MONOGRAPH OF THE GENUS STROPHIA. 
157 
Fig. 50. 
Form of shell, a pointed oval, with the first and second whirls 
the largest, then the shell slopes to a rather acute point, forming an 
angle of sixty-five degrees. The striations are rather numerous, 
twenty-one to the first whirl, are not prominent, but are regular, 
narrow, about as wide as the interspaces and a little flattened, but 
smoothly rounded and polished. They are slightly inclined from 
right to left, but are not arranged in lines. 
Aperture, small, arched, about as wide as high, open, and not 
contracted at the entrance. Lower 
tooth, rather prominent, .05 high,* 
about as wide as high, and about twice 
as long as high. It is placed quite near 
the frontal bar, not quite once its length, 
is not elevated, and is about central in 
position. The upper tooth is but 
slightly developed, being a mere 
tubercle. 
Margin, not produced forward as 
far as the diameter of the shell, and 
placed rather to the right of the center, 
and is not inclined to the right. It is 
thin, a little thicker than the shell 
behind it, and although it is produced 
into a blunt edge, this is not rolled 
backward. The frontal bar is not well 
developed, being thinner than margin, and it completely interrupts the 
striations. 
Color of shell, externally, dull white, shiny on the striations ; 
within, dull brown, rather dark, fading!: into white on the margin, but 
reaching the frontal bar but the central tooth is white, in striking 
contrast with its dark surroundings. 
B 
Strophia glans Kuster. 
side view. 
A, 
A 
front, B 
DIMENSIONS. 
Typical size, .92, by .45. Largest specimen, 1.00 by .50; small, 
est, .80 by .37. Greatest diameter, 1.00. Longest specimen, 1.15; 
shortest, .80. 
OBSERVATIONS. 
Individual variation is considerable, and is in the direction of 
producing a form with a thickened margin, which is sometimes 
