LOWER CRETACEOUS DEPOSITS CALIFORNIA AND OREGON

DESCRIPTION OP 8P£CIE8 201
in older stages; costae of two kinds, major and minor; major costae tritubaroulate,
with one row on each aide of the siphonal line, apinose, with slender elevated apinea;
the two other rows of tubercules low and rounded, lower row transversely elongate;
minor costae finer, non-tuberculato, rounded; there are normally five between each
pair of major costae; section of whorl broadly elliptical, higher than brood; suture
tine not shown.
The holotype (Calif. Acad. 3oi. type Coll.) waa found at Locality 166$ (Calif,
Acad. Sci.) on Duncan Creek, a mile above the County road, in a calcareous concretion
embedded in sandstone overlying a local conglomerate. It belongs to the group
of Criotcrat nolani Kilian, being somewhat closely related to the form figured by
Kilian (1910, pi. 4, figs. 3a, 3b) under this new name.
This specimen was found with the preceding species and with Neoeomite* rueselli
nov., Lytaeeraa ef, irtwfci nov., Pleuromya papyr&cea Gabb, and various ether forms.
A fragmentary but good specimen of SpUieerag, closely related to ducafe
(Matharon), was obtained from a block of limestone lodged in the conglomerate
beneath tbe sandstone.
Crioserai duncanenut is doubtless related to Crioceras latum Gabb but differs
from it in the relative width of coil, the whorls being less widely separated and the
minor costae being more numerous. Both forms occur at thia locality.
HEMiHOrLrriPAB Spath
HopUicrioccra* remandi (Gabb)
(PkLa 63, ftfUTM 1. 3, ], slrts 19, Scum 1, 3)
Crioter aa (? Aneyloceroa) Remondi GABB, Paleont. Calif., vol. 1, 1854, p. 76, pi. 14,
figs. 24, fcia; North fork of Cottonwood Creek, Shasta County, (not Aneyteeeras
sp. mdet. pi. 16, fig. 30).
Aneyloceraa Remondi GABB (in part), Paleont. Calif., vol. 2, ISM, p. 138, pi, 23, fig. 17.
This species appears to have been much misinterpreted not only by later writers,
but by Gabb himself; other species, and even genera, have been included under the
name. The lectotype (probably the holotype) waa token by Gabh to the Academy
of Natural Sciences of Philadelphia where it still remains, It was loaned to the California
Academy for examination and illustration. It beam no distinctive label but
is contained in a tray with other specimens labelled "Ancyloecros Remondi." Some
of these specimens do not belong to this species, The locality of discovery is not
definitely given, but the matrix and associated species in it indicate a locality near
Ono, probably in the Ono zone near the base of the Horsetown group, where they have
all been found.
The species seems to hetong to the group of Crioceras laemuaeulum von Kdaa.cn,
which Spath (1924, p. 73) includes in bis genus Hoploerioceraa.
The holotype is not well illustrated by Gabb's (ISM, pi. 14, fig. 24) drawing, but
the characters of the spcciea are better shown in the photographic illustrations here
given. The costae are fascicled on tho dorsal border, arising from elongated bullae
in ita younger stages, which disappear with the growth of the shell.
According to Gabb, the
"ribs are often diehotomous, and occasionally, though rarely, anastomose near
the dorsum (vantor). In one esse, remains of a few dorsal spines were observed."
This reference to "dorsal apinea" should be understood to refer to tubercules on
the veotro-latcral angles, not true spines.
These tubercules are indicated in bis figure and arc seen on the lectotype. They
disappear when the shell attains a diameter of 60 nun. or leae. In section the whorls
are narrowly olliptieal, the sides rounding abruptly on the dorsal border, but sloping