88 
University of Michigan 
IRIN, DID 
Helicina and Ampullaria. 
Figure 1. Helicina zephyrina. Basal view with operculum in place, 
as in aestivating individuals, to show the sinuation of the basal lip 
and the crack left between the operculum and the lip. 
Ampullaria patula catemacensis. Type specimen. 
Exterior view of operculum. 
Interior view of operculum. 
Figure 2. 
Figure 3. A. p. catemacensis. 
Figure 4. A. p. catemacenstis. 
