LOWER CRETACEOUS DEPOSITS CALIFORNIA AND OREGON

182 lower cretaceotffi deposits IN california and oregon
indicate a diameter of 10 inches. The shell is robust, little compressed,- rounded on
the abdomen, has a small umbilicus, of which the walls are abrupt below and rounded
on the border; surface marked by about eight transverse, shallow, somewhat sigmoidal
grooves, seen only on the cast, bordered in front by rounded ridges on the
shell, more prominent on the abdominal area. The suture line of the species, not
shown on Hyatt's "holotype," is clearly that of Deamacerot, resembling very closely,
aa far as it can be traced on the holotype of D. imtrrttiwt and, on teletypes of the
same, the figure of A Mmonitea lotidormtva given by d'Orbigny, although not showing
the same Dumber of auxiliary elements at its dorsal end. This species is plentiful
at Locality 1659 (Calif. Acad. Sci.) in the Neptune zone of the Horsetown group on
Hulen Creek, where it is associated with Deutrilltieera* mammi'iiatum var., ifatidantieerat
breaeri (Gabb), Punw'o iubq-uadralum (Anderson), and other species of
middle Albian aspect. Other examples of the same genus, and perhaps species, were
found in the Ferris zone at Locality 162 (Calif. Acad. Sci.), about 450 feet lower
in the section, associated with Phyllocerat theretoe nov. and forms of Somwratia
and Pusotia,
No example of D. meiriami baa yet been recorded from any strata or in any association
of forms that permit its reference to an Aptian horizon. Its horizon is
essentially that of the Neptune zone in tbe upper part of tbe Horsetown group;
it has not been found at old Horsetown itself, or in higher beds.
"Detmoceraa" catifomicum Stanton
DAMOCERA* EALIFWMWM STANTON, U. S. Geol. Surv., Bull. 133,1906, p. 76, pi. 15, figs.
6, 7; about 3 miles north of Paskenta, Tehama County, and half a mile east of
Henderson's.
Tbe locality of discovery of this fossil places it very definitely within the area
of the Paskenta group, although not far from its base. It is not known whether
the form figured and described by Stanton under this name is properly referable to
any genua of Desmoceratidae, since representatives of this family are absent or rare
in the Paskenta group. In form, umbilical ratio, ribbing, septal, and other features,
it is unlike any forms belonging to this family known to the writor. Stanton unfortunately
compared it to a nondescript specimen figured by Gabb under the name
Ammonite* breuxri, said to have been found in the uppermost beds of the Horsetown
group. The comparison leaves much to be desired, and is hardly helpful. Spath
has proposed the generic name Eodeamoeeras for certain forms (group of Ammonilta
eefctlttii Pictet and Campeche) from the Valanginian, but Stanton's species can
hardly be placed in thia group, which otherwise is not known in the California Cretaceous.
A better specimen of an ammonite that seemed referable to 4 'Dearrweeras"
catifomicum Stanton was found in nearly its horizon half a mile Bouth of the Wilcox
house, 6 miles north of Paskenta, but it oould not be obtained for description. It is
possible that both examples may represent some hoplitid derivative form, but neither
the figure, horizon, nor description given by Stanton seems sufficient basis for a
positive statement as to its family relationships.
AfeWit'orto Spath 1023
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