OF DENISON UNIVERSITY. 
89 
GENUS TRIPLESIA, Hall. 
XIII. Triplesia Ortoni, Meek. 
Described in Ohio Pal. Vol. 1 . 
Locality and position. Soldiers’ Home and Centreville Quarries, 
Clinton Group; the upper ‘‘shovel ends” are frequent in the upper 
shaly courses of the Group. 
genus 
XIV. triplesiana, sp. n. 
{Plate XIV, Pigs. 13 k; and Fig. 14.) 
The generic relations of the following shell I have been unable to 
determine satisfactorily, although the specimens are in a moderately 
good state of preservation. A specific name is merely suggested for 
the local use of collectors, and a description appended to give notifica- 
tion of at least the existence of such a shell. The specific name is 
intended to suggest its similarity in appearance to certain very flat forms 
of Triplesia Ortoni in which the cardinal area is not much developed. 
Shell subquadrate, or rounded anteriorly and more oval in outline, 
medium or larger in size; cardinal area scarcely developed, very 
narrow, but apparently equalling the hinge line. Beaks approximate, 
with about the same elevation, scarcely elevated above the hinge line, 
not prominent. 
One valve of the shell has a low mesial elevation of moderate 
breadth, corresponding to a mesial sinus on the other valve, which is 
shallow but equally distinct. The comparative breadth of the mesial 
fold and sinus, considering the general contour of the shell, although 
suggesting Triplesia Ortoni, is dissimilar. In other respects it suggests 
to me a strophomenoid shell. 
Surface marked by broad, radiating, scarcely evident folds, and 
similar concentric elevations of growth, in addition to which, very fine, 
fibrous, radiating stri^ are visible in the more or less silicified shell. 
Lateral margin meeting the hinge line at little more than an angle of 
ninety degrees, rounded anteriorly, slightly projecting at the middle. 
Length, 27 mm.; breadth, 29 mm.; convexity, 12 mm. Length of 
another individual, 28 mm.; breadth, 30 mm. 
Locality and position. Soldiers’ Home Quarry, in the middle of the 
Clinton Group. 
