LIMNIAS. 149 



feed on Monads, and other small creatures. The 

 eggs are retained within the case till they are 

 hatched. The Stephanoceros has one eye, which 

 is very conspicuous in the young state. 



The Limnias has only two lobes to its rota- 

 tory organ, and the case, though at first white, 

 becomes of a brown colour, and is often covered 

 with other substances which adhere to it. The 

 rotatory organ of the Limnias ceratopliylli 

 (Drop IV. fig. 2) has a singular appearance when 

 the creature is feeding ; the cilia surrounding the 

 lobes are very short, and, when vibrating very 

 rapidly, have the appearance of a moving band of 

 light round the edge, which is very deceptive to the 

 eye, and the mind can scarcely conceive that the 

 effect is produced by so simple a cause as small 



o3 



