Pecten (Chlamys) clintonius rappahannockensis Mansfield, 1936
MANSFIELD, W. C. 1936. Stratigraphic significance of Miocene, Pliocene and Pleistocene Pectinidae in the Southeastern United States. Journal of Paleontology, 10 (3): 168-192, pls. 22-23. [p. 186, pl. 22, figs. 1-3]
«PECTEN (CHLAMYS) CLINTONIUS RAPPAHANNOCKENSIS
Mansfield, n. subsp. Plate 22, figures 1-3 Pecten (Chlamys) clintonius Say (30b) was reported to have come from Maryland. One right valve deposited in the collection of the U. S. National Museum and identified as Pecten clintonius Say is labelled, on the authority of Doctor Foreman, as collected from Maryland. No one else has reported this species from Maryland. The type locality of Pecten clintonius is unknown, and its occurrence in Maryland is questionable. Say's type as figured bears close resemblance to specimens occurring in the lower bed below Old Kings Mill Wharf on the north shore of the James River, Virginia, and that may be in reality the type locality of the species. I was unable to find the holotype of P. clintonius in the collection of the Academy of Natural Sciences of Philadelphia.
A number of specimens of the subgenus Chlamys, collected frorn the basal bed at Jones Point, right bank of the Rappahannock River, Virginia, are not identical with the specimens tentatively referred to Pecten clintonius from the James River locality, and are here referred to a new subspecies, rappahannockensis. The following is a description of the new subspecies: Shell large, thin and fragile, slightly inequilateral, weakly inflated, the left valve more so than the right. Hinge line ratller short. Ears nearly equal in size; right anterior with a very shallow notch. Ears marked with 7 to 9 weak, finely crenulated radials. Surface of both valves similarly sculptured with many (about 10 to a centimeter) nearly flat radials. Some of the single radials on the early part of the valves divide into two radials distally, and a single radial may come in between the divided pair. Intercostal spaces concentrically crossed by fine diagonal lines. Dimension of larger syntypes (U. S. Nat. Mus. 373072): Left valve, length 115 mm.; height, 111 mm.; convexity, 19 mm. Right valve (margins not entire), length, over 114 mm.; height, over 106 mm.; convexity, 12 mm. Pecten clintonius rappahannockensis differs from specimens collected from the Iower bed below Old Kings Mill Wharf, and referred here to P. cintonius, s.s., in having more uniform and more closely spaced radials and a Ionger hinge line. Type locality: Station 3924, Jones Point, right bank of Rappahannock River, Essex County, Virginia; Collected by the late Frank Burns. Horizon: St. Marys formation, zone 2 (Crassatellites meridionalis zone). Occurrence: Common at the type locality; a large corroded right valve, Station 1/536, lower bed half way between Coggins Point and Indian Point, right bank of the James River, may belong to the new subspecies; specimens collected from Coggins Point, James River, Virginia, by Angelo Heilprin, appear closely related.» WENDELL CLAY MANSFIELD, 1936
|
W. C. Mansfield, 1936, plate 22.
|