CORALLINE LIMESTONE. 
333 
GASTEROPODA OF THE CORALLINE LIMESTONE. 
The most common species in this rock are one of Belleropi-ion and one of Bucania. These, 
as well as all the others, are usually distorted by pressure, and otherwise very imperfect. They 
are nevertheless so peculiar as to be readily recognized, even in that condition, when compared 
with other species of the same genera from other strata. 
695. 4. PLATYOSTOMA - sp. 
Pi. LXXVI. Fig. 1. 
The specimen figured is an imperfect cast. It is not unlike P. hemispherica of the Niagara 
group, but the imperfection of specimens renders it impossible to make satisfactory comparisons. 
Position and locality. In the Coralline limestone at Schoharie. 
(Collection of John Gebhard junior.) 
696. 21. PLEUROTOMARIA SUBDEPRESSA («. sp.). 
Pl. LXXVI. Fig. 2 a, 6. 
Trochiform ; volutions angular, marked by three carinee on each ; spaces between the carinrn 
marked by oblique striae ; shell rather coarse and strong. 
The specimen figured is imperfect, showing about four volutions : the first one is scarcely 
distinct in the figure ; one or more of the last volutions are entirely wanting. In its general 
character this species resembles one in the succeeding rock, but the volutions enlarge much 
more rapidly from the apex, and the angles are more prominent. 
Fig. 2 a. Profile view of the fragment. 
Fig. 2 b. View of the apex of the same. 
Position and locality. In the Coralline limestone at Schoharie. 
{Collection of John Gebhard junior.) 
697. 17. MURCHISONIA 1 OBTUSA. 
Pe. LXXVI. Fig. 3. 
Shell elongated ; spire consisting of seven or eight volutions; volutions rounded, ven- 
tricose, more prominent on the lower side ; aperture somewhat expanded. 
The specimen is a cast, wanting one volution. The surface is nearly smooth, though there 
are slight indications on each volution of a carina just below the centre, with bent strise pro¬ 
ceeding from it. The form of the shell is too peculiar to be mistaken. 
Position and locality. In the Coralline limestone at Schoharie. 
{Collection of John Gebhard junior.) 
