jPhilodinaea.'] infusorial animalcules, 671 



attenuated body. The style, or respiratory tube, is ciliated in a star- 

 like manner. The wheels are prominent, and it is altogether a choice 

 subject for the niicroscoiw. Found in boggy water. Length l-350th. 



RoTiPER tardus. — Body hyaline, fusiform, gradually attenuated to 

 a foot, and having deep strictures in the form of square false articu- 

 lations or joints; ej'es oblong. It resembles internally 11. vulgaris. 

 Length l-80th. 



Of the several species of Rotifer, and of the following one of Adi- 

 tiurus, described by Ehrenbcrg, M. Dujardin confesses his inability 

 to discover the specific diiferences, although he admits the differences 

 of habitat, and of resistance to the process of dessieation. He how- 

 ever believes he has discovered a Rotifer certainly specifically distinct 

 from any variet)'- of Rotifer vulgaris ; this he would designate 



RoTiFEK infiatus. — Its form is less slender than E. vulgaris, its 

 rotatory organs of less size, and its red specks seated very near the 

 jaws. Length 1-5 8th. Found in water or wet moss. 



Of this species he infers that Ehrenberg has constructed at least 

 four others, according to the rose or yellow colour it presents, the 

 form of the eyes, and the length of the caudal appendages, which 

 are, to wit, Philodina criiophalma, P. roseola, P. citrina, P. macrostyla. 

 At the same time he would regard P. coUaris, P. megalotrocha, and P. 

 aculeata, as distinct forms of Rotifera. 



H. macroceros (Gosse.) — Wheels large ; antennal process (the res- 

 piratory tube) of Ehrenberg, very long and mobile. (1-lOOtli.) 



Genus AcTiNUKUs. — The three- toed Rotatoria. — Eyes two, frontal ; 

 foot furnished wdth two little horn-like processes, and tlii'ee toes. In 

 other respects the organization resembles Rotifer vulgaris. 



A. Neptunius {Vorticella Rotatoria, 'hi.) — Body white, fusiform, 

 gradually attenuated into a long foot, having three equal toes exceeding 

 the horn-like processes in length. The chewing action of the jaws in 

 the oesophageal head is often distinctly seen. Fig. 481 represents this 

 animalcule extended, with the wheels withdrawn, which is the case 

 when crawding; the respirator tube is then seen, terminated by a single 

 delicate haii--like point ; fig. 482 shews one contracted, but the head 

 partially withdrawn ; fig. 484 represents the upper part, when the 

 wheels are extended and in action ; fig. 483 the oesophagus and jaws, 

 separated and extended under pressure. Length l-36th to 1-1 8th. 



