292 
Platybdella Anarrhichae 
A. With paired lateral foliaceous branchiae on the abdomen. 
(a) Parasitic on Testudines, branchiae branched and but few pairs (5). 
Ozobranchus. 
O. margov\. 
(13) Parasitic on fish, branchiae unbranched and many pairs (33). 
Branchellion. 
B. torpeddnisj*. 
B. With one row of hemispherical pulsating vesicles on each side of. the 
abdomen. 
(a) Abdominal segments consisting of 14 annuli. Body spotted with 
blackish red-brown star-shaped dots arranged in longitudinal 
and transverse rows. Eyes 4. 
PiscicolaJ. 
P. geometra. 
(13) Abdominal segments consisting of 4-6 annuli, usually 6. Body 
spotted with yellow or green-brown scattered unbranched dots. 
Posterior sucker, larger than the anterior. Eyes none. 
Calliobdella. 
(a) Body spotted with yellow dots, posterior sucker twice 
as broad as the anterior. 
C. nodulifera. 
(b) Body spotted with green-brown dots, posterior sucker 
four times as broad as the anterior. 
C. lophii. 
(•y) Abdominal segments consisting of 6 annuli. Body without spots, 
and very depressed. Anterior sucker four times as broad as 
the posterior and with five muscular bands. Eyes none. 
Respiratory vesicles 3 pairs. 
Ganymedebdella. 
G. cratere*. 
(8) Abdominal segments consisting of 7 annuli. 
Cystibranchus+j (Cystobranchus). 
(a) Eyes 4 and a crown of oculiform points on the posterior 
sucker. 
C. respirans'f. 
(b) Eyes none. 
C. mammillatus. 
Tribe II. ICHTHYOBDELLINAE. (Leeches without external respiratory 
organs. Neck and abdomen scarcely marked off from one another by a con¬ 
striction. ) 
A. Skin with large papillae wart-like and arranged in transverse rows all 
round the body. 
Pontobdella. 
P. muricata. 
