136 
PACIFIC SCIENCE, Vol. II, July, 1948 
Williamson’s earlier findings, and in so doing 
provided the first comprehensive study of a 
crab. In 1909 Herrick summarized many years 
of research in a classic monograph on the 
American lobster, Homarus americanus, which 
for the past 35 years has stood unparalleled in 
the field. In 1915 the natural history and be¬ 
havior of the fiddler crab were presented by 
Schwartz and Safir, and in 1918 Churchill 
amalgamated all the information on the life 
and natural history of the blue crab, Callinectes 
sapidus Rathbun, into a single authoritative 
report. In 1930 MacGinitie published an account 
of the natural history of the mud shrimp, 
Upogebia pugettensis (Dana), which was fol¬ 
lowed by a similar paper (1934) on Callianassa 
californiensis Dana. These investigations pro¬ 
vided the first consequential studies of any west 
coast decapod crustacean which was unimpor¬ 
tant economically. A series of studies through¬ 
out the past quarter century on the life history, 
growth, and migration of the Pacific edible crab, 
Cancer magister Dana, by Weymouth (1917), 
by the same author in collaboration with Mac- 
Kay (1934, 1935, 1936), and by the latter 
author (1942), has furnished considerable sig¬ 
nificant information. More recently, Broekhuy- 
sen (1936) published an account of the devel¬ 
opment, growth, and distribution of a com¬ 
mon European shore crab, Carcinides maenas 
(Linne). This was followed in 1941 by his 
similar investigation of the South African shore 
crab, Cyclograpsus punctatus M. Edwards. Other 
literature of a more specific nature will be dis¬ 
cussed where pertinent in the text of this report. 
In the voluminous literature dealing with the 
decapod Crustacea, only a few brief notes on 
the habits of the crabs of the genus Pachygrapsus 
can be found, and these furnish extremely few 
data on P. crassipes. 
Acknowledgments: The writer is especially in¬ 
debted to the late Dr. S. F. Light, of the Depart¬ 
ment of Zoology at the University of California, 
whose valuable assistance and helpful criticisms 
were most useful in the pursuance of this study. 
Special credit is also due to Dr. L. E. Noland, 
of the Department of Zoology at the University 
of Wisconsin, for many suggestions. I should 
like to express my gratitude to Dr. E. Yale 
Dawson, who provided identification of the algal 
species mentioned in this paper. The tempera¬ 
ture data of surface water in San Francisco Bay 
used in this study were furnished the writer 
through the courtesy of Captain C. D. Wash¬ 
burn, Jr., of the Branch Hydrographic Office, 
U. S. Navy, San Francisco, to whom I am indeed 
grateful. Without the material aid extended by 
the Department of Zoology at the University 
of California, this study would have been im¬ 
possible, and much credit is due to the Univer¬ 
sity of Hawaii for extending many facilities 
necessary to bring this research to a successful 
conclusion. 
To my wife, Elizabeth, I owe an immeasurable 
amount of gratitude for her constant encourage¬ 
ment and generous assistance both in the field 
and in the laboratory. Dr. D. C. Matthews, of 
the Department of Zoology at the University 
of Hawaii, and Mrs. Matthews gave generously 
of their time to assist in critically reviewing the 
manuscript. 
TAXONOMY 
Synonymy 
Pachygrapsus crassipes Randall. 1839. Acad. 
Nat. Sci., Phila., Jour. 8: 127 (type 
locality, Sandwich Islands; this locality is 
probably erroneous; type in Mus. Phila. 
Acad. Nat. Sci.); de Man. 1890. Notes 
Leyden Mus., 12: 86, pi. 5, fig. 11; Rath- 
bun. 1917. U. S. Natl. Mus., Bui. 97: 241, 
pi. 59. 
Grapsus eydouxi Milne-Edwards. 1853. Ann. 
Sci. Nat., ser. 3, Zool., 20: 170 (type 
locality, Chile; this also is probably an 
erroneous locality record; type in Paris 
Mus.). 
Leptograpsus gonagrus Milne-Edwards. 1853. 
Ann. Sci. Nat., ser. 3, Zool., 20: 173 (type 
locality unknown; type in Paris Mus.). 
