92 
BULLETIN OF THE LABORATORIES 
Surface marked by strong, radiating striae, and less conspicuous 
concentric striae. 
The intercalation of radiating striae in some cases gives rise to an 
appearance similar to the dentations and groovings figured in the 
Indiana reports, but not identical with them. The concentric striae 
also are not so prominent. The crystallized character of our speci- 
mens will, perhaps, account in part for these discrepancies. Fig. 14 b 
represents a specimen with fewer radiating striae, referred here. 
Length, i6-i7mm.; height, lo-iimm.; convexity of the left valve, 
about 2 mm. 
Locality and position. Soldiers’ Home Quarries, Clinton Group. 
GENUS GRAMMYSIA, De Verneuil. 
II. Grammysia Caswelli, sp. n. 
[Plate XIV, Figs. 12 a, b.) 
Shell small, transversely sub-ovate; umbonal regions gibbous, an- 
terior regions likewise ; height at the beaks equalling about five-eights 
of the length. Anterior end sloping abruptly from the beaks above, 
with a distinctly concave outline, to the lower end of the lunule, where 
it is met by the rounding base, forming more or less an angle at their 
junction; base forming a -broad semi-elliptic curve; posterior end 
more compressed, the specimen ' at hand being too imperfect to de- 
termine whether it gaps at this extremity, although it is presumed to 
do so a little from the curvature of the better preserved valve ; pos- 
terior end rounded, then curving upward and quite rapidly forward 
almost merging into the hinge line. 
Cardinal margin indistinctly preserved, judged to be nearly hori- 
zontal, slightly concave in outline, and inflected along its entire length, 
forming a well defined escutcheon; lunule distinct, with an ob-ovate 
oudine, quite deep. Beaks prominent, strongly incurved, obliquely 
to the hinge, directed a little forwards, posterior umbonal slopes prom- 
inently, yet rather broadly rounded. 
Surface ornamented in the cast by well-defined concentric ridges 
and furrows, these in the specimen at hand crossed by fine parallel 
lines, almost vertical, directed a little backwards, and which may be 
accidental rather than a special feature of the shell. Ridges strongest 
