ee Oe Fo oy SO ear ee ee 
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164 THE CHICAGO ACADEMY OF SCIENCES. 
Shell: Subglobose, rather solid, imperforate; surface cov- 
ered with numerous short, stiff hairs, beneath which may be 
seen fine growth lines; nuclear whorl without hairs; color red- 
dish-brown or chestnut; periphery subangulated; sutures very 
deeply impressed; whorls five, rounded, slowly and regularly 
increasing, the last deflected near the aperture and constricted 
behind the peristome; spire a little elevated, convex; aperture 
nearly closed by the thickened peristome and parietal tooth; 
parietal tooth long and narrow, elevated, extending from the 
center of the base of the shell into the aperture near the upper 
part; peristome narrow, thickened, reflected against the whorl 
with a small, well-marked notch near the center of the base 
of the aperture; umbilicus covered and the region indented; 
base of shell convex; within the base of the shell, situated be- 
Jaw and radula of POLYGYRA HIRSUTA Say. (Original.) c, central 
tooth; 1, first lateral; 12, intermediate tooth; 16, 20, marginal teeth; J, jaw. 
yond the line of sight, is a transverse tubercle, which starts 
from the apex; this cannot be seen without breaking the whorls. 
Greater diameter, 7.75; lesser, 7.00; height, 5.00 mill. (8451.) 
a es SOs ot TEs 00; ccf TOKE 
s s/ 9.00;°. *- 8.00; “ . 5.00“ (12899,) 
Animal; With a long, narrow foot, truncated before, 
pointed behind; head distinct, blackish or slate color, as well 
as the tentacles and eye-peduncles; tentacles short, blunt; eye- 
peduncles long, thick, cylindrical, the eyes on enlargements 
at their tips; the foot and a part of the body is semi-transpa- 
rent; foot 13 mill. long and 2 mill. wide. Heart situated to 
the left of the center of the parietal tooth, pulsations regular, 
eighty per minute. 
Jaw: Similar to Polygyra monodon, but with eight stout 
ribs ( Fig. 25, J). 
