196 BULLETIN OF THE 
outer lip. Aperture shaped as in muscorum, having a single small parietal denticle. 
Altitude 33, diameter 13 mm. 
Pupa syngenes, Prtspry, The Nautilus, 1890, Vol. IIL. p. 296, Plate V. Figs. 1, 2. 
Two specimens of this form are before me, and I am in doubt whether to give 
them a new name, as they may be only sinistral monstrosities of the common 
P. muscorum. The shells are labelled “ Arizona” in the Academy collection, col- 
lector not known. 
(Since the above paragraphs were in type, I have received a communication from 
my friend, Dr. V. Sterki, to whom I sent a specimen of P. syngenes, which I at first 
described as a variety of muscorum. He says: — 
“Tam satisfied that it is a species, and not a var. of muscorum ; the shape of the 
whole shell, the last whorl so considerably flattened, and ascending, the number of 
whorls, seem to me to prove its specifical rank... . After washing out the aper- 
ture of your specimen, I saw a rather strong lamella or tooth on the columella, and 
a barely perceptible trace of an inter-palatal lamella, which, however, is validified 
by the impression on the outside.”) 
The above is Pilsbry’s description. An authentic specimen drawn by Dr. 
Sterki is figured here, 
Vertigo ovata, Say. 
Of V. tridentata Sterki writes (The Nautilus, 1890, p. 135): “It has a 
wide distribution in the northern part of the country ; originally found in 
Illinois, it has been collected in different parts of Ohio and New York, as 
well as in Minnesota and Colorado. In general it is remarkabl y constant in 
its characters ; yet there are slight differences; here I found a few examples 
from low ground, together with V. ovata; they were a trifle larger, with a 
thicker and deeper colored shell than those from upland places,” 
