MOLLUSCS, VERMES AND HYDROZOA 



A. depressa. Fig. 152, has a greenish-olive two inches long shell, with 

 a series often to fifteen olive bands and yellow margins on the five smooth 

 and polished whorls, which are more or less distinctly marked by lines 

 of growth, a well defined suture and a depressed spire. The operculum 

 is auriculate with the nucleus at the inner margin. The body is grey, 



FIG. 152. Am-pullaria depressa. 



Striated and dotted with black, the tenticles of the males yellowish-brown 

 and of the females reddish or orange. It inhabits canals and ditches of 

 soft muddy bottom and sluggish current in the middle Southern States, 

 is oviparous and lays 30 to 70 eggs on plants above the water level, which 

 are soft when deposited but acquire a hard shell from exposure to the 

 atmosphere. They hatch in about 12 days and are the size of a large pea. 

 A. miamiensis. Fig. 153, has a globose, yellowish-brown 2^ inches 

 long heavy shell with moderately impressed suture, a depressed spire and 

 large body whorl. The aperture occupies about one-half the length ot 



FIG. 153. Ampullaria miamiensis, 



the shell, the operculum is calcarious and striated, with the nucleus at 

 the upper side. This handsome snail occurs only in Southern freshwater, 

 principally in Florida. Probably the largest native North American species 

 is A. pinei, from the same locality, which reaches a length.of 3 to 3 ^ inches. 



226 



