Lindapecten exasperatus morantensis (Woodring, 1925)
WOODRING, W. P. 1925. Miocene mollusks from Bowden, Jamaica. Pelecypods and scaphopods. Carnegie Institution of Washington Publication 366: 222 p., 28 pls. [p. 67, pl. 8, figs. 4-5]
1925 Chlamys (Aequipecten) plurinominis morantensis Woodring, 1925
W. P. Woodring, 1925, plate 8.
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«Pecten exasperatus Guppy (not Sowerby), 1866, Quart. Jour. Geol. Soc. London, vol. 22, p. 294. Guppy (part, not Sowerby), 1874, Geol. mag. dec. 2, vol. 1, p. 443 (list)
Pecten (Aequipecten) thetidis Dall (part, not Sowerby), 1898, Trans. Wagner Free Inst. Sci. Philadelphia, vol. 3, part 4, pp. 714-715 The following is a description of this subspecies: Shell medium-sized, subequivalve, both valves moderately convex, suborbicular; sculpture similar on both valves, consisting of 18 to 20 radial ribs, more or less square on dorsal half of shell, broader and more rounded on ventral half, separated by narrower interspaces; ribs and interspaces on ventral half of shell ornamented with radial rows of short, blunt scales, smaller in the interspaces, inconspicuous on dorsal half of shell, reduced to a single row and often absent in interspaces; submargins sculptured with fine, narrow, irregularly spaced scaly radial ribs; auricles broad, the anterior longer, sculptured with scaly radial ribs of irregular width, wider and higher than those on submargins, on the right anterior auricle the ribs are wider and the scales more prominent; interior of shell bearing paired lirae separated by excavated intervals. A right valve: lenght 34.5 mm.; height 34.4 mm.; diameter 8 mm.; length of hinge 23.5 mm. A left valve: length 33.2 mm.; height 34 mm.; diameter 8.8 mm.; length of hinge 24.5 mm. C. plurinominis morantensis closely resembles C. plurinominis plurinominis Pilsbry and Johnson, the type of which is in the Gabb collection from the Dominican Republic. The Dominican species has been collected from both the Cerado and Gurabo formations, but all the large specimens, which are similar to Gabb's specimens, come from the Gurabo formation. The Bowden subspecies has scales that are not so clearly arranged in radial rows and the interspaces near the ventral margin of the shell are narrower. The Dominican species has been described under a number of names. Gabb and Guppy called it C. oxygonum Sowerby; Dall and Maury called it C. thetidis Sowerby. No figures accompany Sowerby's descriptions of C. oxygonum and C. thetidis, both of which were described from the Dominican Republic. There seems to be no doubt about the features of C. oxygonum, and species in the Gabb collection agree with Sowerby's description of C. thetidis. Pilsbry and Johnson have accordingly renamed the species P. plurinominis. C. thetidis is more inequilateral than C. plurinominis, and has higher ribs that have a median groove and are bounded on both sides by radial threads; the radials are roughened by irregularly spaced concentric lamellae. Cooke has described under the name of P. thetidis Sowerby a species from the upper Oligocene limestone of Anguilla that closely resembles C. plurinominis morantensis, but the Anguillan species is much smaller and the scales are arranged in prominent radial series near the ventral margin of the valve. C. plurinominis morantensis is similar to the living West Indian species C. exasperatus (Sowerby), but is smaller, more orbicular, less inflated, and has scales that are not so clearly arranged in radial series. It more closely resembles C. fuscopurpureus (Conrad), a living species from Florida, but is smaller and has wider and more inflated umbos. Type material.— Holotype (right valve, U. S. Nat. Mus. No 352781); paratype (left valve, U. S. Nat. Mus. No. 352782).» WENDELL PHILLIPS WOODRING, 1925
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