156 BULLETIN 107, UNITED STATES NATIONAL MUSEUM. 
which, like mine, were hatched and reared in January and February is really 
assumed in early spring. After perfecting this plumage the young can be 
distinguished from their parents only by their shorter and weaker bills, by 
the darker (nearly dead black) coloring of their upper parts, and by the 
presence of numerous fine but rather conspicuous blackish spots or bars on 
the tips of the feathers of the sides of the breast and body. 
The sequence of plumages to maturity and the seasonal molts of 
adults are undoubtedly similar to those of the closely related Xantus’s 
murrelet. It probably does not differ materially in habits from its 
northern relative. Its northward migration after the , breeding. 
season must be more pronounced, however, if we are to refer to 
this species the well-marked specimens taken by Mr. Adriaan van 
Rossem (1915) near Los Coronados Islands. 
DISTRIBUTION. 
Breeding range.—Islands in the Gulf of California. From Cape 
San Lucas, San Francisco Island, San Jose Island, Ildefonso Island, 
north to Isla Raza. 
Winter range—Probably near the breeding grounds, but some, at 
least, “winter” on the Pacific side of Lower California north to 
Natividad and Los Coronados Islands. As this species breeds in 
February, the word “ winter” is hardly an appropriate term to desig- 
nate its range during the nonbreeding season. 
Egg dates.—Lower California, Cape Region: 22 records, February 
6 to April 12; 11 records, February 14 to 24. 
CEPPHUS GRYLLE (Linnaeus). 
BLACK GUILLEMOT. 
HABITS. 
The picturesque coast of Maine is deeply cut by numerous rock- 
bound bays and harbors, protected by rugged promontories, and 
dotted. with many attractive islands, where forests of pointed firs 
and spruces grow almost down to the water’s edge. It well deserves 
its popularity, for I can not imagine a more delightful coast for a 
summer cruise. Not the least of its attractions is this beautiful little 
“sea pigeon,” so common about all the rocky islands and harbors, 
where it skims away in front of us in a wide circle, flying close to 
the water, with its trim, little, black body swiftly propelled by the 
rapid movements of its wings, the white wing patches flashing in the 
sunlight and the bright red feet showing behind. It ig interesting 
to watch it as it rises from the water ahead of the boat, flying for- 
ward at first until well ahead of us, then swinging in a long curve 
to one side, and finally dropping into the water again far astern; 
every bird seems to fly in exactly the same course, almost never flying 
