Vor. II, Pr. IT] LOOMIS—A REVIEW OF THE TUBINARES 133 
their fly-line. But two specimens were preserved, and these 
were shot on November 19, 1906, in latitude 35° 40’ N., longi- 
tude 133° 14 W. 
The Academy’s two hundred and twenty-three specimens, 
from the ocean off California, exhibit considerable color varia- 
tion, particularly on the under surfaces of the body and wings. 
In extreme light examples, the chin and throat are grayish 
white ; the basal and subterminal portions of the feathers of the 
jugulum and breast are also grayish white, giving to the lower 
parts a mottled appearance; the shorter axillaries are varied 
with grayish white; the under coverts of the wings are white 
with only slight indications of gray. In extreme dark ex- 
amples, the chin and throat are deep gray, the basal portions 
of the feathers of the jugulum and breast are lighter gray, and 
the general aspect of the under coverts of the wings is gray 
instead of white. 
Whether age, geographic variation, or dichromatism is the 
bottom fact in this dual coloration, can not be affirmed abso- 
lutely from the material at hand—skins of sea-killed birds. 
Nevertheless, the preponderance of evidence is in favor of 
dichromatism, for the growing feathers manifest no age transi- 
tion, being like the worn ones they are succeeding, and on 
breeding grounds parallel examples of bicoloration occur in 
other petrels independent of geographic variation. 
The superficial color of the lower parts varies in different 
specimens from mouse gray to deep mouse gray, more or less 
intensified on the jugulum. New primaries, secondaries, and 
wing-coverts are often frosted with gray and the dorsal 
feathers and tertials are sometimes quite distinctly edged with 
it. With the decline of the plumage, the coloration changes, 
wearing browner on the upper and lower parts. In a few 
specimens the supraloral region is varied with grayish white, 
and in some instances gray filoplumes adorn the occiput, auric- 
ulars, cervix, and sides of neck, and even the back anteriorly. 
No. 9577 C. A. S. has a supernumerary rectrix, the total num- 
ber of rectrices being thirteen instead of twelve. 
Albinism is not uncommon in this species. The Academy’s 
collection contains half a dozen striking examples of it. In 
one specimen (No. 9705, female, June 17, 1907), the plumage 
of the head, neck, and anterior portions of the back and breast 
