Feb., 1920] The Protozoa of Mirror Lake 111 



Class Infusoria. 

 SUBCLASS CILIATA. 

 Order Holotrichida. 



Family Enchelinidce . 



Enchelydon farctus Claparede and Lachmann. 



One individual was taken on March 21 in algae scraped from 

 a submerged stone (Station G). 

 Length 224^^. 



Pseudoprorodon niveus (Ehrenberg). 



One individual was found on December 3 among dead 

 filaments of Oedogonium at Station H. 

 Length 192ju; breadth 96ju. 



Prorodon teres Ehrenberg. 



This species was common throughout January and February 

 in alga-covered poplar roots (Station D), and nearby in algae 

 from a submerged stone (Station G). The form of the animal 

 varied considerably, some individuals being much more elongate 

 than others. 



Length 240-282ai. 



Lacrymaria olor Miiller. 



This form was rare in collections, but was widely distributed 

 in the lake. Throughout the period of study it was taken in 

 sediment from Station B, among algae, both from a submerged 

 stone at Station G and on submerged posts (Stations I and I') 

 and in the bowl of the spring (Station J). It was found also in 

 sediment at Station M. The actions of the organism are very 

 interesting. The flask-shaped body usually lies hidden among 

 debris while the exceedingly elastic neck violently waves about 

 in search of food. 



Length of the contracted animal 112-143iu; the extended 

 form 512ju. 



Coleps hirtus Ehrenberg. 



This species was more frequently recorded perhaps than any 

 other of the Protozoa. It was taken throughout the period of 

 study in algae at Stations C, D, E, G, H, and L. The animal 



