"Chlamys" cushmani (Kellum, 1926)
KELLUM, L. B. 1926.
Paleontology and stratigraphy of the Castle Hayne and Trent marls in North
Carolina. United States Geological Survey Professional Paper, 143: 1-56, pls.
1-11. [p. 20, pl. 2, fig. 1]
1926 Pecten cushmani Kellum, 1926
L. B. Kellum, 1926, plate 2.
|
«Shell equivalve, equilateral, with 29 or 30 simple ribs and equal interspaces; concentric sculpture of fine growth lines, which on the ribs tend to form low lamellae; the ribs becoming smaller and crowded near the submargins; ears erect, extent of anterior ears unknown; ctenolium present; posterior ears small and decorated with five or six radiating ribs, crossed by numerous concentric rows of lamellae; margin of both valves crenulated within, and margin of left valve also beveled within. Height, 18 millimeters; breadth, about 17 millimeters; depth of left valve, 2.5 millimeters.
This species is closely related to P. cookei, which occurs at the same horizon. It differs from cookei in being equilateral and equivalved, in the less convexity of the valves, in the crowding of the ribs near the submargin, and in the erect. position of the ears. P. cushmani also resembles P. suwaneensis Dall , from which it is distinguished by its greater number of ribs, by the crowding of the ribs near the submargins, by the less angular character of the inner marginal crenulations, and by the concentric sculpture of smoothly rolling growth lines instead of the wavy lines characteristic of suwaneensis. Locality: Quinerly Bridge, Pitt County; 3 miles east of Quinerly, Craven County; 3 miles northeast of Maple Hill, Pender County, N. C. Geologic horizon: Castle Hayne marl, of Jackson Eocene age.» LEWIS BURNETT KELLUM, 1926
|