BIRDS OB' KOETH AKD MIDDLE AMERICA. 23 



,?'. No trace of rictal bristles, the plumage of whole head short, 



dense, velvety; body covered with down; aquatic Cinclidae. 



jj. Rictal bristles more or less obvious (usually distinct) , the 



plumage of head normal; body without down; not aquatic. 



k. Tail much longer than wing, graduated for about half its 



length ; ninth primary shorter than secondaries . . ChamaeidEe. 



kk. Tail not longer than wing, not graduated; ninth primary 



longer than secondaries, sometimes longest. 



I. Size (of American forms) very small (wing not more than 



70 mm. ) ; plumage of young not spotted Sylviidae.' 



U. Size larger (wing not less than 82 mm.); plumage of 



young spotted Turdidse. 



a. Acrotarsium scutellate (on both sides) Mimidse. 



ee. Bill elongate-conical, with broad and flattened mesorhinium, or thick- 

 conical (fringilline); outermost (tenth) primary less than half as long 

 as primary coverts. 

 /. Bill elongate-conical (icterine); nostrils exposed, overhung by conspic- 

 uous horny operculum; wing-tip long, the longest primaries exceeding 

 secondaries by much more than length of tarsus; tail emarginate. 



Sturnidae.' 



ff. Bill stout-conical (fringilline); nostrils hidden or nearly hidden by 



loral feathering, without superior operculum; wing-tip short, the 



longest primaries exceeding secondaries by much less than length of 



tarsus; tail graduated Ploceidse.' 



a« Tarsus rounded posterioi-ly, or if ridged the ridge distinctly inside the median 

 line; inner posterior edge of the acrotarsium decidedly posterior to the lateral 

 median line, and separated from the planta tarsal ridge by a narrow groove; 

 planta tarsi scutellate (divided into transverse segments).'' {Latiplantar 

 Oscines *) Alaudidse. 



'Including Regulinae (the Regulidse of some authors) but excluding Polioplila, 

 which is here referred, provisionally, to Mimidse. 



^ Genus Slurnus only. 



' Genera Sponegintlius and Spermestes only. 



The Anaerican representatives of the Sturnidse and Ploceidse are introduced species 

 only, that of the former {Stumus vulgaris) from the Palsearctic Region, those of the 

 latter {Sporseginthus melpodus and Spermestes cucullata) from the African Region. The 

 above characters are drawn exclusively from these introduced species, no account 

 being taken of the numerous exotic forms, among which, as in other groups, great 

 variations in structural details are presented. 



* Except in very old birds, in which they sometimes become fused into a continu- 

 ous plate (as in most " Laminiplantares" ) The divisions or segments of the planta 

 tarsi correspond with those of the acrotarsium. 



^Corresponding to part of Sundevall's Scutelliplantares, which consist otherwise of 

 the superfamily Clamatores. The alaudine tarsal envelope is, however, very different 

 from the clamatorial type, being even more distinct from the latter than from that 

 of the acutiplantar Oscines. 



