816 UUnois State Lahoratoi^y of Natural History. 



length of the body, and is lined with cilia. The endo- 

 plasm in the postet-ior part of the body is clear, and 

 numerous fine longitudinal striations can be differen- 

 tiated. These unite and form the core of the stalk, which 

 has also fine longitudinal striations. The stalk is 

 variously branched. Some of the zooids have long 

 pedicles, while others are nearly sessile. The colonies 

 are large, consisting of several hundred individuals. Mul- 

 tiplication by longitudinal division was noticed. Length, 

 .178 mm. to .20 mm.; width .078 mm. 



This species is similar to Opercular la artioulata Ehrbg., 

 but (lift'ei's from it in the shape of the body, the charac- 

 ter of the peristome border and phai-ynx, and the ele- 

 vation of the ciliary disc. 



It was found during the summer months at many 

 of the stations, always attached to some animal, and 

 seemed to prefer the young musk turtle, Aromochelys 

 odoratus. It also occurred on the backs of the snapping 

 turtle, Chelydra serpentina, and the crayfishes Cambarus 

 diogenes^ and,^'. hlandlngii var. acuta. 



Tokophrya quadripartita C. & L. was found common in 

 comy^any with this species, as was alSo a small Opercidaria 

 which may turn out to be a variety. The zooids are 

 small— length .08 mm.; width .042 mm. — but otherwise 

 they seem to agree with the larger species. A part of 

 the food of this species consists of diatoms and 

 Euglena. 



Collections are still being made at the various stations, 

 and further study will no doubt add other forms to 

 this list. 



Havana, May 12, 1896. 



