160 
MONOGRAPH OF TIIE GENUS STROPH1A. 
Fig. 51. 
Form of shell, cylindrical oval, the first and second whirls 
being the largest and about equal in diameter, then the shell 
slopes to a rather acute point, forming an 
angle of sixty-five degrees. The striations 
are rather numerous, twenty-five to the 
first whirl. They are not prominent, narrow, 
not wider than the interspaces between 
them, are regular, inclined to be arranged 
in lines and rounded, but not polished. 
Aperture, sn all, about as wide as high, 
rather contracted at the entrance. Lower tooth, 
prominent, oval, about .05 high, as wide as 
high and not quite as long as high, it is not 
placed far back, not once its length, and is not 
elevated. The upper tooth is a mere tubercle 
and is placed low, not higher than the top 
of the lower tooth. 
Margin, produced about as far forward 
as the diameter of the shell, is placed a little 
to the right of the center of the shell and is 
inclined slightly to the right It is thick (.12), beveled, and grooved. 
The frontal bar is not very well developed, is thin, not over .02 thick, 
but completely interrupts the striations. 
Color of shell, externally, grayish ash, striations and all ; ashy 
brown, within, which color extends over the teeth, where it is paler, 
however, and quite to the edge of the margin. 
B A 
Strophia glans grisea. A, front 
view of type. B, margin of 
same. 
DIMENSIONS. 
Size of type, 1.10 by .45. Largest specimen, 1.15 by .47 ; 
smallest, .-'>5 by .40. Greatest diameter, .47 ; smallest, .40. Longest 
specimen, 1.15; shortest, .95. 
OBSERVATIONS 
As far as the specimens which came from the type locality are 
concerned, this is a very uniform form of shell, there being only a 
slight individual variation in form and a little in color internally, but 
the peculiar gray tint of the external surface is very constant and 
characteristic. Had I never seen shells from any other locality than 
from the fields north of Fresh Creek, I should have unhesitatingly said 
that this was as strongly marked a species as I had ever seen, with 
