210 University of California Publications in Zoology (Vou. 14 
edge with regard to the mollusea of the West Coast of North America.”’ 
Seven years later (1863) a second paper appeared under the title, 
‘Supplementary report on the present state of our knowledge with 
regard to the mollusks of the West Coast of North America.’’ In these 
papers a number of preliminary descriptions of mollusean species were 
given. The detailed descriptions were subsequently published in 
various scientific publications, of which the Proceedings of the Zoo- 
logical Society of London is perhaps the most important. Frequent 
reference to San Francisco is made in these papers in connection with 
the ranges of certain species, but any comprehensive faunal survey 
of this region is lacking. 
The lst of more recent conchological papers dealing with the 
Californian region is a long one. With a few exceptions their con- 
tributions to the conchology of San Francisco Bay and vicinity have 
been made rather incidental to considerations other than that of 
making a faunal survey of this region. The more important of such 
contributors are: Cooper, Stearns, Tryon, Pilsbry, Dall, Keep, Ray- 
mond, Wood, Arnold, Berry, Bartsch, Clark, and Oreutt. Recog- 
nition of the contributions of these, as well as of many others, is noted 
in the systematic portion of this paper. 
Two articles have been published in which lists of the local fauna 
are given. The first of these, by Wood and Raymond, appeared in 
1891 under the title, ‘‘Mollusks of San Francisco County,’’ together 
with a supplementary note (Wood, 1891) entitled, *‘ Additional mol- 
lusks of San Francisco Bay.’’ These papers give the marine and land 
forms collected by the authors within the region designated. The 
second paper (Blankinship and Keeler, 1892), although not devoted 
primarily to conchology, as might be inferred from the title, ‘‘On the 
natural history of the Farallon Islands,’’ is of interest since it con- 
tains a list of a number of marine mollusks compiled by Dr. J. C. 
Cooper. 
ENVIRONMENT OF THE MOLLUSCAN FAUNA 
San Francisco Bay 
Physical—tThe physical and biological environments found within 
the waters of San Francisco Bay will be discussed briefly before the 
fauna is considered, so that certain peculiarities of mollusean distri- 
bution may be more easily interpreted. The data upon which the 
following discussion is based are taken from the comprehensive paper 
