A SURVEY OF THE GROUP 



33 



2cm 



(d) 



2 mm 



Fig. 20. Various Gnathobdellae and Pharyngobdellae (a) and 

 (b) Haemadipsa, from photographs of living specimens; (c) 

 Erpobdella octoculata; (d) Whitmania laevis; (e) Praobdella 

 biittneri. ((a) and (b) from photographs by Gert Heinrich re- 

 produced in Scriban and Autrum, 1934; (d) after Whitman, 

 1886; (e) after Blanchard, 1896.) 



