PBOCELLABIIDJE — PEOCELLABIIN^: PETBELS. 781 



couverging to narrow tip ; less than half as long as head, about half the tarsus. Wings 

 folding beyond tail ; 2d prhiiary longest, 3d little shorter, 1st less than 4th. Tibia brietly 

 bare below; tarsus equal to middle toe and claw; claws compressed, curved, acute. Tail 

 rouuded or nearly square, with broad feathers ; under tail-coverts very ample. Several sjjecies, 

 distinguished by shape of tail from those of the preceding or following genus. 



822. P. pela'gica. (Gr. niKayL<6s, pelagikos, oceanic.) Stormy Petrel. Above, glossy brown- 

 ish-Vdack, below more fuliginous; upper tail-coverts white, with black tips; white streaking 

 on crissum, and usually white touches under the wings. Bill and feet black ; no yellow on 

 webs. Size of the last; wing about 4.50. Common (?) ofi' the Atlantic Coast; not known to 

 breed on our side. This is the rarest of the three little black white-rumped " Mother Carey's 

 chickens " of our Atlantic Coast, easily distinguished by its short legs and square tail ; Leach's, 

 the most numerous, is also short-legged, but larger and forked-tailed ; Wilson's is interme- 

 diate, with square tail, but very long stilt-like legs. Hat claws, and a yellow spot on the webs. 



327. CYMOCHORE'A. (Gr. Kvfia, kuma, a billow; x"?^"-! ^ dancing.) Sooty Fork-tail 

 Petrels. Bill much shorter than head, about ■§■ as long as tarsus, rather stout, as high 

 as or higher tliau wide at base, the hook strong and acute; nasal tube less than half as long 

 as culmen. Wings moderately long, folding little beyond tail; 2d primary longest; 1st longer 

 than 4th. Tail very long, deeply forked, the feathers all broad, obtusely rouuded. Legs 

 short; tibia little bare below; tarsus equal to middle toe and claw, or slightly longer. Of 

 rather large size (for this group) and robust form. Color fuliginous, unioolor or nearly so. 

 Three or four species are known. 



Analysis of Species. 



Upper tail-coverts white. 



General plumage sooty-brown leucoirhoa 823 



No wbite anywhere. 



Sooty-brown; large; wing 6,75; tail 4,00, forked 1.00 or more melcena 824 



Sooty-gray; »mall; wing 5.00; tail 3.26, forJied about 0,50 homochroa 825 



823. C. leucor'rhoa. (G. Xfu/cdf, Zeid'os, M'hite ; oppoy, o)7»ros, rump. Fig. 525.) Leach's Petrel. 

 White-rumped Petrel. Coloration as in the last species, with white upper tail-coverts, 

 forming a conspicuous mark; but apt to be lighter — rather 

 of a grayish or even ashy hue on some parts ; but easily « 

 recognized, whatever the shade of color. Bill and feet , V»K>^ 

 black; iris brown. Length about 8.00; extent 17.50; X^^-' 

 wing 6.00-6.50; tail 3.00-3.50, forked about 0.75; tarsus 

 1.00; middle toe and claw the same; bill 0.67. N. Am., ^, 

 both coasts, and W. coast of Europe. Abundant on our y "^ia^fc^ 

 N. Atlantic coast, breeding from New England northward, v 

 Nest in burrows in the ground ; egg single, white. 



824. C. melae'na. (Gr. fieXaiva, melaina, black. Fig. 526.) 



Black Petrel. Form of the last very nearly ; biU more „,„ „. r v, .„ , 



1 . . v 1 1 *^*^- 52o. — Leach's Petrel much re- 



robust ; tarsus a httle longer than middle toe and claw. No duced. (From Tenney, after Audubon ) 

 white anywhere. Plumage sooty brownish-black, darkest above and on head, more smoky- 

 brown on under parts, grayer on wing-coverts, quite black on wing- and tail-feathers ; bill and 

 feet black ; iris brown. " Length 9.00 ; extent 18.50 ; " wing 6.75 ; tail 4.00, forked 1 20 • tibia 

 bare 0.50; tarsus 1.25; middle toe and claw 1.10 ; bill 0.60; gape 0.95; height or width at 



«,. n'l °'^^ 1°"'^^ '^^"' °-!°- ^^P' ^*- ^""''' ^- ^'^l^- ' ^ '^"^ ^"d little known species. 



825. C. homo'chroa (Gr. opo., onios, like, equal ; xp6a, chroa, color.) Somewhat like the last • 

 smaUer, ^vith short, weak, compressed bill, and tarsus no longer than middle toe and claw' 

 No white anywhere. Plumage dull plumbeous or slaty-blackish, more smoky-brownish on 

 lower parts, bghter grayish-brown on greater wing-coverts ; wings and tail black. 2d primary 



