BIRDS OK MIDDLE AND NORTH AMERICA. 691 



(k'olhlypk caninacha iclerotin Ridgway, Proc. V. S. Nat. Mus., xi, sig. 34, Sept. 20, 

 1889, 539 (Costa Rica; coll. U. S. Nat. Mus.).— Chekrie, Proc. U. 8. Nat. 

 Mus., xiv, 1891, 526 (San 3oa6, Costa Rica; crit); Auk, ix, 1892, 22 (San 

 Jos6).— Richmond, Proc. U. S. Nat. Mus., xvi, 1893, 485 (Rio Escondido, 

 Nicaragua). — B.vngs, Proc. New Engl. Zool. Club, iii, 1902, 61 (Boquete and 

 Volcan de Chiriqui, Chiriqui, 4,000 to 7,500 ft). 



Geothiypis palpebralis (not of Ridgway) Lantz, Trans. Kansas Ac. Sci. for 1896- 

 97 (1900), 223 (San Juan Valley, Costa Rica). 



Genus ICTERIA Vieillot. 



/c(ma ViEiLLOT, Ois. Am. Sept., i, 1807, pp. iii, 85. (Type, Muscicapa viridis 



Gmelin, = Tardus virens Linnaeus. ) 

 /derio Cabanis, Mus. Hein., i, 1850, 63. 



Very large MniotiltidsB with short, stout, arched and unnotched bill, 

 the tarsus less than one-third as long as wing, tail moderately rounded, 

 with rectrices obtuse or rounded at tips; color olive-greenish above, 

 anterior half of under parts yellow; eyelids, malar stripe, and super- 

 ciliary stripe white, and lores black. 



Bill very much shorter than head, deep (basal depth equal to about 

 half the exposed culmen); culmen strongly curved; maxillary tomium 

 without subterniinal notch; gonys nearly if not quite straight. Nos- 

 tril broadly oval, overhung by rather narrow membraneous operculum. 

 Bictal bristles fairly developed. Wing moderate, rounded (seventh 

 to fifth primaries longest, ninth about equal to fourth); wing-tip equal 

 to or shorter than commissure. Tail equal to or longer than wing, 

 rounded, the rectrices rather narrow, with rounded tips. Tarsus about 

 one-third as long as wing or a little less, its scutella indistinct or obso- 

 lete on outer side; middle toe, with claw, decidedly shorter than tarsus; 

 oasal phalanx of middle toe united for slightly more than half its 

 length to outer toe, for about half its length to inner toe. 



Coloration. — Above plain olive-green or olive-grayish; beneath with 

 anterior half yellow, posterior half whitish; eyelids, superciliary stripe, 

 and malar stripe white, lores black. 



Nidification. — Subarboreal (in brambles or thickets). 



R<mge. — Temperate North America, including Mexico. ^Monotypic.) 



KEY TO THE SUBSPECIES OF ICTBEIA. 



u. Brighter or more decided olive-green above; white of malar region more restricted 

 (occupying less than anterior half); wing, tail, and bill shorter, the tail usually 

 shorter than wing; adult male averaging, wing 76.6, tail 74.5, exposed culmen 

 14.1; adult female, wing 74.4, tail 71.8, exposed culmen 13.5. (Eastern United 

 States, east of Great Plains, south in winter through eastern Mexico and Cen- 

 tral America to Costa Rica.) Icteria virens vireus, adults (p. 692) 



aa. Grayer oKve-green, or gray tinged with olive-green, above; white of malar region 

 more extended, occupying more than anterior half (at least in adult males); 

 wing, tail, and bill longer; adult male averaging, wing 79.1, tail 81.4, exposed 

 culmen 14.5; adult female, wing 77.6, tail 78, exposed culmen 14.6. (Western 

 United States and Mexican plateau)... Icteria virens longicancla, adults (p. 695) 



