606 TRANS. OF THE ACAD. OF SCIENCE. 
cessary to somewhat modify our description, when better pre- 
served specimens are found. The P. subparallela is closely 
allied to P. occidentalis, a Nebraska species described by 
Messrs. Meek and Hayden. The differences exist in the form 
of the extremities, which are of unequal width in the Ne- 
braska shell, while in ours they are about equal. 
orm. and Locality.—In Septaria of the marly clay, near 
base of the Lower Cretacious Group. Red River, Fannin 
County. Collected by Dr. G. G. Shumard. 
GENUS INOCERAMUS. 
I, CAPULUS, N. Sp. 
Shell subequivalve, elongate-ovate, section reba 
ak to 
antero-posterior ‘diameter much shorter than from be 
se; umbonial region very gibbous; anterior slope falling 
abruptly to the margins, flattened above mor 
Length, 1 inch; height, 1.83; thickness, about 1.50. 
There is a fragment of this shell before me which shows 
that in mature age the dimensions are nearly double those 
The JZ. capulus corresponds in many respects qh t 
umbonatus, a species of the Cretaceous Strata of Nebras ° 
and described by Messrs. Meek and Hayden (Proc. a4 
Sci, Phila. Vol. 8, p. 50), but its height is proportion™ = 
greater, and the opening of either valve is distinctly ov@ 
and not subciretlar as in the Nebraska fossil. The pea 
tion, however, of Messrs. Meek and Hayden comes 80 near. a8 
our fossil, that it is not without some hesitation that 4 ™ 
name is proposed. : Green 
Form. and Locality. — Occurs in Concretionary with 
Sandstone of the Lower Cretaceous period, associa ce 
Ammonites Swallovii and Tapes Hilgardi. Bluffs of Red t 
Lamar County. Collected by Dr. G. G. Shumard. 
GENUS GERVILIA. 
G. GREGARIA, DN. Sp. 
aching subgaad- 
Shell inequivalve, oblique, subovate, appro ght valve more 
rate, moderately gibbous ; wider than long ; vi 
