FIELD BOOK OF PONDS AND STREAMS 



in front with short auricles. These animals usually pass as 

 common black planarians. Their backs are irregularly 

 spotted with black, and smaller black spots are scattered 

 among the large ones so that the whole surface looks dark, 

 though a light streak sometimes runs along the middle. In 

 summer they reproduce almost entirely by transverse divi- 

 sions. They live in quiet waters, under stones, among algas, 

 often in groups of 3 to 5, or 15 to 20. 



r 



Occurrence. — Eastern states to Michigan and Nebraska. 

 4. Turbellarians with several pharynges. 



Fig. 99. — Phagocata gracilis. 



Phagocata gracilis. — These planarians are shiny black or 

 sometimes reddish-brown, one third to i inch long. They 

 are round headed and blunt tailed, remarkable in having 

 not one pharynx but twenty-two separate ones, each having 

 a mouth, and opening into the intestine, and all of them ex- 

 tensible through the single opening on the under side of the 

 body (Fig. 99). 



Occurrence. — Common in pools, often in brackish water. 

 Massachusetts and Pennsylvania to Wisconsin. 



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