704 



SYSTEMATIC HISTOET OF THE INFFSOEIA. 



of a compressor. In xxxv. 476-478, ova 

 are seen ; some are developed, and their 

 eyes and oesophageal bulb visible. The 

 ti-ansverse muscles, and the tube pro- 

 jecting from the neck, are seen in the 

 engravings. Found in fresh and sea- 

 water, in infusions, on the flocculent 

 matters of water-plants, and even Avithin 

 the cells of some, e. g. of Sphagnum and 

 Vaucheria, &c. (See Part I. p. 466.) 

 1-50" to 1-24". 



R. (?) citn?uis. — Fusiform, lower part 

 gradually attenuated into a foot ; its 

 horn-like processes elongated ; eyes 

 round and, according to Leydig, con- 

 taining a refracting body ', cei-vical tube 

 toothed. The extremities are transpa- 

 rent, the middle of the body of a citron 

 colour ; it often exhibits longitudinal 

 folds, and is then less transparent. 

 Amongst Oscillatoriae. 1-24". 



R. (?) erythrcBus. — Small, oblong, 

 suddenly attenuated into a long foot. 

 1-240". 



R. macrurus {Vorticella macnira, M.). 

 — Transparent, ovato-oblong, suddenly 

 attenuated into a long foot ; this is di- 

 stinguished from Actmurus by its small 

 toes, horn-like processes, and suddenly- 

 attenuated body. The style, or antennal 

 tube, is ciliated in a star-like manner. 

 The wheels are prominent. A long | 

 stomach is succeeded by a short intes- j 

 tine ; on each side is a convoluted water- 1 

 vascular canal, but without vibratile j 

 tags. Eyes either two, hemispherical, 

 abruptly ' truncate anteriorly, red, and 

 with a refracting medium, or elongated 

 posteriorly, becoming divided into seve- 



ral rows of linear points, without re- 

 fracting media. It is altogether a choice 

 subject for the microscope. In boggy 

 water. 1-350". 



R. tardus. — Hyaline, fusiform, gi'a- 

 dually attenuated to the foot, and having 

 deep strictures in the form of square 

 false articulations or joints ; eyes ob- 

 long. It resembles internally R. vulgaris. 

 1-80". 



Of the several species of Rotifer, and 

 of the following one of Actinurus, de- 

 scribed by Ehrenberg, M. Dujardin con- 

 fesses his inability to discover the specific 

 differences, although he admits diversity 

 of habitat, and of resistance to the pro- 

 cess of desiccation. He, however, be- 

 lieves he has discovered a Rotifer spe- 

 cifically distinct from any variety of 

 Rotifer vulgaris ; this he would desig- 

 nate 



R. injlatus (xxxviii. 1-3). — It is less 

 slender than R. vulgaris, its rotary organs 

 of less size, and its red specks seated 

 ver}^ near the jaws. 1-58". In water 

 or wet moss. 



Of this species Dujardin infers that 

 Ehrenberg has constructed at least four 

 others, accordmg to the rose oi yellow 

 colour it presents, the form of the eyes, 

 and the length of the caudal appendages, 

 viz. Philodina eryophthalma, P. 7'oseola, 

 P. citrina, P. macrostyla. At the same 

 time he would regard P. coUaris, P. me- 

 galotrocha, and P. aculeata as distinct 

 forms of Rotifer a. 



R. macroceros (Gosse). — Wheels large; 

 antennal process (the respiratory tube, 

 Ehr.) very long and mobile. 1-100". 



Genus ACTINURUS (XXXY. 481-484).— Eyes two, frontal ; foot fiu-- 

 nished with two little horn-like processes, and tliree toes. In other respects 

 the organization resembles Rotifer vulgaris. 



Actinurus Neptunius ( Vorticella ro- the case when crawling- ; the antenna is 

 tatoria, M.). — White, fusifonn, gradually 

 attenuated into a long foot, having three 

 equal toes exceeding the horn-like pro- 

 cesses in length. The action of the jaws 

 in the oesophageal head is often distinctly 

 seen. (xxxv. 481, an animal extended, 

 wdth the wheels withdrawn, which is 



the case when crawling ; 

 then seen, terminated by a single delicate 

 hair-like point ; 482, contracted, head 

 partially withdrawn ; 484, the upper part, 

 when the wheels are extended and in 

 action ; 483, the oesophagus and jaws, 

 separated and extended imder pressm-e.) 

 1-36" to 1-18". 



Genus MOXOLABIS (XXXY. 485, 486).— Eyes two, frontal red ; foot 

 with two toes, but no horn-like processes. They are provided with muscles 

 for moving the double rotary apparatus, two for moving the foot, and four 

 belonging to the oesophageal bulb and jaws, which last are furnished with 

 double teeth, or teeth in rows. A very short oesophageal tube and a simple 

 conical alimentary canal are seen in both species; one of them has two 

 spherical glands; an ovarium is seen in both, but in neither have fully- 



