LOWER CRETACEOUS DEPOSITS CALIFORNIA AND OREGON

104 LOWER CRETACEOUS DEPOSITS IN CALIFORNIA. AND OREGON
This is probably the roost abundant species of Aucella found in the Paskenta
group in its type district; it occurs throughout the lower division of this group. The
holotype was found by Stewart in the collections of the Academy of Natural Sciences
of Philadelphia and was designated by him as the "leototype/ 1 although Pavlow
(1907) had already taken it aa the holotype of the species. This form is abundant 11
miles northeast of Wilbur Springs, Colusa County; it has also been found 1200 feet
northeast of Knoxville, Napa County. It ie found more abundantly in the type
district of the Paskenta group about 1500 to 2000 feet above its base, aa on the Wilcox
ranch, 5 miles berth of Paskenta.
Aucella terebraluJciide* Lahusen
Aucella cancentrica var. WHITE, U. S. Geol. Surv., Bull. 4, 18S4, p. 13, pi, 0, figs. 2,
3j 4. 5: "Fossil point," Port Mailer, Alaska, collected by W. H. Ball.
Aucella piochii, var. ovata STAHTQK, U. S. Gaol. Surv., Bull. 133, W6, p. 43, pi. 4,
figs. 11, 12, 13 (not fig, 14); 2 miles north of Wilcox ranch, western Tehama
County.
ATITTTFA tertbralulaidaa, PAVLOW, SOC. Imper. Jfat. Moscou, Nouv. Mem., T. 17, 1907,
p. 60, pi. 6, figs. 6, 7, 10,11; Xioeomiem of Russia and of California.
According to Pavlow, who figures three varieties of this species, its Btratigraphical
range in Russia ia from Upper Jurassic (Portlandian) to lower Neeeomian. It is
not known to have such range in California, although some of its so-called "varieties"
may have. One is recorded from tho top of the Horsetown group in the McCarthy
Creak section. Some references to Aucella pioehi in the lower beds of the Shasta
series found in the literature may be due to wrong determinations of some of these
varieties. Stanton (Stanton and Biller, 1894, p. 447) includes this species in a list
with "fftiicqwlox" bicarinala, "Oleostephanut," Criotxraa latum, and Belemnitei
imprtsius, from a locality 2 miles north of the Wilcox ranch, which appears to be
at the top of the Paskenta group. It is found most plentifully in the upper part of
its loner division in the zone of Dichotomite* mutabilia (Stanton).
Aucella inJlAla Toufa
(Plata S, Bcraa J, 6)
Aucella eoncenlrica var. WHITE, U. S. Geol. Surv., Bull. 4, 1884,p. ll.pl. 6, fig. 11
only; "Fossil point " Port M»lUr, Alaska, collected by W. E. Dull.
Auectta injlala LAHUSEN, Mem. Com. Geo!. St. Petersburg, vol. 8, no. 1, 1888, p. 20,
40, pi. 4, figs. 12-17; Lower Neocamiaa, Russia—PAYWJW, Soc. Imper, Nat.
Moscou, Nouv, Mem, T. 17t 1907, p. 68, pi, 6, fi^a. £a, b, c; Lower Neocomian
of Pekhorka, Govt, of Simbirsk, Russia.
According to Pavlow this species has some resemblance to A. lertbralvloidtt but
differs from it in its greater degree of inflation, greater convexity of the right valve,
and in the more stubby form of the shell and its more convex posterior border, which
projects mora to the rear.
In the type district of the Paskenta group this species ia more abundant in its
lower beds, where it occurs with A. uneilindts, A. sofrda, Lyioeeras »ottirnafc, nov.,
and a fine-ribbed species of Phytloc*ra*. The species is also abundant near Wins]ow
bridge, western Glenn County, in the lower beds of the PaHkenta, group, and in
nearly the same horizon east and northeast of Knoxville, Napa County, Specimens
of the same have been collected here by X. L. Taliaferro, apparently from the locality
mentioned by Turner (1533, p. 316), who has described conglomerates found "in the
Knoxville beds at several points" to tbe north of Knoxville. These conglomerates
are the baas!, or near-basal, beds of the Paskenta group, Tho same species has