SHUMARD——-NEW FOSSILS. 393 
R. INDENTATA, 0. sp. 
‘Shell variable, subovate, gibbous, fed aah | breadth about 
equal, sides converging rapidly from the middle of the shell 
to the beak, and rounded towards the front, which is slightly 
indented. Dorsal valve strongly arched, much more elevated 
than the ventral valve; umbo flattened, broadly and rather 
mot deeply excavated in front by the tongue of the opposite valve ; 
ridge slightly elevated, and in some specimens scarcely 
t e eo at the front ; lateral margins very sinuous, 
) nted at the cardinal goo: on either side 
of the beak by the false area of the opposite valve ; beak 
and closely incurved. Ventral valve convex in the 
umbo and sides, scarcely gibbous, having a broad shallow si- 
2c wee becomes Ao ety on the umbo; false area well de- 
distinetly defined, price he below the e plane of the 
ina ¢ valve, marked with fine strie; beak acute and, 
porate ‘incuryed. Surinee marked with fine strie of 
d from 20 to 25 rounded radiating coste, whi hich be- 
“gree tah ct cost in the mesial fold and in 
' 0.55; width, 0.50; thickness, 0.40. 
1estone of the Agra Mountains. 
