Decatopecten waluensis (Hertlein, 1933)
HERTLEIN, L. G. 1933. Three preoccupied names in the Pectinidae. The Nautilus, 47: 62-64. [p. 62]
Pecten (Chlamys) thomasi, n. sp; W. C. Mansfield, 1926, Fossils from quarries near Suva, Viti Levu, Fiji Islands, and from Vavao, Tonga Islands, with annotated bibliography of the geology of the Fiji Islands, plate 5, figures 1a, 1b.
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«1. PECTEN WALUENSIS, new name for P. thomasi Mansfield, not Sowerby.
A pecten from the late Miocene or early Pliocene of the Fiji Islands was described as Pecten thomasi by Mansfield (Papers Dept. Marine Biol. Carnegie Inst. Washington, Vol. 23, Publ. No. 344, 1926, p. 90, pl. 5, figs, 1a and 1b. "Type locality, Walu Bay, Fiji Islands." Near Suva, Viti Levu, Fiji Islands.). There is an earlier Pecten thomasi described by G. B. Sowerby (Proc. Malacol. Soc. London, Vol. 2, No. 4, 1897, p. 138, pl. 11, fig. 2. The type locality was unknown. The species it was stated, resembles P. natans Philippi.). According to Melvill and Sykes (Proc. Malacol. Soc. London, Vol. 3, No. 1, 1898, p. 46) P. thomasi Sowerby appears to be the adult form of the species described as P. corneus Sowerby and P. natans Philippi. The species from the Fiji Islands described by Mansfield, can take the name Pecten waluensis, from the type locality.» LEO GEORGE HERTLEIN, 1933
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«Pecten (Pallium) waluensis Hertlein (pI. 28, figs. 1-3).
Pecten (Chlamys) thomasi Mansfield, Carnegie Inst. Washington, Pub. 344, p. 90, pI. 5, fig. 1, a, b, 1926.
Pecten waluensis Hertlein, Nautilus, vol. 47, p. 62, 1933. Original description:
Shell of medium size, oblique-ovate, solid, moderately inflated over the middle of the disk and compressed forward at the umbonal area. Hinge line short. Ribs 15 in number, low-keeled above and only slightly below, becoming more rounded distally; ribs separated by interspaces of about one half their width. Radially sculptured over the whole surface of the disk and submargins by fine lines, being stronger over the ribs than interspaces; concentrically sculptured by close-set, minute, nearly erect, imbricated lamellae. Anterior ear small, marked by 3 to 4 fine, minutely crenulated radials within the byssal area and 3 stronger ones in front of it; posterior ear terminally broken off, but indicates similar markings to that of the anterior. Within, the resilium pit is triangular and large, on either side of which there are two other pits, the approximate ones marginate the ligamental area and the distal ones enter it.
The type is founded upon one left valve. Dimensions: length 42 mm., height 45 rnm. [This type now in the U. S. National Museum as no. 372662.] The right valve is slightly more convex than left but similarly sculptured. Neither valve quite bilaterally symmetrical, being produced posteriorly below. Resilium pit in right valve deeper and more sharply set off than in left valve. Two pairs of cardinal crura are well developed on each valve, and on the left valve the broadly elevated margins of the ligamenta! pit may be looked upon as a third pair.
Homeotypes: left valve (B. P. Bishop Mus., Geol. no. 1125), length 39.3 mm., height 43.7 mm., depth 6.0 mm.; right valve (B. P. Bishop Mus., Geol. no. 1126), length 40.0 mm., height 45.1 mm., depth 7.9 mm.
Localities. Type from Station 295, given by Mansfield as "Walu Bay, Fiji Islands." The type was collected by the late A. O. Thomas and is in a matrix of limestone. Such limestones are exposed in two quarries on Walu Bay — Stations 295 and 297, but Thomas stated to me in 1926 that he had not visited the abandoned quarry at station 297. Also collected from Stations 158, 317. and 133. The specimen from Station 133 is poorly preserved and only tentatively referred to P. waluensis.
This species may be easily distinguished from the other Fijian fossil pectens by its striking external sculpture and by the development of the strong cardinal crura. As noted by Mansfield, the sculpture is similar to that found in P. (Chlamys) radula (Linnaeus), a Recent southwest Pacific species, but the shortness of the hinge and the prominent crura seem to place the species in the subgenus Pallium in spite of the excessive number of ribs and the absence of any contraction around the basal margin.»
LADD, H. S. 1934. Geology of Vitilevu, Fiji. Bernice P. Bishop Museum Bulletin, 119: 1-263, pls. 1-44. [p. 173, 174]
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Pecten (Pallium) walluensis Hertlein; H. S. Ladd, 1934, Geology of Vitilevu, Fiji, plate 28, figures 1-3.
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