14 PETROLEUM OF PACIFIC COAST OF ALASKA. [bull. 250. 
lowing lists give the preliminary determinations of fossils from eaeh 
locality. 
2938. West end of Bering Lake, in concretions. Several specimens of a 
crah apparently belonging to the group Catometopa and related to the modern 
genus Pilumnopl,ex of the family Gonioplacidse. The Catometopa range back 
only to the Eocene according to Zittel. It seems probable, therefore, that 
these specimens are not older than Tertiary. 
A fragment labeled " Camp of June 27 to 29, west end of Bering Lake," 
sliows an imprint of a small costate gastropod not well enough preserved for 
identification. 
2939. North end of Bering Lake, Alaska. Fragment of a gastropod that may 
be a Turbo or a related form. Small indeterminate bivalve, possibly a 
venerid. 
2940. Mouth of Bering River, Controller Bay. Fragments of an undeter- 
mined bivalve. 
294G. Chilkat Creek near Controller Bay. Fossil iferous limestone nodule 
with many fragmentary bivalves. Nothing determinable. 
Point Hey, Controller Bay,« Phacoides (?) sp., Callista (?) sp., Conns sp., 
Fusus sp. A (medium). Fusus 2 sp. (small), Turritella sp.. Dentalium sp. 
"Poor material, but the Conns, Fusus, and Dentalium look like Eocene forms." 
Between Point Hey and Strawberry Points Astrodapis (?) sp., Semete (?) 
sp., Dentalium sp. 
The paleontologies evidence concerning the position of the forma- 
tion is therefore rather indefinite, but indicates that the age is cer- 
tainly Tertiary and probably Eocene. There is no stratigraphic 
evidence on this question, for the exact age of neither of the adjacent 
formations has been determined with certainty. While the Katalla 
shales are evidently younger than the semimetamorphosed rocks, 
which may be the equivalent of the Paleozoic or Mesozoic Orca or 
Valdes formation, they are probably older than the Kushtaka coal 
measures, which are doubtful, but probably of Oligocene age. 
KUSHTAKA FORMATION. 
This name is here proposed for a coal-bearing series of strata, 
exposed in the valley of Bering River and its tributaries and on the 
shores of Lake Kushtaka, and consisting of an unknown thickness 
(at least many hundred and probably several thousand feet) of 
shale, arkosic sandstone, and coal seams. No detailed section of the 
formation has been found. Its areal extent, so far as now known, 
has been indicated in a preceding paragraph and is shown on the 
accompanying map (PL III). Its lower boundary may be taken 
at the base of the lowest coal in this region or at the first mappable 
stratigraphic break below that. Its upper limit may be taken at 
the top of the highest coal or at the next succeeding mappable strati- 
graphic break. 
The formation is distinguished from the Katalla formation, which 
a Determined by Dr. W. II. Dall and Dr. Ralph Arnold. 
