72 yORTII AMERICAN BIRDS. 



I 



a'. Bully entirely white. 



6'. Throat and collar round hind-neck white ; length 8.75-9.00 ; tail cmarginatcd 

 for about .75 ; tarsus 1.G5-1.75, middle toe, with claw, 1.25, or more. 

 Hab. Intertropical seas. 



C. tropica (Gih'li>). Tropical Petrel.' 



i'. Throat usuallj' with onlj' concealed white, and without white ou hind-neck; 



length 7.50-8.00, wing 6.00-6.50, tail 3.00-3.30, even ; tar.sus 1.40-1.60, 



middle too, with claw, 1.05-1.10. Hal). Intertropical seas, north, 



casuallj", to coast of Florida. 



110. C. grallaria (ViEiLL.). White-bellied Petrel. 

 «'. Middle line of belly dusky. 



No white on hind-neck, but throat sometimes white, and feathers of 

 forehead white beneath surface ; dusky of belly usually connected with 

 that on chest ; length 8.50-8.75 ; tail usually emarginated for about .75 ; 

 ■wing 6.25-6.75, tarsus 1.60-1.70, middle toe, with claw, 1.05-1.15. Ifab. 

 South Pacific. 



C. melanogaster (Gould). Black-bellied Storm Petrel.^ 



Genus PELAGODROMA Eeichenbach. (Page 56, pi. XV., fig. 2.) 



Species. 



Forehead, superciliary stripe, and lower parts, pure white ; top of head, broad 

 stripe behind ej-e, and upper parts generally, slate-color, sometimes inclining to 

 plumbeous; upper tail-coverts light ash-gray; quills and tail-feathers blackish; 

 bill black ; tarsi deep black ; feet black, the webs mostly yellowish ; wing 5.90-6.40, 

 tail 2.90-3.30 (forked for .25-.35), tarsus 1.52-1.70, middle too, with claw, 1.37-1.40. 

 Hub. Southern seas, accidental off coast of Massachusetts. 



111. P. marina (Lath.). White-faced Petrel. 



1 Thalaaaidroma tropica GoDLD, P. Z. S. 1837, 366. 



' Tkalaeaidromn melauojaatra Gould, Ann. Mag. N. II. xiii. 1S44, 367 ; B. Austr. vii. 1848, pi. 62. 



