SHUMARD—CRETACEOUS FOSSILS. 607 
gibbous than the left, its anterior third strongly rounded; 
umbonial region convex for a short distance ean the beak 
and thence flattened to the anal extremity, which is subtrun- 
cate on the pallial side and furnished on the cardinal side 
gle ; beaks nearly terminal, scarcely passing the cardinal line ; 
ligament facet rather narrow, marked with three or four pits 
which are rather shallow, and about equal to the spaces be- 
tween ; surface with numerous fine, concentric lines of growth, 
which, towards the base, assume a subimbricated character. 
Length of cardinal margin, 1.20 inches; from point of beak 
to anal extremity, 1.86 inches; thickness of right valve, 0.32. 
Form. and Locality.—Blufts of Red River, Lamar Coun- 
ty, in Septaria embedded in the blue indurated marl near the 
base of the Lower Cretaceous Series. Collected by Dr. G. 
G. Shumard. 
GENUS JANIRA. 
J. WriGHTI, n sp. 
namented with four ve rominent, simple radiating ribs or 
folds on the body of the shell, and one shia less developed 
just within the margin on either side. Both valves are also 
> maa marked with crowded, strongly waved concentric 
filiform ‘strie ; beaks elongated, slender, ineurved; wings 
unknown, ; 
Length, 6 lines; width, 8 lines. : 
. This shell differs from Janira occidentalis and J. Texanus 
in having a fewer number of ribs, there being no sm 
M the intervals between the larger as in those species. 
Form. and Locality—Two specimens of this shell were 
found by G. F, Wright, Esq., in he Washita Limestone vag 4 
base of Upper Cretaceous) on Shoal Creek, near A ma ‘a 
Was there found associated with Janira Texana, and Terebra- 
tula Wacoensis, ; cia 
The species is dedicated to Mr. G. F. Wright, to Me 
Politeness I am indebted for the privilege of describing it. 
34 
