404 DESCRIPTION OF [Rotatoria. 



respiratory tube toothed. The extremities are transparent, 

 the middle of the body of a citron colour ; it often exhibits 

 longitudinal folds, and is then less transparent. Found 

 amongst oscillatoria. Length l-24th. 



693. ROTIFER (?) erythraeus. The Arabian Rotifer. 

 Body small, oblong, suddenly attenuated into a long 

 foot. Length l-240th. 



694. ROTIFER macrurus (Vorticella macrura, M.) The 

 long-footed Rotifer. Body transparent, ovato-oblong, 

 suddenly attenuated into a long foot ; this is distinguished 

 from Actinurus by its small toes, horn-like processes, and 

 suddenly-attenuated body. The style, or respiratory tube, 

 is ciliated in a star-like manner. The wheels are promi- 

 nent, and it is altogether a choice subject for the microscope. 

 Found in boggy water. Length l-350th. 



685. ROTIFER tardus. The idle Rotifer. Body hyaline, 

 fusiform, gradually attenuated to a foot, and having deep 

 strictures in the form of square false articulations or joints; 

 eyes oblong. It resembles internally R. vulgaris. Length 

 l-80th. 



Genus CLXXXII. ACTINURUS. The three-toed Rota- 

 toria are provided with two frontal eyes, and a foot, 

 furnished with two little horn-like processes, and three 

 toes. In other respects the organization resembles Rotifer 

 vulgaris. 



696. ACTINURUS Neptunius ( Vorticella Rolatoria, M.) 

 The elongated Actinurus. Body white, fusiform, gradually 

 attenuated into a long foot, having three equal toes exceed- 

 ing the horn-like processes in length. The chewing action 

 of the jaws in the cesophagal head is often distinctly seen. 

 Fig. 481 represents this animalcule extended, with the 



