GASTEROPODA. 
63 
It differs from the E. inops in a more gradual enlargement of the volutions, a 
more regularly convex surface on the lower side, and a shallower umbilical 
depression. 
Several of the specimens are decollated, and the inner volution rounded 
at its upper extremity as if terminated by a septum. A similar feature has been 
noticed in E. Decewi. The species under consideration has none of the aspects of 
a Cephalopodous shell, except in this single feature; and no evidence of septa can 
be seen in any part of the shell below the smooth, rounded, upper extremity. 
Formation and localities. In the Schoharie grit at Schoharie, N. Y., and in 
the upper Helderberg limestone, near Cayuga, Ontario. 
The small group of species of Euomphalidoe above described, present many 
characters in common with those described by d’Archiac and de Verneuil, 
from the older deposits of the Rhenish Provinces; and notably among those 
may be mentioned E. Icevis, E. planorbis, E. annulatus ( E. annulosus, Philips,) and 
E. serpula, de Koninck. The last named is cited as occurring also in the moun¬ 
tain limestone of Belgium and Ireland. The same group of species is illus¬ 
trated by Goldfuss ( Petrefacta , vol. iii), and cited as occurring in the Eifel 
Nassau, etc. As already stated, the E. Wahlenbergii is closely allied to E. De¬ 
cewi , and the figures alone do not offer sufficient evidence of specific distinction. 
De Koninck recognizes, essentially, the same group of species in the carbon¬ 
iferous rocks of Belgium {Descriptions des Animaux Fossiles qui si Trouvent dans 
le Terrain Carbonifere de Belgique). 
Sandberger has recognized the E. annulosus, E. Icevis, d’A.-de V., E. rota, 
Sand., and E. serpula , associated with other Gasteropoda and Cephalopoda of 
similar character to those of our Upper Helderberg, Hamilton and Chemung 
groups {Die Versteinerungen des Rheinischen Schichtensystems in Nassau). 
The species figured on plates 15 and 16 of this volume, are distributed 
through a vertical thickness of about three thousand feet. Similar forms occur 
at the base of the carboniferous rocks in Iowa, Illinois and Missouri, and espe¬ 
cially in the yellow sandstone of Burlington, and the succeeding limestones. 
