Whitney’s Geology of California. 363 
The next year, 1863, the party made a most interesting discov- 
ery of fossils on the north slope of Genesee Valley, in Plumas 
county. The Carboniferous, before spoken-of, with the Triassic 
and Jurassic were all in place. The Triassic were found at 
Gifford’s Ranch in calcareous slates, and some of the species are 
y Mr. Meek and figured in the same volume on plates 7 and 8.. 
1 
task for some time previous. These were found in the rich 
mining region of that vicinity, but neither was in place. The 
same autumn Mr. Gabb succeeded in finding, in this same region . 
and tn place, imperfect remains of Cephalopods which catnot be 
founsuished from the Belemnites found later on the Mariposa 
state, 
Warded by the discovery of many new localities of fossils 
extending from Mariposa to the Stanislaus river, some of the 
Species being identical with those of Mariposa and others new. 
hese discoveries were noticed in the last number of this 
Journal, but no detailed description has yet been published. 
The occurrence of these fossils for a distance of more than 
250 miles along the western flank of the Sierras, and in so 
many localities, leave no doubt in regard to the true age of the 
auriferous slates of California. ‘We omit here many minor de- 
tails, and those other geological features that lead to the same 
conclusion. We can, however, more strongly affirm the state- 
