BIRDS — LANIIDAE — VIBEO, 329 



Sub-Family VIREOMNAE. 



The characters of the Fireoninae, as already given, will serve to distinguish them from the 

 otlior North American LanHdae. The bill, though slenderer and more cylindrical, has the 

 same abrupt and lengthened hook at the tip. 



The association of Ideria with Vtreo, as made by most ornithologists, appears to me highly 

 unnatural, its place being more appropriately among the Sylvicolidae. 



VIREO, A^ieill. 



Ktreo, ViEiLL. Ois. Am. SepU I, 18U7, 83. Type Musckapa novcboracensis, Gm. 

 Cn.— Bill short, strong, straight ; the culmoii slightly curved ; the sides much compressed to the tip, which is rapidly cuived 

 and deflected ; the gonys long and ascending ; the gape with short woak bristles ; the nostrils basal, rouiiiitil, and cvposed, the 

 feathers of the head advancing forward on the bill to the nostril. Wings variable, rather long, and pointed; the first quill 

 sonielinies spurious, the larger outer one always graduated a little. Tail nearly oven, and rather short. Tarsi longer than the 

 middle toe. Outer toe a little longer than the inner ; hind toe rather shorter than the middle one. 



I have found it very difficult to arrange the North American Vireos satisfactorily by dividing 

 into Vireo and Vireosylvia, according as there is a spurious first primary or none. This char- 

 acter, though strongly marked, combines species which otherwise appear quite dissimilar, and 

 separates some which seem very closely related. Thus Vireo gilvus and philadelphicus are in 

 some stages of plumage hardly to be distinguished, except by the spurious primary of the 

 former ; while the V. flavifrons, without this spurious primary, is in other essentials very near 

 novthoracensis and solitarius, which possess it. 



In the difficulty of establishing any trenchant lines of distinction, I have concluded to con- 

 sider all the species as Vireo, and to divide them into the following sections : 



Vireosylvia. — Bill long, rather slender, light horn color. Wings long ; no spurious pri- 

 mary. Body slender. Top of the head plumbeous, very different from the back, bordered by 

 a line of black. 



V. olivaceus, fiavoviridis, altiloquus, virescens. Type V. oUvaceus. 



Vireo. — Bill shorter, rather slender, light horn color, (except in atrieapillus.) Wings 

 shorter. First primary spurious, except in pJdladelphicus. Body slender. Top of the head 

 scarcely different from the back, (except in atrieapillus.) 



V. philadelphicus, gilvus, belli, atrieapillus. Type V. gilvus. 



Laxivhieo. — Bill rather stout and short, dark plumbeous in color. Wings moderate. Body 

 stout. First primary spurious, except m flavifrons. 



V. noveboracensis, huttonii, solitarius, cassini, flavifrons. Type V. flavifrons. 



The following synopsis, though its arrangement is not perfectly natural, may yet aid in a 

 ready identification of the species : 



A. NO SPURIOUS QUILL. 



Crown ash colored, very different from the neck, bordered on each side by a dusky line within 

 a white superciliary one. No black line on the side of the throat, except in altiloquus. 



Nearly pure white beneath ; the under tail coverts with the faintest tinge of sulphur. 



First and fourth quills nearly equal ^- olivaeeus. 



Sides greenish yellow; under tail coverts bright gamboge yellow. First quill longer 



than the fifth and sixth V.flavoviridis. 



42 b 



