178 LEECHES 



OTTONIOBDELLA Moore andMeyer 1951 (= OttoniaM2\m) 

 (Johansson, 1929). Like Oceanohdella except anterior sucker 

 discoid, skin opaque and pigmented, abdomen rounded and ill 

 defined. 



Ottoniohdella hrunnea (Johansson, 1896). 25 mm long, uniformly 

 brown, posterior sucker ringed by 10 ocelli and not much broader 

 than anterior sucker and abdomen. Dorsally on Cottus scorpius. 

 W. Sweden, Greenland. 



Ottoniohdella scorpii (Malm, 1863; Moore andMeyer, 1951). 

 30 mm long, with longitudinally elongated markings on body, 

 posterior sucker ringed by 12-14 ocelli and twice as broad as 

 anterior sucker and abdomen. On Cottus scorpius. Faroes, 

 Iceland, Greenland, Spitzbergen, Bering Sea. 



OXYTONOSTOMA Malm 1863 (Johansson, 1898; Selensky, 

 1914 and 1915; Moore and Meyer, 1951). Suckers discoid, eyes 0, 

 numerous small tubercles arranged longitudinally in 6 rows dorsally 

 and 6 rows or none ventrally, abdomen rounded and ill-defined 

 with 11 pairs pulsatile vesicles, annuli 12-14, coelom typical, 

 diverticula fused with 5 fenestrae, testes 6 pairs. 



Oxytonostoma arctica Johansson. 25 mm long, tubercles present 

 ventrally. Greenland, White Sea, Kara Sea, Alaska. 



Oxytonostoma typica Malm. 20-30 mm long, tubercles absent 

 ventrally. On Raia radiata. W. Sweden, Iceland, Greenland, 

 Alaska. 



OZOBRANCHUS de Quatrefages 1832 (Selensky, 1915; 

 McCallum, 1918; Oka, 1927; Sanjeeva Raj, 1954). Anterior 

 sucker small, posterior sucker discoid, trachelosome narrow, 

 abdomen broad with a pair of finger-shaped branching branchiae 

 on each somite, annuli 2-3, pulsatile vesicles 0, coelom fairly 

 spacious and not divided into lacunae, diverticula separate, 

 testes 4 pairs. On chelonians and crocodiles. 



Ozobranchus margoi de Quatrefages. On Thalassochelys corticata. 

 Naples. 



PARAPONTOBDELLA Harant (1929). Not clearly distin- 

 guished from Pontobdella. 



