Gee: Behavior of Leeches 



207 



small even in specimens killed in a relaxed condition. The 

 recorded range of this species is, so far as I have been able to 

 discover it, Ohio, Illinois, Pennsylvania, and California. The 

 material used in the following experiments was secured in Fruit- 

 vale, California, from a fresh-water pond among the foothills 

 of the Coast Range Mountains. The pond even during the rainy 

 .season is only a few feet in depth and in the autumn months 

 becomes reduced to only a few inches. It is liberallj^ supplied 

 with various aquatic plants, and is provided with a most copious 

 bottom of black mud. By dredging this mud from the bottom 

 of the pond the leeches were secured in great abundance. No 

 difficulty whatever was experienced in keeping them alive and 

 in good condition for months in the laboratory. They were 

 placed in aquaria containing a few inches of water, a few algae, 

 and Ceratophyllum, and a stone for a hiding place. 



Fig. 1. — Outline drawings of leeches studied, showing relative shapes 

 and sizes, (o) Glossiphonia stagnalis Liimia,ens, (b) Dina microstoma Moore, 

 and (c) Hemiclepsis occidentalis Verrill. 



By far the most abundant leech that I have been able to 

 discover in this locality is Glossiphonia stagnalis Linnaeus. The 

 best description of this species is that by Castle (1900). The 

 leech is a relatively small one, approximately 8-10 mm. in length 



