LOWER CRETACEOUS DEPOSITS CALIFORNIA AND OREGON
LOWER CRETACEOUS DEPOSITS CALIFORNIA AND OREGON
LOWER CRETACEOUS DEPOSITS CALIFORNIA AND OREGON
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
description of bpbcte3 149<br />
;at diameter, 171 mm,; width of umbilicus, 57 mm.; height of whorl, 70 mm.; width<br />
jf whorl, 84 mm.; umbilical ratio, 0.333:1. It constats of tbe inner whorls of a shell<br />
whose diameter had been more than 24 inches (60.96 centimeters). The removal of<br />
one whorl from this example would reduce its diameter to one-fifth of its present<br />
measure. If the increment of growth were by heights of whorl in adjacent coils<br />
these ratios for the holotype would be: 1:3; for a second example from Locality 1347<br />
(Calif. Acad. Sci.), 1:3.3; and for the small figured specimen, 1:2.5. These several<br />
ratios seem to reflect the size (and ages) of the examples measured. Other characteristics<br />
of the group will appear in the description of the holo-genotype.<br />
Lyloceroe (Argonattiieerat) argonautarum (Anderson)<br />
(Plata 17. fi*unj 3; pUta 10. S«QXBH 1,2)<br />
Lylaccraa ARPONATDARUM <strong>AND</strong>EHSON, Calif. Acad. Sci., Pr , 3d aer„ vol. 2,1902, p. 85,<br />
' " "gB~ 154, 155; middle Horsetown group, Cottonwood district, Shasta<br />
Shell large, coiling lytoceratid, much inflated, increasing rapidly in diameter;<br />
aectiou of whorl subcircular, broader than high, flattened on the sides and on the<br />
ventral zone; involution slight, having on the dorsum only an impressed zone; surface<br />
of shell ornamented by evenly spaced costae with acute "crinkley" edges, hardly<br />
crcnulated; suture line partly shown in the figure; first lateral lobe not quite symmetrically<br />
bipartite; small siphonal saddle lanceolate in general outline.<br />
An example of thia species, found at Locality 1347 (Calif. Acad. Soi.) near Mitchell<br />
Creek, has the following dimensions', greatest diameter, 250 mm.; width of umbilicus,<br />
87 mm.; height of whorl, 113 mm.; width of whorl, 125 mm.; umbilical ratio, 0.348:1.<br />
This species characterizes the Argonaut zone (middle Aptian) of the Horsetown<br />
group, where it is associated with Gabbioccras angulatum, Pkyllocera* onoenee Stanton,<br />
and Parahopliioidce thoupi nov. The species (and zone) has been found on<br />
Hulen Creek, Roaring River, and Middle fork of Cottonwood Creek. Good examples<br />
of the species were collected by R. M. Kleinpell and E. Wayne Galliber north of<br />
Skidcgatc Indian village, near Village Bay, Graham Island, associated with Detmoeerat<br />
voyi Anderson, Aucella indigenalie nov., and terebraluloidcs Lahusen.<br />
Gabb (1856a, p. 132) seems to have included this specieB in his description oi Lylocera*<br />
bate*i (Traak), regarding it as a variety "in which the whorla increase much more<br />
rapidly in Bias." The species has been found in beds much below the Argonaut<br />
zone in this district.<br />
Qabbioeereu Hyatt, 1366<br />
Genotype, ^MNWMFTEI Batesi GABB (In part), Paleont, Calif,, vol, 2,18&0, p. 132, pi.<br />
20, figa. 0, 9a; pi. 21, &RB. 10, lua, 10b; (not Amm. Traak; not Amm.<br />
bafe*T (Trask) GABB, Paleont. Calif., vol. 1,1864, pi. 13, figs. 10a, L&b).<br />
Gabb gave a good description and figures of a lytoceratid specics in the second<br />
volume of his work on California fossils, but erroneously referred it to A mm. batesi<br />
Trask. This spcciea waa later made the genotype of Cabbiocerae by Hyatt, and in<br />
1002 it was described as Lytoceto* (Gabbiacerat) angulatum, nov. by Anderson. The<br />
holotype of the species is in the Museum of the Academy of Natural Sciences of<br />
Philadelphia.<br />
Charles Jacob (1907, p. 17) proposed the generic name "Jauhertolfo," taking as the<br />
genotype .4mm. Jauberlianua d'Orbigny, said to have come from the Aptian marls of<br />
Barremme. Hyatt's name first appeared in Eastman's translation of Zittel's Textbook<br />
of Paleontology (1000, p. 570). If the two species taken as genotypes by Hyatt<br />
and Charles Jacob respectively prove to be closely related forma, as they appear to