94 Brewster on a Petrel new to North America. 
with the excellent description of mollis given by Dr. Cones, is 
quite sufficient. The peculiar marking of the primaries in gu- 
laris , now confirmed by this second specimen, would alone be 
conclusive, but in addition, I find certain structural differences 
which were apparently overlooked by Dr. Coues. The tail of 
gularis is shorter and much less decidedly rounded than is that 
of mollis. This difference is best shown by the graduation of 
the rectrices. For mollis Dr. Coues gives the graduation as i.30 
(the specimen before me measures 1 .05, but the bird is in a moulting 
state and the tail not fully developed) , while in the two specimens 
of gularis , it is respectively only .60 and .90. Furthermore, 
gularis has the central pair of rectrices broader and more evenly 
rounded at the tips than are those of mollis. 
These characters, although of undoubted specific value, will 
by no means warrant generic separation, the general shape and 
proportions of the two birds being strikingly similar, and the 
bill and feet — in this family the most important of all the generic 
characters — absolutely identical. Accordingly, while I follow 
Dr. Coues in referring Peale’s bird to the genus AEstrelata , I do 
not hesitate to reinstate it as a perfectly valid species. 
In view of the fact that both the previous descriptions are found- 
ed on a young bird, and that one of them (Peale’s) is too superficial 
to be available in nice determinations, while the other, by Dr. 
Coues, is only incidental in character, I take the present oppor- 
tunity to redescribe the species as follows : — 
^Istrelata gularis, ( Peale ), Brewster. Peale’s Petrel. 
Ch. sp. similis rtE mollis sed tectricibus caudae inferioribus candidis ; 
alis subtus fere ex toto candidis; duabus tertiis partibus pogonii interni 
abrupte albis ; cauda breviori ac minus conspicue curvata ; rectricibus me- 
diis latioribus. 
Adult (?) plumage. No. 5224, author’s collection, Mt. Morris, Livings- 
ton Co., New York, April, 1880. Upper parts, including the tail coverts 
and exposed surface of rectrices, pure cinereous, which deepens to plumb- 
eous only on the occiput, rump and wings, the latter having the middle 
and greater coverts of the same tint as the back. The feathers of the 
back (but not those of the rump or occiput), with the greater and middle 
wing-coverts, broadly tipped with ashy-white, giving these parts a scaled 
appearance. The throat, jugulum, upper part of breast, and under tail- 
coverts, pure, silky white. The cinereous of the upper parts comes down 
along the sides of the neck, encroaching more and more and deepening in 
tint as it extends backward, until it throws across the abdomen a broad band 
