No. 8 SMITHSONIAN EXPLORATIONS, 1913 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 born on these Keys, 
the first generation will be like the parent generation unless decided 
Fic. 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 be developed, and 
these make up fully half of the length of the shell. If the present 
2 
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