MONOGRAPH OF TIIE GENUS STROPIIIA. 
27 
Aperture, rather small, but open, not rounded, about as high as 
wide. The lower tooth is quite prominent, about .06, a little more than 
twice aslongas high, it is placed a little to the right of the center, and 
is set back once its length from the frontal bar. The upper tooth is 
very small, and is set back behind the lower, but is not placed high on 
the column. 
The margin is produced forward about as far as the diameter of 
the shell, but is not much inclined to the right, only slightly beyond 
the side of the shell ; it is thin, rolled over, with the edge sharpened. 
The frontal bar is only partly developed, not extending across from 
side to side, but the striations do not appear within. 
Color of shell, externally and internally reddish, but evidently 
stained by contact with some red ochraceous earth. 
DIMENSIONS. 
Size of typical specimen, 1.12 by .42. Size of one other specimen, 
1. 10 by .40. 
OBSERVATIONS. 
There is but little variation in the few specimens which I have 
examined. The lower tooth is quite long, but not excessively so. 
This is a semifossil shell, and is beyond doubt the Pupa rudis of Pfei- 
ffer. I append his description and a translation. 
“ T profunde rimata, ovata-oblongo, costis obtusis leviter arcuatis 
subconfertis sculpta, cretacea ; spira convexiusculo-elongata, sensim in 
conum obtuseulum attenuata ; anfr 11 vix convlxusculi, ultimus 1-4 
longitudinis paulo superana, antice subascendens, juxtariman subcom- 
pressus ; parietati et minore, profundiore collumelari, coarctata ; perist. 
ciassum, breviter patulum, marginibus callo junctis, long. 30, diam. 12 
mill. ap.c. perist 10 mill, longa, 9 lata. — Legitur subfossilis in plan- 
tationibus Dimond et Paradise in insulae St. Croix.” 
Shell deeply rimate ovate-oblong, ribs, blunt, a little arched, quite 
closely sculptured, chalky ; spire elongated and convex, with the cone a 
little obtuse at the tip ; whirls 11, scarcely convex, the last a little more 
than one-fourth longer, (than each of the others) front ascending, near 
the cleft greatly compressed ; aperture, lunately round, parietal tooth 
small and compressed, the one on columella deep, and compressed ; 
peristome, thick, short, open, margins joined by a slender bar. Length 
30, diameter 12 mill, aperture of peristome 10 mill, long, 9 wide. 
Collected as a sub-fossil in the plantation, Dimond and Paradise in the 
Island of St. Croix. 
