LOWER CRETACEOUS DEPOSITS CALIFORNIA AND OREGON

description of species 141
greatest diameter, 27 mm.; width of umbilicus, 2 mm.; height of whorl, 17 an,)
thickness of whorl, Hmin.| umbilical ratio, .074:1.
As far as known, the stratigraphical position of this species is probably in tbe
Mitchell zone of tbe Horsetown group. A second example of the spscioe was found
in the atme zone on Roaring River west of the Millsap rood. Another example that
seems to be closely related, if not identical to this, was found by N. E. A. Hinds near
the Clements ranch, eastern Trinity County, in beds that seem referable to the upper
part oF the Paakenta group (Valanginian).
This species is named in recognition of the interest and fine spirit of cooperation
shown throughout the progress of this work by Mise Veronica Sexton, Librarian of
the California Academy of Sciences.
PhyUCKeraa there*ae Anderson, n. sp. 1
{Plate 12, SjrurtB 4d 5)
Shell of medium size, inflated, smooth, or only faintly striated; umbilicus small,
but not closed, deeply funnel-form; transverse section of whorl broadly elliptical, or
nearly circular; striae when present rising almost vertically; suture line complex,
having broadly ovate terminations on the finer divisions of the saddles; young shells
showing no transverse stristions. In outward form, disregarding costal lines, this
species resembles P. occidentaic, from which it can be distinguished by its more
inflated section, broader whorls, smoother surface in young stages, and in older age,
its more numerous eaetae, which cross the ventral ione without diminution. The
holotype shows no coatae until it attains a diameter of SO mm. The suture line is not
clearly shown on the holotype but, as seen on other examples from the same bed, it
resembles that of P. rcuyanum d'Orbigny, aa illustrated by Kilian (19Q7-I9IQ, pi. 6).
The holotype (Calif. Acad. Sci. type Coll,) has the following measurements:
greatest diameter, 65 mm.; width of umbilicus, 6.5 mm.; height of whorl, 36 mm,;
width of whorl, 32 mm.; umbilical ratio, .100:1.
The holotype was found at Locality 166$ (Calif, Acad- Sci,) on the west branch of
Hulen Creek, Shasta. County, associated with JDtjftnoMriw merriami (Anderson),
Douvilleicerat mammillatum var., and Diptychoeerat laeve Gabb. Five smaller, wellpreserved
examples were found in the same at Locality 152 (Calif, Acad. Sci-),
associated with Chome-erm leeonlei and species of Smneralia. Stoliczka has figured
a form which he referred to P. rouyanum d'Orbigny, but which was later callcd P.
forbceianum by Kossmnt. The present species resembles this form, but cannot be
identified with it.
An example of this species was obtained from the highest bed of the Horsetown
group exposed on McCarthy Creek, Tehama County, in apparently the same zone.
Phytlocera* shantalente Anderson
(Plata 12. 4pm «)
Phylloceraa shoetalenae ANBEBaos, Calif. Acad. Sci., Pr., 3d ser., vol. 2, 1002, p. 80,
pi. 4, figs, 112-H5; Horsetown, Shasta County.
Shell email, globose, increasing rapidly in diameter, section of whorl broadly
elliptical; umbilicus nearly closed in mature shells, slightly open in immature stages;
surface marked by transversa riba which arc somewhat coarser than on any of the
related species; ribs rarely extending to the umbilical pit, heaviest on the periphery.
Most of the ribs begin near the umbilical border and extend outward with & slight
forward curve. The diameter of the largest example seen is about 30 mm., with
moat of the body-chamber missing. The suture line is that of a true Phyllocerai
of the group ol P. Ihcresae, P. occidental*, sod P. trinilense, «)} found in earlier beds,