Pecten (Pseudamusium) [sic] panamensis Dall, 1908
DALL, W. H. 1908. The Mollusca and the Brachiopoda. Reports on the Mollusca and Brachiopoda [U. S. Fish Commission Steamer ''Albatross'' during 1891 and 1905] region. Bulletin of the Museum of Comparative Zoology at Harvard University, 43 (6): 203-487. [p. 404, pl. 6, figs. 8, 10]
«Pecten (Pseudamusium) panamensis DALL, n. sp.
Plate 6, figures 8, 10. Shell translucent yellowish white, very thin, resembling mica in consistency, oblique, compressed; beaks small, low, polished, hardly projecting beyond the hinge line; ears small, subequal, the posterior feebly differentiated; the anterior right ear with a wide fasciole corresponding to the byssal sulcus, above which are five or more radial threads, the whole with stroug incremental lines; on the lower margin of the fasciole is a line of minute beads, apparently a ctenolium which becomes obsolete at maturity; the other ears are sculptured like the rest of the disk; sculpture: on the left valve a feeble but distinct "Camptonectes" striation, rather coarse and irregular incremental lines, the whole crossed by 40-65 fine radial, sparsely, minutely scaly threads, the scales occurring usually at the intersection with a prominent incremental line; left valve with similar sculpture except that the "Camptonectes" striation is so fine as to require strong magnification and a good light to be seen at all; the valves are produced obliquely downward and backward; the surface sculpture yields readily to friction and many of the valves have lost it altogether, retaining only the concentric sculpture; left valve slightly more convex; interior glassy, the resiliary pit very small, the margins entire. Height, 18; length, 18; max. diam. 2.5; hinge line, 9.5 mm. A very large specimen is 22 mm. high.
U. S. S. "Albatross," station 3354, Gulf of Panama, in 322 fathoms, mud, bottom temperature 56° F. U. S. N. Mus. 122,865. Also at stations 3389, 3396, 3407, and 3422, ranging from near Acapulco, Mexico, to the Galapagos Islands, in 141 to 885 fathoms, soft bottom, temperatures 37º.2 to 53°.5 F. The shell was very abundant at some localities, the valves dead and separated, very few retaining the radial sculpture.» WILLIAM HEALEY DALL, 1908
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W. H. Dall, 1908, plate 6.
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