BIRDS OF NORTH AND MIDDLE AMERICA. 755 



Genus SYNTHLIBORAMPHUS Brandt. 



Synthliboramphus Brandt, Bull. Ac. St. Petersb., ii, 1837, 347. (Type, AIca 



antiqua Gmelin.) 

 Synthliborhamphus (emendation) Gray, List Gen. Birds, 2d ed., 1841, 98. 

 Bhamjyhosynthlipsis "■ Coues, Key N. Am. Birds, 5th ed., ii, Dec., 1903, 1075. 



(Type, Una ivumizusume Temminck.) 



Small Phalerinse (wing 125-141 mm.) with acrotarsiiim trans- 

 versely sciitcllate, outer toe (without claw) longer than middle toe 

 (without claw), depth of bill at base of gonys equal to length of 

 gonys, and mandibular rami extensively unfeathered. 



Bill very short (exposed culmen not more than half aslongas tarsus), 

 deep (depth at latero-frontal antise equal to or gi-eater than length 

 of gonys), much compressed anteriorly; culmen regularly and rather 

 strongh^ curved; gonys very short (slightly more than half as long as 

 exposed culmen), straight, ascending terminalh', the mandibular 

 rami relativel}" broad; commissure nearly straight for most of its 

 length, gently decurved terminally, the tomia of both maxilla and 

 mandible indistinctly notched subterminally ; nostril broadly cuneate 

 or triangular, with a broad and prominent oblique operculum over- 

 hanging upper-anterior edge and occupying whole of upper-anterior 

 portion of nasal fossa; latero-frontal antia close to culmen, on same 

 vertical line with anterior end of nostril, the medio-frontal edge of 

 feathering very slightly indented at base of the broadly rounded 

 culmen; malar antia about on line (vertically) with posterior end of 

 nostril, or slightly posterior to it ; mental antia very slightly anterior 

 to anterior end of nasal fossa. Wing small, the longest primary 

 (outermost) exceeding distal secondaries by slightly more than half 

 the length of wing. • Tail less than three-sevenths (very slightly more 

 than one-fourth) as long as wing, very slightly rounded, the rectrices 

 (14) broadly rounded at tips. Tarsus slightl}^ longer than middle toe 

 without claw, the acrotarsium transversely scutellate, the scutella 

 extending over gi'eater part of inner and anterior half of outer side; 

 outer toe, without claw, longer than middle toe without claw, the 

 inner toe (without claw) longer than fii'st two phalanges of middle toe. 



Plumage and coloration. — Plumage of whole frontal region very 

 full, semierect, blended, in one species developed into a distinct crest, 

 that of malar, suborbital and auricular regions, chin, and throat 

 shorter and softer. In breeding plumage, greater part of^iead 

 uniform black (more fuscous or slaty on throat, etc.), the supra- 

 auricular region (in one species the superciliary region also) streaked 

 with white; back, scapulars, rump, and upper tail-coverts plain 

 slate-gray; under parts immaculate white, the sides and flanks 

 uniform sooty black. Winter plumage with whole throat white (the 



a'PdfjLcpos, beak; criiv, with; exii/'ts, pressure. (Richmond.) 



