12 PBOCEEDINGS OF THE NATIONAL MUSEUM vol. 72 



Two of the specimens from the North Carolina locality are fig- 

 ured in the present paper, Cat. No. 73426, U.S.N.M. The other four 

 specimens have the catalogue number 73427. Two typical specimens 

 from Mississippi have been placed with those from North Carolina, 

 Cat. Nos. 73448, 73449. 



GLYCYMERIS SUBGYRATA, new species 



Plate 5, figs. 8, 8a, 9 



Description. — Shell broadly ovate-oblong in outline, a little longer 

 than high, moderately convex. Beaks protruding slightly above 

 the hinge line, incurved, faintly prosogyrate, situated centrally, but 

 slightly in advance of the center of the area. Dimensions of the 

 holotype: Length, 31 mmT; height, 28 mm.; convexity, 9 mm. Di- 

 mensions of the best preserved paratype: Length, 26 mm.; height, 

 22 mm. ; convexity, 7 mm. 



Hinge plate arched and truncated above by the straight lower 

 margin of the area. Several of the central teeth are small, short, 

 and transverse to the hinge line ; in front of the central teeth are 10 or 

 11 larger somewhat oblique teeth, and back of them 9 or 10 similar 

 larger, oblique teeth. 



Cardinal area amphidetic, straight on the lower margin, and 

 arched above; the straight margin is about 11 mm. long on the 

 holotype; the area is covered with about 5 narrow chevron-shaped 

 ligamental grooves, the posterior limbs of which are a little longer 

 than the anterior. 



On the interior of the shell the adductor scars are strong, of mod- 

 erate size, and are distinctly raised above the main inner surface, 

 the lower margin of each scar being slightly overhanging. The 

 inner margin of the shell is rather finely crenulated. 



The margins of the shell form a broad oval, longer than high, the 

 posterior end being a little more sharply rounded than the anterior. 



The outer surface is nearly smooth, with the exception of fine 

 concentric growth lines, and widely spaced stronger lines indicating 

 vigorous growth followed by resting stages. There is no indication 

 of radiating lines such as are usually present on the species of this 

 genus. 



Remarks. — The slight, though distinct forward curvature of the 

 beak is a feature that has not been observed on previously described 

 species of this genus from the Upper Cretaceous of North America. 

 Glycymeris Jiamula (Morton) from the uppermost part of the Upper 

 Cretaceous at Prairie Bluff, Alabama River, Ala., is apparently 

 smooth, but it has a direct beak, is more convex, and has a higher 

 area with more numerous ligamental grooves. 



Localities. — From the new Rocky Point quarries, a mile northeast 

 of Rocky Point station, Pender County, N. C. ; one specimen col- 



