70 NORTH AMERICAN BIRDS. 



«'. Longer upper tiiil-coverts broadlj' tipped with black ; under side of wing with 

 more or less of white; tail even, or slightl}' rounded ; length 5.50-5.75, wing 

 4.50-4.90, tail 2.40-2.1)0, culmen .40-.50, tarsus .90, middle toe .G0-.65. Eg^/ 

 1.09 X -83. Hah. North Atlantic, south to Newfoundland Banks and 

 western coast of Africa 104. P. pelagica Linn. Storm Petrel. 



fl'. Loni^er upper tail-coverts entirely white ; no white on under side of wing ; tail 

 einarginatcd ; wing 5.20, tail 2.40. the middle feathers .20 shorter ; tarsus .85, 

 middle toe (with claw) .70. Jlab. Vicinity of the Galapagos Islands. 



P. tethys BoNAP. Galapagos Storm Petrel.' 



Genus OCEANODROMA Eeichenbach. (Page 56, pi. XYIL, figs. 1, 2.) 



(Species. 



CoMJiON Ch.\racters. — Above dusky or gra3-ish, with or without white on 

 upper tail-covcrts ; lower parts uniform bluish gray or sooty, or white interrupted 

 by a grayish band across chest. 



a'. No white on upper tail-coverts. 



i'. A white collar round hind-neck. 



Lower parts white, with a graj-ish collar across chest ; upper parts 

 grayish, the quills blackish, the forehead and sides of head white ; 



length about 8.25, wing ?, tail 3.75, tarsus 1.00. Hah. North 



Pacific ("Northwest coast of America"). 



— . O. hornbyi (Gray). Hornby's Petrel, 

 t'. No white collar round hind-neck. 



c' Color bluish gray, above and below. 



Uniform bluish graj% fading to white on chin, throat, and under 

 tail-coverts ; orbital region, longer scapulars, innermost wing- 

 coverts, anterior and outer lesser wing-coverts, together with 

 quills, dusk}-; other lesser coverts, middle and greater coverts, 

 and tertials, broadly edged with ashy white ; length 8.00-9.20, 

 wing 5.90-6.40. tail'3.75-4.00 (forkcdfor about 1.00). Efftj 1.37 

 X 1-03. JIab. North Pacific, south on the American side to 



Oregon 105. O. furcata (Gmel.). Fork-tailed Petrel. 



c*. Color sooty brownish or dusky, above and below, 

 t/'. Wing more than 6.50 ; tarsus 1.00. or more. 



e". Sooty blackish, lighter and browner beneath, the greater wing- 

 coverts and outer webs of tertials light grayish brown ; 

 wing 0.80, tail 3.90 (forked for about 1.20), tarsus 1.20. 

 Hah. Coast of Mexico, north to Lower California. 



107. O. melania (Bonav.). Black Petrel. 



e'. Sooty slate-color, the head, including ihroat, a]iprecialily j)uler 



and more plumbeous ; greater wing-coverts light grayish; 



> Procellaria telhyn BojiAP., Comp. Rond. xx.tviii. 1854, 662 ; Consp. ii. 1S57, 137. Salt. Trans. Zool. Soc. 

 Lond. ix. pt. ii. 1875, 507, pi. 88, fig. 2. 



