LOWER CRETACEOUS DEPOSITS CALIFORNIA AND OREGON

description OP ajracixe 195
Sci.) OQ the east branch of Hulen Creek, where it was associated with the preceding,
and with PhyUoetrat thereto*, and the other species of thia locality, including Douvilleieerae
mammillaium, var., 900 feet below the top of the Horsetown group. The
holotype (Calif. Acad. Sci. type Coll.) affords the following measurements: greatest
diameter, 74 mm.; width of umbilicus, 24 mm.; height of whorl, 30 mm.; width of
whorl, 24 mm.; umbilical ratio, 0,324tl,
Thia Spcciea is named in honor of J. A. Taff, whose work and cooperation in the
field explorations ia Shasta and Tehama counties, in the vicinity of Mount Diablo,
Contra Costa County, and in the Diablo Range, have been of much value and importance
in Btratigraphic determinations and measurements.
Sonneralia mulleri Anderson, n. sp.
(Fl»l« SI, figun i; pUta M, t|un J, 0
Shell small, discoidal, compressed, umbilicus moderately broad; sides somewhat
flattened, strongly costate, with "prorsiradinte" costae in two ranks," major costae
arising on the umbilical border in bullae from which they branch into two, or
rarely three, curving strongly forward, especially upon the ventral border; minor
ribs arising near the umbilical border without nodes, branching into two costae; nil
ribs crossing the ventral border without interruption, although weakened, and with a
pronounced emus; section of whorls thinner than in the preceding specics. This
species seems to be somewhat close to Sonneralia ragersi in form and ornamentation,
although it has a wider umbilicus and fewer ribs. The halotypo (Calif. Acad. Sci,
type Coll.) has tbe following dimensions: greatest diameter, 35 mm,} width of umbilicus,
11 mm,; height of whorl, 13 mm.; width of section, 12 mm.; umbilical ratio,
0.314:1. This example was found at Locality 152 (Calif, Aead. Sci.) in the Perrin
zone, where it occurs sparingly with others of the same genus. Another example
of tho same species was f ound by 3, W, Mailer in the same lone farther to the west on
Hulen Creek, Tbe species is named for this enthusiastic worker.
Sonneratia sacramentim (Anderson)
(Fkt* (>, figure* I, 2,1)
Paehpdisem tacramenliem AKDEBSDH, Calif. Acad. 8oi., Pr,, 3d ser., vol. 2, 1902, p.
105, pi, 6, figs, 133, 134; pi. 10, fig. 195; east branch of Hulen Creek, Shasta
County.
Shell moderate in size, discoidal, not strongly compressed, section of whorl inflated
in older Stages, aides rounded; sloping toward tfcs rounded periphery; umbilicus
moderately broad, walla sloping steeply below, rounded above to meet the
gently inflated sides; involution moderate, embracing half of the inner whorl; bodychamber
occupying two-thirds of tho last whorl; sides almost smooth on the umbilical
border, costate on the upper part of the whorl with sharp, slightly ainuoua ribs
inclining forward near the outer border, riba in the older stages moat prominent
above the middle of the side separated by wider interspaces, not noded on the umbilical
border, and tending to diminish in strength in the ventral zone; section of
whorl in the body-chamber subelliptical, showing the inflated form of Sonneralia
kitekim Spath, but possessing a somewhat broader umbilicus. In its younger stages
the shell has mere nearly the form a tad ribbing of Sonnerafta sp. iod. Spath (1925, p.
90, pi. 6), which is leas inflated and more closely costate than S, kilchini. It also
shows nodes Dearths umbilical border, and dividing ribs, similar to those in the young
shell Of the specics here described. The suture line of S. sacramejilica aa shown in
the original description, and here reproduced, may be somewhat emended, in that the
saddles show a less rapid slope toward the dorsum than is shown in the figure.
The holotype (Univ. Calif. Coll.) has the following dimensions: greatest diameter,