LOWER CRETACEOUS DEPOSITS CALIFORNIA AND OREGON

126 lower chetaceous deposits ijf california and oregon
The name of thia species is found in the list given by Stanton (1695, p. 18) from
the locality a quarter of a mile nortbweflt of Shelton's house, where it was found
associated with Aucella craancolli*, "Olcottephanut" mutabili* Stanton, "Hoplita"
angulatui Stanton, and other species belonging in the Paslcenta group of the Shasta
series. It is not confined to the Paskenta group, however, since it baa also been
found at Locality 1353 (Calif. Acad. Sci.) at the baae of the Horsetown group on the
Cottonwood Creek, near Ono, Shasta County.
GASTROPODA
PATELMDAE Carpenter
Hclcion Monfort
Hcleion granvlatia Stanton
Helcion granulatua STANTON, U. S. Geol. Surv., Bull. 133, 1895, p. 63, pi. 12, fig. 4;
Cold fork of Cottonwood Creek, Tehama County, California.
"Shell depressed, conical, with the aj;ex a little in advance of the middle and
directed slightly forward; aperture elliptical; surface marked by numerous slightly
wavy radiating costae, which become somewhat broader on the posterior portion,
crossed by rattier closely arranged, impressed eon sen trie lines, becoming more distant
near the margin cf large specimens.
"The figured type measures 13 mm. in length, 0 mm. in breadth, and about 3 mm.
in height."
The species is included in a list given by Stanton (1895, p. 14) from the type
locality, near Stephenson's bouse, on the Cold fork of Cottonwood Creek, which list
and locality have already been referred to the area and stratigraphic limits of the
Paskenta group of tbe Shasta series. Stanton's account of the species is tbe only
record of its occurrence.
ACKAEIDAE Dall
Am'somyon Meek and Hayden
Aftii&nty&n meeki (Gabb)
Anwmyort Meekii GABB, Paleont. Calif., vol. 1, 1804, p. 142, pi. 21, fig. ICS; North
fork of Cottonwood Creek, Shasta County; vol. 2, 1869, i>. Z31, "Shasta
Group," Cottonwood Crtek—STOWAWT, Phila. Acad. Nat. Sol., Pr., vol. 78,
192C, p. 312.
"Shall elliptical, very thin; the width and length are about as 5 to 0: apex moderately
elevated, small, nearly central* aides sloping nearly straight in all directions
to the baae. Surf ace (of cast) marked by numerous irregular concentric undulations,
which do not always continue entirely around the shell; there are also marks which
probably indicate a few faint radiating lines."
The holotype of this species is in the Museum of the Academy of Natural Sciences,
Philadelphia. According to Stewart tbe shorter diameter is 21 mm.; height, about
6.5 mm.
The exact horizon in tbe Shasta scries at which this spcciea has been found is not
yet definitely known, as Cottonwood Creek crosses the entire series,
PLEBHGTOMAJtimAB d'Orbigny
PleuTtttomaria Sowerby
Pleurolomaria California Anderson, n. sp.
(Plata 9. Sguro 7)
Shell of medium size, spire not high, broader than high, with narrow but open
perforation at base; sculpture consisting of fine spiral threads on the base and lower