APPENDIX A 



153 



Moore, J. P. 1959. Hirudinea in Freshwater Biology (2nd ed.) 



Edited by W. T. Edmondson. 

 Meyer, M. C. and Moore, J. P. 1954. Notes on Canadian Leeches 



(Hirudinea) with the Description of a New Species. Wassman. 



J. Biol 12, 63-96. 

 References to full descriptions will be found in these. 



As the various geographical areas have many species in common 

 a combined key to the freshwater species has been produced. 



Section 1. Key to Families 



1. Mouth a small pore on the oral sucker from which a 

 proboscis may be protruded; no jaws present; blood 

 colourless. 



Suborder Rhynchobdellae 



— Mouth large, occupying entire cavity of the oral 

 sucker ; no proboscis ; blood red 



Fig. 1 



Fig. 2 



Fig. 3 



Fig. 4 



Fig. 5 



Fig. 1-3 and 5. Dorsal views of the heads of various leeches 

 to illustrate the arrangement of the eyes: 1, a gnathobdellid ; 

 2, a pharyngobdellid ; 3, Xerobdella; 5, Theromyzon. 



Fig. 4. Ventral view of the head of Placobdella to show mouth 

 on rim of anterior sucker. 



