MONOGRAPH OF THE GENUS STROPHIA. 
27 
II. STROPHIA NANA Novo. 
Dwarf Strophia, 
Plate II, 11, a, b, & c, shell; d, section. 
DESCRIPTION. 
Sp. Ch. Size, exceedingly small. Shell, moderately heavy. Stri- 
ations, present. Tentacles, short, about one fourth as long as the eye 
peduncles. Whirls, 11. Teeth, long. Examined 2,000 specimens. 
Form of shell, an elongated cone, with the first whirl the largest; 
the next three are successively a trifle smaller, then the shell slopes 
rapidly to a point, making an angle of about 60 degrees. The striations 
are 18 on the upper whirl, prominent, and excepting on the first whirl, 
where they are narrower above and enlarged in the middle, are largest 
at the top, and gradually become narrower, attaining the minimum near 
the suture, where both they and the shell are depressed below the di- 
ameter; from this point to the suture the striations become suddenly 
enlarged and widened as much as at the beginning above, and are slightly 
inclined to the left. The striations are not arranged in lines, and are 
slightly inclined from right to left; the interspaces are a trifle wider 
than the prominences wdiich are roof-shaped, with the ridge somewhat 
rounded, and the surface is smooth. The striations are absent on the 
two or three lowest whirls. The sutures between the whirls are not very 
deep. 
Aperture, large and open, but does not measure any more within 
than at the entrance. Lower tooth, not very prominent, is .10 long and 
.02 high, and the upper which is situated just above it, is not at all 
prominent, being a mere elevation, but more within the cavity is higher, 
and makes a complete turn around the column. 
Margin, not produced forward quite as far as the diameter of the 
shell, and is inclined slightly backward; it is not thickened, and the 
outer portion is produced into a thin, but not prominent, edge that is 
not rolled downward. The frontal bar is quite prominent and interrupts 
the striations. Animal, not large; eye peduncles, .20 long; tentacles, 
.05. Jaw, smooth. 
Color of shell, externally, dull ashy. The frontal bar, teeth, and 
margin, internally, are bluish white, but within the aperture this color 
gradually deepens into pale purplish brown which pervades the whole 
interior. Color of animal, pale brown, with the minute granulations on 
the anterior portion of body and head, black. 
