28 
DESCRIPTION OF SPECIES. 
DIMENSIONS. 
Size of types, .62 by .25 and .60 by .18. Largest specimen, 64 by 
.26; smallest, .53 by .20. Greatest diameter, .28; smallest, .18. Long- 
est specimen, .64; shortest, .53. 
OBSERVATIONS. 
The type as described and figured on Plate II, 11, A, is the most 
prevalent, but a more cylindrical form is very common, ib., B, in which 
there is but very little difference either in diameter or width between 
the second, third, and fourth whirls, the first being wider, but not much 
larger in diameter. The specimen figured has the striations far from 
prominent, but this one is almost, if not wholly, unique in this respect. 
The remaining form is shorter than the type, but has about the same 
proportions. The depressed line above the suture, and the inclined en- 
largment of the base of the striations are some of the singular features 
of this most remarkable Strophia, and remind one of a similar structure 
in the genus Chondropoma. The peculiar ashy colors may be partly due 
to minute, dark, apparently eroded dots, with which the shells are cov- 
ered. Striations vary from 16 to 20; whirls, 10 or 11. 
Known from all other species, by the presence of striations, exceed- 
ingly small size, elongated form, and long teeth. 
DISTRIBUTION AND HABITS. 
t( 
The island of Little Cayman is only ten miles long with an average 
width of two miles, and is thus a mere spot in the waters of the Caribbe- 
an Sea, and the Dwarf Strophias occur in a space which is only five or 
six yards wide by twenty long, on this little key, and as they were rigidly 
confined to this narrow area, which on a good sized chart of the West 
Indies, would be more than covered by the point of a fine cambric nee- 
dle, I consider that this species has the most restricted range of any 
animal with which I am acquainted. This spot is on the west end of 
Little Cayman, on the eastern most of the two paths that cross the key, 
near their junction. 
In habit, this species is social, and I found many of' them clinging 
to a kind of heath-like plant which was about eighteen inches high, and 
which had small gray leaves of nearly the same color as the shells, and 
which on being crushed, gave out a strong odor. Here these Strophias 
were exposed to the burning rays of a nearly vertical sun, and the heat 
in which they lived during the day, was intense. Some, perhaps one 
third of them, had retreated beneath stones, a situation in which it is 
rare to find a Strophia, the only other species that I have found in a sim- 
ilar situation, being S. incana from Key West, which retreated from the 
