VIRKOXID.E — THE VIUEUS. 357 



Family VIREONID-ffl. — Tuk Vii:kos. 



Tlie essential t'eiitiuvs of tins fainily n|tpear to consist in the conihination 

 of tlie dent i rostral bill, notclied in both nian(bl)les ; the ten primaries (exeept 

 V i reus i/l via), of which the outer is usually fr(Mn one fourth to om half tlie 

 seeontl ; the ratlier short, nearly even tail, with narrow feathers, and the 

 great amount of adhesion of the anterior toes, — the whole basal joint of 

 the middle beinj; ^^enerally united on lioth sides to the adjacent joints, and 

 decidedly shorter than the basal of inner or two bjLsal of outer. Th:i outer 

 lateral toe is generally ai»j)reciably longer than the inner, reaching con- 

 siderably beyond the base of the middle claw. The tarsi are always dis- 

 tinctly scutellate anteriorly. The young are never sj)otted, or streaked as 

 in the Thrushes; nor, indeed, do the adults exhibit such markings. 



The Vit'ioniila' are peculiar to the Xew World, and are widely distributed, 

 although but cue genus belongs to the Vnited States. 



Genus VIRXSO, Vieill, 

 Vireo, Vieill. Ois. Am. Sept. I, 1807, 83. (Type, Mumi'oijki vorrfxirarmsi.s, (i\\.) 



No gi'eat violence will be done by considering all the American Vireos as 

 belonging to one genus, divisible into three subgenera, as, however dillerent 

 the extremes of the series may be from each other, the gradation is ijuite 

 complete. 



The North American species take a wide range during their southern 

 winter migration, only i)aralleled in this resi)ect by the Si/lrirofida' ; they do 

 not visit the West Indies, save as very rare stragglers to Cuba ( V. vlicaccas, 

 s(tlif((rius,JI/fviJrons, and noirhoriwensis). They all have a meloilious song, and, 

 so far as known, make a dee]) nest, sus})entled by its npi)er edge l)etween the 

 forks of a horizontal twig. The eggs are white, generally with a few reddish 

 or brown blotches. 



Quite a number are characterized by having the eyes white, red, or 



yellow. 



Siibgenera. 



Vireosylvia. bill compressi'd, njirnnv; ouliiuMi and commis.<5ure straifjht, 

 the tip abruptly curved (or, if this is not the case, there is no trace of light 

 bands on the wing; see section "6"). Superciliary stripe continued back to 

 the occiput. Xo trace of light bands on the wing. No conspicuous ring round 

 the eye. 



a. No spurious primary. Bill comprossed, its tip abruptly hooked ; cuhnop 



and commissure straight. Crown decidetlly more ashy than the back. 



Sp. jlavoviridis^ barbatuhis, olivaceus, phifadelphicus. 



h. An acute spurious primary. Bill depressed, the tip only rlightly hooked ; 



oulmen slightly curved. Crown scarcely more ashy than back . . Sp. ffi^"n<:. 



