W714 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 
Genus 4ATHIA Merrem. 
Aethia @ Merrem, Verz. Grundr. Allg. Gesch. u. Nat. Eintheil. d. V6g., i, Tenta- 
men Nat. Syst. Av., i, 1788, pp. 7, 13, 20. (Type, by monotypy, Alea 
cristatella Pallas. See Hartert, Novit. Zool., xxiii, 1916, 340.) 
Simorhynchus Merrem, in Ersch u. Gruber’s Encycl., 1 sec. ii, 1819, 405. (Type, 
by original designation and monotypy, Alca cristatella Pallas.) 
Tyloramphus Branvt, Bull. Acad. St. Pétersh., ii, 1837, 348. (Type, Alca crista- 
tella Pallas.) “ 
Medium-sized Phalerine (wing 125-143 mm.) with exposed culmen 
less than half as long as commissure and not longer than gonys; 
adults with a slender recurved frontal crest and line of postocular 
acicular plumes, and in breeding season a conspicuous concave supra- 
rictal horny plate and conspicious enlargement of the mandibular 
rami. 
Bill short and stout, its depth from base of exposed culmen to 
gonydeal angle much greater than its width at same point and at 
least equal to length of exposed culmen, thé latter strongly curved; 
gonys as long as or longer than exposed culmen, faintly convex, 
ascending terminally, its basal angle more or less prominent; maxil- 
lary tomium strongly convex basally, distinctly incised terminally, 
the tip of maxilla distinctly uncinate; mandibular tomium nearly 
straight in middle portion, recurved terminally, recurved and arched 
basally, the tip of mandible recurved, with tip obliquely truncate; 
mandibular rami mostly unfeathered (wholly so in breeding season), 
equal to or longer than gonys; nostril longitudinal, narrowly ovate 
(its anterior end acute), overhung in breeding season by the lower 
edge of a prominent supra-nasal saddle or cuirass; anterior line of 
frontal feathering extending almost straight across base of culmen, 
nearly on line (vertically) with middle of nostrils, the mental antia. 
slightly posterior to it. Wing moderate, the longest primary (outer- 
most) exceeding distal secondaries by slighty less than half the 
length of wing. Tail about three-sevenths as long as wing; slightly 
rounded; rectrices 14. Tarsus decidedly shorter than middle toe 
without claw, the acrotarsium reticulate; outer toe (without claw) 
as long as middle toe (without claw), the inner toe as long as first two 
phalanges of middle toe; claws rather small, only moderately curved 
and, acute. 
Nuptial ornaments.—A conspicuous supra-rictal horny plate, with 
concave surface; mandibular rami conspicuously enlarged, and 
supra-nasal saddle or cuirass prominent and corneous. 
Plumage and coloration.—Adults with a conspicuous frontal 
strongly recurved crest of slender, elongated feathers (much as in 
Alcella) and with a narrow line of slender acicular white feathers 
@ Ai@ua, a sea-bird of some kind. (Richmond.) 
