64 NORTH AMERICAN BIRDS. 
toe, with claw, 2.15. Hab. South Pacific 
(Tahiti). 
ZE. rostrata (PEALE). Thick-billed Petrel.! 
#?. Width of upper mandible at base decidedly less 
than height of closed bill at base. 
#, 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. 
Hab. Southern oceans, including vi- 
cinity of Tierra del Fuego. 
ZE. incerta (ScHLEG.). Schlegel’s Petrel.? 
#, Under tail-coverts white. 
Otherwise, much like 2. 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. Hab. South 
Pacific. 
4. magentz Giet. & Satvap. Magenta 
Petrel 
g. Culmen, 1.14, or less. 
h', 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 PEAR, Zool. U.S. Expl. 1848, 296, ot]. pl. 41. etrelata rostrata Covzs, Pr. Ac. 
Nat. Sci. Phil. 1866, 144. 
3 Procellaria incerta Scuuec., Mus. P.-B., Procellarie, 1863, 9. Aistrelata incerta Cours, Pr. Ac, Nat. 
Sci. Phil. 1866, 147. 
8 Zstrelata magente Giat. & SALVAD., Ibis, 1869, 61. Savin, Rowley’s Orn. Mise. pt. iv. 1876, 251, pl. 30. 
