54 THE CANADIAN ENTOMOLOGIST. 
THE BEES OF THE CORONADO ISLANDS, 
BY T. D. A. COCKERELL, BOULDER, COLORADO. 
Out in the Pacific, on the edge of the continental shelf, south- 
west of San Diego, California, are the Coronado Islands. They 
consist of four rocky elevations, submerged mountain-tops ap- 
parently; the largest. South Island, about two miles long. They 
be'long to Lower California, and hence are part of Mexico. Formerly 
they were difficult of access, but now a small vessel makes daily 
trips from San Diego, and tourists visit the islands in numbers. 
On August 21, 1915, my wife and I spent two hours on South 
Island, collecting the hitherto unrecorded insect-fauna, and especi- 
ally the bees.* 
Such isolated spots are extremely interesting to the evolution- 
ist. Their fauna and flora may throw light on the rate of modifica- 
tion of species, or they may preserve formerly widespread, but now 
nearly extinct, types. The vertebrates of the Coronados have 
already been rather carefully studied. They possess a mouse, 
Peromyscus maniciilatus dnhius Allen, which occurs elsewhere only 
on Todos Santos Islands, Lower Ceilifornia. It is a relatively 
large, dark form. The birds, 22 species, have been fully discussed 
in a very interesting paper by J. Grinnell and F. S. Daggett in 
The Auk, XX, 1903, pp. 27-37. One of them, Melospiza corona- 
torum, is peculiar to the islands, differing from its mainland relative 
by its much paler ground colour, narrower streaking and smaller 
bill. Another, Carpodacns dementis, agrees with a San Clemente I. 
form, and differs from that of the mainland by the bulky bill and 
heavy brown streaking. Thus it appears that the modification, 
when there is any, may be in quite opposite directions. Nine species 
of reptiles are recorded by Van Denburgh and Slevin, the most 
interesting being Gerrhonotiis scincicauda ignavus, which belongs 
otherwise to the islands northward, Catalina and San Martin. 
The plants have been little studied, but a fine Malvaceous species, 
*Dr. E. P. Van Duzee, in his account of tlie Hemiptera of San Diego and vicin- 
ity, appears to record species from North Island Coronado but as his preface 
shows, they came from the north end of Coronado Beach, San Diego, locally 
called North Island. There is a possible source of confusion here, to be guarded 
against. 
February, 19 Uj 
