ACADEMY OF NATURAL SCIENCES. 289 



of North America, by J. L. Leconte, M.D. Part 1, 8vo., Wash- 

 ington, 1863. Researches upon the Hydrobiinse and allied forms, 

 by Dr. W. Stimpson, 8vo., Washington, 1865. Monograph of 

 American CorbiculadtB, recent and fossil, by Temple Prime, 8vo., 

 Washington. Catalogue of Minerals, with their formulas, etc., by 

 T. Egleston, 8vo., Washington, 1863. Land and Fresh-water 

 Shells of North America, by W. G. Binney, Parts 2 and 3, 8vo., 

 Washington, 1865. Check list of the Invertebrate Fossils of North 

 America; Eocene and Oligocene, by T. A. Conrad ; Cretaceous 

 and Jurassic, by F. B. Meek, two 8vo. pamphlets, Washington, 

 1864-6. 



All of the above were published and presented by the Smith- 

 sonian Institution. 



Prof. W. P. Blake presented the following communication : 

 Miscellaneous Notices. 



BY WILLIAM P. BLAKE, 



Professor of Mineralogy, Geology, and Mining, Dept. Sci. Coll. of California. 



1. New Locality of Fossils in the Gold-bearing Rocks of California. 



I have obtained specimens of Ammonites from the cut in the rocks on the 

 line of the Central Pacific Railroad, about two miles below Colfax, and in the 

 heart of the main gold belt of the State. 



The rock is a compact aroillite. somewhat altered and much discolored by 

 the peroxydation of iron. The strata are boldly flexed and are interstratified 

 with coarse grits and a thick bed of conglomerate, so much altered that the 

 pebbles are homogeneously cemented. 



The substance of the fossils has been removed by percolating waters, but very 

 perfect casts of them remain and show the details of the external form, but do 

 not permit the septa? to be seen. It is thus not possible, perhaps, to determine 

 the specific characters ; and considering, also, the absence of a typical collection 

 and works of reference, I do not attempt a minute description, preferring to 

 refer the specimens to a palaeontologist. It may, however, be observed that 

 the fossils are undoubtedly of the secondary period', and that they are apparently 

 specifically ideutical with those from the American river, in the same vicinity, 

 of which I sent photographs to Mr. Meek, at the Smithsonian Institution, in 

 1863, and afterwards noticed at one of the meetings of this Academy, in Sep- 

 tember, 1864. They are, also, apparently identical with the species found in 

 the Bear Valley, Mariposa, slates. If this species has not been already named,. 

 I desire to connect with it the name of Mr. Spear, in whose cabinet at George- 

 town, the earliest specimen was carefully preserved. I obtained one specimen at 



PKOC. ACAD. NAT. SCI. VOL. III. ■"" Jan. 1867. 



