Pecten (Chlamys) kindlei Dall, 1920
DALL, W. H. 1920. Pliocene and Pleistocene fossils
from the Artic coast of Alaska and the auriderous beaches of Nome, Norton
Sound, Alaska. United States Geological Survey Professional Paper, 125-C:
23-37, pls. 5, 6. [p. 30, pl. 6, figs. 2, 7]
«Pecten (Chlamys) kindlei Dall, n. sp.
Plate VI, figures 2, 7. Shell large, rather rude, belonging to the group of Pecten swifti Bernardi. Right valve with four broad, low radial ribs separated by much narrower, shallow, ill-defined interspatial furrows; the whole surface sculptured with strong radial, more or less paired flattish cords, often minutely medially grooved and sometimes separating into two distinct radii; the interspaces are about as wide as the cords and distinctly channeled; they also retain patches of a minute reticulated surface lamellation; the beak is pointed, the anterior ear large, aliform, with an acute but not deep notch, leaving a broad concentrically laminate fasciole, the margin of the disk at the notch with a ctenolium of two or three rather widely separated short spinules; the radial threads crossed by rather coarse incremental lines; the posterior ear is very short, narrow, and oblique; inner surface of the valve smooth except near the distal margin, where it reflects the external sculpture; the adductor scar large, the resiliary pit rather small for the size of the shell, with the lateral margins raised; a narrow, transversely striated area exists, broader on the left valve; there are no auricular crura. Left valve with five narrow radial ribs seprated by wider shallow interspaces which are wider on the posterior half of the disk; the surface is covered with radial cords as in the other valve, but these are finer and closely crowded on the submargins; the reticular surface layer is the same as in the left valve, but the right valve as usual is more convex; anterior ear triangular, large, with about eight or ten radial cords; posterior ear narrow and short; both set off from the submargins of the disk by a deep, wide furrow; hinge line straight, with a flat area half as wide as the length of the pit. The young valves retain a reddish tinge in their substance. Height of adult valve, 92 millimeters; width of disk, 78 millimeters; of hinge line, 45 millimeters; diameter, 27 millimeters.
Station 7619, Pliocene of Center Creek mines, 2 miles north of Nome, from the second beach. Collected by E. M. Kindle and R. D. Mesler, 1908. U. S. Nat. Mus. catalogue No. 324301. This species, from fragmentary remains collected by J. J. V. Beaver, of Nome, was identified by me in 1907,¹ with P. (C.) swifti Bernardi, of northern Japan. The present much more complete material, obtained the following year, enables me to correct this identification. The shell indeed much resembles the Japanese form, but it has not the concentric waves due to resting stages that appear in P. swifti, and the posterior ear is of quite different shape. The two bear to one another much such a relation as is found between Pecten nodosus of the Antilles and P. subnodosus of the Pacific coast of America. Related to this species is the P. parmeleei Dall from the Pliocene of San Diego, Calif., with which fragments from Pliocene deposit near Crescent City, Calif., were identified. The latter (figured by Arnold²) upon later and more exact study prove to be indistinguishable from the true P. swiftti of Japan. The minute structure of the reticulated outer layer of P. parmeleei is quite distinct from that of P. swifti or the present species, but this delicate structure is so rarely preserved intact in the fossils that its help in specific discrimination is seldom available.» ¹ Am. Jour. Sci., 4th ser., vol. 23, p. 457,1907.
² Arnold, Ralph, The Tertiary and Quaternary pectens of California: U. S. Geol. Survey Prof. Paper 47, pl. 41, figs. 5, 5a, 1906. WILLIAM HEALEY DALL, 1920
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W. H. Dall, 1920, plate 6.
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