LOWER CRETACEOUS DEPOSITS CALIFORNIA AND OREGON
LOWER CRETACEOUS DEPOSITS CALIFORNIA AND OREGON
LOWER CRETACEOUS DEPOSITS CALIFORNIA AND OREGON
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description of species<br />
triangular, the umbilical riba are thicker and stouter, and they divide at a higher<br />
level than in the English form.<br />
The holotype was found associated with other forms of the genus, as given under<br />
Palyptych.itea ieeonfei, no?.<br />
Palyptychile* iratki (Gabb)<br />
Ammonite* iratki GABB, Paleont. Calif., vol. 1,1864, p. S3, pi. 11, fig. 10; pi. 12, fig. 11<br />
(septum); "Arbuckle Diggings," Shasta County.<br />
OtawlspAanus irasfci STANTON, S. Geol. Surv., Bull, 133,1895, p. 18, 22; near Wilcox<br />
ranch, Tehama County, and (?) Riddle, Oregon,<br />
From the description and figure of this species given by Gabb, although they<br />
are defective, it is evident that this form represents some species of Palyplychiies,<br />
a genus not uncommon in the Paskenta group of the Shasta aeries. Various congeners<br />
of tbe species have been found in the upper part of this group, not only in the<br />
Cottonwood district, but in tho Elder Creek-McCarthy Creek district, The holotype<br />
figured by Gabb was the property of the California Academy of Sciences and was<br />
in tho care of the writer prior to 190B, but waa Inst in the San Francisco fire of that<br />
year. In section the younger whorls were nearly circular, becoming higher than<br />
broad in older stages. According to Gabb's description the surface was marked by<br />
numerous dichotomouB ribs, but this is scarcely borne out by his figure, which shows<br />
the stout umbilical ribs branching into four or more costae below the middle of the<br />
sides. In this respect it is unlike any other of tho group found in the Cottonwood<br />
district.<br />
Tbe locality of discovery given by Gabb is subject to much doubt, as elsewhere<br />
shown. It ia believed to have been found in the Hamlin-Broad zone, which passes<br />
about 2 miles to the east of the old Arbuckle mine in western Shasta County. Its<br />
horizon would be, accordingly, in the upper part of the Paskenta group (upper Valanginian),<br />
as will be shown later. The occurrence of this species near the Wilcox<br />
ranch in Tehama County (Stanton, 1895, p, 18) appears to mark the same horizon<br />
as that of the Hamlin-Broad zone in the Cottonwood district.<br />
The species is also recorded from Riddle, Oregon, by Stanton (1805, p. 22), and<br />
in both these areas it aids in tho correlation of the beds with those of tho Cottonwood<br />
district and the Paskenta group of the Shasta series.<br />
In the Oregon area near Riddle, as will bs shown, more than a single faunal<br />
zone appears to be represented. Stanton has given a list of 15 genera and with them<br />
has named at least eight species. Half of the forms given in the list may weil be of<br />
Chico age, others undoubtedly represent the Horsetown group, and some are from<br />
the Paskenta group, including the present species and A ucella cratmcollit.<br />
Simbirtkitet breadi Anderson, n. sp.<br />
(FlaW S3, firms 2, J; pis l« 28, Spire* 1,1*)<br />
Shell not large, inflated, broadly umbilicate, section of whorl reniform, broader<br />
than high, in younger stages depressed; umbilical walls abrupt, sloping above; umbilical<br />
ribs stout, arising on the wall of the umbilicus with a slight backward slant,<br />
then rising to near tbe middle of the side where it forms a tuberculate node from<br />
which it divides normally jtto three (rarely two) peripheral ribs which cross the<br />
ventral area without interruption; ribs rounded, inclined forward on tho upper part<br />
of tho shell, separated by rounded interspaces, which are broader between the rib<br />
clusters than between the ribs themselves. This species appears to have its nearest<br />
analogue in Simbirtkites dechcni Pavlow (not Roemer), from the Neocomiaa of England,<br />
which Spath appears to regard as synonymous with "OUotlephtiriui"kleini<br />
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