LOWER CRETACEOUS DEPOSITS CALIFORNIA AND OREGON
LOWER CRETACEOUS DEPOSITS CALIFORNIA AND OREGON
LOWER CRETACEOUS DEPOSITS CALIFORNIA AND OREGON
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de8crlpti0n of species 169<br />
broader than the rounded interspaces, divided, or in two ranks; primary ribs arising<br />
on the umbilical walla, eloping backward below tbe rounded umbilical border, sometimes<br />
dividing below the middle of tbe side, more often single, alternating with<br />
secondary ribs; all ribs cross the ventral zone without weakening. In its younger<br />
stages the aboil of this apecies resembles Parahopliltt dtshayt-ti, as figured by Neumayr<br />
and Uhlig (1881, pi. 46), which according to Kilian represents P. contobrintis<br />
d'Orbigny. The suture line IB very similar to that of Parahopliioidet thou pi nov.,<br />
the siphonal saddle being unaymmetrically divided by a deep cleft, tbe left side being<br />
the larger and more developed.<br />
The holotype (Calif. Acad. Sci. type Colt.) affords the following measurements:<br />
greatest diameter, 136 mm.; width of umbilicus, 47 mm.; height of whorl, 38 mm.;<br />
thickness of whorl, S3 mm,; umbilical ratio, 0.31B:1.<br />
This specimen was found near Roaring River, 5J miles south of Ono, Shasta<br />
County, in the Argonaut zone near the middle of the Horsetown group. It is not<br />
uncommon in this horizon in the Cottonwood district, from its type locality north to<br />
Hulen Creek and south to the middle fork of the Cottonwood Creek, The species<br />
seems to have an analogue in "Acanthaplites" laticoalaius Siniow (1007, p. 482,<br />
pi. 5, figs. 0-13), from the Caucasus Mountains, from which it differs chiefly in its<br />
more rounded periphery, Battened sides, and slightly more sinuous ribs,<br />
Parahoplilw Anthula<br />
ParahopliUs alantom Anderson, n. sp.<br />
(Fist* S3, flfara i; piste 1ft. Eguro 3)<br />
Among the interesting hoplitid species found in the Horsetown group of the<br />
Cottonwood district are three species akin to Parahoplitet uhligi Anthula. All are<br />
robust forms with a relatively large umbilical ratio. The present species ia represented<br />
by only the holotype (Calif. Acad, Sci. type Coll.), found at Locality 1348<br />
(Calif. Acad. Sol.), near the forks of Alderson Creek, 1 miles south of Ono, Shasta<br />
County.<br />
This example ia almost wholly septate and affords the following measurements:<br />
greatest diameter, 149 mm.; diameter of umbilicus, 51 mm.; height of whorl, 58 mm.;<br />
width of whorl, 46 mm.; umbilical ratio, 0.340:1.<br />
In section tbe whorl is ellipsoidal, somewhat quadrate, the greatest thickness<br />
being below the middle of the side; surface strongly coatatc, with riba of two ranks;<br />
2B stronger primary riba sinuous, arising on the umbilical wall, inclining at first<br />
backward to tbe umbilical border, then rising vertically to the middle of the aide,<br />
there curving gently backward, then forward to the periphery; secondary riba<br />
smaller, arising singly or in pairs near the middle of the side; on the periphery, about<br />
75 ribs to the whorl; all riba cross the ventral zone without interruption; ventral zone<br />
slightly flattened, rounded on the borders; umbilical walls abrupt, rounded above;<br />
sides flattened, or only slightly convex; septal sutures not fully shown, although the<br />
siphonal saddle and lobes show the lack of symmetry common to most of the California<br />
species of Parahoplitidae, The holotype has the general form and surface<br />
characters of Parahoplitta uhligi Anthula, but a somewhat larger umbilical ratio,<br />
more sinuous ribs, and a thicker section. It was found with Tropaeum percotlalum,<br />
Parahoplitoidet, and other Bpecies in the middle part of the Horaetown group.<br />
FaraJtopiifes daHasi Anderson, n. sp.<br />
mU»34, Sturm S. 3)<br />
A more extreme member of the same group was found in the lower part of the<br />
Shoup zone east of Mitchell Creek. It is considerably thicker and stouter, with