252 Zoology of Colorado 



everywhere in standing water, is probably to be called Amiba 

 difflucns {Proteus dijflucns G. Adams, 1 787), though Doflein prefers 

 to call it Amoeba proteus of Pallas. Penard found a peculiar 

 Amiba on Bald Mountain, Boulder County, at 1 1 ,470 feet altitude. 

 Later he received the same animal from Spitzbergen, and described 

 it as A. radiosa var. gemmifera. 



The shell-forming Difflugia corona, a rounded object with 

 spike-like projections, has been made the subject of classical 

 researches in heredity by Jennings. As the shells are readily 

 preserved, many successive generations may be directly compared. 

 This species, along with seventeen other members of the genus, 

 was found in the mountain lakes of Colorado by Edmondson. 



Quadrulella symmetrica of Wallich, found in Boulder County, 

 but also widely distributed over the world, has the shell formed 

 of quadrangular siliceous (flinty) plates, which will not dissolve 

 in strong acid. 



INFUSORIA 



The species of cilia te Infusoria are extremely numerous, 

 one of the most abundant being Paramoecium caudatum of Ehren- 

 berg,* which has been used so much in studies of heredity, be- 

 havior, etc. It multiplies by division, and by starting with a 

 single individual it is possible to develop a "pure line" of in- 

 dividuals all having the same ancestry. Paramecium may be 

 found in great quantities in water in which cut flowers have 

 stood. A few are of course present in the water drawn from the tap, 

 but with the food supplied by the rotting stems, they multiply 

 enormously. 



A very handsome and remarkable infusorian is Stentor 

 coeruleus of Ehrenberg, blue, and shaped something like a trumpet. 

 The word stentor means a herald, and was suggested by the 

 trumpet-like form. The animal is not rare at Boulder, and 

 Edmondson found it in Redrock Lake near Ward. 



Even the Infusoria have parasitic forms, and we have in 

 Colorado a kind of Opalina, parasitic in the frog. This was not 

 definitely identified, but was presumably 0. obtrigonidea of Metcalf . 

 Protoopalina scaphiopodos Metcalf is reported by its describer as 



•Sherborn credits this name to J. Hermann. 1 784. 



