Leptopecten andersoni barkerianus (Arnold, 1906)
ARNOLD, R. 1906. The Tertiary and Quaternary pectens of California. United States Geological Survey Professional Paper, 47: 1-264, pls. 1-53. [p. 83, pl. 26, fig. 9]
1906 Pecten (Plagioctenium) andersoni var. barkerianus Arnold, 1906
R. Arnold, 1906, plate 26.
|
«Description.— Shell averaging about 40 millimeters in altitude, somewhat longer than high, equilateral, somewhat ventricose, and with serrate margins; base regularly rounded; sides nearly straight, sloping at a moderately low angle. Left valve with 17 rather narrow, prominent rounded ribs, each with a rounded, thread-like rib let running longitudinally along its top; at more or less regular intervals small obsolete spines protrude from the riblet; interspaces wider than the ribs, with sloping sides, and flat bottoms; whole surface of disk crossed by very fine incremental lines; hinge line longer than one-half length of disk; ears subequal, rectangularly truncated, and sculptured by radiating ridges and incremental lines.
Dimensions.—Alt. 40 mm.; long. 44 mm.; hinge line 28 mm.; diameter 7 mm. This variety, which is characterized by the thread-like riblet along the top of each primary rib on the left valve, has been found only in beds of lower Miocene age (Turritella ocoyana zone) in the southern San Joaquin country. It is found associated with the following characteristic fauna in the bluffs of the Kern River, 1 mile below the power-development station, Kern County: Conus n. sp., Mactra near planulata, Phacoides sp., Tellina near idae, Trochita filosa, Agasoma kernianum, Agasoma barkerianum, Leda taphria, Leda (aff.) fossa, Cancellaria n. sp., Pleurotoma (Dolichotoma) n. sp., Pleurotoma (Leucosyrinx) near pedroana, Chione n. sp. near gnidia, Dentalium 2 n. sp., Nassa ( cf.) perpinguis, Pleurotoma sp., Neptunea n. sp., Crucibulum n. sp., Turritella ocayana, Cancellaria (cf.) vetusta, Phacoides (cf.) nuttalli, Natica or Lunatia sp., Terebra sp. (probably new), Trophon (cf.) ponderosum, Drillia (aff.) torosa, Solen (aff.) sicarius. At Avenal Canyon, Kern County, Mr. Eldridge found P. var. barkerianus with P. andersoni, Turritella ocoyana, Dosinia (large and flat), Venus sp., and Ostrea sp. The type of P. var. barkerianus was found east of the Barker ranch house, near Kern River, Kern County, and is now in the collection of the California Academy of Sciences. RANGE.
Miocene (lower). Barker ranch, Kern County (Watts): Avenal Canyon and bluffs of Kern River near power-development station, Kern County (Eldridge).»
RALPH ARNOLD, 1906
|