VIREONID^ — THE VIREOS. 357 



Family VIREONID^. — The Vireos. 



The essential features of this family appear to consist in the combination 

 of tiie dentirostral bill, notched in both mandibles ; the ten primaries (except 

 Vireos;/! via), of winch tlie outer is usually from one fourth to one half tlio 

 second ; tlie rather siiort, nearly even tail, with naii'ow feathers, and the 

 great amount of adliesion of the anterior toes, — tlie whole basal joint of 

 the middle being generally united on both sides to the adjacent joints, and 

 decidedly shorter than the basal of inner or two ba.sal of outer. Tlie outer 

 lateral toe is generally appreciably longer than the inner, reaching con- 

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

 tinctly scutellate anteriorly. The young are ne\'er spotted, or streaked as 

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



Tlie VinoiiidK are peculiar to the New World, and are widely distributed, 

 although but one genus belongs to the United States. 



Genus VIREO, Vieill. 



Vireo, ViF.TLL. Ois. Am. Sept. I, 1807, 83. (Tjqie, Uusckapa noivbnracensis, Gm.) 



No great violence will be done liy considering all the American Vireos as 

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

 the extremes of the series may bo from each other, the gradation is quite 

 complete. 



The North American species take a wide range during their southern 

 winter migration, only paralleled in this respect by the Sylvicolidw ; they do 

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

 soiifarius,favifivns, and iwvcboniccnsia). They all have a melodious song, and, 

 so far as known, make a dee]i nest, sus])ended by its upper edge between the 

 forks of a liorizontal 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. 



Subgenera. 



Vireosylvia. Bill compre.sscHl, narrow; culinen and corami.s.sure straight, 

 tliu tip abrnptly 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. No trace of light bands on the wing. No conspicuous ring round 

 the eye. 



a. No .spurious primary. Bill compressed, its tip iiliruptly hnnkcd ; ciilmcn 

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



Sp. Jlavofiridis, barbululus, olivaceus, phUadelpliicus. 



b. An acute spurious primary. Bill depressed, the tip only slightly hooked ; 

 culmen slightly curved. Crown scai'cely more ashy than back . . Sp. ijilous. 



