THE NAUTILUS. 75 
which upset his former ideas. Land shells are very scarce in the 
state of Maine, at least in the parts I have visited. Asa rule two 
or three specimens of the larger species, would be all one would find 
after a caretul search, not so, however, on the small islands. Pyra- 
midula alternata occurs in great profusion. Polygyra albolabris and 
Helix hortensis are also abundant. P. alternata occurs on one island, 
some distance from any trees, just above high water mark, its only 
shelter being rocks and small raspberry bushes. In this location 
some two hundred, including the albino, were found. On another 
island it occurs in the woods but crawling on the ground, so numer- 
ous is it, that one can hardly step without crushing theshells. Fur- 
thermore it was found feeding on animal matter, dead crabs and 
shells left by the crows were covered with hungry individuals. 
THE SYSTEMATIC POSITION OF SPHYRADIUM (‘‘ PUPA”’) 
EDENTULUM Drap. 
BY DR. V. STERKI. 
a 
For some time, it has been my opinion that this species (— Vertigo 
simplex Gld.) has ngt its proper place under Pupa. The shell, 
though Pupa-like in its general aspect, shows two marked differences 
from all groups of that genus as well as all Pupide. In the first 
place, its aperture is radial, whilein the Pupidee it is lateral, or tan- 
gential, from the columellar wall being prolonged to the periphery 
of the penultimate whorl, or even beyond it. In the second place, 
the peristome in Pupide is more or less everted, generally with a 
more or less distinct lip, or at least the margin is “ finished up,” in 
mature specimens, while in edentulum the peristome is straight and 
simple, and the margin always thin and sharp, as it is in Patula, 
etc., and in the Zonitide. 
This view is now confirmed by the examination of the radula. 
The teeth are small, comparatively, and the cusps of all are very 
short and small. There are r+21 (20) in a transverse row, and 
116-127 such rows were counted. The centrals are tricuspid, the 
laterals all bicuspid, except the last which is a minute nodule; in 
the others there is no difference of laterals and marginals but that 
the plates of attachment become shorter towards the margins, and 
