EPISTYLIS. 127 



cast, and, when contracted, has a folded ap- 

 pearance. E. anastatica has an oval-shaped 

 body, and does not form folds when contracted : 

 it is often found on the shells of small mollusca. 

 E. digitalis is small, but much branched, and is 

 often abundant on the body of the Cyclops qua- 

 dricornis, where it appears to be indifferent to 

 the rapid movement of that active creature, 

 whose passage through the water one would 

 suppose must destroy the life of so delicate a 

 being. E. grandis has not an erect stalk, but it 

 is often of great length, even as much as several 

 feet : it looks like blue slinie to the naked eye. 

 E. nutans has the body drooping when the cilia 

 contract, though it is upright when they are 

 expanded. It is curious to see this little crea- 



