Ammonites in the Auriferous Slates of California.
BY WILLIAM P. BLAKE.
Ammonites occur in the gold-bearing slates of Bear Valley, Mariposa County, in addition to belemnites and other fossils already noted. The specimen I have seen is a cast, somewhat distorted by pressure, but apparently similar to the species from the slates on the American River, which I brought to the notice of the academy last year.