MONOGRAPH OP TIIE GENUS STROPUIA. 
O- 
O/ 
74 STROPUIA REGIA Benson. 
Regal Strophia. 
Plate VII, fig. 5, front, fig. 6, side view of typical, specimen. 
Strophia regia Benson. Ann. and Mag. Nat. Hist., 2d series, Vol. 
IV, page 125, August, 184;). 
DESCRIPTION. 
Sp. On. Size very large. Striations absent. Shell thick and 
heavy. Whirls, 11, the upper of which, including margin, is as long 
as the next five put together. 
Form of shell a pointed cylinder, with the first whirl the largest, 
then each successive whirl is a little smaller to the fourth, and from 
this the shell slopes to a rather obtuse point, forming an angle of about 
sixty-five degrees. The surface of the shell is smooth, marked with 
irregular lines of growth, which are more prominent on the upper 
whirl near the margin. The whirls are not bulging, and the suture on 
the upper whirls is quite deep, but is much more shallow between the 
lower. 
Aperture large and open, about as high as wide, not contracted at 
the entrance. The lower tooth is low, about .Ob, and is about three 
times as long as high, is about central in position, and is set back a 
little over once its length from the frontal bar. It rises gradually 
from the floor of the mouth, thus it is pyramid-shaped. The upper 
tooth is about the same form as the lower, and is about as high, but 
extends hack around the column, ending on the beginning of the second 
whirl. It is placed half way up the column. 
The margin is not produced forward quite as far as the diameter 
of the shell, is considerably inclined to the right, beyond the diameter 
of the shell, it is inclined backward on the upper right, and lower left 
corner ; it is rolled smoothly over, and is considerably flanging, about 
.10, the edge is rolled over and roughened by breaking. 
Color of shell, externally, shining white ; internally, golden brown, 
passing with almost an abrupt line of demarkation hack of the teeth 
into yellowish on the teeth and margin. Frontal bar slightly developed 
on either side, obsolete in the middle. 
DIMENSIONS. 
Size of typical specimen, 1.85 by .70 ; size of two other specimens 
1.67 by .65, and 1.70 by .65. 
OBSERVATIONS. 
There is hut little individual variation shown in the four specimens 
which I have seen of this fine species, which can readily be distin- 
