LEECHES 



are easy to feed, needing only one meal of ground-up meat, 

 beef-liver, earthworms or snail-meat once in a few weeks. 

 When hungry they are very sensitive, and if one even moves 

 one's hand over a dish of hungry leeches so that its shadow 

 falls across them, they will at once begin swinging their heads 

 about exploring for food. 



Identification. — Table of the families of leeches represented 

 here, modified from Moore's key to North American fresh 

 water leeches (see Bibliography, p. 414). 



1. Mouth a small pore in oral sucker from which a mus- 

 cular proboscis may be protruded ; no jaws. 



Suborder RhyncohdellcB. 



Body not divided into two regions; usually much 

 flattened; eyes near median line; typically each 

 segment contains 3 rings; eggs within capsules and 

 young being fixed to the mother's body. 



Family Glossiphonidce, p.- 154. 



Body divided into a narrow anterior and a wider 

 posterior region ; little depressed ; eyes when present 

 usually well separated; chiefly parasites attached to 

 the fins and gills of fishes. No representative is 

 included here. 



Family Ichthyobdellidce. 



2. Mouth large, occupying entire cavity of sucker; 

 pharynx not forming a proboscis; jaws often present. 



Suborder GnathobdellcB. 



Eyes typically five pairs on segments II-VI; com- 

 plete segments five-ringed; toothed jaws usually 

 present. 



Family Hirudinidce, p. 155. 



Eyes three or four pairs (rarely absent), usually 

 one or two pairs on II and two pairs at sides of 

 mouth on IV; no jaws. Predacious. 



Family HerpobdellidcB, p. 156. 

 153 



