172 LEECHES 



18. Annuli 12-14 per mid-body somite 19 



— Annuli 2-6 per mid-body somite 23 



19. Eyes absent 20 



— Eyes 2 or 3 pairs 22 



20. Median spermatheca lying between ovaries; from 

 California Marsipohdella 



— Spermatheca absent 21 



21. Posterior crop diverticula absent; from New Zealand 



Bdellamaris 



— Posterior crop diverticula fused, with 5 fenestra; 

 coelomic system typical, but pulsatile vesicles are 

 hidden in skin Johanssonia 



22. Annuli 12 per somite; testes 5 pairs . . Crangonohdella 



— Annuli 14 per somite; testes 6 pairs . . Carcinobdella 



23. Annuli 2 per mid-body somite; with 2 pairs eyes, each 

 made up of several black pigment spots . . Janusion 



— Annuli 3 (6) per mid-body somite ; if eyes are present, 

 each is a simple, rounded or crescent-shaped spot of 

 pigment 24 



24. Posterior sucker somewhat compressed laterally, typic- 

 ally folded round a fin-ray but also capable of adhering 



to flat surfaces Sanguinothus 



— Posterior sucker more or less circular in outline . . . . 25 



25. Coelom fairly spacious, not divided into lacunae 



Arctobdella 



— Coelom restricted to narrow lacunae 26 



26. Dorsal and ventral lacunae both communicating seg- 

 mentally with a contractile lateral lacuna lying in the 

 dermis on each side Austrohdella 



— Ventral lacuna lacking segmental communications with 

 other lacunae 27 



27. Dorsal lacuna communicating segmentally with lateral 

 lacunae 28 



— Dorsal lacuna lacking segmental communications with 

 other lacunae 29 



