PROCELLARINiE. THALASSIDROMA= 
389 
Puffinus angloi’um, Bonap. Syn. p. 371. 
Shearwater Petrel, Ndtt. Man. v. ii. p. 336. 
Manks Shearwater, Pnffinus anglorum, Ann. Orn. Biog. v. iii. p. 604. 
466. 3. Puffinus obscurus, Lath. Dusky Shearwater. 
Plate CCXCIX. Male. 
Bill light blue, the tips black ; outside of tarsus and toes indigo- 
black, inside and webs pale yellowish flesh-colour ; upper parts sooty- 
black, lower pure white. 
Male, 11, 26. 
Abundant during summer in the Gulf of Mexico, and off the coast 
eastward to Georgia. Some wander as far as Long Island. 
Puffinus obscurus, Bonap. Syn. p. 371. 
Dusky Petrel, Nutt. Man. v. ii. p. 337. 
Dusky Petrel, Puffinus obscurus, Aud. Orn. Biog. v. iii. p. 620. 
GENUS V. THALASSIDROMA, Vigors. PETREL. 
Bill shorter than the head, slender, as high as broad at 
the base, extremely compressed at the end ; upper mandi- 
ble with the nostrils dorsal forming a tube on its ridge at 
the base, on which the dorsal line is concave and ascend- 
ing, then abrupt, afterwards, for a short space, straight, 
and lastly decurved, the sides separated by a groove, con- 
vex, the edges sharp and inflected, the tip decurved, slen- 
der, acute ; lower mandible with the angle rather long, 
narrow, and pointed, the dorsal line beyond it decurved, 
the sides erect, the edges sharp, the tip decurved, acute. 
Head of moderate size, rounded above ; neck short ; body 
rather slender. Feet rather long, slender ; tibia bare at 
its lower part ; tarsus slender, reticulate ; hind toe minute, 
with a conical deflected claw ; anterior toes of moderate 
length, slender, scutellate, webbed, the third and fourth 
about equal. Claws slender, arched, compressed, acute. 
Plumage very soft and blended, the feathers distinct only 
on the wings, which are very long, with the primaries a 
little incurved toward the end, the second longest, the first 
