OCEANITES. 71 



wing 6.90, tail 3.80 (forked for about 1.20), tarsus 1.00. 

 Hab. Coast of Peru. 



O. markhami (Salv.). Markham's Petrel 1 

 d 1 . "Wing less than 6.00 ; tarsus less than 1.00. 



Smoky plumbeous, the wing-coverts lighter and more brown, 

 quills and tail dusky, rump and upper tail-coverts ashy 

 plumbeous; wing 5.30-5.40, tail 3.30-3.50 (forked for .70- 

 .90), tarsus .80-90. Hab. Coast of California. 



108. O. homochroa (Coues). Ashy Petrel. 



a 2 . Upper tail-coverts white. 



b 1 . Upper tail-coverts without black tips; tail-feathers grayish at base; uni- 

 form sooty, darker above ; upper tail-coverts white, usually more or less 

 mixed with grayish; length 7.50-8.90, wing 6.00-6.30, tail 3.50^.00 

 (forked for .80-.90), tarsus .90-.95 ; feet (including webs) entirely black. 

 Egg 1.33 X -97. Hab. Seas of the northern hemisphere. 



106. O. leucorhoa (Vieill.). leach's Petrel. 



b\ Longer upper tail-coverts broadly tipped with black ; tail-feathers exten- 

 sively pure white at base ; bill and feet (including webs) entirely black ; 

 wing 5.80-6.30, tail 3.00-3.15 forked for .20-.30), tarsus .85-90. Hab. 

 Sandwich Islands. 



O. cryptoleucura Eidqw. Sandwich Island Petrel. 3 



Genus OCEANITES Keyserling & Blasius. (Page 56, pi. XVII., fig. 3.) 



Species. 



Common Characters. — Sooty blackish, lighter beneath, the tail and quills 

 nearly or quite black ; upper tail-coverts white. 



a 1 . Belly entirely dusky ; webs of feet mostly yellowish ; tail even or very slightly 

 emarginated; length about 7.00-7.25, wing 5.70-6.20, tail 3.00-3.25, tarsus 

 1.30-1.35. Hab. Cosmopolitan (on the high seas). 



109. O. oceanicus (Ktjhl). Wilson's Petrel. 

 a 2 . Belly white ; webs of feet apparently wholly dusky ; tail distinctly emarginated ; 

 wing 5.20, tail 2.30 (forked for about .30), tarsus 1.15. Hab. Coast of Chili. 



O. gracilis (Elliot). Graceful Petrel. 3 



Genus CYMODROMA Eidgwat. (Page 56, pi. XV., fig. 3.) 



Species. 



Common Characters. — Head, neck, breast, and upper parts dusky, varying 

 from brownish black to plumbeous, the feathers of back and scapulars sometimes 

 (in fresh plumage) margined terminally with ashy whitish. 



1 Cymochorea markhami Salt., P. Z. S. 1883, 430. 



2 Oymoclwrea cryptoleucura Ridgw., Proo. U. S. Nat. Mus. iv. 1882, 337 ; Water B. N. Am. ii. 1884, 406. 



3 Thalaseidroma gracilis Elliot, Ibis, Oct. 1859, 391. Oceanilcs gracilis Coues, Pr. Ac. Nat. Sci. Phil. 

 1864, 85. 



