106 GEOLOGICAL SURVEY OF THE TERRITORIES. 
the district immediately adjacent (and they are numerous and compar- 
atively small in consequence of the great disturbance which they, to- 
gether with their associated strata, have suffered) there are three local- 
ties which are especially interesting because the strata there exposed not 
only contain anumber of specific and generic forms not hitherto known, at 
least not certainly known, in America as regards the latter, but be- 
cause some of the types in which those forms are expressed are such as 
im Kurope are regarded as characteristic of the Middle Trias. For con- 
venience of reference these localities are designated as Nos. 1, 2, and 3. 
Locality No. 1 is within the limits of Idaho, about sixty-five miles north 
of the boundary line between that Territory and Utah, about eighteen miles 
west of the boundary line between Idaho and Wyoming, and about five 
miles west of John Gray’s lake. The lata for the following section at 
that locality have been furnished by Dr. Peale, who has also treated this 
subject at some length in the Bulletin of this survey, vol. v, pp. 119-123. 
Section at locality No. 1. 
arenaceous shales. Ontcrops obscure. The following fossils were 
obtained from near the top of this member: Terebratula semisim- 
plex White; T. augusta Hall & Whitfield?; Aviculopecten idahoensis + 1,00 feet. 
Meek; Gervillia —— ? and an undetermined conchifer.....-...- 
B.—Limestones; outcrops somewhat obscure. The fossils are Humicrotis 
curia and Aviculopecten idahoensis2. +220 s22cs2 e225 jeeeees eesee- =. 
C.—Greenish and reddish fossiliferous sandstones, followed by arenaceous 
shales and limestones. The fossils are Aviculopecten pealei White, > 850 feet. 
and three or four undetermined species of conchifers.......-...-.- 
D.—Bluish-gray limestones, with fossils near their base. The fossils are) . 
Meekoceras gracilitatis White; M. mushbachanum W.; Arcestes? cirra- 700 feet 
A.—Uppermost member of the local series; alternating limestones se] 
tus W.; Arcestes? ————?; Arcestes? (anotherspecies) and Eumicro- 
tis! curta: Tallies. 253th sels ee eee an ape ede ave ha NS oa 
E.—Reddish and greenish laminated sandstones....-.-.----- Bo Cee en HeeS 400 feet. 
if —— Very dark-bluesandstoneiass so. se aeee eee ee eee cee ee eee eeees -- 200 feet 
Gi— Wihite quartzite: 2 sc.ciie cea ee econ en peer ta ie sors er are etrcte crete elas te : 
H.—Base of local series ; massive grayish-blue limestone. ..---..-----.--- 400 feet. 
The strata of this locality have been much displaced, the dip being to 
the southwestward, and at an angle of about 55°. At the southern por- 
tion of the exposures of the strata of this locality, however, the strike 
curves to the eastward, so that the dip is there to the southward, and 
the angle lessened. 
At locality No. 2, which is about fifteen miles a little east of south from 
locality No. 1, occurs another limited exposure of limestonestrata, which 
are equivalent in part with those of locality No. 1, and which there occupy 
a synclinal axis. From these strata Meekoceras aplanatum and M. gra- 
cilitatis were obtained. The presence there of the latter species seems 
to sufficiently indicate the equivalency of those strata with member D. 
of the foregoing section at locality No.1, because numerous examples of 
_ that species were obtained from that member of the section referred to: 
About the same distance as before (fifteen miles), almost due west 
from locality No. 1, is locality No. 3, the strata there being calcareous 
sandstones. From these strata Dr. Peale obtained Aviculopecten ida- 
hoensis Meek, and A. altus White, examples of the former species being 
somewhat abundant and the latterrare. A. idahoensis also occurs in both 
A and B of the foregoing section, with which members of that section the 
strata of locality No. 3 are doubtless equivalent. Mr. Meek’s types 
of this species, which he referred to the Jurassic period, were obtained 
several years ago by Dr. Peale in Lincoln Valley, near Fort Hall, about 
fifty miles northwestward from locality No.1. So far as I am aware no 
other species were found associated with it there, and it has been found atno 
