Protozoa and Rotifera at Havana, III. 325 



to be well defined and valid. It is elongate, with three longi- 

 tudinal spiral furrows or elevations. 



Amblyophis Ehrbg. 



Very similar to Euglena in structure and colors, but with 

 the posterior end rounded, not at all acuminate. 



34. A. viridis Ehrbg. 



Found infrequently in the river channel at E in August 

 and September. 



Trachelomonas Ehrbg. 



Differs but little from Euglena, except that it is enclosed 

 in a lorica or shell, varying in shape from elongate-oval to 

 spherical, and with a minute anterior opening, through which 

 the flagellum issues. 



85. T. caudata Ehrbg. 



This appeared in large numbers in aquaria started with 

 dried mud from the empty bed of Phelps Lake. Within two 

 days after starting the aquaria the Traclielomonas began to 

 develop. At first they had no loricae, and were scarcely dis- 

 tinguishable from Euglena viridis. After a short time the 

 lorica began to appear, first around the central and an- 

 terior parts of the body. At this stage, before the posterior 

 part of the lorica had become fully formed and hardened, the 

 animals while swimming about would occasionally contract 

 the body, drawing the posterior part into the lorica. 



In the second year's work a few were found in August and 

 September in towings from the river at E. 



36. T. acuminata Schmarda. 



Phelps Lake, with its shallow water and lack of vegetation, 

 seemed to be well fitted for the development of the Euglenida 

 during the first season of our work, since more species were 

 found here than at any other of the substations. T. acuminata 

 was scarce, appearing in the lake in July and August. It is 

 also recorded from Matanzas Lake. 



37. T. armata Ehrbg. 



A single occurrence is recorded, namely, at C in July. 



