July, 1922 STATUS OF THE CRESTED JAYS 133 
and increase of light, the northwest coast birds gradually revert to frontalis 
proper; and that most of the intermediates from the northern interior of this 
state are intermediate with stellert and not with carbonacea. In northern Ore- 
gon and in Washington they are probably intermediate with annectens. 
A specimen from central Oregon, taken at Bend, on the Deschutes River, by 
Alexander Walker, is recorded in the Condor, xix, 1917, p. 137, as having been 
identified by Dr. H. C. Oberholser as carbonacea. This diagnosis does not fit 
in with this idea just set forth, but I have not seen the specimen in question and 
can not give any opinion upon it other than to suggest that it may be one of 
those indefinite individuals that are sometimes met with and which are very dif- 
fieult to place. 
While there appears to be some shght gradation between the Coast Jay, 
from south of the open stretch each of ‘'omales Bay to Napa Valley, with the 
Blue-fronted Jay, found just north of that region, such intermediates seem to 
be rather rare, less than half a dozen of the specimens examined showing indica- 
tion of it. This open country is only some twenty miles across, but it seems to 
make a very effective barrier against the intermingling of these two races. In 
tact the above examples of supposed intergradation may be only cases of individ- 
ual variation. 
Toward the southern end of the habitat of the Coast Jay in Monterey Coun- 
ty, however, we know that there is extensive intergradation, as proved by many 
specimens examined, with a gradual merging into the Blue-fronted Jay toward 
the interior and farther south. 
Many geologists believe that at one time in the geological history of this 
coast an insular condition existed in that portion of it extending from Mt. Tam- 
alpais, Just north of San Francisco Bay, as far south as Monterey Bay, and that 
this territory was shut off by water from the interior. From Tomales Bay north, 
however, there seems to be no evidence of similar conditions having prevailed in 
any of that part of the coast of California. 
Cyanocitta stelleri carbonacea now occupies the portion of the central Cali- 
fornia coast that was supposed at one time to be either an island, or a group of 
islands not widely separated. If this were the case, why not suppose that the 
genus Cyanocitta originally occupied the interior mountains of the state and 
spread toward the coast from there? Then, when the central coast subsided so 
as to bring about an insular condition, why not assume the hypothesis that this 
subsidence was of sufficiently long duration to evolve the race of carbonacea to 
suit the prevailing conditions; or, in other words, why may not carbonacea have 
been at one time an insular form? 
California Academy of Sciences, San Francisco, April 3, 1922. 
