LOWER CRETACEOUS DEPOSITS CALIFORNIA AND OREGON

68 LOWER CRETACEQTJ9 DEPOBITfl IN CALIFOBNXA AND OBEGQN
From this zone on Hulen Creek came the holotype of Lytoceras argonautarum
Anderson and probably also that of Lytoceras batesi (Trask), although
differently recorded by Gabb (1869a, p. 127). On Hulen Creek
this zone is underlaid by the pebbly conglomerate at the outlet of tbe
gorge 2 miles above the mouth of the creek, and is thought to represent
the Barr zone, which at its type locality is similarly situated faunally.
The Alderson zone, 100 to 300 feet above the Argonaut zone, is best exposed
on the main branch of Alderson Creek, 2 miles south of Ono, and
also on the Shoup ranch on Bee Creek, a little farther south. Its stratigraphical
thickness, as found near the forks of Alderson Creek, is about
100 feet. It has been recognized at a number of points between Hulen
Creek and the Middle fork of the Cottonwood and bas been found on
Dry Creek and probably also on McCarthy Creek, Tehama County.
Many of the species described by Gabb seem to have come from this zone
on Alderson Creek and from the North fork of the Cottonwood, east of
Ono, The following list of species is somewhat composite, but it probably
correctly represents the zone between Ono and Roaring River:
Phylloceras aldersoni nov. Parahoplittt macfarlandi nov.
Ly{ocara& bafeti (Traak) Shaaioeerat talifornicum nov.
iletchioritet shastensii nov. Hamiticer&s aequicoitatum (Qabb)
DesmoMTW voyi Andersen HemihaculitM eytlvpiwi nov,
CheUmiceraa of. hindsi aov. AcaiUKopliles gardneri nov.
Acanlhoplitei atgit nov. Fossil wood?,
Some species found in this zone occur also in the Argonaut zone, but
most of them are found here for the first time, such as Ska&toceraa californicum,
MelckiorUes shastensii, Hamiticeras aequicostatum (Gabb), and
Desmoceras vayi Anderson. About 200 feet above the Alderson zone was
found the holotype of HanvuliM alderaona nov. which as far as known is
the only example of the species yet found,.
Species occurring in the above list have been found as far south as Mc-
Carthy Creek, including Melchioriies shaeiensis, Cheloniceras cf. hindsi,
Lylcceras batesi (Trask), and probably PhyRoeerae alders&ni.
The Reeside zone, best known on Hulen Creek, is about 750 feet (est.)
above the horizon of Hamidina aktersona, and 1200 feet above the Argonaut
zone, found on both Hulen and Alderson creeks. The Reeside ions
is the highest fossil-bearing zone of the Cottonwood beds and appears to
represent the later part of Aptian time. Thus far only a few species have
been obtained from it, namely;
Chelnniceras reeiidti nov. Acanihopliiett cf. Ipathi nov.
Chtloniccra* irregvlare nov. Much fosail wood
The top of the Cottonwood beds is believed to represent the close of
Aptian time, although this may be subject to doubt. Species of Parahoplites
and of the related genus AcantkoplUes have been obtained from
Alderson Creek, east of its principal branch and therefore above tbe