SYLVIID^ — THE SYLVIAS. 69 



Family SYLVIID^. — The Sylvias. 



Char. Bill much shorter than head, slender, broad, and depressed at the base, distinctly 

 notched and decurved at the tip. Culmen sharp-ridged at base. Frontal feathers reaching 

 to the nostrils, which are oval, with membrane above, and overhung — not concealed — 

 by a few bri.stles or by a feather. Ilictal bristles extending beyond nostrils. Tarsi booted 

 or scutellate. Basal joint of middle toe attached its whole length externally, half-way 

 internally. Primaries ten ; spurious primary about half the second, which is shorter than 

 the seventh. Lateral toes equal. 



The birds of this family are readily distinguished from the Faridm by the 

 slender bill, notched and decurved at tip ; much bristled gape, sharp-ridged 

 culmen, exposed oval nostrils, less adherent toes, etc. They are much smaller 

 than the Turdidce and Saxicolida:, with much more slender, depressed bill, 

 longer rictal bristles, etc. The short outer primary, with the primaries ten 

 in number, distinguish them from the SylvicolidcB. 



The following synopsis will serve to characterize the American forms of 

 their respective subfamilies. The species are all among the most diminutive 

 in size with the exception of the Humming-Birds : — 



A> Wings longer than the nearly even and emarginate tail. Scutellae of tarsus 

 scarcely or not at all appreciable. General color olivaceous above. No white on 

 tail. 



Nostrils naked. Scutellse distinct on inner face of tarsus only. Head plain. 



Sy Iviin ce . 



Nostrils overhung by bristly feathers. ScutelliB of tarsus not appreciable. 



Head with a colored central crest . . . . . . . Regulince. 



B. Wings about equal to the graduated tail. Tarsal scutellae distinct. Above 

 bluish ; tail with white spots or patches. 



Nostrils uncovered. Head plain ; either bluish or black above. Polioptili n ce . 



Subfamily SYLVIINiE. 



Char. Size and form of Sylvicolinm, but with a spurious fu'st primary about one third 

 the second quill. Wings considerably longer than the nearly even or emarginate tail. 

 Feathers of frontal region with bristly points ; but not covering the nostrils. Tarsi 

 scutellate anteriorly, but indistinct externally, (Characters drawn with reference to the 

 American form.) 



The introduction of this subfamily into the present A\'ork is required to 

 accommodate a species of Fh/llojnu'uMe collected on the Yukon by the IJus- 

 sian Telegraph Expedition, tlie first known instance of the existence in North 

 America of a group of birds characteristic of the northern parts of the Old 

 World. Among the smallest of the class, they are eminently sociable, and 

 feed entirely on insects, which they capture mostly on the wing, like tiy- 



