22. 
23. 
25. 
PROCELLARIIDA — PROCELLARIINA: PETRELS. 781 
converging to narrow tip; less than half as long as head, about half the tarsus. Wings 
folding beyond tail; 2d primary longest, 3d little shorter, lst less than 4th. Tibia briefly 
bare below; tarsus equal to middle toe and claw; claws compressed, curved, acute. Tail 
rounded or nearly square, with broad feathers ; under tail-coverts very ample. Several species, 
distinguished by shape of tail from those of the preceding or following genus. 
P. pela/gica. (Gr. wedayixds, pelagikos, oceanic.) STORMY PreTREL. Above, glossy brown- 
ish-black, 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 ou 
webs. Size of the last; wing about 4.50. Common (?) off 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, flat claws, and a yellow spot on the webs. 
CYMOCHORE’A. (Gr. xtya, kuma, a billow; yxopna, a dancing.) Soory ForK-TAIL 
PETRELS. Bill much shorter than head, about #as long as tarsus, rather stout, as high 
as or higher than 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 rounded. 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, unicolor or nearly so. ° 
Three or four species are known. ; 
Analysis of Species. 
Upper tail-coverts white. 
Generaliplamare sooty-browM: «si Bilt (2 hh SMS. iis eile Oo. eS ea sb a Teueorrhod) (828 
No white anywhere. 
Sooty-brown; large; wing 6.75; tail4.00,forked1.00ormore ...... . ee ew ee meleena 824 
Sooty-gray; small; wing 5.00; tail 3.25, forked about 0.50 . . .... 4... =... - homochroa 825 
C. leucor’/rhoa. ((. eukds, leukos, white; dppos, orhros, ramp. Fig. 525.) Leacu’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 
black; iris brown. Length about 8.00; extent 17.50; 
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 
N. Atlantic coast, breeding from New England northward. 
Nest in burrows in the ground; egg single, white. 
C. melew’/na. (Gr. pedawa, melaina, black. Fig. 526.) 
Buack PETREL. Form of the last very nearly ; bill more Fic. 525.—Leach’s Petrel, much re- 
robust ; tarsus a little 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 
base 0.25; nasal tubes 0.30. Cape St. Lucas, L. Cala. ; a rare and little known species. 
C.homo'chroa. (Gr. duds, omos, like, equal; ypéa, chroa, color.) Somewhat like the last; 
smaller, with 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, lighter grayish-brown on greater wing-coverts; wings and tail black. 2d primary 
