100 
THE DUSKY SHEARWATER. 
I preserved the skins of the four specimens procured. One of them I 
sent to the Academy of Natural Sciences of Philadelphia, by Captain John 
R. Butler, of the ship Thalia, then bound from Havana to Minorca. 
Two others were presented to my excellent friend Dr. Traill, on my first 
becoming acquainted with him at Liverpool. 
I found the wings of this species strong and muscular for its size, this 
structure being essentially requisite for birds that traverse such large 
expanses of water, and are liable to be overtaken by heavy squalls. The 
stomach resembles a leather purse, four inches in length, and was much 
distended with fishes of various kinds, partially digested or entire. The 
oesophagus is capable of being greatly expanded. Some of the fishes were 
two and a half inches in length, and one in depth. The flesh of this Petrel 
was fat, but tough, with a strong smell, and unfit for food ; for, on tasting 
it, as is my practice, I found it to resemble that of the porpoises. No dif- 
ference is perceptible in the sexes. 
While on board the United States revenue cutter Marion, and in the 
waters of the Gulf Stream opposite Cape Florida, I saw a flock of these 
birds, which, on our sailing among them, would scarcely swim off from our 
bows, they being apparently gorged with food. As we were running at 
the rate of about ten knots, we procured none of them. I have also seen 
this species off Sandy Hook. 
Puffinus obscurus, Bonap. Syn., p. 3V 1. 
Dusky Petrel, Nutt. Man., vol. ii. p. 337. 
Dusky Petbel, Puffinus obscurus, Aud. Orn. Biog., vol. iii. p. 620. 
Male, 11, 26. 
Abundant during summer in the Gulf of Mexico, and off the coast east- 
ward to Georgia. Some wander as far as Long Island. 
Adult Male. 
Bill about the length of the head, straight, somewhat cylindrical, the tips 
curved. Nostrils tubular, separate, inclosed in a horny sheath, and dorsal, 
the outline straight, curved on the unguis, the sides nearly erect, convex, 
the edges sharp, hard, and inflected, the tip decurved, strong. Lower man- 
dible straight, the angle very narrow and extending nearly to the tip, the 
dorsal line beyond it decurved, the sides convex and inclining inwards, the 
edges sharp and inflected. 
Head of moderate size. Neck of ordinary length ; body ovate. Feet 
stout ; tibia bare a short way above the joint ; tarsus of moderate length, 
rather stout, reticulate ; hind toe a very slight knob, with a small conical 
claw ; fore toes long, slender, connected by reticulated webs with concave 
