332 DESCRIPTION OF \_Rotatorta. 



sometimes appears yellowish ; the ventral surface is flat 

 and ciliated, the dorsal arched and smooth. The large 

 dark ovum has been seen by Ehrenberg. It seldom swims, 

 but mostly creeps. Fig. 356 exhibits a full-grown animal- 

 cule (ventral side) . Found among conferva and oscillatoria. 

 Length 1 -440th to l-140th. 



Genus CXXXVI. Chaetonotus. The brushed Jisfi- 

 Animalculea have hairs upon their dorsal surface, possess a 

 forked tail, but no eyes. Locomotion is performed by a 

 double row of cilii upon the ventral surface, which forms 

 a band-like rotatory organ. The nutritive organs consist 

 of a tubular mouth, probably provided with a cylinder of 

 teeth, a long thin cesophagus, and a long conical stomach 

 (Trachelogastricum), upon whose upper thick end (in the 

 large species), two semi-globular glands are seen; at certain 

 periods from one to three large single ova are formed pos- 

 teriorly, but the ovarium in which they are developed has 

 not been directly observed; male i-eproductive organs un- 

 known. They are sluggish in their movements, except in 

 creeping; they rarely swim. 



565. Chaetonotus maximus. The largeChaetouotus. — 

 Body elongated, slightly constricted anteriorly, turgid and 

 obtusely three-lobed ; the hairs upon the back are short and 

 equal. From the latest observations, Ehrenberg states the 

 mouth to possess teeth, of which he has counted more 

 than eight; he once saw the exclusion of ova immediately 

 over the hinder foot-like tail. It creeps but slowly. Size 

 1-21 6th to l-120th. 



566. Chaetonotus lams {Trichoda acarus, anas et 

 larus, M.) The gull Chaetonotus. — Body elongated, 

 slightly constricted anteriorly, where it is turgid and ob- 



