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.t 
ad’. Wing less than 6.00; targus 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. 
(6.) 108. O. homochroa (Covzs). Ashy Petrel. 
a’. Upper tail-coverts at least partly white. 
. 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 3.50-4.00 
(forked for .80-.90), tarsus .90-.95; feet (including webs) entirely black. 
Ligg 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. 
(7) O. cryptoleucura Ripaw. Sandwich Island Petrel.? 
Genus OCEANITES Keyser.ine & Buasius. (Page 56, pl. XVIL, fig. 3.) 
Species. 
Common CHaracters.—Sooty blackish, lighter beneath, the tail and quills 
nearly or quite black ; upper tail-coverts white ; tail even or slightly emarginate. 
a. Belly entirely dusky; webs of feet mostly yellowish; 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 (KuHL). Wilson’s Petrel. 
a’. Belly white; webs of feet wholly dusky; wing 5.20-5.50, tail 2.25-2.35, tarsus 
1.15-1.24. Hab. Coast of Chili and north to the Galapagos Archipelago. 
O. gracilis (ELLIoT). Graceful Petrel.3 
Genus CYMODROMA Rinaway. (Page 56, pl. 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 Satv., P. Z. 8. 1883, 430. 2 
2 pe eee eryptoleucura Ripew., Proc. U. S. Nat. Mus. iv. 1882, 337; Water B. N. Am. ii, 1884, 406. 
3 Thalassidroma gracilis ELLioT, This, Oct. 1859, 391. Oceanites gracilie Couzs, Pr, Ac. Nat. Sci. Phil. 
1864, 85. 
