158 



AQUATIC MICROSCOPY FOR BEGINNERS. 



This species is often extremely abundant at the 

 bottom of shallow ponds in early spring. The 

 green color then always entirely 

 conceals the red. S. igneus, Fig. 1 16. 

 b. Body large, indigo-blue. This in 

 shape when extended, resembles 

 Fig. 114; when contracted it is 

 not unlike Fig. 116. Very com- 

 mon in some localities. S. coeriileus. 

 b. Body dark brown, almost black. 

 This in form likewise resembles 

 Fig. 116. Common. S. niger. 



. 116. — St6ntor 

 igneus. 



10. AstXsia. (Fig. 117). 



Body long, narrow, and' colorless; exceedingly soft, 

 and changeable in shape, altering its form as it glides 



Fig. 117. — Astasia. 



over the slide, which it does rapidly. It has one long 

 straight flagellum at the front. It is common, but 

 may be overlooked by reason of the absence of color. 



II. Eugl£na (Fig. 118). 



Body long and rather narrow, being widest in the 

 middle and tapering to both ends. It is exceedingly 

 changeable in form, and bright green or red in color. 

 The front end may be seen with a high power to be 

 notched as if the Infusorian had two lips, the long, vi- 

 brating, and colorless flagellum appearing to issue 

 from the notch. There is sometimes a small red spot 

 near the front end, supposed to be an imperfect eye. 



