LOWER CRETACEOUS DEPOSITS CALIFORNIA AND OREGON

description of species 131
NERITIBASJ Lamarck
Nerita Linnaeus
Merita deformit Gabb
Nerita deformia GABB, Paleont. Calif., vol. 1, Ifi64, p. 137, pi. 21, fie. 96; North fork
of Cottonwood Creek, Shasta County—STEWART, Phila. Acad. Nat. Sci.,
Pr., vol. 78, 1928, p. 319; loaality as above,
The holotype of this species is in the Museum of Paleontology, University of
California. According to Stewart it is "related to the Twr&im'doe,"
Search has been made for the species in the Shasta series of the Cottonwood
district, but thus far without results, and there is no other record of its occurrence.
Profit IDEMJPAE Gray
HypHpleura Koken
Hyptipleura grtgaria Stanton
Hyptipleura gregaria STAXTON, U. S, Geol. Surv., Dull. 133, 1895, p. 70, pi. 13, figa.
1, 2; upper part of tbe "Knoxville beds," on the Shelton ranch, 5 miles north
of Paskenta, Tehama County.
This species is briefly but concisely described by Stanton as follows:
"Shell very small, rather slender, elongate, composed of about seven slightly
convex whorls; suture impressed, linear; sculpture consisting of ten or twelve transverse
costae on each whorl extending entirely across the upper whorls of the spire,
but shortened to mere tubercules forming a row on the upper margin of the last two
or three whorls, aperture obliquely ovate with a thin, sharp outer lip,"
Height of an average specimen, 3 mm.; greatest breadth, a little more than 1 mm.
Said to occur with Aucella crassicollis, its stratigraphic position is that of this
latter form, which here and elsewhere has been regarded as near the middle or in the
upper part of the Paskenta group.
Liocium Gabb
IAocium punclaium Gabb
Liocium punclalvm GABD, Paleont. Calif., vol. 2,1889, p. 174. pi. 38, fig. 59; "Shasta
Group, south of the road from Colusa to the Hot Sulphur Springs, in the first
range of foothills, Colusa County 1 "—STANTON, U. 8. Geol. Surv., Bull. 133,
1896, p. 19: "abundant" in "upper Horsetown," bods—STEWART, Phila. Acad.
Nat. Sci., Pr., vol. 78,1925, p. 319, pi. 24, fig. 3; Gabb's holotype figured.
Stanton's record of the occurrence of this species in beds of "upper Horsetown"
age is the only reason for including it in the fauna of the Shasta series. If Gabb's
statement as to the locality of its discovery is to be taken literally, it can hardly
bo older than the upper Turanian beds of the Chico series.
NATICIDAE Forbes
Awjiullixui Lamarck
Ampalh'na avellana (Gabb)
Lunaiia ateltana GABB, Paleont. Calif., vol. 1, 1864, p. 105, pi. 10, fig. 80; North fork
of Cottonwood Creek, Shasta County; vol. 2, 1869, p. 222; locality as above.
AmjntUina avellana (Gabb), STEWART, Phila. Acad. Nat. Sci., Pr,, vol. 78, 1928, p.
333, pi. 21, fig. 9; locality as above.
From seven specimens in the Museum of the Academy of Natural Sciences of Philadelphia,
Stewart has selected and figured a proposed Icetotypc, giving its horizon