Height, from a slightly distorted specimen, 1.1 inch; width, 1.3 inch.
Like the preceding species, all of the specimens have suffered considerably by compression; and had we perfect specimens, the shell would be found to be quite convex.
Belemnites.
B. Pacificus G. Long, slender, tapering very gradually and with a slight convexity to the tip. Section, sub-elliptical; alveolus deep and narrow.
A specimen 3 inches long, measures .35 in. in diameter in the middle. One cast has been found with a diameter of .9 inch at the broadest part.
I first discovered this species, as imperfect casts, in the slates near Spanish Flat, El Dorado County. Since then, numerous fragments and casts have been found at Mariposa, by Mr. C. R. King and Miss Errington.
Communication on the San Luis Obispo Quicksilver Fossils.
BY WM. M. GABB.
Mr. Attwood has recently presented to the collection of the State Geological Survey, a series of Fossils collected by himself, in the formation in which the San Luis Obispo cinnabar deposits occur.
Through the kindness of Prof. B. Silliman, Jr. I have had the opportunity of examining another small collection, made by that gentleman, at the same locality. I consider the result of sufficient interest to warrant a special communication on the subject.