'HE ROTJHERA WHEEL-ANIMALCULES THE KOTIFEBA. VOLUME II. PRINTED BY SPOTTISWOODE AND CO., NEW-STREET SQUARE LONDOU H THE EOTIFEKA; OE WHEEL-ANIMALCULES BOTH BKITISH AND FOKEIGN. BY C. T. HUDSON, LL.D. CANTAB., F.R.S. ASSISTED BY P. H. GOSSE, F.E.S. IN TWO VOLUMES, WITH SUPPLEMENT. VOLUME II. WITH ILL USTIiA TIONS. LONDON : LONGMANS, GREEN, AND CO. AND NEW YOBK : 15 EAST 16th STEEET. 1889. All right* 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 toturn suae Patere menti, ferre qui non sufficit Mediocritatis conscientiam suee, Judex iniquus, estimator est malus Suique naturaeque ; nam reruin parens, Libanda tantum quse venit mortalibus, Nos scire pauca, multa mirari jubet. GROTIUS. CONTENTS OF THE SECOND VOLUME. CHAPTER IX. PAGE PLO'IMA (IL-LORICATA — continued) ...... i CHAPTER X. PLODIA (LORICATA) ....... CHAPTER XL SCIRTOPODA . ADDENDA . . . . - . 13 t APPENDIX : THE VASCULAR SYSTEM . THE SETIGEROUS SENSE-ORGANS . . . .139 BIBLIOGRAPHY OF THE ROTIFERA ...... 110 INDEX ..... ..... 143 CHAPTER IX. PLOIMA IL-LORICATA— continued.) VOL. II Les actions des betes sent peut-etre un des plus profonds abimes su. quoi notre raison se puisso exercer; et je suis surpris que si peu de gens s'en apcrooivent. — BAYLE. 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. — YOUNG. CHAPTER IX. Family VIII. TRIARTHRAD.E. 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 denned ; while Poly- arthra, widely unlike either, has a mastax and trophi closely resembling those of Synchceta. Polyarthra, moreover, is still further separated from Pedetes and Triarthra by having one occipital eye, instead of two frontal. Genus POLYAETHEA, 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 Synchceta ; 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 Synchceta, it possesses but one occipital eye. On the other hand its skipping spines naturally place it with Triarthra 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. TLATYPTERA, Ehrenberg. (PL XIII. fig. 5.) Polyarthra platyptera^ . . Ehrenberg, Die Infus. 1838, p. 441, Taf. liv. fig. 3. . Leydig, Ueb. d. Ban d. Rciderth. 1854, p. 42, Taf. i. fig. 10. „ „ . Gosse, Phil. Trans. 1856, p. 435, pi. xvii. figs. 44-49. . . „ „ „ 1857, p. 320, pi. xv. figs. 27-29. . . Plate, Jcnaisch. Zeits.f. Natur. 1885, p. 16, Taf. i. fir. 4. 1 Ehrenberg's P. trigla is possibly P.platyptem with the blades seen edgewise. B 2 4 THE KOTIFEBA. 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. Be] and being distinctly serrated on both edges. The corona is slightly convex and bears, towards the dorsal surface, two prominences like those of Synchceta 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 Synchcsta 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.1 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 -^ inch. The head is very large (fig. 5/t) 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 setae) 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, ^^ inch. Habitat. Pools and ponds : common. Genus PTEROESSA, Gosse. [GEN. CIT. Lorica entire, save for a large oval opening behind; beset with arti- culate pinnate, styles, and simple setae : foot wanting. P. SURDA, Gosse, sp. nov. (PL XIII. fig. 9.) RP. CH. The only known species. Horny yellow ; pinnae twenty -four, in six longi- tudinal roics. 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 1 An observation of Mr. Gosse's leads him to think that the rectum is turned far forward as in the Eh:~ota ; and that it IB capable of considerable protrusion, though ordinarily invisible. TRIARTIIRAD/E. .1 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 setse, jointed to knobs ; while from the breast, exactly opposite, there issues another, similarly jointed but of great length, descending far behind the extremity of the body. But the chief peculiarity of the creature is that four-and-tvventy styles, regularly arranged, are affixed to the lorica, giving a most unique aspect to it. For every one is a feather in appearance ; the shaft, moderately long and stout, being beset, on its two opposite sides, with regular pinnules like those of a fern (Polypodium, for instance), in considerable number, length, and regularity (fig. 9c). These pinnae 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 ROTIFERA 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 Scaridium eudactylotiim. From the condition of the lorica I have little doubt that it had come to me alive ; but being occupied with the new Scaridium I did not search closely. — P.H.G.] Length. Of lorica, y]-^ inch ; to tips of pinnae, ^3 inch ; from brow of lorica to tip of ventral seta, T\- inch. Habitat. Loch near Dundee (P.H.G.). Genus TRIARTHRA, Ehrenberg. GEN. CH. Spines single, two lateral, one ventral; eyes two frontal ; mastax of moderate size ; tTOTphimallco-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 oesophagus. The first of these characters is one that cannot be much relied on except in the case of T. brcviseta ; 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 T. longiseta possesses this separation and that T. 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 divided into in- testine and stomach. THE ROTIFEKA. T. LONGISETA, Ehroibcrg. (PI. XIII. fig. 6.) Triarthra longiseta . . . Ehrenberg, Die Infus. 1838, p. 447, Taf. Iv. fig. 7. „ „ ... Hudson, Mon. Micr. J. vol. i. 1869, p. 176, pi. vi. „ „ ... Grenacher, Sieb. u. Koll. Zeits. Bd. xix. 1869, p. 491, Taf. xxx vii. fig. 3. SP. CH. Body oval; buccal orifice prominent but not beaked, cup-sJiaped; spines more than twice the length of the body ; eyes wide apart; oesophagus 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 buccal funnel slopes backwards and upwards towards the dorsal surface to meet the mastax, whose trophi are almost identical with those of Melicerta ringens. The asophagus 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. I have 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 is a 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. (>/) 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 antennae, one on each side (fig. 6e) just under the surface. Each eye (fig. 6b) is a clear, colourless, refracting sphere -j^Vo mcu m diameter, resting on, and partly imbedded in, a flat plate of red pigment. The longitudinal muscles are very powerful, and are strongly striated ; the strict not being straight transverse lines, but irregular obliquely transverse curves (fig. Gc). 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 stria», 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 ventral surface, at the spot from which the foot springs, in those Eotifera that possess one. The spines are notched hero and there (fig. GtZ), 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 stiff ventral cuticle. Fine muscular fibres surround the trunk at regular TRIARTHRAD.E. 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, T£7 inch. Habitat. Fresh-water ponds and ditches : common. T. MYSTACINA, Ehrenberg. (PI. XIII. fig. 8.) Triarthra mystacina . . . Ehrenberg, Die In/us. 1838, p. 447, Taf. Iv. 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 ; oesophagus 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 oesophagus — the stomach coming into contact with the mastax — marked the species as Ehrenberg's mystacina. The absence of the oesophagus is doubtless only apparent, this duct, as is the case with Polyarthra (see PI. 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. The stomach is large and saccate, and is supplemented by a distinct intestine. The animals are very subject to be infested by two species of Colacium, which are seen in fig. 8. They cling to its ppines 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 seise, ^ inch. Habitat. Around London : ditches and orna- mental waters (P.H.G.. T. BEEVISETA, 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 ventricose, and extends much beyond the base of its spine ; the belly is deeply sulcate, 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 direc- 8 THE ROTIFEEA. tion as the bead 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 oesophagus 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 Grenadier'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, T^ to T]y 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, GOSSC, Sp. 110V. (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, immoveable, 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 immoveable. Dr. Hudson (" M. M. J.") long ago explained the action of the pectoral styles in the parallel case of Triarthra (see T. longiseta, p. G). We may conclude the mechanism to be the same in both cases ; but I arn 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. Each 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. T.he 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 divisionr The only sppe-imen I have seen occurred in HYDATINAD^E. 0 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 T}-G inch. Habitat. A pool near Birmingham (P.H.G.). Family IX. HYDATINAD^. Corona truncate ivith 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 Hydatincea, under the name of Hydatinadce, 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 buccal orifice, which lies just within a deep notch in the wall of the cup 011 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 Bhinops tolerate even very dirty water, provided that it contains an abundance of the minute organisms on which they feed. Genus HYDATINA, Ehrenberg. GEN. CH. Body conical, tapering toicards the foot ; foot short, and confluent icith the trunk ; eye absent. H. SENTA, Ehrenberg. (PL XIV. fig. 1.) Hydatina scnta .... Ehrenberg, Die In/us. 1838, p. 413, Taf. xlvii. fig. 2. „ Cohn, Sieb. u. Ktill. Zeits. Bd. vii. 1856, p. 430, Taf. xxiii. „ „ Leydig, Mailer's Archiv, 1857, p. 404, Taf. xvi. „ „ Hudson, Mon. Micr. J. vol. ii. 18G9, p. 22, pi. xix. H. senta is one of the largest of the Rotifera, and its flashing styles, lAiddy teeth, and yellow stomach, often stuffed with brilliantly green Euglence, 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. Ib), 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 EOTIFEEA. also on its whole surface, and may fairly be considered to be the buccal 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. la), 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 styligerous 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 antennae (fig. la, 16), and the other two nerve-threads pass to the dorsal antenna (fig. Ib). 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 Enteroplcea 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. In. 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 -g-flfl- inch in length, and swims up and down its host's stomach by jerking the contents of its body constantly backwards and forwards (figs. lh, Ik). There are curious bodies inside the parasite itself something like the globe of a lamp in shape (fig. 11). Length. From ^ inch to ^ inch. Habitat. In water swarming with Euglena, &c. : common. Genus BHINOPS, Hudson. GEN. CH. Body conical, tapering to the foot ; a long 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. E. VITKEA, Hudson. (PL XIV. fig. 2.) Bhinops vitrea .... Hudson, Ann. Nat. Hist. 4 Ser. vol. iii. 1869, p. 27, pi. ii. ,, „ .... Plate, Jenaisch. Zcits. /. Natur. Bd. 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 Eotiferon, 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 tho eyes is free from cilia, and seems to act HYDATINAD^. 11 as an organ of touch. The inner ciliary wreath consists of larger cilia which are some- times held erect. The oesophagus is long and narrow, and the gastric 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 has an 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. Bhinops vitrea usually swims at a moderate pace, rolling gentlj round its longer axis as it goes, and every now and then bending back its proboscis, or turning somersaults as Synchceta 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 Algce, 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.1 Length, ^ 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- pital. 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 Hydatinadce 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. BRACHIONUS, Ehrcnberg . (PI. XV. fig. 1.) Nutommata Iracliiomts . . . Ehrenberg, Die Infus. 1838, p. 433, Taf. 1. fig. 3. „ Leydig, Ueb. d. Ban d. Raderth., 1854, p. 99. „ „ Hudson, Man. Micr. J. vol. xiii. 1875, p. 46, pi. 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 Eotifera 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 Peak in 1 Dr. Plate (loc. cit.) says that /?. ritrea has but one toe. 1 thought so myself, till I saw the creature, of its own accord, separate the apparently single toe, into two. 12 THE KOTIFEIU. Ceylon. It is a remarkable Eotiferon, surpassing almost every other in the number and variety of its styles, setae, 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 curved styles, pointing upwards. On each side of the wedge-shaped opening, at the entrance to the buccal funnel, are large setse set horizontally above one another in short sheaths, and fringed at their bases with minute vertical setse (fig. Ic). The trophi are malleate, and Mr. Gosse says that they are the exact repetition of those of N. clavulatus (Notommata clavnlata) as figured by him in " Phil. Trans." 1856, PI. xvi. fig. 23. 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 scnta ; and, like it, giving off nerve-threads at its corners, two of which doubtless pass to the large dorso-lateral antennae 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 summit. 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, and a side view (fig. Ib) shows that the head slopes back to a hump, on the apex of which is a bunch of tactile setse. A nerve-thread from the nervous ganglioa passes to these, and lies between two fine muscular fibres. A moderately sized spsim- 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.1 Length, ^j inch. Habitat. Ponds and pools ; Clifton (C.T.H.); Kingswood(P.H.G., T.B.) : not common. N. CLAVULATUS, Ehrcnbcrf/. (PL XV. fig. 3.) Notommata clavnlata . . . Ehrenberg, Die In/us. 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. brachiomis and N. clavulatus, it will be found that they are, in many important points of their structure, exact counterparts of each other. The coronas, for instance, are closely alike, although N. clavulatus has a greater number of styligerous lobes, and lacks the ring of curved styles that lie 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 N. clavulatus. The contractile vesicle in the latter, however, has much thicker walls, and is sluggish in action. The eye is seated on the 1 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. granular is, and which he credited with laying its eggs on the backs of Bracliiomis pala and Notops bracJiionns. Leydig explained the error (he. ci'r.l. HYDATINAD^E. 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. 8a) 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. Ib). The ovaries in both species are flat horseshoe-shaped ribbons bearing a single row of germs. The chief points 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 casca 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, 5J5 inch. Habitat. Hampstead (P.H.G.) ; Clifton (C.T.H.) : not common. N. HYPTOPUS, Ehrenberg. (PL XV. fig. 2.) Notommata hyptopus . . . Ehrenberg, Die In/us. 1838, p. 426, Taf. 1. fig. 6. SP. CH. Corona without setigerous 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/o rcipate. Partially loricated. This must be a rare animal ; for, since Ehrenberg found two specimens in 1835, no one but Dujardin and Perty records having seen it. I have 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 oesophagus 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 oesophagus similar to those in Asplanchna and Synchceta ; 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 floccose ribbons, close to the skin : they are well shown in fig. 26. The same figure 14 THE EOTIFEEA. shows the chief longitudinal muscles. The ovary (fig. 2a) is very large, and has largo germs : a maturing ovum is visible in fig. 2. A large nervous ganglion of Notommataa type stretches back from the corona to the dorsal surface and bears a large red eye. I failed to find any antennae. The male is unknown. Length, ^ 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 Eotifera 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 flat 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 incus-rami, the fulcrum and the labium — corresponding homo- logically to the labrum, the mandibles, the maxilla and the labium, of insects,1 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 Algaj, 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 vortices in the water. The Notommatada are the most highly organised of all Eotifera ; 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 Furcularia and the Loricata, through Diascliiza, is very close : that Proales, with its long prone face, leads to the Bdclloida through Adineta : that the skipping species of Furcularia, as longiseta and cequalis, look towards the Scirtopoda : and that in the mucous investiture common in the genus Copeus, we perceive a reflection of the excreted tubes of the Bhizota. — P.H.G.] 1 Sec my mem. " On Mand. Organs," Phil. Trans. 1855 p. 449. NOTOMMATADJE. 15 Genus ALBERTIA, Dujardin. [GEN. CH. Body vermiform, lengthened ; ciliated face sub-prone ; eyes wanting ; jaws minute, forcipate ; foot small, one-toed. Entozoically parasitic in Annellida. — P.H.G.] A. INTRUSOR, Gosse, sp. nov. (PL XVII. fig. 13.) [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. PI. 22. 1 A, B). 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 following 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 oesophagus 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 sette on it. A long pointed occipital sac descends far below the mastax, but is destitute of any eye-s.peck. 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 *~ ^ parts. I had looked over it with a lens, but had no suspicion that my Nais 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 Nats, 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 BOTIFEKA. 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. Examining 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 faecal matter, which pushed it along. The opacity of the bowel prevented my seeing whether any matured parasites were present or not in this case. — P.H.G.] Length, TJ0 inch ; diameter, ^ff to TTTVff inch. Habitat, Walthamstow (P.H.G.) : entozoic. A. NAIDIS, Bous field, sp. nov. (PI. 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 Nats barbata, living free within the cavity of the stomach of its host." "Body cylindrical, soft, hyaline, vermicular, extremely flexible and telescopic, espe- cially the hinder part. Anterior extremity truncate. Trochal disc small, oblique, on dorsal aspect of body. [One drawing shows that it is invertile, the cilia being depicted far 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, cylindro-conical ; the ova developed serially. A minute contractile vesicle. " Caudal 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 Nats, in which it moves freely. Egg about one-third of length of parent's body. Length, ^^ inch." l — P.H.G.] Genus TAPHROCAMPA, Gosse. [GEN. CH. ~BoA.y fusiform or cylindrical, annulose, furnished with two furcate toes; trophi forcipate ; rotatory cilia wanting or very limited. T. ANNULOSA, Gosse. (PL XVII. fig. 12.) Taphrocantpa annulosa . . . Gosse, Ann. Nat. Hist. 2 Ser. 1851, p. 199. SP. CH. Body cylindrical, short and thick, marked throughout with distinct articu- lations; 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. Each of these, if viewed through the longitudinal line, would be of a sub-square outline, with four projecting angles, as seen at fig. 12&. In general no vortices are seen, nor any trace of vibratile cilia, so that I long concluded 1 Thus the three recorded species differ notably in their respective dimensions : — A. vermiculus being -^ inch to ^ inch (Duj.) ; A. intrusor, 1-ijJ in. (P.H.G.) ; A. na'idis, 5fs in. (Bousfield). NOTOMMATAD^E. 17 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. I 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 Taphrocampa " put out very small auricles from the head, and swim with a slight vermiform movement." He had made a pen-and- ink sketch of the creature in both conditions ; which sketch is in my possession, and represents indubitably T. 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." This fact affords an interesting link with the present family. The form of the mastax and trophi, too, though not yet quite satisfactorily denned, is evidently Notommatous, and seems to resemble the pattern seen in some of the Fur- cularice, and some of the Hattulida also, consisting of an incus with a long fulcrum and a pair of long incurved mallei. The 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 Notommatce, with which it is another link, it lies at the bottom of a wide and deep sac. I 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 I 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 Ckcetonotus, crawling sluggishly about the glass, and the masses of sediment.1 — P.H.G.] Length. About -^^ 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. The 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, mallei, and incus, almost exactly of the same familiar pattern as in Notommata aiirita (PJiil. Trans. 1856, pi. xvi. figs. 16-21). VOL, II. 18 THE KOTIFERA. T. SAUNDEKSI^B, Gosse, sp. nov. (PL XVII. fig. 11.) Taphrocampa Saundersice . . Hudson, J. Roy. Micr. Soc. 2 Ser. vol. v. 1885, p. 614, pi. xii. [SP. CH. Body lengthened, fusiform, annulate; brain clear; a decurved frontal hood; tivo 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 Kotiferous 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 Eotifera. But Dr. Hudson had observed the same species in waier from Birmingham, in July 1884 ; and had prepared a notice of it for the " Journ. Eoy. Mic. Soc." The publication was delayed, however, through press of matter, 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. 11&), 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 undimmished, 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. lla). The front of the head bears a projection, which, on a lateral vievf (fig. Ha), 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.1 The front is oblique ; it is composed of several fleshy 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 1 These seem to be the blades of an incus (of the pattern Fig. 21 of my memoir in Phil. Trans. 18-r)fi, pi. :i.niata ecqiuilts . . . Ehrenberg, Die Infus. 1838, p. 432, Taf. liii. fig. 3. [SP. CII. Indistinguishable from the preceding, save that the toes are equal. Though the resemblance between these two species is very close, Ehrenborg was NOTOMMATAD^E. 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. ^Equalis 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 Scaridium, with which they have apparent affinity, depend, doubtless, on the length and elasticity of the toes : and suggest a certain relation to the Triarthradce, and even to the order SCIRTOPODA, in which, toes being wholly wanting, the same function is performed by special limbs, long, taper, and elastic. — P.H.G.] Total length, about T£T inch. Habitat. Woolston (P.H.G.). Genus EOSPHOKA, Ehrenberg. [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, tivo 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 Eosphora, 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 Eosphora, if it prove to be an eye " (" Die Inf." p. 444). Judging by this species, there is little to distinguish Eosphora 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. AURITA, Ehrenberg. (PI. XVII. fig. 14.) lyialena aurita ) Eosphora aurita . . . \ Ehrenberg, Die In/us. 1838, p. 444, Taf. Iv. fig. 2. „ , Gosse, Pop. Sci. Rev. 1863, vol. ii. p. 475, pi. xx. [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 1 The frontal specks Dr. Leydig denies to be eyes, in the species aurita ; but I have no hesitation in pronouncing them to bo strictly analogous with what we call eyes throughout the class. 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.1 All three are beautifully rich and distinct, even by trans- mitted light. It is indubitably Werneck's Eosphora 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, -j--^ to TJ¥ inch. Habitat. Greenwich Park ; Hampstead Heath ; Birming- ham : pools ; not rare (P.H.G.). Genus DIGLENA, Ehrcnbcrg. [GEN. CH. Body sub-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 larvae, 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 ; aurita is an Eosphora, and has been just described. To the remaining four, seven species are now added. — P.H.G.] D. GEANDIS, 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 in 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 1 Eckstein says that these are connected with the great cervical eye by nerve-threads. 2 Eyferth (On the Lowest Forms of Life, 1878) says that Triophthalmus of Ehrenberg is but the young condition of Eosphora ; and that, even in the egg, are seen two dark specks, near the eye, which subsequently disappear. But Eckstein (Sieb. u. Koll. 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. PLATE XVI. 1. Copeus labiatus .... dorsal view G la. „ „ edges of lip G 2. Copeus spicatus .... dorsal view ...... G 2#, 2b. ., ,,.... side views of head . . . . G 3. Copeus Cerberus .... dorsal view G 3er. ,, ...... side view ...... G 4. Copeus pachynrus . . . dorsal view G 4a. ,. ...... transverse section G 46. ., head, showing buccal orifice . . G 5. Copeus caudatus .... dorsal view G 5a. „ ...... side view ...... G 56. .. ...... mastax and trophi . . . . G 5c. .. .. . . . . occipital antenna G 5d. ,, ...... hind dorsal tentacle G 6. Notommata collaris (?) . . dorsal view ...... H Grt. side view H c •r '~ PLATE XVII. 1. Notommata braehyota . la. 16. 2. Notommata saccigera . Za. 3. Notommata ansata 3«. 4. Notommata tripus 4a. 46. 4c. 5. Notommata pilarius 56. 6. Notommata aurita 7. Notommata cyrtopus la. „ „ 76. 8. Notommata tuba . 9. Notommata lacinulata . 9a, 96. 9c. 10. Eosphora aurita 10a. „ „ 11. Taphrocampa Saundersiae Ha. „ „ • 116. „ „ . 12. Taphrocampa annulosa . 12«, 126. 12c. 12rf. 13. Albertia intrusor . 13(7. „ „ . . 136. „ „ . . 14. Albertia naiadis dorsal view G side view ....... G end of brain, with eye ; side view . . G dorsal view G side view ....... G dorsal view G side view ....... G dorsal view G side view (smaller scale) . . . . G head, showing auricles . . . G trophi ........ G dorsal view G side view G transverse section G dorsal view ....... G side view ....... G central lobe of brain, with eye . . . G dorsal view ....... G side view ....... G trophi G dorsal view ....... G dorsal view . . . _ . . . . G side view ....... G trophi, ventral view . . . . . G trophi, side view . . . . . G dorsal view ....... G side view ....... G dorsal view ....... G side view G transverse section . . . . . G dorsal view ....... G side view G transverse section G trophi, side view ...... G trophi, ventral view G tail (var.) ....... G ventral view ...... G side view ....... G trophi, ventral view G side view . . (after Mr. E. C. Bousfield) .- ; ' .;:' 2-: _ *-" . !-~J as '-'•'. c PLATE XVIII. 1. Notommata forcipata . la. „ „ lb. 2. Notommata naias . 2a. „ „ . 26. „ „ • 3. Pleurotrocha conetricta. 3a. „ „ . . 36. „ „ . . 3c. „ „ . 4. Pleurotrocha leptura 4«. „ „ 5. Pleurotrocha gibba 5a. „ „ G. Proales decipiens . Ga. ,, „ 7. Proales sordida 7a, 76. „ „ . 7c. „ „ . . . 8. Proales gibba 9. Proales petromyzon 9«. „ „ • 96. „ „ . 9c. „ „ . . Qd. „ „ . 10. Proales tigridia 10a. „ 11. Proales parasita lla. „ „ 12. Distemma labiatum 12a. „ „ 13. Distemma Collinsii 14. TriophthulinuB dorsualis (?) . 14*. „ 15. Furcularia sequalis 15a. „ „ . 10. Furcularia longiseta 16a. „ „ . . 17. Proales felis .... 17a. „ „ . 176. dorsal view . side view . toes .... ventral view head ; dorsal view rnastax 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 .... G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G v^ "*^ JL' I f • W /'»». 1. vy PLATE XIX. 1. Distemma raptor la. 16. le. 2. Diglena forcipata 2ff. 26. 2c. 8. Diglena biraphis 3(T. ,, ,1 4. Diglena circinator 4ff. 46. 5. Diglena clastopis 5a. 0. Diglena grandis . Ga. „ „ 7. Diglena gibber . 8. Diglena cautlata '.). Diglena giraffa . £ LD £-. .— O a u PLATE XX. 1. Furcularia forficula . la. „ ,, 16. 2. Furcularia Boltoni 2a. 3. Furcularia ensifera Sa. „ „ 4. Furcularia caeca 4a. 5. Mastigocerca bicornis . 56. 6. 6a. 66. 7. la. 8. 9. 9a, „ 10. Mastigocerca lophoessa Wa. 11. 12. 13. 13«. „ „ . 136, 18c. 14. Rattulus cimolius Mastigocerca stylata . Mastigocerca carinata Mastigocerca elongata Mastiocerca rattus . Mastigocerca scipio . Mastigocerca macera . Rattulus tigris . 146, 14c. 15. Rattulus sejunctipes . 15rt. 16. Rattulus calyptus 17. Rattulus helminthoides 17rt. 18. 18d. Ccelopus porcellus 186. 18c. 18d. 19. Ccelopus tenuior . 19«, „ . . 20. Ccelopus minutus 20«. 21. Ccelopus brachyurus . 22. Ccelopus cavia dorsal view ..... side view ..... toe dorsal view ..... side view ..... dorsal view ..... side view ..... dorsal view ..... side view dorsal view side view ..... muscles side view mastax and trophi muscles ..... side view ..... insertion of toe .... side view ..... dorsal view side view side view empty lorica .... side view ..... side view ; dead .... side view ..... mastax and trophi foot and toes .... dorsal view ..... side view mastax and trophi dorsal view ..... side view ..... side view ..... obliquely ventral view . side view side views ..... front of lorica .... transverse muscles ; and toes, apart toes, one within the other . dorsal view ..... side view dorsal view . . . ... side view ..... side view ..... side view G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G X • — ( PM t- t; E-. c en — ' a, u, o NOTOMMATADvE. 40 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 each 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. GIBBEK, Gosse, sp. nov. (PI. XIX. fig. 7.) [SP. CH. Body encased in a transparent leathery sheath, hunch-backed; face prone ; frontal proboscis small ; toes long, deciirved. In sediment from one of my window-reservoirs, I found this large Diylcna. 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 hi 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 incus 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. The 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 floccose 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.U.G.] VOL. II. E 50 THE EOTIFEBA. Length. Of head and body, ^ inch ; of toes, -^ inch ; total length, about j$ inch ; vertical height at hunch, about ^ inch. Habitat. An aquarium (P.H.G.). D. FORCIPATA, Ehrenberg. (PI. XIX. fig. 2.) Diglena forcipata . - . Ehrenberg, Die In/us. 1838, p. 443, Taf. Iv. fig. 1. [SP. CH. Body cylindric, rather stout, obtuse at each end; face long, prone; trophi typically fo rcipate; 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,1 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.Gr.] Length, -^ to 7J2- inch. Habitat. Domestic aquaria near London, and Torquay (P.H.G.) ; Sandhurst, Berks (Collins). D. CIRCINATOK, Oosse, sp. nov. (PI. XIX. fig. 4.) [SP. CH. Body slender at each end, gibbous in the middle; proboscis acute; niastax 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 to a 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 decurved, 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 Mom. " On the Hand. 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 l^ave little doubt, the present species. NOTOMMATAD^E. 61 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. 4b. 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, T^ inch. Habitat, An aquarium at Torquay ; Dundee (P.H.G.). D. GIBAFFA, GoSSe, Sp. nOV. (PI. 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 front 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 every 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 a right-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, T^ inch. Habitat. Woolston (P. E.G.) : rare. D. CAUDATA, Ehrcnberg. (PI. XIX. fig. 8.) Diglena caudata . . . Ehrenberg, Die In/us, p. 4<15, Taf. Iv. fig. 6. [SP. CH. Body cylindric, long, slender ; front broadly truncate, with two frontal colourless eyes; foot short, rcri/ thick, with two long straight slender toes. It is excessively versatile and variable in form, constantly contracting into inde- E 2 52 THE ROTIFEKA. scribable shapes (of which fig. 8b may serve as an example), with various sharp folds and angles. 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. I 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 Vf5 inch. Habitat. Woolston (P.H.G.) ; Sandhurst (Collins). D. PEKMOLLIS, Gosse, sp. nov. (PL XIX. fig. 11.) [SP. CH. Body extremely soft and versatile inform, swollen in the middle, broad and truncate in front, tapering behind to a thick and long foot ; toes tw o 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 Eotiferon 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 venter. 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 ^-0 inch. Habitat. A pool near Dundee (P.H.G.) D. CLASTOPIS, Gosse, sp. nov. (PL XIX. fig. 5.) [SP. CH. Body cylindric, long, slender; front rounded, without visible hook; foot long, slender, icitli tico long dccurred toes. NOTOMMATAD^E. 58 I am 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 Diylena, 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, Tj^ inch. Habitat. Sandhurst, Berks (P.H.G.). D. CATELLINA, Ehrenberg. (PI. XIX. fig. 10.) Diglcna catellina . . . Ehrenberg, Die Infus. 1838, p. 444, Taf. Iv. 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 occurred 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))Tr to ,1^ inch. Habitat. A garden near London; a pond at Snaresbrook (P.H.G.) ; Sandhurst (Dr. Collins) ; marine tide-pools in the Firth of Tay (P.H.G.). DIGLENA (?) BiRArms, Gosse. (PI. XIX. fig. 3.) Diglena (?) biraphis . . . 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 KOTIFERA. protrusile ; alimentary canal very large, projected behind and above the mastax, 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 my 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 Euglena], 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- nivorous 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, T ^ inch. Habitat. A garden-pan near London (P.H.G.) : rare. Genus DISTEMMA, Ehrcnberg. [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. setigerum clearly belongs to the family Battulidce ; 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, Gosse, sp. nov. (PI. 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. Ic). 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, !«•), quite straight, thus differing from the proboscis of Diglena. The lateral projections, when this NOTOMMATAD^l. 65 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, hut 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 denned ; but in some specimens they are quite invisible. The trophi consist of an incus, with rami broad and circularly forcipate, on which work slender bowed mallei (fig. lb}. 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 Kotifera. 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 Eotifera, 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 buccal funnel, to reject it instantly. The jaws were protruded and retracted every moment with lightning-like rapidity. Now and 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 Eotifera 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 l 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 vigour with which it seizes them, are admirable, and quite unparalleled among Kotifera, 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 Distemma a person of great decision of character. — P.H.Gr.]. Length, (as in figs 1, la) T^ inch. Habitat. Tay-mouth : tide-pools (J.H.). • D. COLLINSII, Gosse, sp. nov. (PL XVIII. fig. 13.) [SP. CIL Body cylindric, long; head large; foot stout; toes two, furcate, long, slender, unnotchcd, 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, 1 " 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. Wherever 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 Aniin. pp. 47, 17. 66 THE EOTIFEEA. which are thick, decurved at the tips, and of a length equal to one third of tlie 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. (?) LABIATUM, Gosse, sp. nov. (PI. 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 in a moment it was new to me, but my attention was already occupied. There were in that live-box, at that instant, three or four Eotifera 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 cmbarras des richesscs. What could I do ? 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 outre 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. I can find nothing in Ehrenberg with which satisfactorily to identify it. — P.H.G.] Length. About T^ 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- gnosis ; and there arc no descriptive notes. I have not myself met with anything like it. — F.H.G.] CHAPTBE X. PLOIMA (LORICATA). How much weariness has there been in the human race during tho 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. HAMKRTON. 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 lie know, by the strength of his understanding, the secret and internal motions of animals ? — MONTAIGNE. CHAPTER X. Sub-Order LOEICATA. Integument stiffened to a wholly, or partially, inclosing shell ; foot various. Family XI. BATTULID^E. [Body cylindric or fusiform, smooth, without plicce 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 ; bicornis 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. GO--62 of my Memoir " On the Manduc. 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 antennae 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 Ccelopus. 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 MASTIGOCEECA, Ehrenberg. [GEN. CH. Body fusiform or irregularly thick, not lunate ; toe a single style, with accessory stylets at its base ; lorica of ten 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 O3sophagus, a sinuate duct, leads from it almost at its very summit occipitally, just where the mallei work upon the incus. 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 Eotifera 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 foofc-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. CAEINATA, Ehrenberg. (PL XX. fig. 7.) Mastigocerca carinata . . . Ehrenberg, Die Infus. 1838, p. 4CO, Taf. Ivii. fig. 7. [SP. CH. Body long-oval ; lorica ridged ; ridge high, arched, reaching to middle of body ; toe straight, equal in length to body -ami-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 (i.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 alulre 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, TJ)7T inch ; of toe, Tl 0- inch ; depth to summit of ridge, L, J0- inch. Habitat. Pools ; generally distributed : common. M. LOFHOESSA, Gosse, sp. nov. (PL XX. fig. 10.) [SP. CH. Body long-oval; dorsal ridge reaching to the foot, nearly uniform in height ; toe straight, two-thirds as long as body ; sub-styles one-third of toe-lcmjth. 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 micrometric measurement. Thp mastax and jaws seemed much shorter than usual, but of the common . RATTULUXE. Cl 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 from 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, ^ to ^ inch ; lorica, ^^ inch ; depth at middle of ridge, T^5 inch. Habitat. Birmingham ; Dundee. Pools : rare (P.H.G.). M. SCIPIO, Gosse, sp. nov. (PI. 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 spine, 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 its 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, Tig- inch. Habitat. On water-moss in pools (P.H.G. ). M. MACEKA, GoSSe; Sp. 110V. (PI. XX. fig. 12.; [SP. CH. Body fusiform, thickest behind the middle ; lorica smooth-edged in front; without visible ridge; toe Jut If the length of the lorica; sub-styles one-fourth the length of the toe. 62 THE EOTIFERA. 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 M. 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, rj«y inch. — P.H.G.] Habitat. Woolston (P.H.G.). M. ELONGATA, GOSSO, Sp. 110V. (PI. 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- twentietli 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 M. carinata than they ; yet sufficiently remote 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 lorica. It bears one toe, a spine of great length and slenderness, almost quite straight, nearly uniform in thickness to the fine point. 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 M. carinata, having 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, 5\ inch ; of toe, yj^ inch ; of sub-styles, yyVrr inch ; depth of lorica, 3^0 inch. Habitat. Loch near Dundee (J.H.) ; Birmingham (P.II.G.) : not rare. M. RATTUS, Ehrenberg. (PI. XX. fig. 9.) Monoccrca rattus . . . Ehrenberg, Die In/us. 1838, p. 422, Taf. xlviii. fig. 7. [SP. CH. Body ovate, truncate in front, pointed behind ; ridge reaching to tico- thirds, evenly arched ; toe longer than body-and-hcad 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 RATTULID^E. 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- smidece, 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 fseces, 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, -j-^-g- inch ; of toe, ^s inch ; total, ^. Habitat. Pools, widely dispersed, not uncommon (P.H.G.). M. BICORNIS, Ehrenberg. (PI. XX. fig. 5.) Monocerca bicornis . . . Ehrenberg, Die In/us. 1838, p. 423, Taf. xlviii. fig. 8. [SP. CH. Body fusiform-ovate, zvith long thick head armed luith two projecting unequal spines; lorica not ridged; toe tioo-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 rattus 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 nqar its middle. There are small gastric glands at the base of the stomach, and tivo 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 antennae, 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. (Of. Monoc. valga, Ehr.) In ponds and lakes around London, I met with this species and the preceding, six- aiid-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 EOTIFERA. 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, T} ff inch ; of toe, T^ inch ; total, ^5 inch. Habitat. Pools near London ; Birmingham (P.H.G.). M. STYLATA, (PL XX. fig. 6.) Monocerca stylata . . . Gosse, Ann. and Mag. Nat. Hist. Sept. 1851, p. 199. [SP. CH. Body irregularly oval ; heads/tor^; IOTICQ, flexible, puckered in contrac- tion, not ridged; tos less than half as long as body-and-head, simple, icith 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 to a 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 creca, 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 (Gi), 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 Anurcea, 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, generally 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, .>10 inch; including toe, T1(V inch. Habitat. South London; Ilampstead Heath ; Stapleton Park, Yorkshire ; Birmingham (P.H.G.). Genus RATTULUS, Ehrenberg. [GEN. CH. Body cylindric, curved; lorica smooth, (usually) without a ridge; toes two, decurvcd, symmetric. The Notommata tig r is 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 link with the Notommatada, 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.] RATTULID^E. C5 R. TIGRIS, Mutter. (PL XX, fig. 18.) Notommata tigris • . , Ehrenberg, Die In/us. 1838, p. 431, pi, liii. fig. 1. [SP. CH. Body subcylindric, largest in front; foot thick; toes two, stylate, long ; sub-styles two 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 Euchlanis. 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. 186), 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.Gr.] Length, y^y inch, of which the toes are ¥^ inch. Habitat. Sandhurst, Berks ; Woolston, Hants : rare (P.H.G.). B. HELMINTHODES, GoSSB, Sp. nOV. (PI. XX. fig. 17.) [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 R. 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 IOAV 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 furcate toes, which are simple styles, very slender, tapering to fine points, decurved, closely resembling those of R. 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 ratljer a swelling of the basal part of each toe. It 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, TJ 0 inch ; of toes, ^Tt inch ; width (and depth) of body, inch. Habitat. A pool near Birmingham (P.H.G.). VOL. II. P 60 THE EOTIFEEA. R. CIMOLIUS, Gosse, sp. nov. (PL XX. fig. 14.) [SP. CH. Body arched, parallel-sided ; skin flexible ; brain opaque ; toes short, blade-like, decurved; 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 /a/teoAia = 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. 146, 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 floccose. I have lately found a second in water from Mr Bolton. — P.H.G.] Length, 2J0 inch. Habitat. Sandhurst, Berks; Kingswood Pool, Birmingham (P.H.G.). B. CALYPTUS, Gosse, sp. nov. (PL XX. fig. 1G.) [SP. CH. Body and toes as in 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 oesophagus 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 Battulus 1 found in October 1885, with many other species of Eotifera, 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, T^ inch. Habitat. Tide-pools on the Scottish coast (P.H.G.). B. SEJUNCTirES, 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 lunaris 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, apa rt. RATTULID^E. 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 Battulus lunaris. Found in a pool near Wellington Military College, Berks."— P.H.G.] Length. Unrecorded. Habitat. As above. Genus CCELOPUS, 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 Battulus 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 Diurclla rattulus, Eyf., 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 Battulus ; if the latter, a Ccelopus. His text also is ambiguous. " Two toes, long, much bent bellyward, and slender," seem to point to Battulus ; 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 Gcelopus, ill-understood. — P.H.G.] C. PORCELLUS, Gosse. (PI. XX. fig. 18.) Monocerca porcellus .... 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 bodi/. 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 F 2 G8 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 furnished 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 (cf. 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. 186). 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.1 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 fulcrum 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 aluhe, 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 gliding 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 freces, 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 mastax is 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 oiitline of the back forms an arc. — P.H.G.] Length, T^ inch, of which the double toe forms about one-fifth. Habitat. Pools and lakes : widespread through Middle and South England (P.H.Gr.). C. TENUIOR, Gosse, sp. nov. (PI. XX. fig. 19.) [SP. CH. Body cylindric, decurved, slender ; lorica without sensible ridge; head defended by tioo or three projecting points ; toe with two sub-styles. 1 I am 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 M. carinata. — P.H.G. RATTULID.E. 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 ; whereas in 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, T^ to rlf inch ; depth, ^J^ to -^ inch. Habitat. Weedy pools. Wool- ston : Button Park and Coleshill, Birmingham (P.H.G.). C. BEACHYUBUS, (PI. XX. fig. 21.) Monocerca brachyura . . . Gosse, Ann. and Mag. Nat. Hist- Sept. 1851. [SP. CH. Body cyUndric, short, plump, decurved ; lorica not ridged; head witlwut 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 scarce. 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 spines. 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), T]^ inch ; toe, 7J-0- inch ; total, r^ inch. Habitat. Hampstead Heath ; Sandhurst ; Woolston ; Caversham (P.H.G.) : pools : rare. C. CAVIA, Gosse, sp. nov. (PI. XX. fig. 22.) [SP. CH. Body elevated and globose, very protuberant behind the foot; lorica ivithout 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 mett with this pretty little creature, which at first I was inclined to identify with C. brachyurus. It differs from it in 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. E.G.] Length (without toe), ^i0 inch. Habitat. Epping Forest (P.H.G.). 70 THE BOTIFEEA. [I suspect the Distemma setigerum of Ehrenberg to belong to this genus. He himself alludes to the liability of confounding it with Eattulus, 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 Coelopus known to me. — P.H.G.] CffiLOPUS (?) MINUTUS, GoSSC, Sp. 110V. (PI. XX. fig. 20.) [SP. CH. Two eyes, wide apart; mastax and rotating cilia (apparently'] wanting ; body rotund, minute. Little as I know of this tiny animal, enough is manifest to show that it is one of much physiological interest. Though for convenience of reference, and because of certain conspicuous resemblances, I place it with the Ccelopods, it must be considered a species incertce 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 Coelopus, — 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 oesophagus 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, jjff inch. Habitat. Black Loch, near Dundee (P.H.G). Family XII. DINOCHARID^. 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 Dinocharida, two, viz. Dinocharis and Scaridium, 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 chitiiious cuticle is thin, somewhat flexible, smooth, and transparent, in Dinocharis it attains a greater development than in any other genus of the Eotifera. 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 chitiiious 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^E. 71 three genera is also very different, and Stephanops has two eyes remote from the mastax, while Dinocharis and Scandium have but one, closely applied to it. In all, however, the trophi are symmetrical, the family differing widely in this respect from the Rattulidce. Genus DINOCHARIS, Ehrcnberg. GEN. CH. Lorica vase- shaped, dense, shagreencd ; 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. Collinsii, is strikingly unlike the other two, in several respects. Their loricae 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. POCILLUM, Ehrcnberg. (PL XXL fig. 1.) Dinocharis pocillum . . . Ehrenberg, Die Infus., 1838, p. 472, Taf. lix. fig. 1. „ „ ... Grenadier, Sieb. u. Kull. Zeits. Bd. xix. 18G9, 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 ; and a 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 Ic, 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 tAvo 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. Grenadier (loc. cit.} has seen two lateral rocket-headed antennae 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 BOTIFEKA. 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 Scaridium eiidactylotum. Length, -$$ inch. Habitat. Clear ponds and ditches, Hampstead Heath ; Kew Gardens ; Woolston (P.H.G.) ; Clifton, Birmingham (C.T.H.) : not very common. D. TETEACTIS, Ehrenberg. (PI. XXI. fig. 2.) Dinocharis tetractis . . . Ehrenberg, Die Infus. 1838, p. 473, Taf. lix. fig. 2. SP. CH. Lorica vase-shaped, narroioing 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. pocillum. Mr. Gosse has also seen many specimens of D. tetractis, 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 ^?> mcn (P.H.G. ). Habitat Clear ponds and ditches throughout England and Scotland (P.H.G. ; C.T.H.) : common. D. COLLINSII, Gosse. (PI. XXI. fig. 3.) Polycluctus Kitbqiirtdratns (?) . . . Perty, Z. Kcnntn. Id. Lcl. 1852, p. 45. Taf. 1. fig. G«. Dinocliaris Collinsii ..... Gosse, Intcll. Observer, vol. x. I860, p. 26'J. Polijchcctus spinulosus .... 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 Eotiferou 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. DINOCHARID^l. 78 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 Polychatus subquadratus may possibly, but not probably, be the same creature ; if so, it is most inaccurately drawn and described. Mr. Archer's Polychcetus spimilosus is undoubtedly D. Collinsii. 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, -^ inch. Habitat. Sandhurst, Berks (Dr. F. Collins); Clifton (Mr. Brayley) ; Carrig and Gallery districts, Ireland (Mr. T. Archer) ; Dundee (P.H.G.) : rare. Genus SCAEIDIUM, 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 Scaridium 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. eudactylotum 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.1 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. S. LONGICAUDUM, Ehrenberg. (PI. XXI. fig. 5.) Scaridium longicaudum . . . Ehrenberg, Die Infus. 1838, p. 440, Taf. liv. fig. 1. „ „ Gosse, Phil. Trans. 1856, pi. 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 jjuite 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.J 1 I suspect this to be the case in S. eudactylotum ; but in S. longicaudum Mr. Gosse is confident that ihe eye is inseparably seated on the mastax. 74 THE EOTIFEEA. Length, ^ inch. Habitat. Stratford ; Maidenhead ; Cheltenham ; Birmingham ; Starmont Loch, Dundee (P.H.G.) ; pools and dykes : rare. S. EUDACTYLOTUM, Gosse, sp. nov. (PL XXI. fig. 4.) SP. CH. Lorica. pear-shaped, depressed and narrowed in front; toes as long as all the rest of the animal. [S. cudactylotum 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 longicaudum, 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 longicaudum. 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 O3sophagus, 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. longicaudum. The toes are very flexible, and highly clastic ; sometimes when the animal suddenly turns, I have seen the toes bent almost double, but recovering their straightness in 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 oesophagus, at a little distance from the stomach, are two small stalked glands (fig. 4a) similar to those in Ptcrodina 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. 46), 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. 46) looks as if 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 DINOCHARID^E. 75 follow the arch of the dorsal. I detected four vibratile tags (fig. 46) 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, 4cd) 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 antennae 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, ^r 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 Coluridce, 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.] S. LAMELLARIS, Ehrenberg. (PL XXI. fig. 7.) Steplianops lamellaris . . . Ehrenberg, Die Infus. 1838, p. 478, Taf. lix. fig. 13. [SP. CH. Lorica pyriform, having a narrow neck, and slightly prolonged behind into three siib-parallel slender acute spines ; foot furnished with a toe-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 Euchlanis. 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, TJ,j inch. Habitat. A garden tub (P.H.G.) : rather scarce.' S. MUTICUS, Ehrenberg. (PI. XXI. fig. 6.) Steplianops muticus . . . 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 EOTIFEEA. 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, T^ inch. Habitat. Fresh waters around London ; an aquarium at Tor- quay (P.H.G.) : scarce. S. UNISETATUS, ColUllS. (PI. XXI. fig. 8.) Steplianops uniscta . . . 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. Micr. 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, 2^ff to T|0 inch. Habitat. Sandhurst (Collins ; P.H.G.) : not rare. S. CHL^NA, Gosse, sp. nov. (PI. 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, ^ to T^). This mistake, and the omission to draw or account for the line b, b, has led to endless confusion in determining the species. Dr. Colin, however (in Sieb. u. Koll. Zcits. ix. 1858, p. 289), fully explained the error about the lines c, c ; but missed the flange of the ventral plate witli its edges b, b. 90 THE EOTIFERA. I found this large and beautiful new Euchlanis, in June 1885, in water sent to me by Mr. Tbos. Bolton, from Button 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 Euchlanis, is widest at the hind end, and elliptical there in outline. As in E. 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 (PI. xiv. fig. Ic). 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 PI. C. fig. 10. Two papillae 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. Plate1 figures the similar organs in E. 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 gastric glands are curiously lobed on the ventral side (fig. la) and contain large nucleated cells. The foot-glands are very long, club-shaped, and bent over 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. Ib), 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 setae. 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. la 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 papillre mentioned above. On the neck is another setigerous eminence, the dorsal antenna. I have not succeeded in finding any dorso-lateral antennas. 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 Bracliionus rubcns. Length, ^ inch. Habitat. A pond in Button Park (C.T.H.) : rare. E. DILATATA, Ehreiiberg. (PI. XXIII. fig. 5.) EucManis dilatata . . . Ehrenbcrg, Die In/us. 1838, p. 463, Taf. Iviii. fig. 2. „ „ Cohn, Sicb. u. Kull. Zcits. ix. 1858, p. 289, Taf. xiii. fig. 4. 1 Jcnaisch. Zcits. f. Natur. 1885, Taf. ii. fig. 18. EUCHLANID^E. 91 Euclilanis dilaiata . . . Moxon, Trans. Linn. Soc. vol. xxiv. 1864, p. 459, with figs. „ „ Eckstein, Sieb. u. KUll. Zeils. 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 Inj a membrane; hind dorsal edge notcJied; ventral plate flat ivith 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 to end. Ehrenberg says that there are no setae on the foot, but both Dr. Moxon and Herr Eckstein draw a pair of pedal setae, and I have met with specimens bearing setae in no other respect differing from those that lacked them. Dr. Cohn (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. Colin has seen the wand-like spermatozoa " swarming" in the sperm-sac. Length. Female, T\j-, male, -^ inch. Habitat. Clear ponds and ditches : common. E. MACRURA, Ehrenberg. (PL XXIII. fig. 6.) Euclilanis macrura . . . Ehrenberg, Die In/us. 1838, p. 4G3, Taf. Iviii. fig. 1. SP. CH. " Closely resembling E. dilatata; lorica a narrower oval ; toes somewJtat longer ; trophi with seven teeth in each uncus ; a pair of recurved setae on the foot." I have met with an Euchlanis, whose figure is given in fig. 6, which had all the above characteristics given by Ehrenberg, but I doubt whether E. macrura is a good species, as none of the corresponding characters seem constant in E. dilatata, except the number of teeth in each uncus ; and, unfortunately, I found several specimens, of what I should otherwise have termed E. macrura, with only five teeth in each uncus. Length. About ^ inch. Habitat. Clear ponds and ditches : not uncommon. E. TRIQUETRA, Ehrenberg. (PL XXIII. fig. 4.) Euclilanis triquctra . . . Ehrenberg, Die Infus. 1838, p. 4G1, Taf. Ivii. fig. 8. „ „ Hudson, Hon. Micr. J. viii. 1872, p. 97, pi. 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 curved downwards all round its edge, so that the lateral furrow between the two plates is wide ; and, as shown in fig. 4Z>, 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. 46) in the dorsal plate, through which a short, stout, dorsal antenna usually protrudes. Dr. Grenadier has detected two dorso-lateral antennae close together " lying near the crest of the lorica." Ehrenberg says that there are no setae 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 E. 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 algaa. 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 setoa, form a picture that once seen can never be forgotten. There is a variety of E. 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 E. uniseta (PI. xxiii. fig. 3). Length. Up to ^5 inch. Habitat. Clear ponds and ditches : not uncommon. E. DEFLEXA, (PL XXIV. fig. 1.) Euchlanis dcflcxa . . . 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, Uade-sliaped ; lateral horns of incus 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, i.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 Euchlanis, 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 setae, one or both of which are sometimes wanting. Each toe has a cor- rugated mucus-gland (?) running through it. The broad head is composed of many (ten ?) 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 months 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 arc seen, some indubitably EUCIILANID^E. 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 thft head from the foot. — P.H.G.] I once found among a number of specimens of E. deflexa a perfectly empty lorica, belonging to this species, and fortunately standing up vertically, so that it turned round and round on its pointed end, as on a pivot (PI. xxiv. fig. Ic). I was thus enabled to see with the utmost distinctness that it was closed everyivherc 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. Ic ; 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 •£$ inch ; breadth, T^ inch. Habitat. Pools and lakes (P.H.G. : C.T.H.) : widespread. E. PYEIFOEMIS, Gosse. (PI. XXIII. fig. 2.) Euchlanis pyriformis 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 incus 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 E. 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 setae, 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 pro- 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 E. 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 have 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 setae 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 E. lyra. Length. Up to ^ inch ; of lorica, (;V incn 5 of toes' TV* mcn- Habitat. Orna- mental waters (P.H.G.) ; garden pond, Clifton (C.T.H.) : rare. 94 THE KOTIFERA. Family XV. CATHYPNAD^. [Body inclosed in a lorica, open at each 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, virgate. 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. Five species were known to Ehrenberg, who placed the two with furcate toes in the genus Euchlanis, with which, however, they have no close affinity. — P.H.G.] Genus CATHYPNA, Gosse, gen. nov. [GEN. CH. Lorica sub-circular horizontally, usually much arched vertically ; lateral inangulation wide and deep ; toes tivo, 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. LUNA, Ehrenberg. (PL XXIV. fig. 4.) Euchlanis luna . . . Ehrenberg, Die In/us. 1838, p. 462, Taf. Ivii., fig. 10. [SP. CH. Dorsal and ventral plates of lorica sub-equal, occipital edge crescent ic ; 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, CATHYPNAD.E. 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 oesophagus, with large gastric glands, and followed by a separate intestine, passes obliquely across the dorsal region ; and the ovary, as usual, occupies the ventral.1 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 sluggishness 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 allow 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, -^s inch ; of lorica, T|^ inch. Habitat. Fresh waters (P.H.G.j : common everywhere. C. KUSTICULA, Gosse, sp. nov. (PI. XXIV. fig. G.) [SP. CH. Lorica regularly ovate, with the frontal opening very narrow ; dorsal surface coarsely tesselated ; ventral plate nearly flat ; toes blade- shaved . 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 tumed-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. 66). 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 been 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 rusticula. 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, yi^- inch. Habitat. Pools throughout England and Scotland (P.H.G.) : common. 1 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 (rig. 4). Long threads (muscular ?) with like enlargements were seen to pass from the foot-bulb to near the same points, if not higher. 9G THE KOTIFEEA. C. SULCATA, Gosse, sp. nov. . (PI. 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-shai^ed. 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 graving 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 historic pool at Sand- hurst. For awhile I thought I had got hold of the Euchl. 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 E. luna. — P.H.G.] Length. Extended, y-J-ff inch; of lorica, ^\^ inch; of toes, ^^ inch; width of lorica, ?^3 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. (PI. XXIV. fig. 8.) Distyla Gisscnsis . . . Eckstein, Sieb. u. Koll. Zeits. xxxix. 1883, p. 383, pi. xxvii. [SP. CH. Lorica round behind, broadly truncate in front, with short lateral points ; toes rod-shaped, thick, obscurely tic o- shouldered, claios 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, PLATE XXI. Dinocharis pocilluru . 1. la. 16. le. Id. le. 2. 2a. 26. 2d, 3. 36. 3c. 4. 4a. 46. 4c. 5. Scaridiurn longicauduni Dinocharis tetractis . Dinocharis Collinsii Scaridiuin eudactylotuiu 56. 6. 6a. 7. 7a. 8. 8a. 9. 9a. Stephanops muticus . )) >! • Stephanops laniellaris Stephanops iinisetatus Stephanops chlaena dorsal view ....... H side view ....... H ventral view ....... H transverse section H variety ; foot ....... H trophi ........ G dorsal view G side view ....... G transverse section G head ; cap closed . . . . . G head ; cap open ...... G dorsal view, the armature omitted . . G dorsal view, showing spines G side view ....... G transverse section ...... G dorsal view ....... H side view ....... H ventral view H junction of foot and toes . . . . H niastax and brain H mastax, trophi, and eye G dorsal view ....... G side view ....... G head, showing mastax, trophi. and eye . . G dorsal view ....... G side view ....... G dorsal view ....... G side view ....... G dorsal view G side view ....... G dorsal view ....... G side view . . G ?>J>Nvv\3 vtt^ v^n^ ^7- _i P- /*-A . ::*4^fe en i — •. E— « o '-r ^-. 59 £ 5 < =1 - CO *=* o ^ o t=l — } Q V^ CO < CO E-i O W t- E~* ^ Q CNJ CO U CD O^ CO PLATE XXII. 1. Salpina mucronata . dorsal view . la. „ „ . side view .... 16. „ . lorica, oblique view 2. Salpina spinigera . . dorsal view .... 2«. . side view .... 26. . transverse section, dorsal half 3. Salpina mutica . dorsal view .... 3a. „ . side view .... 4. Salpina brevispina . side view .... 4e&. ,, ,, . lorica, dorsal view 46. „ . lorica, side view . 5. Salpina eustala . dorsal view .... 5a. „ „ . side view .... 6. Salpina macracantha . dorsal view .... Get. „ „ . side view .... G6. . trophi, side view . 7. Salpina stilcata . dorsal view .... 7«. „ „ . side view .... 76. . rear view .... 8. Diplax compressa . . side view .... 8a. „ „ . dorsal view .... 86. . transverse section 9. Diplax trigona . dorsal view .... 9«, „ „ . side view .... 96. . transverse section 10. Diaschiza seiiiiaperta . side view .... 10a. „ „ . lorica, dorsal view 106. . head and eye 10c. . trophi ..... 11. Diaschiza paeta . side view .... llrt. . dorsal view .... 12. Diaschiza valga . dorsal view .... 12«. „ „ . side view .... 13. Diaschiza exigua . . dorsal view .... 13a. „ „ . side view .... 14. Diaschiza tenuior . . dorsal view .... 14d. ,, ,, . . side view .... 15. Diaschiza Hoodii . . dorsal view .... 15«. „ „ . side view .... G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G , .,q/**:* ^v^%^gfe:? i', ^ • ..&)&!..• •3*&':-<- . co ffi '< y ^-, CD « -r < < ^ PLATE XXIII. 1. Euchlanis lyra . . . dorsal view H la. „ „ ventral view H 16. „ ,, foot, and contained vessels . . . H 2. Euchlanis pyriforniis . . ventral view H 2a. „ „ transverse section ...... H 26. „ „ front-edges of lorica . . . . . H 3. Euchlanis uniseta (?) . . side view H 4. Euchlanis triquetra . . dorsal view H 4«. „ „ side view ....... H 46. „ „ ventral view of lorica H 4c. „ „ transverse section . . . . . H 5. Euchlanis dilatata . . ventral view : a, edge of dorsal plate ; 6, 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. „ „ dorsal front-edge of lorica . . . . H 56. ,, „ . . ventral front-edge of lorica . . . H 6. Euchlanis macrura . . dorsal view . H //,?;-)•-/- "/ -:*?W ; ';j^^w_/ W-m Jy :%Sfe%^- I ->v \-*j - * i? ,™io''. '•<.' DC CJ CO Q -o fc £ S < » « C/D o PLATE XXIV. 1. Euchlanis deflexa la. „ „ 2. Diplois propatula 2a. „ „ 3. Diplois Daviesise 3er. „ „ 36. „ „ 3c. „ „ M. 4. Cathypna luna . 4a. „ „ . 46. „ „ . 4c. „ „ . 5. Cathypna sulcata 5«. „ „ 56. oc. ,, ,, 0. Cathypna rusticula 7. Distyla flexilis . la. „ „ 8. Distjia Gissensis 8a. ventral view dorsal view side view .... empty lorica, ventral view dorsal view side view .... dorsal view side view .... transverse section hind end of lorica, dorsal view trophi .... dorsal view, head extended dorsal view, head retracted side view, head retracted . rear view .... dorsal view 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 . G G G H G G G G G G G G G G G G G G G G G G G G G G G X N ' '• . '^tO^ :y ' ^V-V- PLATE XXV. 1. Monostyla eornnta la. ,, „ 16. 2. Monostyla lunaris 2a, 26. „ 2c. 3. Monostyla quadridentata 4. Monostyla bulla . 4a. „ „ 46, 4c. ,, ,j > &. Monostyla Lordii 6. Metopidia lepadella 6a. „ „ * 66. 7. Metopidia triptera la. „ 76. 8. Metopidia oxysternon Sa, 86, „ „ 8c. 8d. Be. „ rt Sh. . 9. Metopidia acnminata . 9a. '96. 9c. 10. Metopidia rtoomboides 10a. „ 106. 11. Metopidia solidns llfl. 116 ...... lie. lid. lie. ll/- 12. Colurns dactylotus 12a. 13. Colnrus pedatns dorsal view G side view ....... G transverse section ...... G dorsal view ....... G side view ....... G rear view ....... G dorsal view G dorsal view ....... G side view G rear view ....... G front of lorica G dorsal view ....... G dorsal view G side view ....... G transverse section ..... G dorsal view ....... G side view ....... G front view G ventral view ....... G side view G lorica ; ventral view G lorica ; dorsal view G transverse section . . . . . G head ; side view G trophi G pectoral notch of lorica ... . G hind end of ventral plate, showing orifice for the foot G dorsal view ....... G side view ....... G lorica ; ventral view . . . . . G transverse section G dorsal view ....... G side view ....... G transverse section . . . . . G dorsal view ....... G ventral view, head rfitracted . . , . Gr side view ....... G rear view ..•,.... G front of lorica . . , . , . G hind end df lorica, . . . . . G stomach G dorsal view ....... G side view ....... G side view ....... G foot and toes G X X CATHYPNAD^J. 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 centrums 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 averaging 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, T^ to T^- inch ; width, ^ to -%}-$ inch. Habitat. Bracebridge Pool, Birmingham : rare. Starmont Loch, Dundee : abundant (P.H.G.). D. FLEXILIS, Gosse, sp. nov. (PI. 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 M. 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. Expanded, ^ 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 tiie 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. II. H 98 THE ROTIFERA. suggest that Cathy pna 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. LUNAEIS, Ehrenberg. (PL XXV. fig. 2.) Monostyla lunaris .... Ehrenberg, Die In/us. 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 ivide, 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 seerns 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 Eck- 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 ; l 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, T^ to T^ inch. Habitat. Woolston ; Sandhurst ; Thames, near Beading ; Snaresbrook (P.H.G.) : mostly in pools : not uncommon. M. COKNUTA, Ehrenberg. (PI. XXV. fig. 1.) Monostyla cornuta .... Ehrenberg, Die In/us. 1838, p. 459, Taf. Ivii. 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 M. 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 1 During the latter part of the time, however, it became very sluggish, and less willing to move and jerk about. CATHYPNADJE. 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 hmaris. 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, arid 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, ^^ inch; total, extended, T^ inch. Habitat. Still waters (P.H.G.) : common everywhere. M. BULLA, Gosse. (PI. XXV. fig. 4.) Monostyla bulla .... Gosse, Ann, Nat. Hist. 2 Ser. vol. viii., 1851, p. 200. [SP. CH. Lorica a pointed oval ; dorsal and ventral plates loth 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 Eichmoiid 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 decurvatioii 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 cornuta. The mallei are certainly two-fingered. The animal burrows among Chane, Conferva?, &c. — P.H.G.] Length. Expanded, T|5 inch ; of lorica, T|- inch. Habitat. Pools (P.H.G-.). M. LORDII, Gosse, sp. nov. (PI. XXV. fig. 5.) [SP. CH. Dorsal plate o/ lorica tesselate, its hinder end excavate, the excavation forming three sides of a square ; toe rod-sliaped ; claw shouldered. , This is a rare species, bearing much the same relation as Cathy pna 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 cormita, 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 jomt of the foot. The shoulder is double, viewed vertically, but single and much rounded, viewed laterally. The outlines of the too, however viewed, are always a little uneven ; suggesting that the surface is irregularly pitted. The lorica ii 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 (PI. 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 M. cornuta is his fig. 21. I therefore distinguish it with his name. I have met with it myself, on rare occasions recently, among decaying vegetation in the water of Woolston Pond, and abundantly in water kindly sent me by Miss Saunders. Length, ^^ to T^ inch. Habitat. Woolston ; Newbury ; Dundee (P.H.G.) : rare. There is a form, — of which I am 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 Button Park.— P.H.G.] M. QUADKIDENTATA, Ehrcnberg. (PI. XXV. fig. 3.) Monostyla quadridentata . . . Ehrenberg, Die In/us. 1838, p. 459, Taf. Ivii., fig. 5. [SP. CH. Lorica nearly circular, greatly depressed, especially behind ; front deeply cleft, with two horn-like spines dccurved and expanding at their tips. The horns well distinguish this form. During retraction these are drawn together, and made even to cross each other (fig. c). Besides these, and outside them, the dorsal plate projects into a broad-based triangular point 011 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, y}^ to 0\. inch ; of lorica, TJff to T^-0- inch. Habitat. Barking ; Stratford ; Maidenhead; Hampstead (P.H.G.) ; among duckweed, in pools and ditches : rare. COLURUm 101 Family XVI. COLURIDjE. [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 Metopidia with the high-backed Coluri. 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 Metopidice, for instance, is so very uncertain and indetermin- able, that I incline to agree with Dujardin in rejecting some of Ehrenberg's genera. The distinction between Lepadella, Metopidm, 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 subglobose, 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-circular 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, acmte, 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 subjeet 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-point as on a pivot, and then awkwardly tumble over, as if they had not power to maintain their balance. The MonostylcB 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. DEFLEXUS, Ehrenberg. (PI. XXVI. fig. 1.) Colurus deflexus . . . Ehrenberg, Die Infiis. 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 Euchla- 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 Colurus 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.Gr.] Length. Of lorica, ^rn- inch ; from hook to toes, 1 j^ inch. Habitat. Ponds and ditches ; quite common (P.H.G.). C. BICUSPIDATUS, Ehrenberg. (PL XXVI. fig. 2.) Colurus bicuspidatus . . Ehrenberg, Die In/us. 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 Button 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^E. 108 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 rising 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 Button 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.J Length. Extended, -^ inch ; transverse width ^^. Habitat. Woolston ; Birming- ham (P.H.G.) ; very rare. C. UNCINATUS, Ehrenberg. Colurus uncinatus . . . Ehrenberg, Die In/us. 1838, p. 475, Taf. lix. fig. 6. [SP. CH. Lorica, viewed dorsally, broadly ovate, truncate before, produced behind into two short spines : vieived laterally, the outline is rondo -triangular, high in the middle 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 Euchlanis 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 denned. It is usually of minute dimensions, and, though widely spread, rather rare. I have known it since 1849. — P.H.G.] Length. Lorica, from ^^ to ¥^ inch. Habitat. Clapton ; Battersea ; Bath ; (P.H.G.). C. OBTUSUS, Gosse, 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 minute 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 circumference, 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 setae 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 011 the brain, which may be eyes. Its manners are sluggish, swimming laboriously, with jerks. — P.H.G.] Length. Without foot, r^ to ^^ inch. Habitat. Near London ; Woolston ; Lea- mington ; Dundee (P.H.G.) : not uncommon. 104 THE EOTIFERA, C. CAUDATUS, Ehrenberg. (PI. XXVI. fig. 6.) Colurus caudatus .... Ehrenberg, Die In/us. 1838, p. 476, Taf. lix. fig. 8. [SP. CH. Lorica, in dorsal aspect, pear-shaped, widest behind ; dorsal hind sinus shallow, betioeen 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 01 Ehrenberg, to distinguish which requires minute examination. The ahove 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 ^ inch. Habitat. Birmingham ; Woolston (P.H.G.) : weedy pools. C. AMBLYTELUS, GoSSC, Sp. HOV. (PI. XXVI. fig. 5.) [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 Metopidice, &c., 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 algfe, collected by Mr. Hood from tide-pools at low-water at Taymouth, near Dundee, and also in Torbay. It is very 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.] 1 I am 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^E. 105 Length. From hood to ends of lorica, -^^ inch ; foot and toe, ^v inch ; total, T|j inch. Habitat. Marine pools at low tide (P.H.G.). C. DACTYLOTUS, GoSSe, Sp. 110V. (PL XXV. fig. 12.) [SP. CH. Lorica wide in front, shallowly tubular behind, without 2)oints; 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 furcate, 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. — P.H.G.] Length, T|5 inch. Habitat. Marine pools (P.H.G.). C. PEDATUS, Gosse, sp. nov. (PL XXV. fig. 13.) [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.1. C. CO3LOPINUS, 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 Cceloptts, in the Rattulidae. 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 ROTIFEBA. 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 lorica 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, TJ ^ inch ; of which the spine is about one-fourth. Habitat- Among conferva in tide-pools in the Firth of Tay (P.H.G.) ; rare. Genus METOPIDIA, Ehrcnbcrg. [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 liook ; foot and toes as in Colurus ; eyes usually tico. 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. 632) while I cannot accept his details. They seem to fall into the same natural family as Colurus ; for though the prevailing plate-like form seems at first sight to differ greatly from the compressed Coluri, 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 Eotifera. — P.H.G.] M. LEPADELLA, Ehrenberg. (PI. XXV. fig. 6.) Melopidia lepadclla . . . Ehrenberg, Die Infus. 1838, p. 477, pi. 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&nd S. oblonga, and Metopidia lepadclla 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 Colurus, 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, 3-'-^ inch. Habitat. Fresh waters everywhere (P.H.G.). M. SOLIDUS, Gossc. (PI. XXV. fig. 11.) Metopidia solidus .... Gossc, 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 u-ith the dorsal behind, but deeply excavate ; dorsal having a submarginal line of corrugation. COLURIDyE. 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 Pterodince, of which it is no unworthy 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 exca- 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. ll/, 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, T!-(7 inch. Habitat. Walthamstow ; Leamington ; Birmingham ; Woolston ; Dundee (P.H.G.). M. ACUMINATA, EJirenberg. (PI. XXV. fig. 9.) Mctopidla acuminata . . . Ehrenberg, Die In/us, 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 decurved 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, ni(T to ^j^ inch. Habitat. North London ; Leamington ; Sand- hurst (P.H.G.) ; very scarce. M. OXYSTERNUM, Gosse. , (PI. XXV. fig. 8.) Metopidia oxystcrnon . . . Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 201. [SP. CH. Lorica an ovate box 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 sinus. 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 omission of the foot. The whole loiica is cut into facets, as 108 THE ROTIFERA. in Noteus and in many Anuraa, and all minutely shagreened. The bead 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 Coluri, 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 N. triptera. The trophi are on the plan common in the Euchlanidce, 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 (Ecistes Stycjis and (E. brachiatus. It is of lively manners. — P.H.G.] Length, Tiy inch. Habitat. London ; South Devon ; Dundee (P.H.G.) : rare. M. KHOMBOIDES, Gosse, sp. nov. (PI. XXV. fig. 10.) [SP. CH. Lorica rliomboid-ovate in outline ; dorsal surface tcctiform, lower behind, ending in an obtuse point ; ventral surface flat. This seems to come between oxysternum and triptera. The oesophagus is long, and often thrown into curves. The gastric glands are peculiar, being placed at the ends of two long threads, probably tubular, which are seated on the corners of the stomach, the globular glands themselves being affixed to the lining of the lorica.— P.H.G.] Length, TJT inch. Habitat. North London (P.H.G.) : very rare. M. TRIPTERA, Ehrenberg. (PI. XXV. fig. 7.) Mctopidia triptera .... Ehrenberg, Die In/us. 1838, p. 478, Taf. lix. fig. 12. [SP. CH. Lorica nearly circular, as vieived 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 M. 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. Each 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 scrapes 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 Euchlanis. The contrast, and yet the resemblance, was curious ; the one could have lain comfortably within the ample mastax of the other. — P.H.G.] Length, ^-^ inch. Habitat. Sandhurst (Collins) ; Woolston; Dundee (P.H.G.): rare. COLURIIXaS. 109 M. BEACTEA, Ehrenberg. Squamella bractca . . . Ehrenberg, Die In/us, 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. P.H.G.] Length. Of lorica, 3^ inch. Habitat. Pools and infusions ; common (P.H.G.). Genus MONUEA, Ehrenberg. [GEN. CH. .4s 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. COLURUS, Ehrenberg. (PL XXVI. fig. 7.) Monura colurus .... 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. la], 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 cvary 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 EOTIFERA. 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, ^^ inch ; of foot and toe, -g^ inch ; total extended, ¥}7 to ^^ inch. Habitat. Marine pools in Forfarshire and Devonshire ; domestic aquarium (P.H.G.). Very recently specimens of what I suppose M. dulcis, Ehr., have been sent me, from fresh Avater, by Mr. Lord of Eawtenstall. The lorica is acute, instead of obtuse, behind.— P.H.G.] Genus MYTILIA, Gosse, gen. nov. [GEN. CH. Body ovate ; lorica as in Colurus, biLt the head and neck habitually protruded, as well as the ivhole foot ; no frontal hook. — P.H.G.] M. TAVINA, Gosse, sp. nov. (PI. XXVI. fig. 8.) [SP. CH. Eyes iwo, frontal, wide apart. Marine. The lorica is essentially similar to that of Colurus (though the facies of the animal is quite different), being a shell of two lateral valves, like 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 Pterodina, 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 Colurus, 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 Illoricate forms is involuntarily suggested.1 This is augmented by the circumstances, that the foot is long and thick, especially at its base, that it tapers there gradually from the thickness of the trunk, and that it is habitually carried in the line of the body. Whereas, in Colurus 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 Colurus 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 internal 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. amblytehis, is its constant 1 I cannot avoid a lurking suspicion that under Ehrenberg's figure of Distcmma marinum may have lain Mytilia iaviiia, notwithstanding discrepancies. COLURHXE. Ill 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, -j-J^ to -j^ inch ; width and depth equal, about T^-j inch. Habitat. Tide- pools at the mouth of the River Tay (J.H.) ; and in Torbay (P.H.G.). Genus COCHLEAEE, Gosse, gen. nov. [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 on a pivot. Both the species are lacustrine. — P.H.G.] C. STAPHYLINUS, Gosse, sp. nov. (PI. 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 joints, 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, TJff inch ; width, ^^ inch (P.H.G.). C. TURBO, Gosse, sp. nov. (PL XXVI. fig. 10.) [SP. CH. Lorica three-sided. The form of the lorica 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; yen 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 chlcena, 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 point. The toes are dis- tinctly furcate. — P.H.G.] Length, ^-^ inch ; width, T^