208 AQUATIC MICROSCOPY FOR BEGINNERS. 



none in advance of the mouth, which is large U-shaped, 

 the arms of the U pointing forward, the whole being 

 surrounded with a thick border. The pharynx is 

 broad and ciliated within. 



The body is colorless, the brick-red or orange- 

 colored spots scattered over the internal surface giv- 

 ing the worm a beautiful appearance. 



^Solosdma is found in ditches among Algae, on which 

 it feeds. It is not very active in its movements. 

 The'blood is colorless. It increases rapidly by trans- 

 verse fission. 



Among the Sphagnum in the writer's locality there 

 not uncommonly occurs a worm which I have ventured 

 to identify as a member of this genus. It externally 

 differs from the species referred to above in having 

 fewer and larger red spots, which seem to be on the 

 outer surface of the skin, where they are most abun- 

 dantly collected near the two extremities, being few- 

 est on the central region of the body. The bristles 

 are so arranged that they appear to form two rows of 

 clusters on each side, being separated into two groups 

 in each cluster. The worm 'thus seems to have four 

 rows, instead of two as in the preceding species. Its 

 movements are also much more active. It is likewise 

 a vegetarian. 



9. Ocner6drilus. 



This remarkable worm has thus far been found, by 

 Dr. Gustav Eisen who discovered it, only in Fresno 

 County, California, where it was obtained among fine 

 AlgK growing to the sides of a submerged wooden 

 box, and also occasionally in the mud with a part of 

 the tail end protruding and motionless. The body is 



