Anterior end pointed or narrowly rounded 19. 



14. With an adhesive circle in the middle of the anterior margin; eyes two 



to several, near the front and well separated; color white 

 Procotyla fluviatilis Leidy 

 (Dendrocoelum lacteum Oersted) 

 No adhesive circle; with two eyes farther back and closer together; color 

 various 15. 



15. Color white 16. 

 Color gray or black 17. 



16. With one pharynx from the middle of the ventral side 



Phagocata morgani (Stevens 6? Boring) 

 (FonUcola truyicata (Leidy) ) 

 With several pharynxes; Indiana 



Phagocata subterranea Hyman 



17. Color gray; with one pharynx from the middle of the ventral side 



Phagocata velata (Stringer) 

 Color gray to black; with several pharynxes 18. 



18. Head lobes conspicuous 



Phagocata gracilis (Haldeman) 

 Head lobes less evident 



Phagocata woodworthi Hyman 



19. Head lobes slender and acutely pointed; anterior end sharply pointed; 



large (to one inch) , active animals 20. 



Head lobes thick and bluntly pointed; anterior end more rounded; smaller, 



sluggish animals 21. 



20. Dark above and below 



Dugesia agihs (Stringer) 

 (Euplanana agiUs (Stringer) ) 

 Brown above, lighter below 



Dugesia dorotocephala (Woodworth) 

 (Euplanaria philadelphica Hyman) 



21. With scattered, unpigmented areas on a grayish or purplish background 



Dugesia tigrina (Girard) 

 (Euplanana maculata (Leidy) ) 

 (Planaria lata Sivickis) 

 Uniformly dark colored above 22. 



22. Head lobes obscure; color usually blackish 



Curtisia foremanii (Girard) 

 (Planaria simplissima Curtis) 

 (Planaria luguhris Schmidt) 

 Head lobes evident; color usually brownish 



Dugesia microhursalis (Hyman) 

 (Euplanaria microhursalis Hyman) 



KEY TO THE PRINCIPAL GENERA OF ANNELIDS, INCLUDING 

 SOME OF THE COMMON SPECIES OF LEECHES 

 AND EARTHWORMS 

 1. With a sucker on the posterior end of the body (often difficult to see); 



84 



