Los 
392  Binney's Monograph of the Helices 
_ Shell. Discoidal, sub-carinated; epidermis cor- 
neous ; whorls from less than six to more than eight, 
narrow, compressed; diminishing very gradually in 
width from the aperture to the apex, with raised, 
acute, tranverse lines, which are nearly obsolete on 
the base; lips- continuous round the aperture ; outer 
lip reflected, with a groove behind the reflection, 
regularly rounded so as to describe two thirds of a 
circle; pillar-lip with an acute fold, or tooth, pro- 
jecting towards the aperture; base showing from 
two to four volutions in the same plane, with a 
moderaté umbilicus, extending to the apex. 
Greatest transverse diameter nearly five eighths of 
an inch, commonly much less. 
GrocenaPHICAL Distrisutron. Inhabits Georgia, 
Florida, and Alabama. Very common on the. sea. 
islands. I noticed immense numbers of them on a 
small island in St. Joseph's Bay, Florida, under the 
decaying leaves of. the palm tree, in conpany with 
a species of HELICINA. 
Remarks. The compressed, discoidal shape of 
this shell, and its numerous narrow whorls revolving 
round their axis in the same. plane, seem to distin- 
guish it from other species. It varies in being occa 
sionally a little convex, more or less carinate, and in 
exhibiting a greater or less number of full volutions 
on the base. I have seen specimens of this shell, 
which were said to be brought from one of the West 
India islands. It is very probable that this, as well 
as other species, is common both to the peninsula 
of Florida and the nearest islands of the Gulf of 
Mexico. 
