WILSON’S PETKEL. 
109 
caught, they squirt an oily substance through the nostrils, and often disgorge' 
the same. The sexes are similar in their external appearance. 
Stormy Petrel, Procellaria pelagica, Wils. Amer. Orn., vol. vii. p. 90. 
Thalassidroma Wilsonxt, Bonap. Syn., p. 367. 
Wilson’s Stormy Petrel, Nutt. Man., vol. ii. p. 322. 
Wilson’s Petrel, Thalassidroma Wilsonii , Aud. Orn. Biog., vol. iii. p. 486 ; vol. 
v. p. 645. 
Male, 151. 
Wanders from the Gulf of Mexico, off the whole Atlantic coast to Baffin’s 
Bay, and often almost across the ocean towards Europe. Breeds in vast 
numbers from Maine to Baffin’s Bay. 
Adult Male. 
Bill shorter than the head, slender, straight, with the tips curved, as broad 
as high at the base, compressed towards the end. Upper mandible with 
the nostrils forming a tube at the base, beyond which, for a short space, the 
dorsal line is straight, then decurved, the ridge narrow and separated from 
the sides by a narrow groove, the edges sharp, inflected, the tip compressed, 
obliquely deflected. Lower mandible with the angle rather long, narrow 
and pointed, the dorsal line beyond it very slightly concave and decurved, 
the sides erect, the edges sharp, the tip slightly decurved. 
Head of moderate size, roundish, anteriorly narrowed. Neck short. 
Body rather slender. Feet long, very slender ; tibia bare at its lower part ; 
tarsus very slender, reticulate, anteriorly with a long plate which is very 
slightly marked. Hind toe conical, so minute as scarcely to be perceptible ; 
anterior toes rather long and extremely slender, obscurely scutellate above, 
connected by striated webs with concave margins ; the third and fourth toes 
longest, and about equal. Claws slender, arched, depressed, acute. 
Plumage very soft, blended, the feathers distinct only on the wings, which 
are very long ; primary quills tapering, but rounded, the third longest, the 
second slightly longer than the fourth, the first much shorter and a little 
longer than the sixth ; secondaries short, the outer incurved, obliquely 
rounded. Tail rather long, even, of twelve broad rounded feathers. 
Bill and feet black, but the webs yellow excepting at the margin. Iris 
dark brown. The general colour of the plumage is dark greyish-brown, the 
quills and tail brownish-black, the outer secondary wing-coverts and some 
of the secondary quills light greyish-brown, and tipped with whitish. The 
rump, sides of the abdomen, and exterior lower tail-coverts, white. 
Length to end of tail inches, to end of wings 8, to end of claws 8 ; 
extent of wings 15f ; wing from flexure 6 ; tail 31 ; bill along the back r \. 
