152 BULLETIN 107, UNITED STATES NATIONAL MUSEUM. 
upper parts are “sooty black,” blacker on the head and more sooty 
on the back; this color extends down on the sides of the head to in- 
clude the lores and a space below the eyes; it also includes the sides 
of the neck and the flanks. There is a small white spot above and 
another below the eye. The under parts are pure white from the 
chin to the belly and grayish white posteriorly. 
I have never seen any specimens showing the change from the 
downy young to the first winter plumage, nor have I been able to detect 
any difference between young birds during their first winter and 
adults, except that young birds have slightly smaller bills and a 
more blackish cast to the dorsal plumage. It has been suggested 
by several writers that the dusky mottling of the under wing coverts, 
which is the principal character of Craveri’s murrelet, is a sign of 
immaturity; I have not examined enough material to decide the 
matter definitely, but am inclined to think that the young of both 
species will be found to have more dusy in the under wing coverts 
than old birds; this need not necessarily affect, however, the validity 
of Brachyramphus craveri as a species. 
The seasonal plumage changes of Xantus’s murrelet are not con- 
spicuous. A complete postnuptial molt occurs in August and prob- 
ably there is an incomplete prenuptial molt late in the winter. Mr. 
Adriaan van Rossem (1915) has made some study of the plumages of 
this and the next species, which has thrown some light on the subject. 
He has illustrated his paper with a good photograph showing the 
seasonal changes in adults of the present species. 
Food.—Mr. Howell contributes the following notes on the food and 
habits of this murrelet: 
It has been stated that the species vomits a thin yellow oil when handled, 
after the manner of the petrels, but from a hundred or more birds which I have 
had in the hand not one has shown any inclination to do this, nor has their 
stomach contained any oily substance, but only a clotted greenish slime and very 
little of that. This was no doubt some kind of sea vegetation mixed with saliva. 
They must dive for their food, and I believe that a very small proportion of 
their fare, if any, consists of fish, for their throats are not capable of enough 
expansion to indicate that they are fish eaters. Probably they are partial to all 
forms of small crustacea and minute forms of sea life which are so plentiful 
among the weeds and rocks. 
Behavior.—In flight the wing beats are very rapid, almost a buzz, and they 
are capable of great speed. When attacked by a duck hawk while flying they 
will suffer themselves to be caught rather than take to the water. Shortly 
after dark large numbers of the birds make their way into the coves and shallow 
water near the islands. From then until dawn they can be heard giving their 
eharacteristic cry, which can best be described as a shrill slow twitter, about 
four notes to the second. At night, especially when hunting a nesting site, 
they are sometimes attracted by a light on shore. Doubtless they make several 
trips to the burrows throughout the night. During the day they keep well out 
to sea and are usually to be found in pairs or family parties. When pressed 
too closely they rise to the wind and fly into the distance, but refuse to dive 
unless wounded. 
