Protozoa and Rotifera at Havana, III. 355 



A. aculeata Ehrbg. 



A. cochlearis Gosse. 



Notholca acuminata Ehrbg. 



Pedalion mirum Hudson. 



Among these pelagic forms the most abundant were As- 

 planchna brightwelli,Synchata pectinata, Polyarthra platyptera, 

 Triarthra terminalis, Brachionus pala, and Anurcea cochlearis. 

 Brachionus militaris was probably the most abundant form 

 of the littoral species. 



Of all the substations under examination, C yielded the 

 greatest number of species. There were two reasons for this. 

 In the first place, a variety of conditions prevailed here. 

 There was dense floating vegetation on each side of the lake, 

 and at the same time a tolerably clear channel through the 

 middle. Again, a greater number of collections were made 

 here than at any other substation on account of the location 

 of the field headquarters at this point. A and B were not 

 satisfactory locations since they had to be abandoned early 

 in the season. F was a constant source of surprise, and the 

 catches made there were very interesting in regard to both 

 numbers and variety. This was a very fruitful substation 

 until August, when it completely dried up. D yielded noth- 

 ing unusual, and the catches there were essentially the same 

 as those among vegetation at the other substations. E was 

 a typical river situation, and was satisfactory in every way. 

 Next to C it yielded the largest number of species and, as 

 might have been expected, all of the pelagic forms were found 

 here. G was in a lake typical of the larger and more per- 

 manent lakes of the river bottoms, and contained a remark- 

 able variety and number of organisms. Unfortunately its 

 usefulness to us was reduced by the fact that it was difficult 

 of access, and was consequently visited only at long in- 

 tervals — usually a month, but sometimes longer. 



AFFINITIES AND CLASSIFICATION. 



There has been much discussion about the affinities of the 

 Rotifera. Dr. C. F. Hudson ('75) thinks that such forms as 

 Pedalion link them with the Crustacea, while, on the other 



