158 LEECHES 



at the level of the genital pores, but on the dorsal sur- 

 face, 2 large irregular blotches of colour ; eyes, 3 pairs, 

 in two close parallel rows, often with the first pair 

 smaller than the others or almost touching in the mid- 

 dorsal line; colour, dark green, spotted with yellow, 

 with 2 longitudinal regularly interrupted dark lines 

 dorsally; about 25 mm X 10 mm. 



Batracohdella verrucata (Fr. MuUer 1884) 



— No conspicuous tubercles or dorsal blotches; eyes, 2 

 pairs, often fused in various ways; colour similar to 

 above species; smaller, about 10 mm X 4mm. 



Batracohdella paludosa (Carena 1824) 



19. Eyes, 2 pairs, first pair close together or fused. 



Batracohdella paludosa (Carena 1824) 



— Eyes, 1 pair, close together or fused; no white bar on 

 segment VI. Batracohdella picta (Verrill 1872) 



— Eyes, 1 pair, usually fused, surrounded by a white area ; 

 a dense white bar on segment VI. 



Batracohdella phaler a Graf 1899 



20. Mid-body segments with 3 annuli of which the first and 

 third may be faintly subdivided; body at rest very 

 broad and flat; salivary glands compact; epididymis a 

 tight mass. Placohdella Blanchard 1896 21 



— Mid-body segments with 2-6 annuli; body at rest less 

 broad and flat; salivary glands diffuse; epididymis 

 loosely coiled 28 



21. European species. 



Placohdella [= Haementerta] costata (Fr. Miiller 1846) 



— American species 22 



22. Head distinctly wider than the segments just behind it; 

 3 prominent dorsal ridges bearing tubercles ; eyes clearly 

 separated. Placohdella montifera Moore 1912. 



— Without widened head and dorsal ridges 23 



23. Anus separated from posterior sucker by a slender, 

 tapering peduncle comprising about 16 annuli - 



Placohdella pediculata Heminway 1912 



