454 THE CHICAGO ACADEMY OF SCIENCES. 
slightly twisted, as is also the axis of the inner whorls of adult speci- 
mens. Young specimens resemble petersi but have a less number of 
whorls, besides differing in rotundity, the whorls of petersi being en- 
tirely without angularity. The umbilicus varies from a rather wide 
chink to a round hole, the aperture in specimens with this kind of an 
umbilicus being entire and almost separated from the body whorl. The 
| RANDOLPHI 
nt 
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Fie. 51. 
whorls vary greatly in angularity and in their general form. When 
perfect, randolphi is one of the finest of our American Lymneas, at- 
taining a length of an inch and a half (41 mill.). 
The writer cannot agree with Dr. Dall in referring randolphi to 
Radix. Its affinities, judging by the shell alone, are entirely with the 
cmarginata group of the genus Galba. The specimens from near Coll- 
