786 SYSTEM A TIC SYNOPSIS. — L ONGIPENNES — TUBINARES. 
834. P. anglo'rum. (Lat. Anglorum, of the English.) Manx Shearwater. Smaller and other- 
wise very different from any of the foregoing. Upper parts uniform lustrous black, or blackish 
with slight brown shade, rather ashy across hind neck ; the dark color extending on sides of 
liead much below eyes, but there marbled with white ; under eyelid white, set in black. On 
sides of neck the white reaches part way around ; on sides of breast the dark extends some 
distance, dilute and. marbled with white. Primaries black, with black shafts, their inner webs 
dull grayish-brown ; tail-feathers like primaries. Entire under parts, from chin to anus, pure 
white, except a few feathers of the flanks, and the outer webs of the outer under tail-coverts, 
which are plumbeous-black. Lining of wings and axillars white, mottled with black just 
along the edge. Length about 13.50; extent 30.00; wing 9.25; tail 4.00, graduated 0.75 j 
tarsus 1.80; middle toe and claw 1.90; outer do. 2.00; inner do. 1.55; chord of culmen 1.40; 
gape 2.10 ; height or width of bill at base 0.45. Varies much, but the small size and black- 
ishness are distinctive. This species chiefly inhabits the Atlantic coast of Europe, and the 
Mediterranean ; it is the commonest British species of the genus, said to range the N. Atlantic 
at large, and to occur on our coast ; but those who suppose it to be one of our common species 
are apparently mistaken. Nest in burrows in the ground, dug by the birds ; egg single, dead 
white, smooth, 2.35 X 1.60. 
835. P. obscu'rus. (Lat. ohscurus, dusky.) Dusky Shearwater. Bill small and weak, 
about f as long as head, f as long as tarsus; stout only at base, where higher than wide; 
hook rising abruptly from line of culmen ; commissure lower, and outline of bill almost 
straight from feathers to hook. Wings folding to end of tail, which is comparatively long, 
and much graduated. Tar- 
sus as long as middle toe 
without claw ; outer toe 
and claw equal to middle 
toe and claw ; tip of inner 
claw reaching base of mid- 
dle. Blackish of upper 
parts with much grayish 
or plumbeous cast, with 
lighter borders of the feath- 
FiG. 527. — Black-vented Shearwater, nat. size. (From Elliot.) especially on the scap- 
ulars and tertials ; darkest 
on rump and upper tail-coverts ; on sides of head not extending below eyes, and even there 
marbled with whitish ; both eyelids white, and there is indication of a light superciliary stripe. 
Quills and tail-feathers as in P. anglorum. Under parts from chin to vent, white, as are lining 
of wings and axillars, only a few plumbeous black feathers on flanks. The longest and outer- 
most under tail-coverts are black, the rest white, pure or with a plumbeous shade. Bill dull 
leaden-blue, blackening at tip ; iris bluish-black ; edges of eyelids bluish ; outside of tarsus and 
outer toe bluish-black, inside and webs of all yellowish flesh-color. Small : length 11.00- 
12.00; extent 26.00; wing 7.50-8.00 ; tail 4.25, graduated nearly 1.00; tarsus 1.60; middle 
toe and claw 1.80 ; chord of culmen 1.25 ; gape 1.70; nasal case to tip 0.90; depth of bill at 
base 0.40 ; width 0.35. A small bicolor species, readily distinguished from any of the foregoing. 
S. Atlantic and G-ulf coast, common, straying N. to the Middle States. (P. ohscurus Gm. ? 
P. auduboni Finsch.) 
836. P. opistho'melas. (Gr. oma-de, opisthe, backward ; fxeXas, melas, black. Fig. 527.) Black- 
vented Shearwater. Resembling the last, and little larger. Bill about ^ as long as tarsus. 
Tail relatively shorter, less graduated. Tarsus as long as middle toe and half its claw. Frontal 
feathers extending in a point on culmen. Dark color of upper parts extending farther on sides 
of head than in ohscurus, leaving no white about eye. Under tail-coverts entirely sooty- 
