LOWER CRETACEOUS DEPOSITS CALIFORNIA AND OREGON

140 lower cretaceous deposits of california and obeook
bigny, as illustrated by Kilian (1907-1910, pi. 8), to which it seeroB to be nearly
related.
The holotype of the species was found at Locality 1347 (Calif. Acad. Sci.) east of
Mitchell Creek in the Barr zone; it was associated with Aeroteuthit aboriffinalie,
nov. and Gabbiocerat angulation Anderson.
Possible successors of this species appear in the upper beds of the Horsetown
group on Hulen Creek, and at old Horsetown on Clear Creek. Phylloceras theresae
occurs in the Perrin zone on the east fork of Hulen Creek, and P. shaelalente waa
described from the site of the old mining camp at Horsetown. The group of related
forma to which P. occidentals belongs includes the next four species to be described,
and ranges from the upper part o( the Paskenta group to tho top of tho Hometown
group.
Phylloceras trinileme Anderson, n. Bp.
(Plat* SS.fifuna 1,4. S,
This species belongs to the group represented by P. ocddtniale and may be contemporary
with it. It is of medium size, the holotype being 52 mm, in diameter.
The umbilicus is slightly larger and more open than in P. occidental* and is bordered
by smooth slopes from the upper part of which primary ribs arise and cross the ventral
zone without interruption or weakening; ribs often branching a little below the
ventral zone; tho secondary ribs arising near the middle of the side, and with growth
extending downward toward the umbilical slope; all ribs arising as simple linear
ridges, equally spaced, and inclining forward; interspaces two or three times the
width of the riba themselves; suture lines not shown on the holotype. Holotype
(Calif. Acad. Sci. type Coll.) has the following dimensions, as measured on the cast:
greatest diameter, 52 mm.; width of umbilicus, 5 mm.; height of whorl, 30 mm.;
width of whorl, 24 mm. This shell differs from P. occidentals in havin g stronger and
sharper, often branching riba that continue without weakening across the ventral
tone. The holotype was found in the detached area of Lower Cretaceous beds on
Redding Creek, eastern Trinity County, where it was associated with species of
Gomomya, Glycymerin, Pleuromya papyracca, and other pelecypods. Probably
from this area the holotype of Crioctras latum Gabb, which is moat abundant in the
upper part of the Paskenta group, was originally derived. The same species, or one
closely related to it, waa found by E. L. Packard in the Lower Crctaceau* bede at
Riddle, Oregon, and was loaned to the California Academy of Sciences for study and
comparison. Its association in the Riddle locality with species of ifeocomiiea indicates
a low position in the Cretaceous column, possibly near its base.
Phyllaceras texioni Anderson, n, sp.
(Flut® U, t|pn 2)
Shell small, moderately inflated, costate, with costae of two kinda; primary
costae forming first at a diameter of 15 mm.; at this stage possessing about 8 to I
•cm., arising on the umbilical slope and extending upward at right angles to tho
periphery, crossing the ventral J otic without interruption, not inclining forward in
young stages; secondary costae arising above the middle of the sides, Icbb numerous
than the primary; umbilicus small, or nearly closed, with gently sloping sides, forming
a shallow, funnel-form depression, smooth or polished within; sides of shell
flattened; periphery flatly rounded, the section of the whorl being aiibquadrate in
young stages. The holotype (Calif. Acad. Sci. type Coll.) was found near the Jordan
gate on the Ono-Beegum road, Smiles south of Ono.ShastaCounty. It possesses
dbout 44 ribs, moat of which are primary. It has the following measurements: