KG. 8 



S.MITliSONIAN EXPLORATIONS, I913 



29 



a good many may be present in places where they were not discovered 

 previously, for the nepionic shells are quite small and hard to find. 



judging from the young collected, which were l)orn on these Keys, 

 the first generation will he like the parent generation unless decided 



Fig. 29. — " Peanut " shells on living vegetation. Key West. Florida. 

 Photograph by Bartsch. 



changes should take place in the later whorls, which have not as yet 

 been developed. The largest specimens found have only seven post- 

 nuclear whorls, leaving two to three whorls still to 1)e developed, and 

 these make U]) fully half of the length of the shell. If the present 



