0 
MONOGRAPH OF THE GENUS STROPHIA. 
to left, are narrow, and the interspaces are thus about twice as wide as 
the prominences. The striations are not furrowed, but are smoothly 
rounded and polished. The whirls are not bulging and the suture is 
shallow. 
Aperture, large and widely open measuring considerably less with- 
in than at the entrance. The lower tooth is very small, about .07 long 
and is about one half as high as long, its position is about central, but 
it is set back about twice its length from the frontal bar. The upper 
tooth is about the same height as the lower, but extends backward a* 
round the column. 
The margin is not produced forward beyond the diameter of the 
shell, but is considerably inclined to the right, quite beyond the side, 
is not thickened ( measuring .OT only ) but is reflexed outward at least 
.10, with the edge rolled over and smoothly rounded. The frontal bar 
is rather indistinct, is well inclined to the right, as the striations ap- 
pear within it as distinct ridges which continue to appear as far down 
as they can be seen from the entrance. 
Color of shell externally, yellowish white, quite prominently 
marked with a rather pale yellowish brown which is inclined to form 
longitudinal patches between the striations. These patches are quite 
frequently encroached upon by the white along their sides, hence their 
edges have an undulating or serrated appearance. In some cases the 
patches are broken quite across by the encroaching white, then the 
brown appears as a series of thick horizontal lines one above the other. 
Internally brown, paler than the external markings. This color pales 
into yellowish white on the tooth and margin. 
DIMENSIONS. 
Size of typical specimen, 1.35 by .45. Largest specimen, 1.37 by 
47 ; smallest, 1.25 by .41. Longest specimen 1.35; shortest, 1.25. 
Greatest diameter, .47 ; smallest, .41. 
OBSERVATIONS. 
The tendency among the specimens examined is to produce on 
one hand a rather more slender form than the type with the angle of 
the apex more acute, and on the other, a proportionally shorter, stouter 
form, measuring, about 1.20 long ; rather more highly ornamented with 
brown markings. 
This beautiful species can be readily distinguished by the large 
size, always over 1.25 long, open mouth with the flanging margin, the 
prominent striations within, which even appear on the upper wall, and 
the singular, broken, pale brown markings, which recall those of 
Strophia mumia. 
