EUGLENA. 



105 



crease at an astonishing rate, and, assuming a 

 blood-red colour, give a tinge to waters, for 

 which the ignorant cannot account. It has a 

 spindle-shaped body. A.pusilla occurs in my- 

 riads, so as to form occasionally quite a stratum 

 on the surface of the water : it has no colour. 

 A. nivalis is found in snow in Switzerland. 



Most of the species of the genus Euylena are 

 beautiful objects, the bright colours rendering 

 them very attractive. JEJ. sangmnea (Drop II. 

 fig. 10) is of a spindle shape, the head rounded, 

 tail short, proboscis long : the colour varies 

 some may be found quite green, which seem to 

 be the young ones, others mixed red and green, 

 and others quite red. E. viridis is green, 

 except the head and tail these are white, 



