LOWER CRETACEOUS DEPOSITS CALIFORNIA AND OREGON

198 LOWER CRETACEOtffi DEPOSITS IN CALIFORNIA AND OREGON
Lytoeeras cf. aulaeum nov. and Aeroteulhis shastensis nor. The holotype is the property
of the California Institute of Technology, Pasadena, California.
Oxytropidoceras Sticlcr 1920
Genotype Ammonites roissyanus d'Orbigny
Oxytropidoceraa paekardi Anderson, n. sp,
(Flat* SO, Sgv« 1)
Shell large, diseoldal, inflated near and below the middle of the sides, which
converge toward the periphery; keel high and thin; sides heavily coatate with about
40 "proreiradiate" riba; umbilicus moderately broad, bordered by sloping walla, the
slope blending evenly with the convex Bides; costae arising at the umbilical suture,
inclining forward, crossing the sides in a sigmoid curve, bending strongly forward
upon approaching the keel; sides of keel'marked by growth lines almost parallel
with the periphery; septa numerous, but not well shown.
The holotype is a large fragment making two-thirds of a whorl. It is in the
Museum of Paleontology, University of California. It was found by E, L. Packard,
of the University of Oregon, about 2 miles south of Ono and near the top of the Horsetown
group, where it waa associated with Puzosia hoffmarmi (Gabb) and £>OUM'4leiceras
mammillatum var, It has the following dimensions: greatest diameter, 170
mm.; width of umbilicus, 47 mm,; height of whorl, SO mm.; apparent thickness, 45
mm. The species appears to be most closely related to Oxytropideeeras btlknapi
(Marcou), aa figured by Adkins (1938, pi. 4, fig. 3), although it possesses fewer and
coarser ribs, has a more elevated keel, a gentler umbilical slope, and more strongly
curved ribs. It is also closely related to the genotype Ammonites roistyanus
d'Orbigny.
Three examples of this species, obtained at the type locality by G. D. Hanna and
the writer, arc now in the Museum of the California Academy of Sciences. Its horizon
is near, or above, that of the Neptune zone of the Hulen beds as found on Hulen
Creek.
PsnviMQmsBiDAS Spath
Peroinquieria J. Bohm 1910
Ptrvinquieria hulenana Anderson, n. sp.
(PUuaj.fltursS)
Species of Pemnguten'o have long been known in the uppermost Albian beds
in the Cottonwood district, but thus far have been confined to the Chico series.
The holotype of the present species was found in the Hulea beds below the lowest
strata assignable to the Chico series, and beneath the unconformity that marks its
base. Its horiton ia near the middle of this stage, but within a few hundred feet of
the top of the Hulen beds.
The shall ia large and brondly uubllicate, strongly eostate with a distinctly ovate
section in its mature stages; umbilical walls in its younger stages abrupt, rounded and
sloping in older shells; in younger whorls the periphery is flattened, but in the older
whorls it becomes sloping and ridge-like; keel elevated, wedge-shaped, and prominent;
in younger stages of growth (diameter 65 mm.) the section of the whorl ia inflated,
aa broad as high; in older stages (diameter 150 mm.) the section becomes
thinner; in youth the ribs on the ventral border are faintly marked by flutings, but
with growth these are lost.
The holotype, found by E. L. Packard, is the property of the Oregon State College.