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MONOGRAPH OF THE GENUS STROPHlA. 
thirty on the first whirl, are small, slender, and regular, but not 
arranged in lines ; they are slightly inclined from right to left, are not 
furrowed, but are smooth and rounded and a little more than one half 
as wide as the interspaces between them. 
Aperture, rather small, and considerably contracted at the 
entrance. Lower tooth, not prominent, about .04 high, and about 
twice as long as high ; it is not elevated, and is set back about once its 
length. The upper tooth is represented by a mere tubercle. 
Margin produced forward nearly as far as the diameter of the shell, 
and is very slightly inclined to the right, a trifle beyond the diameter 
of the shell ; it is thickened all around, hollowed out in the middle, 
and then projected backward into a sharp edge, which is not rolled 
over. The frontal bar is very thin and completely interrupts the 
striations. 
Color of shell, deep umber brown, with most of the striations 
cream v white. Brown within, becoming creamy white on the edge of 
the margin and frontal bar. 
DIMENSIONS. 
Size of type, 1.15 by .40. Largest specimen, 1.14 by .50. 
smallest, .88 by .38. Greatest diameter, .50; smallest, .oS. Longest 
specimen, 1.25 ; shortest, .88. 
OBSERVATIONS. 
Individual variation consists of gradual gradation into a smallei 
form, on one hand, with rather less number of striations, twent} T -five 
on first whirl, and on the other, to a larger, thicker form with more 
numerous striations, thirt} T -seven on the first whirl, but there is no 
decided form among these. 
No. 1. The only inclination to assume a form is, singularly 
enough, one which grades directly into typical S. cinerea. In fact, at 
one extremity of this form we have a cylindrical shell much like 
typical S. a mutata, and at the other, shells which I confess 1 cannot 
distinguish m the smallest particular from typical S. cmeiea. 
The presence of this singular sub-species of S cinerea on Long 
Key was a great surprise to me, the more so, as on Spruce Key, an 
island only about a half mile to the north of Long Key, I found two 
distinct species, not only different from anything on either Hog Island 
or on New Providence, but varying widely from one another. 
