LOWER CRETACEOUS DEPOSITS CALIFORNIA AND OREGON
LOWER CRETACEOUS DEPOSITS CALIFORNIA AND OREGON
LOWER CRETACEOUS DEPOSITS CALIFORNIA AND OREGON
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description 1 of species 143<br />
Phylloecrat aldcraoni Anderson, n, sp.<br />
(Pill® 11, &CWI9 3. t. S. S)<br />
Shell email, discoidal, slightly inflated, rounded on the sides which slope rapidly<br />
to the periphery; umbilicus small, with steep walls curving roundly to tho sides;<br />
surface mostly smooth, or polished, but marked by six or more slightly sinuous<br />
periodic constrictions, between which are numerous fine costal lines (10 or more<br />
to a centimeter) arising on the umbilical walls, curving at first forward, then gently<br />
backward, and again forward on approaching the ventral border; intercostal spaces<br />
relatively wide and smooth; cross-section of whorl somewhat elliptical, being broadest<br />
near the middle of the side, and rounding ofT above and below.<br />
The suture line ia not unlike that of P. onoenne Stanton, although the septa are<br />
more numerous and more crowded, and also more complicated; the small siphonal<br />
saddle is narrower and more pointed. The essential differences between this species<br />
and the latter are in its smaller size, more inflated Bides, its periodic constrictions,<br />
and the form and character of its costal markings. The largest specimen of this<br />
species so far found has a diameter of mm., including the body-chamber. About<br />
14 examples of the species were obtained, most of them from Locality 1348 (Calif.<br />
Acad. Sci.) on Alderson Creek, 2 miles south of One, Shasta County, The holotype<br />
(Calif. Acad. Sci. type Coll.), septate throughout, has the following dimensions:<br />
greatest diameter, 40 mm.; width of umbilicus, 5 mm.; height of whorl, 21 mm.;<br />
thickness of whorl, 17 mm.; umbilical ratio, 0.125:1. All the examples came from the<br />
Alderson aone and were associated with Jfclefcimfti thaslmtit nov., Lyioteta* baltti<br />
(Trask), Kamilicera* aequicoitatum nov., and a species of Aucella resembling A.<br />
keyserlingi Lahusen.<br />
Phylloc&raa californieum Anderson, n. sp.<br />
(Tints 19, figurc 7)<br />
Thia epecies is intermediate between Phylloceraa onotmw Stanton and the California<br />
form of P. velledae Michelin in both form of ahcll and in its stratigraphic<br />
position. It differs from both also in the character of its suture lines. The species<br />
occurs in tho upper part of the Hulen hede (middle Albian) on Huleo Creek, and has<br />
also been found at the upper limit of the Horsetown group at the old mining camp of<br />
Horsetown on Clear Creek, Shaata County, where it is associated with Putoria<br />
hoffmanni (Gabb) and Bcudanliceras breweri (Gabb),<br />
The epecice differs from P. onoeme in its thicker and more robust form, in its<br />
stronger and straighter coatae, which have little forward curvature upon their<br />
approach to the ventral zone, and in Butural details.' In its outward form it resembles<br />
the figures of P. velledae given by Stoliczka (1858, PI. 19, figs. 1-4), although it is<br />
larger, whereas in the general and detailed character of its sutures it more nearly<br />
approaches P. onoente Stanton. Phylloceraa velledae, or a closely related form, has<br />
been found in the lower beds of th e Chico series half a mile cast of the mouth of Hulen<br />
Creek, and about 1100 feet above the position of P. ealifornicum of the Horsetown<br />
group.<br />
The holotype (Calif. Acad. Sci. type Coll.) is a large fragment, representing an<br />
individual 8 inches (203 mm.) in diameter, obtained from the upper part of the Hulen<br />
beds, 50 feet beneath the Neptune zone at Locality 1580 (Calif. Acad. Sci.).<br />
Phylioceras umpquanum Anderson, n. sp.<br />
(I>Uu 30, figures », 10)<br />
Shell small, robust, with small but deep umbilicus and inflated cross-section;<br />
surface thickly coatate, with almost uniform, rounded costae, separated by some-