Pecten (Pecten) hawleyi Hertlein, 1925
HERTLEIN, L. G. 1925. New species of marine fossil Mollusca from western North America. Southern California Academy of Sciences Bulletin, 24 (2): 39-46, pls. 3-4. [p. 40, pl. 4, figs. 4, 5]
Pecten (Pecten) hawleyi Hertlein, new species
Plate 4, figures 4, 5. «Shell small, moderately thick, inequivalve. Right valve moderately convex, the point of greatest convexity being about one-third the distance from the apex to the ventral margin of the disk, the umbos gently rounded to the plane of the ears; surface ornamented by 17 to 18 prominent, sharply rounded ribs with nearly flat interspaces, toward the posterior extremity the ribs become flattened, and broader, and the interspaces broader proportionately; toward the periphery of the disk the ribs become somewhat less elevated and the sides of the ribs are more sloping to the flattened interspaces, in addition the surface of the right valve is ornamented by closely spaced, very fine, concentric lines, which are most prominent near the periphery of the disk; ears ornamented by concentric lines of growth, the anterior with a small byssal notch. Left valve slightly convex, slightly depressed near the anterior and posterior dorsal margins, ornamented by 16 to 17 very narrow, round ribs which expand but slightly towards the periphery of the disk, and are separated by interspaces wider than the ribs, the surface also sculptured by numerous fine, concentric growth lines which are more prominent than those on the right valve; ears crossed by very fine lines of growth. Height 32 mm.; length 34 mm.; apical angle of left valve approximately 125º.
Type: Left valve No. 19 (L. S. J. U. Type collection) from L. S. J. U. Geol. Surv. Loc. 860, upper beds of the Vaqueros sandstones, Santa Inez Mountains, Santa Barbara County, California; H. J. Hawley collector, Vaqueros Miocene; Paratype: right valve No. 22 (L. S. J. U. Type collection), same locality. Pecten hawleyi Hertlein resembles P. sanctaecruzensis Arnold, but the present species is smaller, has a greater number of ribs, and has more prominent concentric sculpture on both valves than P. sanctaecruzensis. At the type locality P. hawleyi Hertlein is associated with: Pecten vanvlecki Arnold, Rapana vaquerosensis Arnold, Turritella inezana Conrad. This species is named in honor of Mr. H. J. Hawley who collected the type specimen.» LEO GEORGE HERTLEIN, 1925
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L. G. Hertlein, 1925, plate 4.
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