Protozoa and Rotifer a at Havana, III. 353 



Cathypnidae: Mar.-May, June-Oct., Nov.-Dec. 



Colurus : Mar., Apr., June-Sept., Oct. 



Metopidia : Mar., June, July-Sept., Oct., Dec. 



Pterodma patina : June-Oct., Nov.-May. 



Brachionus pala : May-July, Aug. -Apr. 



B. dorcas : Oct., Nov., Dec-Apr., May. 



B. punctatus : June-Sept. 



B. urceolaris : Jan., Feb., Mar., Apr. 



B. bakeri, angularis, and militaris : Feb.-May, June-Sept., 



Oct., Dec. 

 Schizocerca : June-Sept. 



Noteus quadricornis : May, June, July-Sept., Oct., Nov. 

 Anursea tecta and cochlearis : Jan., Feb., Mar -Aug., Sept.- 



Dec. 

 A. aculeata : Jan.-June, Nov., Dec. 

 Notholca acuminata: Oct., Nov., Dec-Apr., May. 

 Pedalion mirum : May, July-Sept., Oct. 



LOCAL DISTRIBUTION. 



The Rotifera were widely distributed, being well repre- 

 sented at all of the substations. One hundred and eight 

 forms were observed and identified. The five lakes under 

 examination reflect their peculiarities in the species records. 

 Thompson's, Quiver, and Dogfish lakes have well-defined 

 shores, never become dry, and are more or less permanently 

 supplied with aquatic vegetation. Their rotifer fauna was 

 much the same. Phelps and Flag lakes, on the other hand, 

 were very shallow, margined by mud flats which grew in size 

 as the water dried up under the summer sun, the latter lake 

 being substantially a reedy swamp. Species found in the 

 other three lakes were often not present in these two, while a 

 few forms were conspicuously more abundant in one of these 

 than in the other three. 



It is difficult to distinguish littoral and pelagic forms in 

 this list. At most of the substations the water was compara- 

 tively shallow, its average depth where the tow-net was used 

 ranging from abou^, one and a half feet in Phelps Lake to 

 nine feet in the river at E. Because of this shallowness 



