BIRDS OF NORTH AND MIDDLE AMERICA. 545 
Bill about as long as head, the exposed culmen longer than middle 
toe with claw, its greatest depth equal to more than one-third the 
distance from anterior end of nostril to tip of maxilla; culmen straight 
for basal two-thirds (approximately), sometimes even faintly concave 
above nostrils, rather abruptly and-strongly decurved for terminal 
third; gonys decidedly to much shorter than mandibular rami, 
nearly if not quite straight, prominent basally; nostril narrowly 
elliptical, longitudinal, separated from nearest loral feathering by a 
space greater in extent than length of nostril; anterior outline of 
feathering of forehead and lores forming an angle on base of culmen 
(frontal antia), sloping thence backward and downward to rictus, 
without trace of projection on lateral base of maxilla (latero-frontal 
or loral antia). Wing long and pointed, the longest primary (outer- 
most) exceeding distal secondaries by decidedly less than twice the 
distance from tips of the latter to bend of wing, the primaries rather 
broad terminally, with narrowly rounded tips. Tail more tian half 
as long as wing, graduated and slightly forked, the lateral rectrices 
about two-thirds as long as the longest (third or third and fourth 
pairs, counting from middle), the middle pair shorter than the longest 
by less than length of tarsus; rectrices not attenuated terminally, 
though distinctly tapering, their tips narrowly rounded. Tarsus 
much shorter than middle toe without claw; outer toe as long as 
middle toe; webs between anterior toes slightly excised. 
Plumage and coloration Plumage blended throughout, the occipi- 
tal feathers without trace of elongation. Adults plain grayish 
brown, grayer on pileum, the forehead sometimes white or grayish 
white; a white streak on lower eyelid and small white spot on upper 
‘eyelid. 
Range.—Tropical seas of both hemispheres. (Monotypic.) 
KEY TO THE AMERICAN FORMS OF ANOUS STOLIDUS.2 
a, General color lighter and browner; pileum lighter gray, becoming more distinctly 
and extensively whitish anteriorly. (Tropical and subtropical portions of 
Atlantic Ocean; breeding northward to coasts of Florida and Louisiana.) 
Anous stolidus stolidus (p. 546). 
@ In addition to the forms of this species occurring in American waters, the follow- 
ing subspecies are recognized by Mathews (Birds of Australia, ii, pt. 4, Nov. 1, 1912, 
405-411): 
(1) Anous stolidus unicolor. Sterna wnicolor Nordmann, in Erman’s Verz. u. Pfl., 
1835, 17 (South Seas; coll. Berlin Mus.).—Anous wnicolor Boie, Isis, 1844, 188.— 
Anous stolidus unicolor Mathews, Birds Australia, ii, no. 4, Nov. 1, 1912, 411 (Society 
Islands; Paumotu, etc.). 
(2) Anous stolidus gilberti. (Mathews, Birds Australia, ii, no. 4, Nov. 1, 1912, 
405, 411) (Australia.) 
(3) Anous stolidus pileatus. “Sterna pileata Scopoli, Del. Faun. et Flor. Insubr., 
ii, 1786, 92 (Philippines; based on Le Petit Fouquet des Philippines Sonnini, Voy. 
40017—19—Bull. 50, pt 8——36 
