64 NORTH AMERICAN BIRDS. 



toe, with claw, 2.15. Hab. South Pacific 

 (Tahiti). 



2E.. rostrata (Peale). Thick-billed Petrel.^ 

 Al Width of upper mandible at base decidedly less 

 than height of closed bill at base. 

 i}. Under tail-coverts dusky. 



Head, neck, and chest smoky grayish 

 brown, paler on chest (where feath- 

 ers are white immediately beneath 

 the surface), still paler on throat, 

 where almost white ; sides and top of 

 head, hind-neck, back, and scapulars 

 deeper smoky brownish gray, the 

 dorsal feathers with paler narrow 

 tips ; wings, rump, and tail dusky ; 

 breast and belly soiled white ; wing 

 12.17-12.50, tail 5.15-5.40 (graduated 

 for 1.60), culmen 1.42-1.60, tarsus 

 1.65, middle toe, with claw, 1.95-2.42. 

 Hah. Southern oceans, including vi- 

 cinity of Tierra del Fuego. 

 M. incerta (Schleg.). Schlegel's Petrel.'' 

 i"^. Under tail-coverts white. 



Otherwise, much like ^. incerta, but 

 throat and a superciliary space more 

 distinctly white; wing 12.00-12.21, 

 tail 5.00-5.50, tarsus 1.49-1.60, mid- 

 dle toe, with claw, 2.20. Hah. South 

 Pacific. 



JE,. magentse Gigl. & Salvad. Magenta 



Petrel.2 

 g^. Culmen, 1.14, or less. 



A\ Tail 4.75, or more ; culmen 1.12, or more. 



Above uniform dusky, more grayish an- 

 teriorly, especially on forehead ; chest, 

 entire sides, and under surface of wing 

 dusky sooty brown, more gray across 

 chest ; throat whitish ; breast, belly, and 

 greater part of under tail-coverts white ; 

 wing 11.20-11.41, tail 4.75-5.50, culmen 

 1.12-1.14, tarsus 1.30-1.35, middle toe, 



1 Procellaria rostrata Peale, Zool. U. S. Expl. 1848, 296, atl. pi. 41. j^strelata rostrata Codes, Pr. Ac. 

 Nat. Sci. Phil. 1866, 144. 



2 Procellaria incerta ScHLEG., Mus. P.-B., Procellariie, 1863, 9. vEstrelata incerta CouES, Pr. Ac. Nat. 

 Sci. Phil. 1866, 147. 



' ^strelata magentse GiGL. & Salvad., Ibis, 1869, 61. Salvin, Rowley's Orn. Misc. pt. iv. 1876, 251, pi. 30. 



