MONOGRAPH OF THE GENUS STROPHIA. 
173 
51 STROPHIA PILSBRYI EVOLVA Novo. 
Pilsbry’s Mottled Strophia. 
Fig. 57, A, Front view, B, margin, of type, 
DESCRIPTION. 
Sp. Cii. Size, rather small. Shell, rather heav} 7 . Striations. 
present. Whirls, ten. Examined seventy specimens. 
Form of shell, a pointed cylinder, with the first and second 
whirls equal in diameter, the third is but little smaller, then the shell 
slopes to a point, forming an angle of sixty two degrees. First 
whirl, short, equal to the next four smaller. The striations are not 
numerous, twenty-two to the first whirl, are rather regular, but 
somewhat broken, narrow, not as wide 
as the interspaces between them, 
smoothly rounded, polished, but some 
of them are slightly furrowed, and the 
interspaces are slightly ridged with 
lines of growth. 
Aperture, rather small, arched, 
about as high as wide, and is slightly 
wider within than at the entrance. 
Lower tooth, not very prominent, .03 
high, wider than high, and a little 
more than twice as long as high, it is not 
elevated, but the floor of the entrance strophia piisbryi evoiva. a, front view, 
B, side view of type. C, Lowor tooth as 
slopes away from it, and the tooth is seen from above, 
projected forward nearly to the frontal 
bar. Its position is about central. Upper tooth is a mere tubercle. 
Margin produced forward about as far as the diameter of the 
shell, and is considerably inclined toward the right, quite beyond the 
diameter of the shell, it is thick, about .07, beveled, grooved, and 
very faintly marked with lines of growth. The frontal bar is quite well 
developed, protruding slightly beyond the striations, and is very 
obliquely inclined to the right. 
Color of shell, externally, ashy yellow, mottled and blotched with 
ashy brown, the mottlings assuming a transverse direction, somewhat 
as in Strophia mumia; internally, dark brown, which color extends 
quite to the margin, leaving the tooth, however, pale, and the margin 
nearly white. 
Fig. 57. 
C A 
