LOWER CRETACEOUS DEPOSITS CALIFORNIA AND OREGON

166 lower crstacequ9 defobit3 in california and obegon
on tbe sides, crossing tbe periphery without interruption; secondary ribs interpolated
between the others, not extending into the umbilicus; total number of ribs
(est,}, about 50 to the whorl; suture lines unknown.
The holotype of this species (Calif. Acad. Sci. type Coll.), as found by R. Dana
Russell at Locality 1635 on Duncan Creek, associated with Crioceras iaiim Gabb,
Lyiocerae cf. traski, and Sptticeraa duticaitcnee nov., has tbe following dimensions:
greatest diameter, 73 ram,; width of umbilicus, 13 mm.; height of whorl, mm.;
thickness of whorl, 20 mm.
This species, although thicker in section and possessing fewer ribs, seems to
helong to the group represented by Neocomites stippi nov. It represents the lowest
fossil-bearing bed exposed in the Shaata series of the Cottonwood district, although
not the loweHt bed exposed in this area, This ia one of the two examples of Neoeomiiei
that have been found in this district.
Nctmomitet tiippi Anderson, n. sp.
(PtAtO 2S, dfUTI S)
Two fragmentary examples of a hoplitid species were found in the upper part
of the "Aucella crassicaUi* zone" on McCarthy Creek, associated with Aueeifa era aa,
Aucella crassiccllia, Aaroteuthis onwnrts, Lytaceras taiurnale nov., and other spcciea.
Although incomplete, theae examples are sufficiently well preserved for generic
determination and for partial description. Thay belong to the group represented by
HopUlei (Neocomilet) angulicoatatue (d'Orbigny), although they have some char^
aetera of "Berriaeella" benecki (Stcuer) from tha Valanginian of western Argentine..
Tho section of the whorl is flatly elliptical and slightly inflated; sides eostats,
the riba arising on the umbilical wall, forming on its borders elongated nodes from
which some of them branch; others branch from above the middle of tha side, all
curving gently forward and crossing the ventral ZGILG with a slight forward curve;
umbilicus moderately wide, with abrupt walls; sutures closely crowded, showing
a tout, much-divided lobes and saddles; lateral lobe somewhat extended, trifid, each
branch terminating in long, slender digitoid points.
The holotypa (Calif. Acad. Sci. type Coll.) was found by Mr. Thomas Stipp on
the south bank of McCarthy Creek, about 1,000 feet beneath the zone containing
Ncocomiics jenJcinei. The horizon is that Of the lower part of the Paskenta group
(Infra-Valanginian) of the McCarthy Creek section.
The nodes on the umbilical borders, more prominent on the shell than on the cast,
somewhat resemble Kilian's (1010, pi. 1) figure of Thurmwnia boissieri (Pictet).
Neocomites neocomiensii (d'Orbigny)
(Plata S, Spue* S, 2s)
Ammmitea neacamiensit D'ORDIGHT, Paleont. Francaise, vol, 1, 1340, p. 203, pi. 58,
figs, 8-10; lower beds of the Neocomian terrain, central France.
Only a single specimen sufficiently well preserved for illustration has been found
in the Lower Cretaceous of California; this was obtained by N. L. Taliaferro in
the Waltham Creek Valley, on tbe southwest quarter of section 17, T. 20 S,, ft. 13 E,
M. D. M., north of the Coalings-Priest Valley road. In thia example the shell is
Compressed, diaeoidal, ornamented by transverse costae, 71 in number, a little flexuous,
bifurcating from small nodes on the umbilical border, and again dividing near
the middle of the side into two, three, or mors costae as counted nejtr periphery;
sides slightly inflated, thickest in the lower one-third of the aide, sloping toward the
periphery; costae interrupted on the ventral zone, which is slightly excavated, and
bordered by minute costal nodes; maximum width of ventral sone, 2 mm,; maximum