Protozoa and Rotifera at Havana, III. 381 



95. B. annularis bidens Plate ('85). (Fig. 4, 5.) 



B. caudatus Barrois et Daday ("94.) 

 This form was present from April 

 to September, most abundantly in 

 July and August. It was found at the 



#same substations as 

 the preceding species. 

 Dr. Plate, in describ- 

 ing this form, gives it 

 specific rank. Barrois 

 and Daday have re- 

 cently described a form 



_,. . _ under the name B. cau- 



Fifir 4 Brach- 



ionus caudatus datus. A careful com- Fig. 5. Brachionus bidens 



Barrois&Daday. par i SO n of the figures of Plate ' 



the two forms shows that they are identical. As Plate says : 



"The animal is closely related to B. angularis Gosse, with 



which it corresponds in size and shape of the lorica; and 



differs from it alone in that the surface of the lorica is not 



roughened by angular ridges but is entirely smooth, or, at 



most, very finely punctate." The opening for the protrusion 



of the foot is characteristic in both forms. I found individuals 



grading from angularis to forms that had the two posterior 



spines even more developed than in caudatus. I see no 



reason why this form should not be recognized as a variety 



with the name proposed by Plate. 



96. B. militaris Ehrbg. 



This is also a summer species, occurring in both years 

 from June to October, and found but once outside this period 

 — in December. It was most abundant from July to Sep- 

 tember, and was found in all the bodies of water studied, 

 although it was rarer in the two shallower lakes. It was 

 equally abundant among vegetation and in open water. Not- 

 withstanding the short period of its occurrence this was the 

 most abundant species of the genus. Collections made 

 among vegetation during the summer months were almost a 

 "pure culture" of it. It became abundant very suddenly and 

 disappeared with equal abruptness. 



