startling, unless we were used to it, than that we should have a race of beings about us, whom we do but see, and as little know their state, or can describe their interests, or their destiny, as we can tell of the inhabitants of the sun and moon? It is indeed a very overpowering thought, when we get to fix our minds on it, that we familiarly use, I may say hold intercourse with, creatures who are as much strangers to us, as mysterious, as if they were the fabulous, unearthly beings, more powerful than man, yet his slaves, which Eastern superstitions have invented.—NEwmMan, Parochial Sermons, ‘ The Invisible World.’ CHAPTER XI. Order IV. SCIRTOPODA. Swimming with their ciliary wreath, and skipping with Arthropodous limbs ; foot absent. The fourth order, Scirtopoda, although it contains but two Rotifera, each in a genus by itself, is one of no little importance, as it is that in which the Rorirmra and Crus- TACEA most nearly touch. The true position of the Rorirera in the animal kingdom has long been a matter of keen dispute, and the chief authorities have taken opposite sides: Professor Owen, Dr. Leydig, and others, rank them among Crustacrea!; while M. Milne-Edwards, Dr. Cohn, Professor Huxley, with the majority, would consider them as VERMES. Nor is this surprising ; for the Rotirera possess many characters that are common, in various degrees, to ARTHROPODA and VERMES alike; and, so far as their nutri- tive, reproductive, or nervous systems are concerned, might with little difficulty be placed in either sub-kingdom. But there were three respects, before the discovery of Pedalion and Hexarthra, in which the Rorrrera appeared to differ from ARTHROPODA, and to resemble VERMES. These are, first, that they do not possess pairs of jointed appendages, articu- lated to the body, with muscles prolonged into their interior; and on this point great stress was laid. Secondly, that they swim by means of ciliary wreaths; and thirdly, that they possess a vascular system, with ciliated tags, whose chief function is probably a respiratory one. But the discoveries of Pedalion and Hexarthra have shewn that Rotifera exist whose internal structure is perfectly normal, and which yet possess three pairs of unquestion- ably Arthropodous limbs ; and these discoveries have in consequence disposed of the chief objection to the ranking of the RorrrmRA among ARTHROPODA. It may, on the other hand, be fairly urged that the balance of argument even now inclines towards those who are in favour of the opinion that the Rorrrmra, as a class, are nearer to VERMES: yet no one, I think, who has studied both Pedalion and the Nauplius larva of one of our fresh-water Entomostraca, would feel satisfied with their being placed in two distinct sub-kingdoms. In conclusion, I see no reason why the Rorrrera should be assigned solely to VERMES or ARTHROPODA, and I would propose to consider them as a class that links these two sub-kingdoms together.? Family XX. PEDALIONIDA. Arthropodous limbs siz ; head truncate; corona of two concave lobes ; ciliary wreath as in Plulodinade ; trophi malleo-ramate. The family contains two genera, Pedalion and Hexarthra, each containing only a single species. The two are much alike* in the possession of six Arthropodous limbs ‘ {I consider the Rorrrera a class of the sub-kinglom ARTHROPODA, co-equal in rank with Insecta and Crustracea.—P.H.G.] * Of course I am here treating the matter simply as one of formal classification ; and from this point of view it is enough to say that if we knew none but the humbler forms of the Rorrrera, we should eall them VERMES; whereas if Pedalion and Hezarthra were our only examples, we should call them the lowest forms of ARTHROPODA. * Mr. Julien Deby, in the J. Roy. Micr. Soc. 1879, p. 384, has suggested that the two Rotifera are K2 132 THE ROTIFERA. ending in fans of imbricated sets, in the conical shape of the body, and in the broad truncate corona; but they differ strikingly in the way in which the limbs are set on the body : for in Pedalion they are arranged around it parallel to its longitudinal axis, while in Herarthra, as in the Nauplius larva, they radiate from the centre of the ventral surface. Nor is this the only difference. Hexarthra’s limbs are in three graduated pairs, while Pedalion’s ventral limb is far longer than any of the others: moreover, Hexarthra lacks two long stylate appendages, ciliated at the ends, which are to be found on the posterior end of Pedalion’s dorsal surface. Genus PEDALION, Hudson. GEN. CH. Limbs arranged round the body in pairs, and parallel to its longitudinal axis ; two stylate, ciliated appendages on the posterior dorsal surface. P. mium, Hudson. (Pl. XXX. fig. 1.) Pedalion mirum . 5 . Hudson, Mon. Micr. J. vol. vi. 1871, p. 121, pl. xciv.; and p. 215. “4 sr : : 7 4 Quart. J. Micr. Sci. vol. xii. 1872, p. 333, pl. xix. ” se : ‘ + Mon. Mier. J. vol. viii. 1872, p. 209, pl. xxxiii. = a - 5 5 Lankester, Quart. J. Micr. Sci. vol. xii. 1872, p. 338. SP. CH. Ventral limb much the largest; dorsal limb on the median line ; lateral limbs in two wnequal dissimilar pairs ; the bases of all the limbs, lying in a transverse section dehind the dorsal antenna; their free ends terminating in fans of imbricated Sete. It was in July 1871 that Ihad the good fortune to discover this remarkable Rotiferon in a small road-side pond near the head of Nightingale Valley at Clifton. On placing a specimen of it under the microscope I for a moment fancied that I had brought home by mistake some Entomostracous larva, for its outline, its six limbs ending in fans of imbricated sete, and its habit of jerking itself through the water, made it resemble the ordinary Nauplius of a Cyclops. However, a brief examination showed it to be a true Rotiferon, with a splendid corona and with internal organs much like those of Triarthra longiseta. The external form is extraordinary ; not only has it six well-developed limbs, but all these limbs are hollow, communicating with the body cavity, and containing pairs of opposing muscles prolonged into theirinterior. The arrangement of the limbs too is more effective for locomotion than that in a Nauplius ; for in Pedalion they are attached in pairs to its anterior end, and lie parallel to the longitudinal axis of the body, so that their united stroke acts at a great mechanical advantage ; but in the Nauplius larva the limbs radiate from a spot on the ventral surface; and, in consequence of this inferior method of attach- ment, produce a very feeble skip compared with the furious rush of Pedalion. The corona is unusually large, and consists of two oval saucer-like lobes, so set as to five together a heart-shaped appearance to the head. The ciliary wreath is double, and precisely on the pattern of the Philodinade (Pl. C, fig. 3). Between the upper and lower wreath is the usual groove along which the food is conducted to the mouth. On either side the lower wreath dips down to the buccal orifice, which is prolonged ventrally into a great curved lip, fringed with very large cilia. The rather small mastax has two identical, and that the differences between my description and Dr. Schmarda’s “reside principally in the incompleteness of the details given by the latter, and are consequently differences of omission rather than anything else.” It is difficult to understand how it can be an “‘ omission” to describe and draw all the six legs as radiating from a spot on the ventral surface, while (on the supposition of the identity of the two creatures) there is only one on that surface, and all lie round the body and parallel to its length. Neither can it well be an ‘ omission”’ or an “incomplete detail” to say that there are two legs of equal size longer than all the others, when there is only one such leg. Indeed, were Dr. Scl marda really capable of the gross blunders attributed to him by Mr. Deby, the whole of his observa- tions would be worthless, PEDALIONIDA. 133 chitinous lips, which may be seen constantly advancing and receding in the buceal funnel, and apparently selecting the morsels which are allowed to reach the trophi. The cesophagus is short, and the nearly cylindrical stomach has very thick elastic walls ; in a dying specimen I have seen the food expelled, and the walls close in quite upon them- selves. The gastric glands are somewhat oval; and I think that I have seen two small stalked glandular-looking bodies attached to the wsophagus. The intestine is a broad short chamber with thicker walls and coarser cilia than those of the stomach. The two ciliated straight processes, on the hind end of the dorsal surface, have also a glandular structure and secrete a viscous fluid, by threads of which Pedalion may be found moored to algz, or to the floating masses of floccose sediment. These processes vary greatly in length in different individuals; they are always very short in the newly hatched female, and are wanting in the male. It is unusually difficult to demonstrate the vascular system, as its parts are so frequently obscured by the alimentary canal and the limbs. There are two lateral canals, each commencing in a plexus close to an eye and bearing a vibratile tag. Hence the canal runs down toa second plexus, halfway down the body, with two vibratile tags ; and, slirting the side, finally unites with the cloaca. ‘There is no contractile vesicle. The ovary requires no notice. Pedalion carries its extruded egg attached to its posterior extremity till it is hatched. Of the large oval female eggs only one at a time is so carried; the small, round male eggs are carried in clusters: the eggs of different sexes are never present together. The newly hatched female resembles its mother, and passes through no change but that of growth. The muscular system is very greatly developed. There are at least forty striated muscles arranged in pairs of elevators and depressors, not mere repetitions of each other like the muscles of a caterpillar, but very various in shape and arrangement, and obviously intended for different duties. Figs. 1d, le, 1f show these pairs very carefully drawn and, with the printed explanation facing Pl. XXX., render any detailed account superfluous. The nervous ganglion lies closely applied to the dorsal side of the buccal funnel, and has above it two eyes, widely apart and close to the surface of the corona; one in each of its lobes. ‘They are clear refractive spheres set on plates of red pigment. Nerve-threads pass from the ganglion to lateral rocket-headed antenne, one on each shoulder; and another nervous thread supplies a similar antenna which moves up and down in a protuberance on the dorsal median line (figs. la, 1b) just behind the dorsal gap in the ciliary wreath. The male (figs. 1h, 1k) is the merest caricature of the adult female. The large, shapely corona, with its flowing curves has become a ciliated knob; the six limbs, with their fan-shaped plumes, have been altered into three little stumps, with a bristle or two at the end of each; even the huge ventral limb has vanished, and the whole creature has shrunk up to barely one-fifth of the length of the adult female. It swims very dif- ferently from its mother; for it spins constantly round its own length, like a joint on a spit, while at the same time moving forward. Now and then it jerks its side limbs, and it uses them to free itself from its shell. There are two longitudinal muscles for retract- ing the head and a pair of red eyes, but I could discover no other internal organs except the testis and penis. This latter I have seen protruded to a length quite equal to that of half the animal. Length. Female, corona and body, ;4; inch; from corona to end of ventral limb, excluding sete, .~; inch: male, 51, inch. Habitat. Clifton (C.T.H.); Birmingham (T.B.); warm water-lily tank in the Duke of Westminster’s gardens at Eaton, and ponds in the neighbourhood of Chester (Mr. Thos. Shepheard): very rare. The only other Rotiferon in this Order is Hexarthra polyptera (Pl. XXX. fig. 2),! which was discovered by Dr. Schmarda in some brackish water near El] Kab in Egypt, in March 1853. He describes the body as a blunt cone with a right and left group of cilia on its broad end, The trophi resemble those of Tvriarthra. The stomach is short and broad ; the 1 Copied from Dr, Schmarda’s fig. 1, Zw Naturgesch. Agyptens, Taf. iii, 134 THE ROTIFERA. intestine is frequently constricted and narrow towards its end. The gastric glands are two lobed. He further notices the lateral canals, and a bladder-like organ which he conjee- tures to be the testicle, but which was probably the contractile vesicle. Two red globular eyes are seated in the corona, not far asunder. The mature eggs, which are green, are carried at the posterior end of the body. There are three pairs of limbs attached to the ventral surface. The foremost pair is the longest, the middle pair is less, and the lowest pair is the least. Two streaked muscles run down the first pair of limbs, and one muscle down each of the other four. All the limbs are terminated by fans of sete. H. poly- ptera does not appear to have any ciliated processes on the dorsal hind surface. ADDENDA. [ASPLANCHNA MYRMELEO, Ehrenberg (vol. i. p. 123: footnote). This interesting species is no longer an alien. Mr. Hood has lately sent me, from Dundee, living and healthy examples. They seemed to possess no contractile vesicle.-—P.H.G.] [ERETMIA TRITHRIX, Gosse, sp. noy. (Pl. XXVIII. fig. 2). Lorica a three-sided box, of which the posterior end is a triangle, and carries a long elastic seta at each angle: egg, when laid, carried between the alvine set. Length, ;45 inch. Lacustrine—P.H.G.] [EReTMIA TETRATHRIX, Hood, sp. nov. (Pl. XXVIII. fig. 1). Lorica shaped like a deep obconic wine-glass, of which the foot is represented by a very long straight seta: three similar sete stand up from the occipital margin. Length, of lorica, +35 inch; total giz inch. Lacustrine.—P.H.G.] Norommata WerneEcktl, Ehrenberg. I am indebted to Mr. Fred. Bates for some threads of Vaucheria sessilis bearing many of the galls caused by this parasitical Rotiferon. Mr. Bates says that he has found the animal in abundance inhabiting these galls, which may occur anywhere along the thread of the Vaucheria: but that he has not found the parasites in the reproductive cells (see vol. 1. p. 89). Length (according to Balbiani), 35 inch. Habitat. Neighbourhood of Leicester (Mr. F. Bates). (ictstes pryaura, Ehrenberg (Pl. XXX. fig. 8). This is no doubt Ehrenberg’s Ptygura melicerta. It has a two-lobed corona; a wide dorsal gap; no visible ventral antenne; a pair of large dorsal hooks, adnate for half their length; a stout wrinkled foot; and an irregular floecose tube. It was found last May, at Twickenham, by Mr. G. Western, who kindly sent me the living specimen, from which fig. 3 has been drawn. Its position, in one of the axils of the plant to which it was attached, prevented me from measuring it; but it seemed to be about the size of an ordinary @cistes crystallinus. The following remarkable Rotifera are as yet unknown in Britain. Banatro caztyus (Pl. XXX. fig. 6), Hd. Claparéde (15). This is an il-loricated Rotiferon, parasitic on different species of Oligocheta. Its peculiar hind extremity is shown in the figure. Mastax very small, containing two minute curved rami; stomach, simple and straight; ovary large; ciliary wreath and antenna wanting ; nervous, and vascular systems apparently absent. DrinopHaGa BUCEPHALUS (Pl. XXX. fig. 5), F'. Vejdovsky (150). An il-loricated Proales-like Rotiferon, parasitic on Lumbriculus variegatus ; it adheres by its trophi to the worm’s hinder segments, and sucks its juices; nutritive, secreting, and vascular systems normal. Srison Grupet (Pl. XXX. fig. 4), C. Claus (17, 18). A doubtful Rotiferon ; il-lori- cated, of extraordinary form, parasitic on Nebalia; aliary wreath a few cilia at the mouth; secreting system highly developed; nutritive system present in the male as well as in the female; vascular system very rudimentary ; jaws rotiferous. ta JE Jessa NB) Ee THE VASCULAR SYSTEM. *,” The numbers in brackets, as (188), refer to the memoirs in the Bibliography, pp. 140-142. 1. This system of vessels, in its usual form, has already been described in vol. i. p. 8. There are three! principal varieties of it, including that already given above. (i.) The lateral canals open into a contractile vesicle, which discharges itself into the cloaca. This is the ordinary plan. (ii.) Each of the lateral canals ends in an expanded portion which dilates, and con- tracts, and discharges into the cloaca. This doubling of the contractile vessel is to be found, among others, in Conchilus volvox ? and Salpina macracantha.3 (i1.) The lateral canals pass unexpanded directly into the cloaca, and the contractile vesicle is absent.4 2. It is probable that the contractile vesicle is filled by a fluid flowing into it through the lateral canals, and it is certain that it usually ° empties itself outwards through the cloaca. This has been directly observed ® in Asplanchna priodonta and in Hydatina senta by myself, and can be easily verified. It has been suggested that a return current of fresh water is drawn up by the expanding contractile vesicle through the cloaca ; but no one has seen any appearance of this in the cloaca itself; and though Dr. Cohn’ thinks that he saw a return current draw particles of carmine towards the opening of the cloaca of Brachionus militaris, after the outward current had driven them away from it, no one else seems to have succeeded in repeating the observation.® Occasionally the contents of the cloaca are driven into the intestine. Dr. Moxon has seen this in Huchlanis dilatata,® and Dr. Semper has seen it in Trochosphera equa- torealis.° In each case it was effected by closing the aperture of the cloaca and open- ing that of the intestine simultaneously ; but this is not the usual action, and (as Dr. Moxon suggests) seems only to be a method of obtaining a natural enema for a clogged intestine. 8. In all the three plans, given in § 1, the lateral canals sometimes appear surrounded by a filmy, floccose substance, through which they meander (generally two on each side) 1 Dr. Semper (138) says that in Trochosphera equatorealis there is a contractile vesicle which has no connection with the lateral canals: if this is really the case, it would be unique. Mr. Gosse has described, p. 138, another variety of the vascular system in Pterodina, and in other Rotifera; but, as we differ widely here about the facts, as well as about the inferences drawn from them, I have (for the sake of brevity and clearness) omitted this variety from my account. ZaViolegiups 90s 3 Vol. ii. p. 85. * Professor Huxley (91) states that this is the case in Lacinularia socialis; but Dr. Leydig (108) says he has seen a small contractile vesicle in this Rotiferon. Neither Pedalion mirum, Pterodina patina, nor P. valvata appears to haye any contractile vesicle. ® See below; same paragraph. ® Vol. i. p. 123. 7 (21). 8 T have never seen B. militaris, which from the great size of its contractile vesicle is pdmicably, adapted for such observations. aA (US) Ie Violeie ps Se. 136 THE ROTIFERA. in many loops and curves, and occasionally forming a plexus of complicated inter- twinings. Attached to the canals by long stalks are the little flickering bodies called vibratile tags. The canals are generally visible just under the head, near a plexus, and run down each side of the body, from one plexus to another, till they reach the surface of the contractile vesicle. There are usually five vibratile tags on a side, and a plexus is a favourite point of attachment. 4. The tags are of various shapes. In some they seem to be simple cylinders, or cones with their bases at the free end. In others they are somewhat wedge-shaped ; so that they have a broad triangular surface from one point of view, and a narrow spindle- shaped surface from another. If a tag happens to point straight up the microscope, a full view may be obtained of its free end; and the outlines, so obtained, of these free ends, vary considerably : in the case of Euchlanis dilatata it is a narrow oval with pro- longed pointed ends; } and in that of Brachionus pala,? only a fine straight edge. When- ever I have obtained a distinct edgewise view of a tag, it has had the appearance of being closed at its free end with a knob. Down the length of the tag (when so seen) run an endless succession of swift undulations; which, on several occasions, in the dying animal, I have seen slowly slacken, till they have gradually resolved themselves into what seemed to be one stout, tapering, undulating cilium, of the length of the tag itself, attached by its broad base to the knob mentioned above, and pointing its taper extremity to the lateral canal. But when the tag presents its broad triangular surface to the observer, there is a totally different appearance; and it seems to be crossed by quivering, parallel, straight lines that stretch from one side to the other (Pl. XIII. fig. 3b). It is obvious that no single cilium could present such an appearance. Possibly an undulating membrane might, the cross-lines being the summits of the waves which happened to be in focus ; but the lines seem to be too sharp for this. Dr. Moxon suggests that the cross-lines are produced by rows of extremely minute cilia on each inner broad surface of the tag. It is not easy to imagine what such an apparatus might look like when seen in motion sidewise ; but possibly the apparent waves produced by the cilia on either side might together cause the illusory appearance of an undulating cilium as long as the vibratile tag. That many of the inner surfaces of the Rotifera are lined with minute cilia has long been known. The whole alimentary tract is so; and, what is more to the point, this very appearance of a long undulating cilium is certainly produced in the tube of Floscularia campanulata by very minute cilia running in straight lines down its length.* 5. The next point is whether these tags are open or closed at their free ends. On this point it is enough to say that direct observation has entirely failed to decide the question. The chief authorities have come to opposite conclusions, and there seems to be no hope of settling the point by the microscope. The close analogy between the vibratile tags of the Rotifera and the appendages on the water-vessels of the Naids would, however, lead us to infer that in the former case, as well as in the latter, the tags in spite of appearances may be open funnels, furred inside with minute cilia. A similar difficulty awaits us when we inquire how the lateral canals originate in the head. In some cases the canals on either side are said to have their fore ends on the surface 4 in communication with the free water, in others to cross from side to side and anastomose®; so that the whole apparatus forms a loop with its two ends attached either to the cloaca or to the contractile vesicle; while in the great majority of cases it is im- possible to say what is the real arrangement. 6. In attempting to determine the use of this apparatus we are met by this obvious difficulty ; that we are not sure of the facts. Are the vibratile tags open at their free 1 Dr. Plate (126) Taf. ii. fig. 19, ¢. 2 C.T.H. vol. ii. p. 117. 3 Pl. D, fig. 1; also Dr. Moxon (118). 4 As observed by Mr. Gosse in Pterodina patina and P. valvata, vol. ii. p. 138. 5 As observed by Professor Huxley in Lacinularia socialis (91); by Dr. Leydig in the same (108) ; and by myself in Stephanoceros Eichhornit, Pl, iv. figs. 2, 4. APPENDIX, 137 ends, or are they closed? Do they contain an undulating membrane, or are their inner surfaces furred with minute cilia? Does a current pass through them (supposing them to be open funnels) towards the lateral canals, as it seems to do, or in the opposite direction? Are the lateral canals open at their upper ends, or are they blind passages haying no outlet save at the contractile vesicle? Is the substance surrounding the lateral canals a glandular secreting substance, or a mere mechanical support for the canals? Does the contractile vesicle fill itself by drawing up fresh water through the cloaca, or is it filled by fluid passing into it from the lateral canals ? I do not know how these questions are to be answered with any approach to certainty, and I have no expectation of their receiving any answers that will meet with general acceptance, for on all these points the best observers disagree: I shall, therefore, do no more than state, in the following paragraph, the view of those who consider the vascular system to be an excreting one; and leave to my colleague the advocacy of the opinion which he has long held, viz. that the system is mainly branchial, with, possibly, a sub- ordinate excreting function. 7. The perivisceral fluid is in part! derived from the products of digestion which pass by endosmose through the cellular walls of the stomach ; and it is out of this fluid that the various organs are repaired, and at its expense that the animal moves and grows. This growth, repair, and action change the constitution of parts of the perivisceral fluid, and render an excreting organ anecessity. The vascular system is this excreting organ ; and, indeed, no other has ever been suggested as having an excreting function. The lateral canals with their floccose investments, or the vibratile tags,? or both, are the excreting vessels; while the part played by the contractile vesicle is one probably of storage and discharge : for the contractile vesicle varies extremely in size and frequency of action in different Rotifera, and in some is altogether absent. The oxygenation of the perivisceral fluid, both in males and females, probably takes place at the fore part of the head, where the skin is never loricated, but appears to be thin; and, where, too, it is possible that there may be definite spots, covered with deli- cate membrane, so as to take advantage of the constant rush of water, drawn to the head by the ceaseless action of the cilia. 8. Now it is obvious (from § 6) that the above explanation (given in § 7) of the vascular system, rests on a number of assumptions which it is impossible to verify. But then as much, I think, may be said of the explanation that would make the function of this system a branchial one, or a combination in various degrees of both. ! Leydig is of opinion (110) that water passes by endosmosis into the body cavity. This, indeed, seems probable; for indigo-coloured water when swallowed (e.g. by R. vulgaris) almost instantly imparts a blue tint to the thick cellular walls of the stomach up to their outmost boundary. It can hardly be supposed that it goes no further, if the products of digestion do. It seems unlikely that the inner walls of these stomach-cells should be pervious to the products of digestion, and to water, alike ; and that the outer walls should be pervious to the former, and impervious to the latter. It has, how- ever, been objected, that we never see the indigo-coloured water in the perivisceral fluid. But it is hardly to be expected that we should. When we look at the blue stomach-walls, we are looking at a colour produced by a depth of solution equal to that of one or two thick cells; whereas the coloured fluid, oozing out through the stomach-walls, would be presented to our eyes in films of almost infinitesimal thinness; which would never be suffered to accumulate and so become visible, but would be at once broken up and Jost, by the constant motion of the perivisceral fluid. Besides the blue tint after a time disappears from the cells. It seems more likely that this is due to the indigo-solution continuing its course through the cells into the body cavity along with the products of digestion, than to its parting company with these latter at the outer wall, and then alone reversing its course, and returning into the stomach. * If the vibratile tags be supposed to be open ciliated funnels, through which the perivisceral fluid passes into the lateral canals, to be discharged through the cloaca, then we are met with the difficulty that this supposition would imply the frequent discharge of a fluid analogous to blood. But, on the other hand, if it were admitted that, in the perivisceral fluid, the products of digestion are largely diluted with water (see previous note), the force of this objection would be much weakened ; for the supposed difficulty would be mainly due to our having applied, to so simple a fluid, the name of such a highly organised product as blood. 138 THE ROTIFERA. The conclusion seems a lame one, and yet I fear that it is hardly possible to hope for a better, when dealing with an apparatus of whose structure we know so little ; one which we are unable to examine except with our eyes, and yet one in which we have strong reasons for suspecting that, on crucial matters of detail, our sight deceives us. P.H.G. on the Vascular System. [My opinion is,—as it was in 1850 (‘‘ On the Anat. of Not. awrita;”’ Tr. Micr. Soe. Lond., iii. 98),—that the vascular system is a proper respiratory system, and that the lateral canals are proper branchiw. The water enters at the head, circulates, and is poured out at the cloaca. I believe these three facts may be predicated of the entire class. Accessories to the process are: (1) the afferent tubules; (2) the ‘“ gastric glands ;”’ (3) the vibratile tags; (4) the contractile vesicle. 1. In so many species that I consider the arrangement universal, I trace up the canals to the funnel through which the head-mass constantly moves up and down. The canals never partake of this motion, and it is evident that they are attached to the wall of the funnel, which I presume to be perforated with minute orifices through which the external water constantly percolates into the afferent tubules. In many species these appear to be numerous, and they are seen to branch and to anastomose very irregularly into each other, forming single, double, or multiple canals, which run, sometimes nearly straight, but more commonly bent sinuately in various degrees, throughout the length of the animal. In Pterodina, (especially in patina and clypeata) the tubules ramify and spread into broad fan-shaped plexuses of flat lamin (which I consider tubular, and ciliate within), filling the wide triangular areas on each side of the mastax. Then they begin to unite again, and presently (in P. valvata especially), bending abruptly from the ven- tral to the dorsal side, form one broad and long pyriform sac which narrows to a long slender duct, and joins the cesophagus one on each side, pouring the effete water into the alimentary canal, and ultimately through the cloaca, without the intervention of a con- tractile vesicle. 2. The “ gastric glands.’-—The organs thus named have usually been considered as ancillary to the digestive system. But their evident connection with the aquiferous system in Péterodina makes this doubtful; and a number of other curious facts are observable, which confirm, more or less manifestly, this connection. Sometimes these organs take the form of large reservoirs of delicate texture and wrinkled surface, joined to the esophagus by long ducts, and affixed by threads (perhaps tubular) to the lateral canals, or to the lorica. In Metopidia solidus, each appears as an aggregation of saccules into a large three-sided and three-angled body, one angle passing up to the origin of the canal, and another by a long duct to the wsophagus, while the canal seems in some inexplicable way united with both. This, excessively slender at its origin, expands as it proceeds, becoming corrugate, till it attains a width almost rivalling the plexus of Pterodina patina, just before it enters the cloaca, without the intervention of a contractile vesicle. Yet, in some individuals, the contractile vesicle itself and its action are quite distinct. In Notholca acuminata the ‘gastric gland’”’ much resembles the pyriform of Pter. valvata, with a slender duct to the long cesophagus, and another duct from an outer angle leading down for some distance closely parallel with the lateral canal, and con- nected with it by a short transverse duct at each end. Cathypna luna has a structure somewhat like this; and, in a less degree, Metopidia rhonboides. Several species of Brachionus display anomalies in these organs. Thus in B. Bakeri and B. urceolaris each is a great wrinkled sac of very delicate tissue, and of retort-shape, at the end of along neck. In B. rubens there are two sacs on each side, united by a long sinuous duct. In B. Miillevi there is but one.on each side, but it is cleft almost to the base into two varying portions. In all these the organs seem to haye more or APPENDIX. 1389 less obvious connection with the expansions of the lateral canals. But, in one example, which I cannot distinguish from wrecolaris, the sac is, at its outer extremity, indefinitely expanded, fore and aft, and seems to merge into the length of the canal itself, which yet begins clearly in the wall of the head-funnel, and terminates normally in a con- tractile vesicle. On the other hand, in Asplanchna, the glands, which are small oval organs, are connate, on each side of the very long esophagus, remote from, and apparently quite unconnected with, the canals. 3. Of the ‘“ vibratile tags ’’ I have little to say of direct observation. In Pterodina they seem to me whclly wanting. I judge it nearly certain that they are tubular, and that something is driven through them, whose course is from the lateral canal to the body- cavity.!. Assuming that the function of the system is the separation of oxygen from the water, may it not be that the tags are reservoirs in which pure oxygen collects, and from which it is pumped into the perivisceral blood, while the hydrogen left pursues its course, perhaps to fulfil some office still, mechanical or vital ? 4, Of the contractile vesicle, the normal position, form, structure, and function are well known.? But in the two largest species of Salpina, macracantha and eustala, there are two of these organs, of ample dimensions, one on each side, into which the com- paratively straight and thick lateral canals empty by trumpet-mouths. Strange to say, in the former species the ‘‘ gastric glands’? seem wholly wanting. In the great Asplanchne, the organ, though manifest enough, is very small; in Metopidia, as already mentioned, it is only now and then present ; while in Péerodina, it is (according to my experience) invariably wanting. On the whole, then, I judge that Rortrmra possess a well-marked branchial system, which has several striking parallels with that of the ANNELLIDA—the Lumbricide in particular.—P.H.G.] THE SETIGEROUS SENSE-ORGANS, The nervous system of the Rotifera is simple. It consists of one nervous ganglion situated on the dorsal side of the buccal funnel, usually near the mastax; and sending out nervous threads to the eyes,? and to certain organs of sense, which have been termed antenne or tentacles as they are possibly tactile organs; but whose function is by no means certain. They consist of knobs or cylinders, which usually carry a bunch of fine sete at their outer extremity. Sometimes they are enclosed in tubular sheaths rising from the surface of the body; and at others their extremities le close to apertures in that surface, through which the sets may be seen to protrude. The antenne are in two pairs. Of these the upper pair is invariably dorsal; and its constituents, though some- times widely separate,’ are most frequently pressed close together,® or fused into one.° The lower pair is to be found sometimes on the dorsal surface,’ sometimes on the ventral,’ and sometimes on the line between the two.2 In one ease this lower pair is also fused together,!° and the creature has but two antenne ; both dorsal, and both on the median line. It is only necessary to add that, in many species, one or other pair appears to be absent; notably the lower pair in all the Philodinade: but in some of these cases their absence may be only apparent; as the antennx are often reduced to minute setigerous pimples, and so can be easily missed. 1 The perivisceral fluid, or blood, is surely neither effused from the body, nor augmented in quaz.tity, sensibly. 2 Since a special reservoir would seem needless for the mere discharge of the effete water, an urinary office may belong to this bladder. * When there is only one eye it is generally seated on the nervous ganglion itself. ‘ As in Asplanchna priodonta, Pl. xii. fig. 2c: Copeus spicatus, Pl. xxx. fig. 7: and Brachionus plicatilis (117). * As in Syncheta pectinata ; PI. xiii. fig. 3c. 6 The common case. 7 As in Notops Brachionus ; Pl. xv. fig. 1. 8 As in Melicerta ringens ; Pl. v. fig. 4. ° As in Stephanoceros Eichhornii; Pl. iv. fig. 2. ™ As in Copeus caudatus; Pl, xvi. fig. 5a. 140 THE ROTIFERA. BIBLIOGRAPHY OF THE ROTIFERA. N.B. The references marked -+ haye been copied from Herr Eckstein’s list in “ Sieb. u. K6ll. Zeits.,”’ Bd. xxxix. 1883, p. 433; and those marked * from Mr. Darcey W. Thompson’s “ Bibliography of Protozoa, Sponges, Coelenterata, and Worms,’’ 1885. I possess, or have had access to nearly the whole of these memoirs, but have been unable to consult those which are marked §. 1. Archer, W. . . . Polychetus spinulosus, Quart. Journ. Mier. Sci., viil., 1868, p. 72. 2. Atwood, H.F. . . § Brachionus conitwm, Amer. Mon. Mier. Journ., 11., 1881, p. 102. 3. Badcock, J. . . . Hyes of Rotifers, Journ. Roy. Micr. Soc., i., 1882, p. 512. 4, Balbiani, S$. . . . Notommata Werneckw, Ann. Sci. Nat. Zool., vii. +3 1878, (1 pl.) 5%, . OK Journ. Roy. Mier. Sous rity, 1879, p- 530, (1 pl.) 6. Barrois, i 68c4 0 Embryology of "‘Pedalion (Syncheeta), Rey. Sci. ., 1877, p. 303. 7. Bartsch,S. . . . Die Rdderth. b. Tiibingen, Stuttgart, 1870. 8. R3 » + » « Rotatoria Hungaria, Budapest, ‘1877, (4 pls.) 9. Bedwell, F. A. . . Melicerta ringens (building apparatus), Mon. Micr. Journ., xviii., 1877, p- 214, (2 pls.) Oars » «© « M, ringens & Conochilus volvox (mastax), Journ. Roy. Mier. Soe., i., 1878, p. 176, (2 pls.) 1. A « « Melicerta ringens, Midland Naturalist, i., 1878, p. 245. 12. Billet, Ike og . *§ Philodina roseola, Bull. Sci. Dep. du Nord, u., 1883, pp. 1 & 69. 3. Brightwell, Thos. . Adiacious Rotifer (Asplanchna Brightwellii), Ann. Nat. Hist.,1848,p.153. 14. Burmeister, H. . Die systemat. Stellung. d. Rdaderth, Sieb. u. Koll. Zeits., Usb p. 152. 15. Claparéde, Ed.. . Miscellanées Zoologiques, Ann. Sci. Nat. Zool., viii., 1867, p. 5, (2 pls. 16. or aahecfomans Quart. Journ. Mier. Sci., viii., 1868, p. yale i, lm, (Ch oo a 6 Seison Grubei, Festschrift d. k. k. Zool. bot. Ges. in Wi ien, 1876, (2 pls.) 18. 4, 5 »- - . « *t § Z. Kennt. d. Organts. von Seison, Zool. Anzeig., iii., 1880, p. 548. 19. Cohn, F.. . . . 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Floscularia campanulata, Trans. Bristol Micr. Soe., 1867, (2 pls.) Rhinops vitrea, Ann. Nat. Hist., 1869, p. 27, (1 pl.) Triarthra longiseta, Mon. Mier. Journ., i., 1869, p. 176, (1 pl.) Hydatina senta, Mon. Micr. Journ., ii., 1869, p. 22, (1 pl.) Syncheta mordax, Mon. Mier. Journ., iv., 1870. p. 26, (1 pl.) Pterodina valvata, Mon. Micr. Journ., v., 1871, p. 25, (1 pl.) Pedalion mirum, Mon. Mier. Journ., vi., 1871, pp. 121 & 215, (1 pl.) Pedalion mirum, Quart. Journ. Mier. Sci., xii., 1872. p. 333, (1 pl.) Is Pedalion a Rotiferon ? Mon. Mier. Journ., viil., 1872, p. 209, (1 pl.) Euchlanis triquetra & E. dilatata, Mon. Micr. Journ., 1872,p. 97, (1 pl.) Desiccation of Rotifera, Mon. Micr. Journ., ix., 1878, p. 274. Male Rotiferaand N.brachionus, Mon. Mier. Journ.,xiil., 1875, p.45, (1 pl.) Cephalostphon limnias, Mon. Micr. Journ., xiv., 1875, p. 165, (1 pl.) Melicerta tyro (M.tubicolaria), Mon. Mier. Journ., xiv., 1875, p. 226, (1 pl.) CEcistes wumbella and other Rotifera, Journ. Roy. Mier. Soe., i., 1879, p- 1, (2. pls.) Note on Mr. Deby’s ‘Pedalion and Hexarthra,’ Journ. Roy. Mier. Soc., u., 1879, p. 386. Geistes janus, Floseularia trifolium, Journ. Roy. Micr. Soc., 1., 1881, p- 1, (2 pls.) Floscularia regalis, Midland Naturalist, v., 1882, p. 252. Floscularia regalis, Journ. Roy. Mier. Soc., 11., 1882, p. 787. Five new Hloscules &c., Journ. Roy. Micr. Soc., iii., 1883, p. 161, (2 pls.) Asplanchna Ebbesbornii, Journ. Roy. Mier. Soe., il1., 1888, p. 621, (2 pls.) Classification of Rotifera, Quart. Journ. Micr. Sci., xxiy., 1884, p. 335, (with figs.) Four new Floscules and five other new Rotifera, Journ. Roy. Micr. Soce., 1885, p. 608, (1 pl.) Lacinularia socialis, Trans. Mier. Soe., London, i., 1853, p. 1, (8 pls.) Pelagic Fauna of Swiss Lakes, Zool. Anzeig., Septr., 1883. Observations sur les rotateurs du genre Meélicerte, Comptes Rendus, xcili., 1881, p. 748. Développement del’ wuf des Mélicertes, Comptes Rendus,xeii.,1881,p.856. § Monographie des Mélicertes, Arch. de Zool. Expér. et géner., 1., 1883, p- 131, Z. Kennt. d. in d. Krainer Tropfsteingrotten einheimisch. Raderth., Zool. Anzeig., Feb., 1579, p. 61. Anurea longispina, Amer. Journ. Micr., iv., 1879, p. 20. § Furchung u. Samenfaden b. ein. Raderth., Froriep, Notizen, xxviii. _, Oct. 1843. Ub. ein. Réiderth. a. d. Fam. d. Asplanchneen, Arch. f. Naturgesch., 1876, p. 179, (1 pl.) A new parasitic Rotifer, Quart. Journ. Micr. Sci., viil., 1868, p. 54, (with figs.) Remarks on Pedalion, Quart. Journ. Mier. Sci., xii., 1872, p. 888, Dictyophora vorax, Proc. Acad. Nat. Sci. Pa., 1857, p. 204, Limnias socialis, (loc. cit.), 1874, p. 140. Revivification of Rotifer vulgaris, (loc. cit.), 1874, p. 88. Rotifera without rotary organs (Acyclus Inquietus), (loc. cit.), 1882, p- 243, (1 pl.) Anurea longispina, Midland Naturalist, i1., 1879, p. 241, (1 pl.) § Egg segmentation ; Notommata, Euchlanis, Megalotrocha, Isis, 1848, p. 170. Lacinulaiia socialis, Sieb. u. K6ll Zeits., 1851, p. 452, (1 pl.) + § Ub. d. Geschlecht d. Raderth., Verhancl. d. phys. Gesellsch. Wiirz- burg. 1854, p. 104. Ub. d. Bau. u. d. system. Stellung. d. Rdderth., Leipzig, 1854 (4 pls.) ele ed WA BAAS 9 bb] . Schmidt,O. . . Leydig, F. . - Lord, J. BE. 3. Maggi, L. . Marion, A. F.. . 5. Metschnikoff, E. . . Milne, W. . » Mobius, K. .. . Moxon, W. e Naeeliy Elec i as ; Peirceni\GIN. 2 . Peltier, A. . ‘ 2. Pereyaslavtseff, C. ” ” . Perty, M. . Plate, L. St Oy OO . Plessis, G. Du . Poggenpohl, . . . Pritchard, A. . } Reiter, HH... . Rosseter, T. B. 2. Rolleston,G.. . Salensky, W.. . . Schmarda, L. K.. . Scoch,G. . . Semper, C. ” ” oan”, . Slack, H. J. ” ” Se mith ee ele . Stein, F. . Tatem, J.G. . ” ” . Toth, A. Udekem, J. da’. . Up ‘de Graff, T. S. . Vejdovsky, F.. . - Vogt, C.. 2. Weisse, J. F. . ” ” . Werneck, W.. . . Williamson, W.C. . Wills, A. W. Oo ” ” e . Zacharias, O.. . ” ” . ” ” ” ” THE ROTIFERA, Hydatina senta, Miiller’s Archiv, 1857, p. 404. (1 pl.) Notes on free-swimming Rotifers, Micr. News, 1884, pp. 72, 145, 177, 233; (with figs.) § Primo elenco d. Rotif. d. Valewvia, Atti d. Soc. Ital. d. Sci. Natur. xxi., 1878, p. 320. § Rotateurs parasites des Nébalies, Comptes Rendus, lxxiv., 1872, p. 1115. Apsilus lentiformis, Sieb. u. K6ll Zeits., 1866, p. 846, (1 pl.) Pleurotrocha mustela, Proc. Phil. Soe. Glasgow, xvi., 1885, p. 188, (1 pl.) Brachionus plicatilis, Sieb. u. Kéll. Zeits, xxv., 1874, p. 108. Some points in anatomy of Rotatoria, Trans. Linn. Soc., xxiv., p. 455, (1. pl.) § Zur Entwicklungsgeschichte d. Raderthiere, Zurich, 1852. Stephanoceros Eichhornii, Proc. Acad. Nat. Sci. Pa., 1875, p. 121. Sur une nouvelle espéce de Floscularia, Ann. Sci. Nat. Zool, 1838, p. 41. § Development of Rotifer Inflatus, Mem. Noyorossian Soc.,ix.,1884,(1 pl.) Development of Rotifer Inflatus, Nature, xxxii., 1885, p. 579. Zur Kenntniss Kleinst. Lebensf., Bern, 1852. Zur Kenntniss d. Rotatorien, Zool. Anzeig., Oct., 1884, p. 573. Zur Naturgesch. d. Rotatorien, Jenaische Zeits. f. Natur., xix., 1885, p- 1, (8 pls.) Note sur L’ Hydatina senta, Bull. Soc. Vand., 1875, p. 167. Strophosphera ismailoviensis, Trans. Nat. Hist. Soc., Moscow, x. p. 9. A history of Infusoria, including Desmidiacee and Diatomacee, London, 1861. t § Conochilus Volwox, Naturhistoriker, iii. Jahrg., No. 12, p. 92. Stephanoceros Eichhornii, Journ. Roy. Micr. Soc., 1884, p. 169 (1 pl.) Forms of animal life (Rotifera), Oxford, 1870, p. exxxviil. Entwicklungsg. d. Brachionus urceolaris, Sieb. u. Koll. Zeits., xxii., 1872, p. 455, (3 pls.) Zur Naturgesch. Agyptens, Akad. d. Wissensch. math. natur. K1., Wien, 1854, (7 pls.) Neue wirbellose Thiere (Rotatoria), Leipzig, 1859, p. 47, (pls. xii.—xv.) D. Organisation d. Rdderthiere, Archiv fiir Naturgesch., 1846, p. 67, (with figs.) *§ Die mikrosk. Thiere d. Siisswasscraquariums, ii., Die Riderth., Leipzig, 1869, (8 pls.) Trochosphara equatorealis, Sieb. u. Koll. Zeits., 1872, p. 311, (1 pl.) Trochosphera equatorealis, (Translated), Mon. Micr. Journ,, xiv., 1875, p- 237, (3 pls.) Cephalosiphon limnias, Intellectual Observer, i., 1862, p. 53, (with figs.) On a species of Triarthra, Quart. Journ. Micr. Sci., 1, 1861, p. 132, (with fig.) § On animal life in water containing free acids, Mem. Phil. Soc. Man- chester, 1876, p. 185. § Ub. d. Mannchen : v. Diglena éc., Tageblatt d. Leipzig. Naturforsch., 1872, p. 140. On a new Melicertian éc., Journ. Quek. Micr. Club, 1868, p. 124, (2 pls.) Stephanops longispinatus dc., Quart. Journ. Mier. Sci., vii., 1867, p- 252, (with figs.) Die Rotatorien de.: v. Pest-Ofen, Verhandl. d. Zool. bot. Gesellsch. Wien, xi., 1861, p. 183. Le systeme circul. d. Lacinularia socialis, Ann. Sci. Nat. Zool., xiv., 1850, p. 146. § Floscularia cornuta, L’Institut, 1851, xix. p. 223. Anurea Gleasonii, Proc. Amer. Soe. Microscopists, Chicago, 1883, p. 118. Drilophaga Bucephalus, Verlag d. kénigl. bbhm. Gesellschaft, Prag, 1883, p. 391. Ub. d. system. Stellung d. Réderth., Sieb. u. Koll. Zeits., vii., 1856, p. 193. Zur Dates d. Raderth., Mem. Acad. Imp. St. Petersb., 1862, p. 1, (1 pl.) Zur Oologie d. Raderth. Zweiter Beitrag, Bull. Acad. St. Petersb., 1865, p- 208, (1 pl.) § Sur Vorganisation des Rotiféres, L’ Institut, x. 1842, p. 174. Melicerta ringens, Quart. Journ. Mier. Soe., i., 1853, pp. 1 & 65, (1 pl.) (Gcistes pilula, Midland Naturalist, i., 1878, p. 302. GBeistes longipes and Gi. pilula, Midland Naturalist, i., 1878, p. 317, (1 pl.) Rotifer vulgaris, (Reproduction and Development &c.), Sieb. u. Koll. Zeits., xli., p. 226. Rotifer vulgaris, (translated), Ann. Nat. Hist., 1885, p. 125, (with figs.) § Relationship of Rotifera and Nematodes, Biol. Centralbl.,v.,18t 5, p.228. Relutionship of Rotifera and Nematodes, abstracted in Journ. Roy. Mier. Soe., 1885, p. 1006. GENERAL INDEX. Vol.| Page Vol. |P age | Vol.| Page Classification . : Si) os 30 (Esophagus. . i 7 | ‘Types of foot . i 26 Egg . . ° . alec! 10 Reproductive system . Se] x 10 || ‘Types of ciliary w reath . 2 i 27 Glinds . 6 . 5 ome a Rotifern, defined . Pela 4 || ites of trophi. 4 ceil 28 Male - c . . cafe 10 _ typical one described ead! 5 || Vascular system, brief de- Mastax ¢ C = ined 6 Rotifera, discovered before | scription of i 8 Muscles c ° Sih at 8 1838 . 0 . 5 Alek 17 — its funetion (C. TH. No ii | 135 Nervous system, . i 9 Setigerous sense-organs . ii | 139 || — — (?.H.G.) : > Fey (eet ee tS 3 Orgaas of sense 5 5 Sil 9 || Stomach and intestine i 7 INDEX OF THE ORDERS, FAMILIES, GENERA, AND SPECIES DESCRIBED IN THIS WORK. -| a a || Cd P| a a z a A Ge | | | Actinurus . i} 108) Cephalosiphon = |u| esce Diplax trigona —. | ii) 82 | XXII | 9 Actinurus neptunius 1) 108 x 6 || Cephalosiphon can- Diplois . . - [ii] 86 Acyclus . oi |all) Ge Ghhity Gg | eel ae) _ Diplois Daviesie . Jii} 87 | XXIV | 3 Acyelus inquietus . | i) 57 D 3 || —limnias . a ielae VI 3 | —propatula . ii) 87 | XXIV | 2 Adinetade . ./|i/112 | Cochleare » ii} 111 _Distemma. ii] 54 Adineta . ‘ 5 lal alate Cochleare — staphy- ' Distemma Collinsii. ii] 55 | XVIII | 13 Adineta vaga. 5 Wael) al axa 10 linus . ; . {ii} 111 9 || —forticula . . {ii} 41 Albertia. . . |ii| 15 —Trme o alain 10 || —labiatum . . |ii] 56 | XVIII | 12 Albertia intrusor . |ii) 15 | XVII | 13 || Celopus. . ii| 67 | — raptor : ~ fai] 54) XE | 1 — naidis e .- |i} 16 XVII 14 Ceelopus brachyur Aa 11) 69 XxX al Distyla 0 O . |ii| 96 7 Anureade . . | ii) 122 —cavia . ~ . {ii] 69 | XX | 22 || Distyla flexilis . |ii] 97 | XXIV | 7 Anurea . - | ii} 122 —minutus . » ii] 70 OL 20 || —Gissensis . ii] 96 | XXIV | 8 Anurea aculeata - 11/123) XXIX | 3 || —- porcellus . . jil| 67 xX 18 || Diurella rattulus ii| 67 — acuminata . - [ii] 125 —tenuior . ey (68a) xox 19 || — tigris . ° . fii} 65 — brevispina . « | ii] 123 Coluride . 2 ii| 101 Drilophaga — buce- —cochleais . . {ii} 124) XXTX | 7 || Colurus . 11/101 phalus : . |ii} 134] XXX | 5 — curvicornis. - |i) 192) XXIX | 9 || Colurus amblytelus. ii} 104| XXVI | 5 || Enteroplea hyda- —fissa . . . jii/ 123 | — bicuspidatus ii) 102) XXVI | 2 Gee Gg eg (etl 5K) — hypelasma . - |ii] 123) XXIX | 6 || — eaudatus . |i] 104) XXVI | 6 Eosphora ii] 47 —longispina . + | ii} 125] —elopinus . . {ii} 105| XXVI | 4 |) Eosphora aurita ii] 47 | XVII | 10 — serrulata . |} 124) XXIX | 8 || — dactylotus . . |ii] 105) XXV_ | 12 || Eretmia . 5 ii| 128 — spinosa Ei » |ii} 125 | —deflexus . . {ii} 102} XXVI | 1 || Eretmia cubeutes ii] 128] XOXTX | 11 —tecta . 6 - |ii/123| XXIX | 10 || — obtusus . (1i] 1038) XXVI | 3 — pentathrix . =. fai] 128)|) ROXIE hz: Apsilus . i] 58 — pedatus . {11/105} XXV | 13 || —tetrathrix . . | ii] 134)/XXVITT} 1 Apsilus lentiformis . 1} 58 D 4 || _ uncinatus . . |i} 103 — trithrix ‘ . {ii} 184;XXVIII} 2 — bipera i} 59 D 5 || Conochilus . Paso Euchlanide . ii| 88 Ascomorpha anglica i| 122 Conochilus dossua- Euchlanis 3 ii| &8 — germanica . i| 124 rius. x 5 ee Gee Viana 4 |) Euchlanis deflexa ii| 92 | XXIV} 1 —helvetica , 5 | alae — volvox $ . |i) 89 | VITL 3 || —dilatata . ii] 90 | XXIII | 5 — sultans . |i} 124 Copeus . ii| 28 | —luna . . ii) 94 Asplanchnade elt) 219 Copeus eeadatns ii) 83°] XVI 5 | —lyra ° - jit] 89 | XXIIT} 1 Asplanchna . |i} 120 —cerberus . li} 3: XVI | 8 || —macrura . . {ii] 91 | XXIII] 6 Asplanchna Bowesii | i | 122 —Jnbiatus . ii; 28 | XVI 1 || — pyriformis . ii] 93 | XXIII} 2 — Brightwellii tea Sane | aU ||) pachyurus. . |i) 31] XVI | 4 || —triquetra . . ii] 91 | XXTIT| 4 — Ebbesbornii 1/120] XI 3 || — spicatus ii] 29] XVI | 2 || —umiscta . . ii} 92 | XXIII] 3 —myrmeleo . » |ii} 134] Cupelopagus inna Flosculariade . i| 43 —priodonta . Ril 22) NOU daxgeke Wise © qililt68 || Floseularin . . |i} 43 Balatro calvus. ii}134| XXX | 6 || Diaschiza iS . fit] 77 Floscularia algicola |i} 54 I 3 Bdelloida so fh SB Diaschiza exigua . |ii) 78 | XXII | 18 ||—ambigua . 5 || ae} I 2 Brachionide , » | ii] 116 —Hoodii . . |i] 79 | XXIT | 15 || — appendiculata rt} a lirachionus ii) 116 ee etaien Ac }ii] 79 | XXIL | 11 || —calva. i]56| Ill | 3 Brachionus amphi- a — semi-anerta ii) $0 | XXII | 10 | — campanulata 1 | a2 I 1 cerog . . | ii] 117 Btenuior . {ii} 81 | XXII | 14 || —cornuta . i| 51 I 7 —angularis . » |21)120| XXVIT] 4 || — valga. 5 . ii] 77 | XXII | 12 |] — coronetta i] 49 I 5 ay 2 : + }11}120; XXX | 9 || Dictyophora vorax. | i} 58 | —cyelops . i) 51 I 6 — Bakeri a 5 ie 8 || Digiena . x ais || — edentata i| 57 Ill 4 — doreas E . fii 4 |! Diclena aurita . |ii| 47 || — Hoodii 6 «| i] 55 II 5 —Millleri «i. J ii} 119 XXVII | 7 || —Diraphis . .{11] 53 | XIX | 3 || — longicaudata i| 53 1 4 ae -|4/119} XXX | 8 || —catellina , ./ii| 53] XIX | 10 || — longilobata « |i} 49 —oén ., c » | ii] 118 | —caudata . . |ii] 51 | XIX | 8 || —mira . F - |i} 50 III 1 —pala . cl + |") 117) XXVIII} 3 || —eircinator . . {ii| 50} XIX | 4 || —mutabilis . . {|i} 56 Hil 2 — polyacanthus —. | ii) 117) —clastopis . . {ii} 52 | XIX | 5 || — ornata 0 . |i! 50 I 9 — rubens F - |i7/ 119) XXVII} 5 || —forcipata . Sai 5Ou|| SkeeX 2 | — proboscidea = || 62 -_-— ae + 41) 119 A 1 || — gibber F . jill] 49 | XIX 7 || — regalis a - {|i} 49 I 8 —urceolaris . + |4) 118) XXVII) 6 || — giraffa . Pi biui nay lal) ©.4 &.< 9 || —trifolium . ~ fi] 54 Callidina — - | i| 109 —grandis . .|ii) 48) XIX | 6 | —trilobata . ./i/ 54) IL | 6 Callidina bidens . 1/109 Xe 8 || —permollis . . jul] 52°] XIX | 11 |) Fureularia . . {ii} 40 —bihamata . papel d€ 7 || Dinocharide . . ii} 70 Fureularia equalis. |ii} 46 | XVIII} 15 —elegans .° .|i/|109 || Dinocharig . . |ii| 71 = Bolton! |p sulle cll ttl|\-45) | meXoXGn ee — parasitica . . | i) 110 Xe 9 || Dinocharis Collinsii |ii} 72 | XXI | 3 || ceca. . .|ii] 42} XX 4 Cathypnade . - | il} 94 — pauper 3 Be th ae |) —ensifera . » |i} 43 xX 3 Cathypna + || 94 —pocillum . ii] 71 | XXI | 1 || —forficula . - {it 41 | Xx 1 Cathypna luna + |ii| 94 | XXIV | 4 || —tetractis . Se eri -O.41 2 | — gibba r . |i) 43 | XIEX | 13 —rTusticula . ii] 99 | XXIV | 6 || Diplax . p . |ii| 81 || «= gracilis . oe | RMI 42.7 |)) NCTE | — suleata n} 9 XXIV | 5 || Diplax compressa . {ii} 82 | XXII 8 || —longiseta . . |ii] 46 | XVIII 4 16 THE ROTIFERA. |e A | - Ay 2] Fureularia marina . | ii x 'X || Notommata ansata , | ii XVII | 3 || Pteredina : — micropus fir] XIX | — aurita f i XVII | 6 | Pterodina clypeata. — Reinhardti. - |ii| — brachionus . ii | — elliptica Hertwigia volvoci- || —brachyota . ii XVII | — mucronata . cola. | ii| — centrura ii — patina ‘ > Hexarthri a poly ptera in| XXX | 2 || — clavulata il — truncata Hydatinade - | ii] — collaris ii XVI —valvata . 5 tHydarina : . fii — copeus : il | Pteroessa 2 Hydatina senta —. |ii| XIV —cyrtopus . ii XVII Pteroessa surda L-loricata 5 ona —decipiens . + fii Ptygura melicerta . Lacinularia . Set — felis . = Slled Rattulide O 5 Lacinularia — albo- —forcipata . . fii XVIII Rattulus. . . flavicans . «fi — gibba. 5 oe Rattulus ealyptus . — socialis : fl VALUE — granularis . oii —cimolius . . Lepadella ii —hyptopus . Sit —helminthodes . Lepadella ovatis ii —lacimulata . . |jii XVII — lunaris 5 Limnias . i — longiseta aif — sejunctipes. . Limnias annulatus. | i VI —myrmeleo . = fd — tigris. : . — ceratophylli i VI —naias . é 6 lett XVIII Rhinops . : . — socialis c |e — parasita ait Rhinops vitrea, Loricatu. . «Jil —petromyzon —. |ii Rhizota. . Mastigocerea . ii| — pilarius 5 |ipti XVII | 5 || Rotifer . 0 : Mastigocerea_bicor- —saceivera , . ii XVII | 2 || Rotifercitrinus . nis > ls + |i) XX 5 || — Sieboldii i —hapticus . . —cearinata . aby XOX 7 || — spicata c - {ii — macroceros. . —elonsata . ii xX 8 || —syrinx i —macrurus . . — lophoesse i*| XX | 10 || —tigris. . « |ii —motacilla . . —macera. . | ii] XX | 12 || —tripus 3 Sales XVII | 4 || — tardus . : — rattus ii, XX 9 || —tuba . - sea XVII | 8 || —vulgaris . . — scipio. : ii XX 11 || — vermicularis <1) Sacculus . ° ¢ — stylata ii XX 6 || —Werneckii. J ii Sacculus viridis. Megalotrocha. . | i| Notops) =) Sit} Salpinade , é Mevalotrocha albo- Notops brachionus . | ii XV Salpina . . . flavicans. - {il VIII | 2 || —clavulatus . || XV 3 || Salpina brevispina . — socialis ; cy {Pru} —hyptopus . 5 Writ XV 2 || — eustala ; — velata 0 i (Ecistes . : i —macracantha , — volvox Fe ip (Ecistes brachiatus i IX 2 || — mucronata . . Melicertade . i| — erystallinus li VII 3 || — mutica ; Melicerta a (ia — intermedius a |e Vil 5 || —redunca . Melicerta cephalo- — Janus. : oa —spinigera . - siphon. , ail — longicornis efi VII 6 || —suleata 6 — ceratophylli eal —longipes . eas — ventralis . O —conifern . 6 Wi Vv — pilula. ail Wau 2 || Scaridium : — erystallina [ia —ptygura. Phi XXX | 3 || Scaridium eudacty- —janus. 5 a ial Vil — serpentinus elha 1X 1 lotum . c: A —pilula. . .|fi —Stygis . «fi IX | 8 || —longicaudum_. —ptygura. 5 |e —umbella. cy [hit Vil 4 || Scirtopoda, ; — ringens 5 or hat Vv — velatus a lla D 8 || Seison Grubei : —socialis . aaa Pedalionidx ii Squamella . — tubicolaria 5 ls Vv Pedalion. . . fii Squamella bractea . —tyro . 5 a hit Pedalion mirum ii XXX Stephanoceros. 6 Metopidia : 5 Pedetes . 6 . {ii Stephanoceros Eich- Metopidia acuminata | ij XXV Pedetes saltator . | ii XIII hornii . . 6 — bractea . ° Mi Philodinade . wii — glacialis —lepadella .. |i XXV Philodina . Ji —Horatii . . — oxysternum ii DOF Philodina aculeata. | i IX Stephanops . . — rhombvides ii KXV. — citrina r i IX Stephanops armatus —solidus . fii XXV _ erythrophthalina i —bifureus . —triptera . aid XXV —megalotrocha . | i IX — chlena . . Microcodide . i = roseola 5 Sha 1X — lamellaris . 5 Microcodon i — tuberculata alka — longispinatus Microcodon clavus. | 1 XI Pleurotrocha . apt —muticus . : Monocerca 5 is Pleurotrocha con- — unisetatus . 5 Monocerca. bicornis il stricta ‘ ii XVIII Strophosphera — is- — porcellus ii — gibba. alba XVIII mailoviensis O — rattus il | — leptura - Apt XVII Sy nehetade . —stylata P ii | Ploima . A ene Synchxta : : Monostyla j oa Polyarthra. Salen Sy neheta baltica . Monostyla bulla. | ii XXV_ | 4 | Polyarthra platy- —mordax . ci —cornuta . . fii XXV | 1 || ptera . : . ii XII | 5 || —oblonga . : — Lordii : lien XXV | 5 || —trigla é meal —pectinata . A — lunaris 5 - fii XXV | 2 || Polychetus spinu- —tremula. a — quadridentata . | ii XXV | 3 losus . A - fil Taphrocampa . Monura . , o |r —subquadratus . | ii Taphrocampa annu- Monura colurus .. |ii XXVI | 7 || Pompholyx li losa. 6 0 Mytilia . : . fii Pompholyx — com- — Saundersie A Mytilia Tavina Jai XXVI| 8 planata 3 . ii XXVII| 1 || Triarthrade . A Noteus . ii — suleata ; . [li XXVII| 2 || Triarthra : Noteus quadric ris ii XXVIII} 5 || Proales . . ii Triarthra breviseta Notholea il Proales decipiens ii XVIII | 6 || —longiseta . E Notholca acuminata |ii XXIX | 4 || —felis . A Sui XVIII | 17 || — mystacina < — lonsispina . ii XXVIII} 6 || — gibba ii XVII | 8 || Triophthalmus dor- — scapha F « [ii SONIEXSTY — parasita ii XVIII | 11 sualis . . . —thalassia . o/h XXIX | 2 |! — petromyzon ii XVIII | 9 || Trochosphera . Notommmatade ii | — sordida ii XVIII | 7 || Trochosphiera aqua- Notommata .. /1i || — tigvidia oles XVIII | 10 || _ torealis oppe||| Notommata iequalis | ii || Pterudinade . sii || Tubicolaria naias . | | CIO Re pe te pes es ee Plate XXVI XXXVI XXVI XXVI XXVI XXVI XUI nH Ki b I al XXII XXII XXII XXI XXI XXX IV XXI XXI XXI XXI XII XII XIII XIII XVII XVII XII1 XIII XII XVIII D i) snp Oran ona r0o bl 1. Colurus deflexus la. ” ” 2. Colurus Micngatininey 2a. ” ” 3. Colurus obtusus 3a. ” ” 3D. ¥) ” 3c. ” ” 4. Colurus ccelopinus 4a. ” ” 4b. 5 . 5. Colurus amblytelus . 5a. ” ” 6. Colurus caudatus 6a, ” ” 6D. ” ” 7. Monura colurus Ta. ” ” 8. Mytilia Tavina 8a. ” ” 8b. ” ” 8c. ” ” . 9. Cochleare staphylinus 9a. ” ” 10. Cochleare turbo 10a. ” 11. Pterodina aefitae lla. ” ” 110. ” ” lle. 5 12. Pterodina Renae vanity 12a, ” ” 13. orersdina valvata 13a. 5 ' 14. Pterodina akin 14a. ” ” 15. Pterodina maneron ate 15a. 1 5 16. Pterodina truncata 17. Pterodina elliptica PLATE XXVI. dorsal view . ‘ side view, head rotated : . dorsal view . side view side view, head retracted! side view, head protruded ventral view 5 obliquely ventral view side view 4 extremity of foot, al too junction of foot and toe . ventral view side view ventral view side view rear view side view, head proeaced side view, head retracted ventral view di ; side view, head and foot meoreiied : side view, head and foot retracted . trophi. . dorsal view side view dorsal view side view dorsal view ventral view, head oteacted side view front view dorsal view ventral view, head and foot potratted ventral view : dorsal view, lorica folded . dorsal view j dorsal view, head meuncted dorsal view 5 ventral view, lorica . ventral view lorica, ventral view . AQ ORR RHEE HHH ARARARARRAAAARAAARAARRARAARAARARD a a a, del VIVATVA del , VUILdGITIG d “Al VIVINNYL d ST VIYNOSINW d St VIVadkT9 (4) VNILVdd Zl YNilvd di] O84NL H309 OUSONIIAHAVLS "HI09 6 YNIAVI'A TILAIGNY 3S SNNIdOTDII+ SNSALEO Oe Shit tar Van DOD t Wi LA Snlvanvs 33 SNTaL “VNICOGAILd AAV a ims — oy 2 @ 1. Pompholyx complanata la. ” ” 1b. 0 96 le. ” ” 1d; er Gs +s 2. Pompholyx suleata 2a. ” ” 2b. ” ” VX DY) fra oe 3 3. Brachionus pala ba. ” ” 3d. 4 I 8c, 3d, 3e. x) Bf. ” ” 4. Brachionus angularis 4a. ” ” 5. Brachionus rubens 5a. . 5D. 5 5e. 7 % 5d. " + 6. Brachionus urceolaris Ga. ” ” Brachionus Miilleri W ” ” 8. Brachionus Bakeri 8a. ” ” PLATE XXVII. dorsal view, extended . dorsal view, retracted . front view outline of corona occipital and pectoral edges of lorica . dorsal view . side view front view trophi. dorsal view ventral view side view 5 : lorice of three varieties male , lorica, dorsal view lorica, ventral view dorsal view, extended dorsal view, retracted hind end of lorica end of foot . brain and eye dorsal view male dorsal view . extremities of lorica male penis and foot spermatozoa dorsal view. male MDAAARAGRMAHAOPAMHHMOMHHHeatHaanaga ‘ TWauva de TdagTTOW d Z crav1070an a9 SNaaNue as SINVININVEY Vivd & ¢ W1V3 ‘SONOIMIVEE “XLIOHANOd esata pane Sd Z VIVNVIdNO) di PEA PY Fuorpay |) ‘a*RPH *CC ETL Nhe Y % PLATE XXVIII. 1. Eretmia tetrathrix . dorsal view 2. Eretmia trithrix . side view 3. Brachionus pala . variety; dorsal view Ba. 3 " . variety; ventral view 3b. 43 ; . male, side view 3c. PA c . male, dorsal view 3d. 5 ey . female egg 4. Brachionus Doreas . dorsal view 4a. ee PA . side view 4b, ‘i 0 . male, dorsal view 4c. 5 ‘ . male, side view 4d. a * . vVibratile tag . : a 5. Noteusquadricornis. dorsal view; to show viscera . 5a. on . . lorica, dorsal view . A 0 5 5 0 6. Notholea longispina . lorica, obliquely dorsal view 6a. 5 " . lorica, side view 6b. > " . trunk, dorsal view 6c. fe " . trunk, ventral view 0 q 6d. 0 ” . top of lorica, ventral view; to: show moy 7able Aap Be ee onen Suncanic tere wees vee BRACHIONUS; NOTEUS; ERETMIA; NOTHOLCA. 6d, C.T.Hudson ; © einen fad vive IE. TETRATHRIX.2.E TRITHRIX 3B.PALA(? ) 4B.DORCAS 5.NOT. QUADRICORNIS. 6.NOTH LONGISP. 1. Notholea seapha . la. ” ” 1b. H eee 2. Notholea thalassia 2a. 54 on 2b. H » 2c. i sre a 2d. A ier 3. Notholea acuminata 3a. = “A 4. Anurea aculeata. 4a. | iy ! 4b. 5 igs 5. Anuriea brevispin 5a. 0 si 6. Anurea hypelasma 6a. 7 ” 6b. i 3 7. Anurvea cochlearis Ta cp ” 7b. ” ” 8. Anurea serrulata Ba. | a 8b. sp y 9. Anuriea curvicornis 9a. Fi ie 10. Anurea tecta 10a. ,, as A 100. ,, 5p : 11. Eretmia cubeutes lla. $5 3 5 12. Eretmia pentathrix PLATE XXIX. dorsal view, extended dorsal view, retracted transverse section dorsal view . lorica, dorsal view lorica, side view lorica, pectoral edge trophi dorsal view side view dorsal view side view : mastax and trophi dorsal view side view dorsal view ventral view, with eggs attached . transverse section . dorsal view side view rear view dorsal view lorica, dorsal view lorica, side view lorica, dorsal view lorica, side view dorsal view lorica, side view rear view : lorica, dorsal view lorica, side view lorica, dorsal view DAA AARAARAARRAARRAAARARAARRAAARARAAA Pl. XXIX 6a iia Mi od — MN a — ro ) A 9a ~ a annart “a9 @. PLATE XXX. 1. Pedalion mirum : . side view. H la. * : . dorsal view H 1b. r y 5 . front view 5 ; H ilies 7 * : . side view (side ieabe ea) snort viscera H ld. PA i ; . dorsal view, showing muscles . H a, dorsal limb (1, depressors (2, elevators 8, inner lateral limb ie dapressors 4, elevators y, outer lateral limb | b; depressors 6, elevators 3S. saute limb {© depressors (8, elevators The ventral depressors (5, 5), of the outer lateral limbs, meet a similar dorsal pair on the mid-dorsal and mid-ventral surfaces; and the four together encircle the body. There is a similar encircling set of four (1, 1) belonging to the dorsal limb. le. “ mi : . ventral view, showing muscles 3 : a JEL 9, ventral longitudinal muscles for retract- ing head If. “p 5 . . side view, showing muscles . : =) 10, dorsal longitudinal muscles for eee ing head 11, right depressor of dorsal antenna 12, circular muscles of the neck 13, right depressor of chin 1g. - < . . male, dorsal view . : : 5 7 5 18! 1h. oo - , . male, side view F A 6 5 P > del 2. Hexarthra polyptera . dorsal view . , . (after Dr. Schmarda) 3. Cicistes ptygura. . head, dorsal view, showing hooks . 9 = Ef 4. Seison Grubei . : . female, retracted; side view 4a. 3 FA ; ‘ . male, extended; side view + (after Dr. Claus) Ab. 5 ' a ; . trophi. 5 . F F 3 : : F eee ey ae “a (after Prof. 5. Drilophaga bucephalus . side view; attached to Lumbriculus| Vavaoealee ejdovsky) 6. Balatro calvus . a . ventral view . 0 (after M. Ed. Claparéde) 7. Copeus spicatus c . side view. : a D 5 ‘ c a des 8. Brachionus Miilleri . . ventral view . 5 : A ; a lat 9. Brachionus angularis . dorsal view ; H 9a. " Siar he . aperture for lateral antanin r A i 5 dsl 4) a pie ov at Al ‘ | . ) + 7 f > { i ii fi f 5 | e i , ai . | ‘é ioe , Aaa > i ‘a ‘3 ees = ae fen 1) ™ = a ae ; 1 2 ‘ d - ‘ ad —_ 5. ; = ee ee @ - i i t " M /} I NS as A> “ye a d e n“ 7 e | i B ie] fal a) & , A. a2) 8 y : fa - re MS : 4 a ¥ Listh. 3 6.3 > - eas i s (™m ‘ A Xs) 70 SPICATHS:6,BRMUI oe K % iy 5 un 3 ae = mE a : wo “ < : gs Dx. 4 wy a [=| i oa B oO Aa pa 6 NS = a =. Au JP e018) deOM Ia lesc SUPPLEMENT. PRINTED BY SPOTTISWOODE AND CO., NEW-STREET SQUARE LONDON THE ROTIPEHRA ; OR Prem hp NE MA CU ie, S; BOTH BRITISH AND FOREIGN. BY Cc. T; HUDSON, LL.D. Canras., F.R.S. ASSISTED BY P. H. GOSSE, F.RS. SUPPLEMENT. WITH ILLUSTRATIONS. LONDON: HONG MANS Gina N, AUN DCO; AND NEW YORK: 15 EAST 16% STREET. 1889, Jel eidad a 0G 1 he Ir was originally intended that the two volumes of the ‘ Rotifera’ should contain all the foreion, as well as all the British species; but, while the work was being written, so many new British forms were discovered, that want of space compelled the authors to omit all but a few of the more remarkable foreign Rotifera. The Supplement, however, now remedies this omission ; and completes the work, by describing every known foreign species, as well as the British that have been discovered since its publication in 1886. Upwards of one hundred and fifty species ' have been added, in the Supplement, to the two hundred and fifty already described in vols. i. and ii.; and, in almost every case, the description is ac- companied by a figure. Besides these, more than forty doubtful, or imperfectly described species, have been briefly discussed, and occasionally illustrated. Both the descriptions and drawings of the foreign species have been taken from the original memoirs in which they first appeared ; the doubtful, or insufficiently described species, as well as the mere synonyms, being distinguished from the others by their position in each genus, and by the arrangement of the type. The Bibliography has been considerably enlarged, and now exceeds two hundred memoirs, the greater part of which I have studied: all of them directly refer to the subject, and most of them are well worth the reading. It is hardly necessary to add, that the labour of condensing such a mass of materials into a short Supplement has been great ; especially when conflicting statements had to be weighed, and there was no opportunity of checking them by observations on the animals themselves ; but I was anxious to complete the work, and ’ Sixty of these are new British species discovered by Mr. Gosse. vi THE ROTIFERA. specially anxious that my colleague’s last discoveries should be placed where he himself wished to have them. The natural pleasure, with which I see the observations and studies of thirty-five years thus brought to a successful conclusion, has been indeed marred by the sad loss of my deeply lamented friend. His great knowledge and experience, his keen powers of observation, his artistic skill, and his rare gift of description are known to all, and have made him facile princeps among the writers on the Rotifera; but it is only those who, like myself, were privi- lezed to know him intimately, that are aware how much more he was than an enthusiastic naturalist. I shall never forget the hearty welcome (when I first met him) that the veteran gave to the com- paratively unknown student, or the gracious kindness with which he subsequently placed at my disposal his beautiful unpublished drawings and his ample notes. A happy chance had led our observations to differmg parts of the same subject, and our united labours have produced, in con- sequence, the now completed work; but I shall ever count it a still happier chance, that gave me not only such a colleague, but also such a friend. Cc. T. HUDSON. CONTENTS OF (ERR SU ese he MEN —08g400—_. PAGE FLOSCULARIADE . j : F ‘ - : : a) h3 MELICERTADD : : : : . F : : sed PHILODINAD® : : : : ; : : : 5 Ou ADINETADE é : : ‘ : ‘ : ‘ = ip ASPLANCHNAD® : ‘ : : ; E P ‘ een2 SYNCHAITADA . é : ; : : ; ; : 5 iy TRIARTHRADAS : : : 5 : : : : . 18 HYDATINADE . : : , 3 F : : : es NOTOMMATAD® : : 4 ; : ; : : . 19 SEISONIDEH ; ‘ : : i ‘ : : 5 RATTULIDA . ; : : : : ‘ : : 5 BS DINOCHARIDA® . ‘ : : : : : : 5 5 8G SALPINADE 37 EUCHLANIDA . : : : : : : ‘ ‘ a oe CATHYPNADE . 3 : ; 3 : . ‘ : 5 a COLURIDE. : : ‘ ‘ : : : : 5 OG PTERODINAD ‘ : ‘ ; ; : : : . 50 BRACHIONID® . 50 ANURMHADE ; : : : ‘ : ; : ad DOUBTFUL AND REJECTED GENERA. : : : ; 5 ADDENDA AND CORRIGENDA ; ‘ ‘ : 5 : . 61 BIBLIOGRAPHY (continued from vol. ti.) . E ; : oY INDEX OF FAMILIES, GENERA, AND SPECIES (continued from vol. ti.) 63 SUPPLEMENT TO Oe Eel, Oe SAG: OR WHEEL-ANIMALCULES. BY C. T. HUDSON, LL.D. Cantas., F.R.S. All these things, I say, declared by Jason of Cyrene in five books, we will assay to abridge in one volume. We have been careful, that they that will read may have delight, and that they that are desirous to commit to memory may have ease, and that all, into whose hands it comes, may have profit; leaving to the author the exact handling of every particular, and labouring to follow the rules of an abridgement. For to stand upon every point, and to go over things at large, and to be curious in particulars, belongeth to the first author of the story; but to use brevity, and to avoid much labouring of the work, is to be granted to him that will make an abridgement.—Book ii. of the Maccabees. We continually forget, that brutes have not the advantage of obtaining accurate ideas, by spoken or written language. We do not realise the immensity of their ignorance. That ignorance, in combination with perfect cerebral clearness (ignor- ance and mental clearness are quite compatible), and with inconceivably strong instincts, produces a creature whose mental states we can never accurately under- stand. The impossibility of knowing the real sensations of animals—and the sensations are the life—stands, like an inaccessible and immovable rock, right in the pathway of our studies.—P. G. Hamerton, “ Chapters on Animals.” The earth may smile, And deck herself, each May, vain thing! with flowers, And seem forgetful of the cruelties Enacted on her ever-changing stage, Till every spot, upon the storied surface, Is rank with tragic memories. The earth may smile, I say, But, like a new-made widow’s mirth, it shocks one. Sir Arruur Herpes, “ Realmah.’ There is much slaughter in the world of brutes, but there is little slavery; and the killing is done with merciful rapidity, ending life whilst its pulses still beat in their energy, and preventing infirmity and age. The brute creation has its diseases, but on the whole it is astonishingly healthy. It is full of an amazing vitality. The more we study animals, the more evident it is that they live, for the most part, in a heaven of exuberant health. That gladness which we seek, how often vainly, in artificial stimulants, the brute finds in the free coursing of his own uncontaminated blood. Which of us has not envied the glee of his own dog 2— P. G. Hamerron, “ Chapters on Animals.” ‘Tis a very excellent piece of work, madam lady: would ’twere done.— SHAKESPEARE, “ The Taming of the Shrew.” eS U2e 2 EH BN a, FLOSCULARIAD. Froscunaria Minus, Kellicott (180), (Pl. XXXII. fig. 1), SP. CH. Lobes five; of very great length; extremely slender, twig-like, without knobs ; fringed with two opposite rows of cilia, not in whorls. This elegant and very curious creature was found, by Dr. Kellicott, in Black Creek, Ontario, U. §., on Utricularia vulgaris, in 1885.