C. F. ROUSSELET ON TROCHOSPH.ERA SOLSTITIALIS. 193 



the ciliary wreath, by means of which only this zone can 

 be slightly contracted, complete the summary description of 

 Trochosphcera solstitialis. In size and shape it is like a young 

 volvox globator, with perfectly transparent integument. I under- 

 stand Dr. Kofoid has in preparation an exhaustive paper on this 

 very interesting rotifer. 



Keferences in the Drawing. 



hr. — brain. 



cl. — cloaca. 



c. V, — contractile vesicle. 



d.a. — dorsal antenna. 



e. — eye. 



La. — lateral antenna. 



I.e. — lateral canals of water vascular system. 



m. — mouth and mastax. 



m.h. — muscular bands. 



n. — nerve-threads. 



ov. — ovary. 



St. — stomach and intestine. 



