15. With three distinct jaws within the mouth area (appearing as opposing 



ridges or folds) 16. 



Jaws not evident, being small, retractile or absent 17. 



16. Back greenish, with a central row of red spots and with a row of black 



spots along each side 



MacrohdeUa decora (Say) Common Northern Blood Sucker 

 Back greenish, with four to six complete or interrupted lengthwise stripes; 

 an introduced species 



Hirudo medicinalis Linn. Medicinal Leech of Europe 



17. With three, yellow, lengthwise stripes or with reddish and dark stripes; 



blood suckers; Gulf states 



Philohdella Verrill Southern Blood Suckers 18. 



Body blotched, plain dark, or with a yellow stripe along each side; feed' 

 ing on worms, insect larvae, etc.; not true blood suckers; aquatic or ter' 

 restrial or both, typically found on pond edges; widely distributed 



Haemopsis Savigny Land and Pond Leeches 19. 



18. With a narrow yellow stripe along the middle of the back and with a 



broader yellow stripe along each side; with brown spots 



Philohdella gracxle Moore Spotted Southern Blood Sucker 

 With two dark stripes along the back, each bordered below by a reddish 



stripe; without spots 



Philohdella floridana Verrill Southern Blood Sucker 



19. Usually with a median dark stripe and a yellowish stripe along each side 



Haemopsis lateralis (Say) Striped Leech 

 Back dark or blotched; no mid-dorsal stripe but often with a yellowish 

 stripe along each side 20. 



20. Back scarcely blotched and about the same shade or lighter than the under 



side 



Haemopsis plumheus Moore 

 Back blotched and darker than the under side 21. 



21. With very irregular dark blotches on the back 



Haemopsis marmoratis (Say) Common Horse Leech 

 With almost squarish dark blotches on the back 



Haemopsis grandis (Verrill) Giant Leech 



22. Body usually cylindrical, extremely long and narrow, when extended; 



stomach with two posterior caeca; usually parasitic on fishes; Family 



Piscicohdae or Ichthyohdellidae 23. 



Body usually flattened, not so slender; stomach with many lateral caeca; 



habitat varied; Family Glossiphonidae 30. 



23. Anterior sucker quite distinct from the body; with pulsating structures 



along the sides serving as gills 24. 



Anterior sucker not distinct from the body; without such pulsating struc' 



tures. 26. 



24. Posterior part of body flatter and wider than anterior part; central body 



segments (larger divisions of body) composed of about seven small rings 

 Cystohranchus vividus (Verrill) 

 (Trachelohdella vivida (Verrill) ) 

 Body more uniform throughout; central body segments composed of about 

 fourteen small rings. 25. 



87 



