POLIOPTILA. 



69 



Polioptila nigrlceps. 



Polioptila nigriceps, Baikd, n. s. 



% . Above clear pure light bluish gray ; beneath pure white, including the 

 flanks. Entire top of the head and sides, including lower eyelids, lustrous 

 black. A slight ashy tinge on the sides of the neck. Only a few feathers 

 in the eyelids white. Outer tail feather white, except for the basal con- 

 cealed third, as is also the outer web, except at the base, and the terminal 

 fourth (or .65 of an inch) of the next. Third feather with the inner web 

 tipped with white for about a quarter of an inch : perhaps in the unworn 

 feather extending a little on the outer web. First primary broad, about half 

 as long as the 2d. No white on secondaries, or else worn off in this specimen. 



Length, about 4.50 inches; wing, 1.95; tail, 2.15; bill above, .48; from 

 gape, .32; tarsus, .75. 



Sab. Mazatlan. 



This interesting new species of Polioptila resembles P. melanura 

 in general appearance, but will be readily distinguished by the white 

 outer tail feather and much purer white of the under parts. The 

 gray above is lighter and clearer ; the bill is larger (equal to that of 

 cseruled), and the tarsi are longer. The black cap seems to extend 

 farther down the side of the head, and along the nape. 



The species appears well characterized by the length of the tarsi, 

 which exceed those of any other species known to me ; the bill is 

 not so stout as, and decidedly shorter than that of P. alhiloris (32,556), 

 and there is no trace of white in the lores, or between eye and bill. 

 The tail is longer; the 1st primary only half the 2d. 



From leucogastra it differs in the smaller size, shorter bill and 

 longer tarsi, narrower tail feathers and less amount of white on the 

 tail, as well as different geographical distribution. P. huffoni has 

 the outer tail feather entirely white, and the 2d and 3d white almost 

 to the base. The tail is considerably shorter. 



23,781. Type. 



Polioptila leucogastra. 



Sylvia leucogastra, Max. Beit. Ill, 1830, 710. — Polioptila leucogastra, 

 ScLATEK, P. Z. S. 1855, 12 (in part).— 1b. Cat. 1861, 12, no. 74.— 

 Culicivora leucogastra, BuRM. Th. Bras. Vo.el, 1856, 111. 



Culicivora atricapilla, Sw. Zool. 111. N. S. pi. Ivii (not of Lawrence). 



Culicivora dumecola. Bos. Consp. 1850, 316 (not of Vieillot;. 



