OPHRYDINA. 129 



pleasure derivable from watching the habits and 

 peculiarities of these extraordinary and beautiful 

 little beings. 



In the next family, Oplirydina, I shall only 

 mention two genera Vaginicola and Cothurnia. 

 Vagmicola crystallina (Drop III. fig. 4) has a 

 transparent, crystalline, pitcher- shaped lorica, 

 fixed to the stalks of duckweed ; the body is 

 bright green, from the granules with which it 

 is filled, and often appears double : it expands 

 slowly as if afraid, and protruding from its lorica, 

 it then unfolds its cilia for a short time, but 

 again suddenly retires. V. decumbens has the 

 lorica flat on the stalk or leaf not erect, like 

 the last. Cothurnia imberbis (Drop III. fig. 5) 

 has the transparent lorica round at the bottom, 



