194 
PROCEEDINGS OF 
PECTEN.— {Lam.) 
Pecten Humphreysii, pi. 2, fig. 2. Suborbicular, inferior valve convex; superior 
flat, and with about seven remote, narrow, convex ribs, and concentrically wrinkled ; 
towards the apex is a concave depression; ears equal, sides direct and straight; infe¬ 
rior valve with the ribs wide, approximate, plano-convex and longitudinally striated; 
one of the ears emarginate at base. 
Localities: Near Fairhaven, Anne Arundel county, Md. Mr. Wilkinson’s farm, 
in Calvert county. .1 am indebted to Dr. Humphreys, of Annapolis, for the loan of 
the specimen figured, that which I found at Fairhaven being too imperfect for the 
purpose. I gladly attach the name of this gentleman to the species, in considera¬ 
tion of his love of and proficiency in scientific pursuits. 
Of two specimens in the collection of the college at Annapolis, the largest mea¬ 
sures three inches from beak to base. 
DISPOTiEA.— {Say.) 
Dispotaa constricta, pi. 1, fig. 2.—Shell irregular, elevated; laterally compressed, 
marked with simple lines of growth; apex prominent, with one or two minute vo¬ 
lutions ; diaphragm very profound. 
Locality : Captain Hance’s Landing, Calvert Cliffs, Maryland. 
SCALARIA.— {Lam.) 
Scalaria expansa, pi. 2, fig. 3.—Shell acutely ovate, moderately thick, with nu¬ 
merous robust recurved ribs, twelve in number, counting from the summit of the 
aperture to the reflected lip, inclusive; whirls profoundly ventricose at the sides, 
somewhat flattened above ; four or five in number. 
Locality : St. Mary’s river, Maryland. 
Two specimens of this fine Scalaria were obtained by Mr. Markoe, and none 
other is known to have been discovered. 
BUCCINUM.— {Lami) 
Buccinum integrum, pi. 2, fig. 5.—Shell short, subfusiform or elliptical; smooth ; 
destitute of ribs or striae; spire conical, the volutions convex; aperture elliptical, 
about half the length of the shell; columella thick ; labium reflected. 
Localities: St. Mary’s river and Calvert Cliffs, near the mouth of Patuxent 
river. 
SCUTELLA.— {Lam.) 
Scutella Aberti. —Discoidal, orbicular, very much depressed, but swelling to¬ 
wards the middle, and depressed at the apex; diameter five arid a half inches. 
Locality: Patuxent river, St. Mary’s county, Maryland. 
This large Scutella is very abundant; but those I have, at present, are too imper¬ 
fect for minute description. A figure of it will be published when specimens in 
better condition shall be obtained. It is dedicated to my scientific friend Colonel 
J. J. Abert, of Washington, whose name it gives me great pleasure thus to con¬ 
nect with the tertiary rocks of Maryland. 
