Euchlam'dota.] the INFUSORIA. 383 



species. No male organs, vessels, nor respiratory tubes, 

 are seen. Owing to the almost constant vibration of the 

 foot-like tail, it is difficult to observe the true form of its 

 termination, the motion producing an optical deception ; 

 hence it appears double, though in reality it is single. 



655. MoNOSTYLA cornuta ( Trichoda coruuta, M.) 

 The smooth Monostyhi. — Lorica hyaline, unarmed, and 

 truncated anteriorly. Found amongst chara and conferva. 

 Length 1 -250th. 



656. MoNOSTYLA quadridetitata. The four-horiied 

 Monostyla. — Lorica yellowish, the anterior deeply dentated, 

 resembling four horns. It is generally of a yellow leather 

 colour, but Ehrenberg has seen it colourless. Figs. 434 

 and 435 represent ventral views of this animalcule ; the 

 latter is extended beyond its lorica, which happens when 

 the rotatory cilii are in motion. Fig. 436 is a side view, 

 and Jig. 437 the jaws and teeth separate. Found in 

 floccose matter about conferva and the leaves of water- 

 plants. Length l-120th. 



657. Monostyla (?) lunaris. The moon-shaped Mo- 

 nostyla. — Lorica hyaline, the anterior cre§cent-shaped. 

 Length 1-1 44th. 



Genus CLXIX. Mastigocerca. The whip-tailed 

 Rotatory Animalcule is characterized by its having a single 

 cervical eye, a simple styliform foot, the lorica prismatic 

 and crested on the back. It has a four-partile rotatory 

 organ, a small muscle to move the foot, an oblique oeso- 

 phagal head, with unequal jaws, two-toothed; a short 

 oesophagus, simple intestine, with two spherical glands, a 

 globular ovarium, a contractile vesicle, and a long- 

 ganglion. 



