NO ae: 
THE following list is based on that published by P. P. Carpenter, in his Report to 
the British Association for the Advancement of Science, 1863, with the addition of 
about 130 species which have been described since then, or were omitted. The land 
and fresh water species, at that time only partially determined and not embodied in the 
general list, are also added. The changes in range of distribution here made are 
founded on more recent and correct information than was at his command, including 
unpublished collections of Dr. Canfield, of Monterey ; Dr. Newcomb, of Oakland ; Rey. 
J. Rowell, Mr. J. Hepburn and R. E. C. Stearns, of San Francisco; Mr. Gabb, Prof. 
Brewer and Mr. Bolander, of the Geological Survey; Mr. W. H. Dall, of the W. U. 
Telegraph Expedition, and others, whose special discoveries and labors have been all 
acknowledged and tabulated in the Report on Mollusca to be published as one of the 
series of the Geological Survey. 
There are twenty or thirty species still undetermined, and now in Mr. Carpenter’s 
hands, which will appear in the final report. 
It need scarcely be added that this list is not intended for a final authority on the 
subject of names, which will probably be considerably changed by the time the volume 
on Mollusea is printed. 
Most of these living species are found fossil also in the tertiary formations along this 
coast, and have a wider range of distribution, many extending inland to the Sierra 
Nevada, but the localities could not be included here. Specimens are found nearly as 
perfect as the living shells. 
The list is intended for use both as a reference or check-list, and for labels. 
Copies may be obtamed at the office of the State Geological Survey, No. 90 Mont- 
gomery Block, San Francisco. 
N. B.—Ponyzoa and Tuntcata are not included. 
San Francisco, April, 1867. 
