BIBD8 OF NOKTH AND MIDDLE AMERICA. 21 



66. Outermost obvious primary (tenth) not more than half as long as the next, 

 usually shorter, sometimes rudimentary.' {" Ten-primaried" Oscines.) 

 c. Basal phalanx of middle toe adherent for entire length to both lateral toes, 



the hallux not longer than outer toe Vireonidae, part. 



cc. Basal phalanx of middle toe free from inner toe for most if not all its length, 



and from outer toe for (approximately) half its length, or else (Oerthiida?, 



Troglodytidse) hallux decidedly longer than outer toe. 



rf. Bill short, broad, and depressed at base, the length of gonys decidedly 



less than basal width of bill; feet weak with tarsus decidedly shorter 



than middle toe with claw, or else (Ptiliogonatidas, part'') the acrotarsium 



booted, the young not spotted, and tenth primary half as long as ninth.' 



e. Wing-tip long and pointed, the longest primaries exceeding secondaries 



by much more than one-third the length of wing; tenth primary minute, 



less than half as long as primary coverts, the ninth longer than seventh, 



sometimest longest; tail shorter than distance from bend of wing to 



tip of secondaries; loral feathers dense, velvety, filling greater part of 



nasal fossae Ampelidse. 



ee. Wing-tip short, rounded, the longest primaries exceeding secondaries 

 by less than one-fourth the length of wing; tenth primary well devel- 

 oped, much longer than primary coverts; the ninth primary shorter 

 than third, sometimes shorter than first; tail longer than distance from 

 bend of wing to tip of secondaries, usually equal to or longer than 



wing; loral feathers normal Ptiliogonatidae. 



dd. Bill not short, broad and depressed at base, etc., or else (Turdidee, parf) 

 acrotarsium booted, young spotted, and tenth primary much less than 

 half as long as ninth. 

 e. Bill neither elongate-conical, with broad and flattened mesorhinium, nor 

 thick-conical (fringilline) ; outermost (tenth) primary more than half as 

 long as primary coverts, usually much longei' than the latter. 

 /. Bill deep and compressed (depth at nostrils more than half length of 

 exposed culmen), the culmen strongly curved. 



' Considerable care is necessary to determine whether the outermost obvious pri- 

 mary is the ninth or tenth, since in case the latter is rudimentary, though exposed, 

 it may easily be overlooked. The present section includes all forms in which there 

 is a visible rudimentary primary, those of the first section having the tenth primary 

 still more rudimentary and entirely concealed. In so-called ten-primaried birds in 

 which the tenth primary is rudimentary it consists of a minute, narrow, and pointed 

 quill, less than half as long as the primary coverts, lying upon the inner side of the 

 basal portion of the outer web of the outermost large primary, whereas in all so- 

 called nine-primaried Oscines it is still more minute and lies upon the outer side 

 of the wing next to the outermost primary covert. (See Baikd, Review of American 

 Birds, p. 325, footnote. ) 



^ Reference of the genus Phainopiila to the Ptiliogonatidae complicates the diagnosis 

 'of this group, which otherwise would be very easily characterized; but unless Phai- 

 nopiila is placed with the Ptiliogonatidse it must constitute a family by itself. So far 

 as the adult is concerned, there is nothing in its external structure that I can dis- 

 cover which would forbid its reference to the Turdidse (subfamily Myadestinse), 

 without materially modifying the diagnosis of the latter; but the young are abso- 

 lutely plain-colored, have the acrotarsium distinctly scutellate, and the tenth pri- 

 mary half as long as the ninth. 



' In the Myadestinse the tenth primary is less than half as long as the ninth, the 

 young conspicuously spotted, and with the acrotarsium indistinctly if at all scutellate. 



* Subfamily Myadestina?. 



