’ 
48 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
straight or nearly so; lower border slightly convex and longer than the 
upper border; posterior border nearly straight or slightly convex, trun- 
eating the shell obliquely downward and backward, meeting the upper 
border at a more or less distinct obtuse angle and the lower border by 
an abrupt curve. Surface marked by abundant coarse lines and imbri- 
cations of growth, which traverse the shell in slightly curved lines corre- 
sponding with the posterior border, and is apparently without trace of 
any radiating lines or ribs. 
Entire length from beak to postero-basal extremity about 215 milli- 
meters; breadth, from the postero-dorsal extremity to the base, meas- 
ured at right angles with the upper border, 95 millimeters. — 
This shell is so unlike any described American species that no detailed 
comparison with any of them is necessary ; but it is so closely related 
to P. legeriensis V@Orbigny, from the department of Sarthe, France, that 
it is not without some hesitation that I have decided to propose a sepa- 
rate specific name. Ihave never had an opportunity to examine any 
of the few examples of P. legeriensis that have keen discovered, and 
my comparisons are therefore only with the description and figures of 
WOrbigny, in Pal. Francaise, Vol. II, p. 257, pl. 334. From these it 
appears that our shell differs from P. legeriensis in the following particu- 
lars. The angle of divergence of the upper and lower margins is not so 
great, in consequence of which the breadth of the shell is not propor- 
tionally so great; the curve by which the posterior border meets the 
lower border is more abrupt, and the greatest transverse diameter of the 
shell is near the median line instead of being much below it, as it is rep- 
resented to be in P. legeriensis. The internal median grooves upon each 
valve, and also the undulations of the lower border, mentioned by @Or- 
bigny, appear to be entirely wanting in our shell. 
Position and locality.x—Cretaceous strata; about 14 miles southwest- 
ward from Fort Wingate, Northern New Mexico, where it was collected 
by Mr. James Stevenson, in whose honor the specific name is given. 
WASHINGTON, D. C., February 15, 1880. 
NOTE ON THE OCCURRENCE OF STRICKLANDINIA SALTERZ AND 
S. DAVEDSONE IN GHORGHA. 
By C. A. WEHIITE. 
A few months ago Lieut. A. W. Vogdes, United States Army, gave 
me a few fragmentary fossiis from a collection which he had then lately 
made at Taylor’s Ridge, in the town of Ringgold, Catoosa County, 
Georgia. The other fossils of this collection and the geology of the 
region referred to were discussed by Lieutenant Vogdes in the Decem- 
ber, 1879, number of the American Journal of Science and Arts, pp. 
475-477. He there refers, and doubtless correctly, the horizon from 
which he obtained the fossils he gave me to that of the Clinton Group 
