MONOGRAPH OP THE GENUS STROPHIA. 
01 
o I 
mg around the center of the upper half of the upper whirl from one side 
of the margin to the other. The elevated lines in the middle of the up- 
per part of the upper whirl is very prominent, and ispreedeed above by 
a depression. When it is crossed by the striations it is raised into pro- 
tuberances and ends in a prominent projection on the right margin. 
There are also numerous, transverse depressed lines on the upper whirls. 
The suture is quite shallow, even between the upper whirls, and this 
grows more and more shallow toward the apex until on the lower 
whirls it is scarcely to be distinguished with the unaided eye. 
Aperture, rather small, but open, nut contracted within. The 
lower tooth is not prominent, being tubercle, arising gradually from the 
floor of the mouth, without any sharply defined sides ; it is placed to the 
right of the center and set back about .20 from the frontal bar. The up- 
per tooth is scarcely developed at all. 
The margin is produced forward about as far as the diameter of 
the shell, it is inclined a little backward on the upper left hand side, 
but elsewhere a little forward ; it is about .00 thick, is rolled backward, 
somewhat, but not beveled, the edge is blunt ; it is not inclined to the 
right. The frontal bar is quite well developed, slightly inclined and 
completely interrupts the striations, and the septa is smooth through- 
out. 
Color of shell externally, yellowish white, pale flesh color within, 
fading into white on the tooth and margin. 
DIMENSIONS. 
Size of typical specimen, 1.02 by .64. Size of two other specimens 
1.07 by .64, and 1.03 by .67. 
OBSERVATIONS. 
There is probably considerable individual variation, as well as 
some clearly defined forms in this singular species, it is also probable 
that there are sub-species and allied species, but the material which I 
have at hand will not warrant any, even sub-specific, separation. I 
give below one form, which was also observed by Pfeiffer. 
Form No. 1. Similar to the type form, but without any distinct 
keel on the upper whirl, this being merely indicated, and the depressed 
lines are wholly absent, while the striations are confined to the two 
upper whirls. 
These depressed lines, as already mentioned, show a tendency to 
revert toward S. scalarina, and in this connection it is worthy of note 
that both species came from the same portion of Cuba. 
This species was first described by Pfeiffer in 1847 in Zeitschr. f. 
Mai ., as Pupa dimidiata, but in 1861 in Malak. Blat. in a paper pub- 
lished jointly by himself and Dr. Gundlach, we find the same species 
redescribed and renamed Pupa proteus, because, as Dr. Pfeiffer states, 
