148 
Monograph op the genes strophia. 
long in being covered ; thus it was that I found so many dead shells on 
the surface. 
Why the species did not retreat to the rocks on either side can be 
explained by supposing that the shrubbery there was not of the proper 
kind for their sustenance, for it is a fact that the species of Strophia 
live by preference upon particular trees, shrubs or herbiage, as I have 
shown in several cases, and seen in several others. 
One other fact remains to be mentioned before closing this brief 
history of the Ivory Strophia, and that is that I discovered a single 
specimen of what I must at present consider as this species (although 
it is too stout, lacks the upper tooth, and differs somewhat otherwise 
to be quite typical) on a key that lies about a half mile north of U 
Key, wdiich I have called Pimlico Key, on account of the abundance 
of the Pimlico, or Audobon’s Shearwater which inhabit it. I did not 
find a single specimen, besides this, of any form of Strophia, either 
living or dead, on the key, therefore conclude that this must have been 
drifted there bv ocean currents. 
%/ 
41 STROFHIA ELONGATA Novo. 
Long Strophia. 
FrG. 46, A, front view, B, side view of type. 
DESCRIPTION. 
Sp. Ch. Size, rather large. Shell, thick and heavy. Striations, 
present. Whirls, eleven. Examined twenty-five specimens. 
Form of shell, a long cylinder, with the first three whirls about 
equal in diameter, the fourth is but little smaller, then the shell 
slopes to an acute point, forming an angle of sixty-nine degrees. The 
striations are numerous, thirty-three to the first whirl, are not 
prominent, are narrow, and although numerous, no wider than the 
interspaces between them ; they are inclined to be angular rather than 
rounded, are regular, but not arranged in lines, and are very slightly 
inclined from right to left. 
Aperture, quite small, somewhat elongated, but rather open. 
Lower tooth very large, prominent and double, having an elevation to 
the left, and also a small tubercle to the right. This tooth is about 
.11 high, and about as Avide and long as high. The upper tooth is small 
and about on a level with the top of the loAver tooth. 
Margin, produced fonvard nearly as far as the diameter of the 
