Part 42

The body is cylindrical, pellucid, muscular, and capable of being folded up; it appears double; the interior part is full of molecules, with an orbicular muscular appendage which it can open and shut, and this forms the mouth. The external part is membranaceous, pellucid, dilated, and marked with transverse streaks; the animalculum can protrude or withdraw the orbicular membrane at pleasure. Some have four articulations in the tail, others five; and it has two pair of bristles, or projecting parts, one placed at the second joint, the other at the last. It has been frequently found in marshes. In Fig. 6 it is seen with the mouth open; in Fig. 5, with it shut, _a a_, the jaws; _b b_, the first bristles; _c c_, the second pair; _d_, the spine at the tail.

230. TRICHODA CLAVUS. T. antice rotundata, crinita, postice acuminato-caudata. The fore-part round and hairy, the hind-part furnished with a sharp tail. This animalculum has a considerable resemblance to a common nail.

231. TRICHODA CORNUTA. T. supra convexa, subtus plana, apice crinita, cauda lineari simplici. Trichoda with the upper part convex, the under side plain, the apex hairy, the tail linear and simple.

To these characters we may add, that the body is membranaceous, elliptical, closely filled with molecules; the fore-part lunated, the hinder-part round, and terminating in a tail as long as the body.

232. TRICHODA GALLINA. T. elongata, antice sinuata, fronte crinita, cauda pilosa. Long trichoda, the fore-part sinuated, the front hairy, the tail formed of small hairs.

It is of a grey colour, flat, with seven large molecules and globules within it, the front obtuse, and set with hairs; the hinder-part terminating in a tail formed of very fine hairs. It was found in river water.

233. TRICHODA MUSCULUS. T. ovalis, antice crinita, postice subtus caudata. Plate XXVII. Fig. 7. Egg-shaped, the fore-part hairy, the tail projecting from the under part.

A smooth egg-shaped animalculum, with a double margin or line drawn underneath it; the fore-part narrow, and furnished with short hairs, which are continually playing about; underneath the hind-part is a small tail. It has molecular intestines, and moves slowly. It is found in infusions of hay which have been kept for some months, _a_, the head; _b_, the tail.

234. TRICHODA DELPHIS. T. clavata, fronte crinita, cauda acuminata, subreflexa. Clubbed trichoda, the front hairy, the tail small and rather bent upwards.

It is smooth and pellucid, having the fore-part dilated into a semicircle, gradually decreasing in breadth towards the tail; the front is hairy, the hairs standing as rays from the semicircular edge; one of these edges is sometimes contracted. It is to be found in river water.

235. TRICHODA DELPHINUS. T. oblonga, antice crinita, postice cauda reflexa truncata. Plate XXVII. Fig. 8. Oblong, the fore-part hairy; in the hind-part is the tail, which is turned back, the end of it truncated.

A pellucid, smooth, egg-shaped animalculum; the hind-part terminating in a tail about half the length of the body, dilated at the upper end, truncated, and always bent upwards.

In the inside are vesicles of an unequal size; it moves sometimes on its belly, sometimes on its side; the tail seldom varies its position. It was found in hay which had been infused for some months, _a_, the hairs on the fore-part; _b_, the tail.

236. TRICHODA CLAVA. T. clavata, fronte crinita, cauda reflexili. Club trichoda, the fore-part hairy, the tail turned back.

The fore-part is thick, the hind-part narrow; both extremities obtuse, pellucid, and replete with molecules; the hind-part bent down towards the middle.

237. TRICHODA CUNICULUS. T. oblonga, antice crinita, postice subacuminata. Oblong, the fore-part hairy, the hind-part rather acute, filled with molecules and black vesicles.

238. TRICHODA FELIS. T. curvata, grossa, antice angustior, postice in caudam attenuata, subtus longitudinaliter crinita. Plate XXVII. Fig. 9. Curved trichoda, large, the fore-part small, the hinder-part gradually diminishing into a tail; the under part set longitudinally with hairs. _a_, the head; _b_, the tail; _c_, the hairs.

239. TRICHODA PISCIS. T. oblongata, antice crinita, postice in caudam exquisitam attenuata. Plate XXVII. Fig. 13 and 14. Oblong, the fore-part is hairy, the hind-part terminating in a very slender tail. It is smooth, pellucid, much longer than broad, but of nearly an equal breadth throughout, and filled with yellow molecules; the fore-part obtuse, the hind-part exquisitely slender and transparent; the upper side is convex. _a_, the fore-part; _b_, the tail.

240. TRICHODA LARUS. T. elongata, teres, crinita, cuspidi caudali duplici. Long, round trichoda, surrounded with hairs, the tail divided into two points. See Zoologia Danica.

241. TRICHODA LONGICAUDA. T. cylindracea, antice truncata et crinita, cauda elongata, biarticulata et biseta. Plate XXVII. Fig. 10. Cylindrical trichoda, the fore-part truncated and surrounded with hairs, the tail long, furnished with two bristles, and having two joints. _a_, the hairs at the mouth; _d_, the oesophagus; _e_, the articulation of the tail; _f_, the bristles.

242. TRICHODA FIXA. T. sphærica, peripheria crinita, pedicello solitario. Spherical trichoda; this has the circumference set with hairs, and a little solitary pedicle projecting from the body.

243. TRICHODA INQUILINUS. T. vaginata, folliculo cylindrico hyalino, pedicello intra folliculum retortili. Sheathed trichoda, in a cylindrical transparent bag, having a little pedicle bent back within the bag. See Zool. Dan. prodr. addend. p. 281.

244. TRICHODA INGENITA. T. vaginata, folliculo depressa, basi latiore sessilis. Sheathed trichoda, the bag depressed, the base broadest.

The animalculum that is contained in this sheath is funnel-shaped, with one or more hairs, proceeding from each side of the mouth of the funnel. It can extend or contract itself freely in the bag, fixing its tail to the base, without touching the sides. It was found in salt water.

245. TRICHODA INNATA. T. vaginata, folliculo cylindrico, pedicello extra folliculum. Plate XXVII. Fig. 11. Trichoda sheathed in a cylindrical bag, with a pedicle passing through and projecting beyond it. These characters distinguish it sufficiently from the preceding one. _b_, the animalculum in the sheath; _d_, the tail.

246. TRICHODA TRANSFUGA. T. latiuscula, antice crinita, postice setosa, altero latere sinuata, altero mucronata. Broad trichoda, the fore-part hairy, the hinder-part full of bristles; one side sinuated, and the other pointed. See Zool. Dan. prod. addend. p. 281.

247. TRICHODA CILIATA. T. ventricosa, postice crinibus pectinata. Ventricose, the hinder-part covered with hair. See Zool. Dan. Icon. Tab. 73, Fig. 13, 15.

248. TRICHODA BULLA. T. membranacea, lateribus inflexis, antice et postice crinita. Membranaceous trichoda, the sides bent inwards; the fore and hind-part are both furnished with hairs.

249. TRICHODA PELLIONELLA. T. cylindracea, antice crinita, postice setosa. Cylindrical, the fore-part hairy, the hinder-part furnished with bristles.

This trichoda is rather thick in the middle, and pellucid, with a few molecules here and there, the sides obtuse, the fore-part ciliated with very fine hairs, the hind part terminating in a kind of bristles.

250. TRICHODA CYLLIDIUM. T. ovata, apice hiante, basique crinita. Plate XXVII. Fig. 15. Egg-shaped, the apex gaping, the base hairy.

Pellucid, the hinder extremity filled with globules of various sizes, the fore-part narrower, without any appearance of an external organ. It vacillates upon the edge, commonly advancing on its flat side, and continually drawing in water; it then gapes, and opens into a very acute angle, almost to the middle of the body; but this is done so instantaneously, that it is scarcely perceptible. _a_, the mouth; _b_, the hairs or bristles, which it extends when nearly expiring.

251. TRICHODA CURSOR. T. ovata, antice crinita, postice duplici pilorum strictorum et curvorum fasciculo. Oval trichoda, the fore-part hairy, and the hinder-part also furnished with some straight and curved hairs in two fascicles.

The body is flat and filled with molecules; in the fore-part is an oblong empty space, into which we may sometimes see the water sucked in.

252. TRICHODA PULEX. T. ovata, antice incisa, fronte et basi crinita. Plate XXVII. Fig. 12. Egg-shaped, with an incision in the fore-part; the front and base hairy. _a_, the anterior part; _b_, the posterior part; _c_, the incision.

253. TRICHODA LYNCEUS. T. subquadrata, rostro adunco, ore crinito. Plate XXVII. Fig. 16. Nearly square, with a crooked beak, the mouth hairy.

At first sight it does not seem very dissimilar to some of the monoculi. The body is membranaceous, and appears compressed, stretched out into a beak above, the lower part truncated; under the beak is a little bundle of hairs; the lower edge bends in and out, and is surrounded with a few bristles. The intestines are beautifully visible, and a small bent tube goes from the mouth to them in the middle of the body; these, as well as the tube, are in frequent agitation. There is likewise another tube between the fore and hind edge filled with a blue liquor. _a_, the beak; _b_, the mouth; _c_, the base.

254. TRICHODA EROSA. T. orbicularis, antice emarginata, altero latere crinita, postice setosa. Orbicular trichoda, the fore-part notched; one side furnished with hairs, the hinder-part with bristles.

255. TRICHODA ROSTRATA. T. depressa, mutabilis, flavescens, ciliis longis setisque pediformibus. Depressed trichoda, mutable, yellow, with long ciliated hairs, and feet tapering to a point.

The figure of the body is generally triangular; the apex formed into an obtuse beak, which the animalculum sometimes draws in, so that it appears quite round; the feet are four in number, one of them is longer than the rest; both feet and hairs are within the margin. It is found in water where duck-weed has been kept.

256. TRICHODA LAGENA. T. teres, ventricosa, rostro producta, postice setosa. Round ventricose trichoda, with a long neck, and the lower end set with bristles.

257. TRICHODA CHARON. T. cymbiformis fulcata, antice et postice crinita. Plate XXVII. Fig. 17 and 18. Boat-shaped trichoda with furrows, the fore and hind-parts both hairy.

The body is oval; it resembles a boat as well in its motion as shape; the upper part is hollowed, the under part furrowed and convex; the stern round, with several hairs proceeding from it. It was found in salt water. Fig. 17, _a_, the head; _b_, the tail. Fig. 18, _d_, a pellucid bubble that is sometimes to be perceived.

258. TRICHODA CIMEX. T. ovalis, marginibus lucidis, antice et postice crinita. Plate XXVII. Fig. 19. Oval trichoda, with a lucid margin, both the fore and hind-part hairy.

It is about the size of the trichoda lynceus, No. 253, has an oval body, with a convex back, flat belly, and an incision in the margin of the fore-part, the edges of which incision appear to be in motion. Its intestines are pellucid and ill-defined. When it meets with any obstacles in swimming, it makes use of four small bristles, which are fixed to the under side, as feet. _a_, the hairs in the fore-part; _b_, the bristles at the hind-part; _d_, the back; _e_, two small projecting hairs; _f_, the substance to which the animalculum has affixed itself.

259. TRICHODA CICADA. T. ovalis, marginibus obscuris, antice et subtus crinita, postice mutica. Oval trichoda, with an obscure margin, the fore-part covered with hairs on the under side, and the hinder-part beardless.

It does not differ considerably from the preceding, though Müller has pointed out some shades by which they may be discriminated.

XIV. KERONA.

Vermis inconspicuus corniculatus. An invisible worm with horns.

260. KERONA RASTELLUM. K. orbicularis membranacea, nasuta, corniculis in tota pagina. Membranaceous, orbicular kerona, with one projecting point, the upper surface covered with small horns. There are three rows of horns on the back, which nearly occupy the whole of it. It was found in river water.

261. KERONA LYNCASTER. K. subquadrata, rostro obtuso, disco corniculis micantibus. This species of kerona is rather square, and its disc furnished with shining horns. See Zool. Dan. prod. add. p. 281.

262. KERONA HISTRIO. K. oblonga, antice punctis mucronatis nigris, postice pinnulis longitudinalibus instructa. Plate XXVII. Fig. 20.

It is an oblong membrane, pellucid, with four or five black points in the fore-part, which are continually changing their situation, thick set with small globules in the middle, among which four larger ones are sometimes perceived, these are probably eggs; in the middle space of the hind-part are some longitudinal strokes resembling bristles, which, however, do not seem to project beyond the body. _b_, the horns; _c_, some hairs; _d_, a solitary horn; _e_, a large globule; _f_, some bristles.

263. KERONA CYPRIS. K. obovata, versus postica superne sinuata, antice crinita. Plate XXVII. Fig. 21. Egg-shaped, towards the hind-part sinuated, the fore-part hairy.

This animalculum is compressed, and somewhat of a pear-shape; the fore-part broad and blunt; the front is furnished with short hairs or little vibrating points inserted under the edge _a_, shorter in the hind-part _e_, partly extended straight, and partly bent down, having a retrograde motion. It is found in water which is covered with lemna.

264. KERONA HAUSTRUM. K. orbiculata, corniculis mediis, antice membranacea ciliata, postice setosa. Orbicular kerona, with the horns in the middle, the fore-part membranaceous and ciliated, and several bristles at the hinder-part.

265. KERONA HAUSTELLUM. Differs from the preceding only in having the hinder-part without any bristles.

266. KERONA PATELLA. K. univalvis, antice emarginata corniculata, postice setis flexilibus pendulis. Plate XXVII. Fig. 22 and 23. Kerona with a univalved shell, orbicular, crystalline; the fore-part somewhat notched; the fleshy body lies in the middle of the shell; above and below are hairs or horns of different lengths jutting out beyond the shell, and acting instead of feet and oars, some of which are bent; the superior ones constitute a double transverse row. _a_, the fore-part; _b_, the horns; _d_, a lunated figure in the shell; _c_, a pulpous body; _f_, bristles at the hinder-part.

267. KERONA VANNUS. K. ovalis subdepressa, margine altero flexo, opposito ciliato, corniculis anticis, setisque posticis. Oval and rather flat kerona, with one edge bent, the opposite one ciliated, the front furnished with horns, and the hind-part with bristles.

268. KERONA PULLASTER. K. ovata, antice sinuata, fronte crestata, basi crinita. Plate XXVII. Fig. 24 and 25. Oval, the fore-part sinuated, a crest on the front, the base hairy.

It agrees in many respects with the trichoda pulex, No. 252; but the upper part is pellucid, without any black molecules; the front truncated, the whole surface of the head covered with hair, and the fore-part sinuous. _a_, the horns; _b_, the hairs at the hinder-part; _c_, the cilia of the front.

269. KERONA MYTILLUS. K. subclavata, utraque extremitate latiori, hyalina ciliata. Plate XXVII. Fig. 29. Rather clubbed, broad at both extremities, clear and ciliated.

A large animalculum, the fore and hind-part rounded, very pellucid and white, dark in the middle, with black intestines, intermixed with a few pellucid vesicles; both extremities appear as if composed of two thin plates. The fore-part is ciliated, the hairs short, lying within the margin; it is also ornamented with two small horns, erected from an obscure mass; with these it agitates the water, forming a little whirlpool. The hind-part is likewise ciliated, and furnished with two bristles, extending beyond the margin. _a_, the horns; _b_, the fore-part ciliated; _c_, the hind-part; _d_, projecting bristles.

270. KERONA LEPUS. K. ovata, apice crinito, basi setosa. Egg-shaped, the fore-part hairy, the base furnished with bristles.

The body is egg-shaped, compressed, pellucid, and crowned with short waving hairs, the base terminating with bristles.

271. KERONA SILURUS. K. oblonga, antice et postice crinita, dorso ciliato. Oblong, the fore and hind-part hairy, the back ciliated.

An oval smooth animalculum, somewhat crooked and opake, with a fascicle of vibrating hair on the fore-part; it has a sharp tail, furnished with unequal rows of moveable hairs, producing a rotatory motion; in the inside are some partly lucid, and partly opake points. The figure varies from oval to oblong, the filaments of the conferva are often entangled in the tail.

272. KERONA CALVITIUM. R. latiuscula, oblonga, antice corniculis micantibus. Rather broad, oblong, with glittering horns on the fore-part.

The body is rather broad and flat, both sides obtuse, filled with black molecules, and there is a dark spot near the hinder-part, where there are likewise a few short bristles. The interjacent vesicles are pellucid; no hairs on the fore-part, but instead thereof two little moveable horns, and from three to five moveable black points. It is found in the infusions of vegetables.

273. KERONA PUSTULATA. K. ovalis convexa, postice altero margine sinuata, utraque extremitate crinita, corniculisque anticis. Oval, convex, kerona, one edge of the hinder-part sinuated, both ends set with hairs, and some horns placed on the fore-part. This animalculum was found in salt water.

XV. HIMANTOPUS.

Vermis inconspicuus, pellucidus, cirratus. A pellucid, invisible, cirrated[127] worm.

[127] That is, furnished with a tuft or lock of hair.

274. HIMANTOPUS ACARUS. H. ventrosus, postice cirratus, antice acuminatus. Plate XXVII. Fig. 27. Round and prominent himantopus, the hinder-part cirrated, the fore-part sharp.

It is a lively, conical, ventricose animalculum, full of black molecules, the fore-part bright and transparent. The apex, which has long hairs on the under part set like rays, is more or less attenuated, at the will of the little creature; four locks of long and crooked hair, or feet, proceed from the belly; and it is continually moving these and the other hairs in various directions. It is found, though seldom, where the lemna grows. _a_, the apex; _b_, the ciliated part; _c_, the feet.

275. HIMANTOPUS LUDIO. H. cirrata, supra crinita, cauda sursum extensa. Plate XXVII. Fig. 26. Curled himantopus, the upper part hairy, the tail extended upwards.

This is a lively and diverting animalculum, smooth, pellucid, full of small points, the fore-part clubbed and a little bent, the hind-part narrow; the base obliquely truncated, and terminating in a tail stretched out transversely. The top of the head, and the middle of the back _b_, are furnished with long vibrating hairs; three moveable and flexible curls _a_, are suspended from the side of the head, at a distance from each other. When the animalculum is at rest, its tail is curled; but when in motion, it is drawn tight, and extended upwards, frequently appearing as if it were cleft, as at _f_.

276. HIMANTOPUS SANNIO. H. incurvata, supra ciliata, infra crinita. Crooked himantopus, the upper part ciliated, the under part hairy.

This very much resembles the himantopus ludio, the cilia are longer than the hairs, and are continually vibrating; it has two moveable curls hanging on the side of the head. Is found, though seldom, in water where the lemna grows.

277. HIMANTOPUS VOLUTATOR. H. lunatus, antice cirratus. Lunated himantopus, the fore-part hairy.

A very lively animalculum, often turning round in a circular direction. Its shape is that of a crescent, with some crystalline points; the convex part is furnished with a row of hairs, which are longest towards the tail, and underneath are four feet.

278. HIMANTOPUS LARVA. H. elongatus, medio cirratus. Long himantopus, cirrated in the middle.

The body is rather depressed and long; the hinder-parts acute, and generally curved, pellucid, and filled with granular molecules. Its motion resembles that of the himantopus ludio, No. 275, but its figure, and the situation of its parts are different.

279. HIMANTOPUS CHARON. H. cymbæformis fulcata, in fovea ventrali cirrata. Boat-shaped furrowed himantopus, the hollow part of the belly cirrated.

An oval pellucid membrane, the fore-part hairy, furrowed longitudinally, each side bent up, so as to form an intermediate hollow place, or belly, filled with grey molecules; beneath the middle it has several bent diverging rows of hairs; no hairs on the hinder-part. It is found in sea water, but rarely.

280. HIMANTOPUS CORONA. H. semiorbiculata, depressa, in utraque pagina cirrata. Semiorbicular himantopus, flattened, both sides cirrated.

A membranaceous lamina, very thin, pellucid, crystalline, and semilunar; the edge of the base is thick set with molecular intestines; the fore-part furnished with short hairs, or a kind of mane; towards the hind-part are three equal curved hairs, or spines.

XVI. VORTICELLA.

Vermis contractilis, nudus, ciliis rotatoriis. A naked worm, with rotatory cilia, capable of contracting and extending itself.

281. VORTICELLA CINCTA. V. trapeziformis, nigro-viridis, opaca. Plate XXVII. Fig. 30. This vorticella is in the form of a trapezium, of a blackish green colour, and opake.

It is of an irregular shape, sometimes assuming an oval figure, and appearing as if girt round with a transverse keel, _a_. It is invisible to the naked eye, ciliated on every side; the hairs all moveable, and longer on one side than the other.

282. VORTICELLA SPHÆROIDA. V. cylindrico-globosa, uniformis, opaca. A globous cylinder, uniform and opake.

To the naked eye this appears also little more than a point, but the microscope exhibits it as a globular mass of a dark green colour. It occasions a vehement motion in the surrounding water, which is probably effected by some very short hairs, which are perceptible.

283. VORTICELLA VIRIDIS. V. cylindracea, uniformis, viridis opaca. Plate XXVII. Fig. 31. Cylindrical, uniform, green, and opake.

This vorticella is visible to the naked eye, appearing like a minute green point; but the microscope discovers it to be nearly cylindrical, of a dark green colour, a little thicker at the fore-part _a_, than the hinder-part _b_, and both extremities obtuse. It appears to be totally destitute of limbs; notwithstanding which, it keeps the water in constant motion; so that it has probably some invisible rotatory instrument. It does not change its figure. Its motion is sometimes circular, at others, in a straight line. At _c_, some short hairs are visible.

284. VORTICELLA LUNIFERA. V. viridis, postice lunata, medio margine mucronato. Green vorticella, the hinder part lunated, with a point in the middle projecting from the edge.

The fore-part obtuse, the base broad, and hollowed away like a crescent, with a protuberance in the middle of the concave part shorter than the horns or points of the crescent; the fore-part is ciliated. It is found in salt water.

285. VORTICELLA BURSATA. V. viridis, apertura truncata, papillaque centrali. Plate XXVII. Fig. 32. Green vorticella, the aperture truncated, with a central papillary projection.

Round and prominent, filled with molecules; the fore-part truncated, and both sides of it pellucid; in the center of the aperture there is a prominent papilla or nipple, which when the animalculum is at rest, appears notched; the edge of the aperture is surrounded with cilia; these are sometimes all erect, shining, and in motion, or part bent back and quiescent, and part in motion; sometimes a few of them are collected together, and turned back like little hooks, one on each side. It is found in salt water. _a_, the cilia; _b_, the projecting papilla; _c_, the pellucid space at the fore-part.

286. VORTICELLA VARIA. V. cylindrica, truncata, opaca, nigricans. Cylindrical, truncated, opake, blackish-coloured vorticella, the fore-part ciliated.