156 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4TH SER. 
In the types the dark neutral gray of the crown, occiput, and 
upper cervix forms a cap, contrasting with the deep neutral 
gray of the lower cervix and interscapulars. 
Three downy young from the Carnegie Museum, taken by 
Mr. A. W. Anthony May 26, 1892, vary considerably in size 
and in plumage development. In No. 22239 the secondary 
natal down has appeared on the body and posterior portions of 
the neck, but is only partially developed. In No. 22240 the 
secondary natal down is well developed on these areas, and the 
primary natal down is worn on the lower parts, especially pos- 
teriorly. The chin and throat are nearly naked in each of the 
three specimens. In No. 22241 definitive feathers, concealed 
by the natal down, cover the body and contiguous portions of 
the neck. The white upper tail-coverts have appeared and the 
wings and tail are assuming definite shape. The head and an- 
terior neck are still clothed with natal down. The color of the 
natal down in the three specimens is warm deep mouse gray, 
the distinct brownish cast perhaps due to museum deterioration. 
Oceanodroma castro (Harcourt): Harcourt’s PETREL 
SaLvin—Oceanodroma cryptoleucura, 347, 350. 
GopMaNn—Oceanodroma castro, xxxvi, 15, pl. 5. 
The Expedition, Mr. Gifford states, did not find these petrels 
numerous in the Galapagos Archipelago; never more than 
three or four were seen at one time. They were noted in the 
vicinity of Albemarle, Charles, Chatham, Cowley, Hood, 
James, Seymour, and Wenman islands during the months of 
January, February, May, June, July, August, and December. 
A small breeding colony was discovered on August 13, 1906, 
on Cowley Island, a steep tufaceous islet about two hundred 
feet in altitude, situate east of Cowley Mountain, Albemarle 
Island. Two hard-set eggs, with parent birds, were secured, 
also an egg with a dried embryo. Mr. Beck’s labels furnish 
the following particulars concerning them: One of the eggs 
with living embryo was deposited in a slight hollow in the soil 
of a small cave in a hillside amongst “lava boulders ;” the other 
was placed on a little soil under a large “lava boulder” on a 
hillside. The egg with the dead embryo was found im a slight 
