BIRDS PARIDAE — POLIOPTILA. 379 



Family PARIDAE. 



First primary very short, generally less than half the second, which is considerably less than the third. Tarsus longer than 

 the middle toe, strongly seutellate anteriorly ; hind too rather shorter than the middle. Entire basal joint of middle toe united 

 to the lateral toes. Bill short, straight, conical, usually without notch. "Wings short ; tail rather long, rounded, or graduated. 



In the limited number of forms of this family in North America, I am unable to define the 

 sub-families with any degree of precision, except to state that Polioptila appears to belong to 

 one, and the true titmice to another. In Polioptila the bill is long, slender, and distinctly 

 notched, the nostrils open, while in the titmice the bill is shorter, more conical, entirely without 

 notch, and the nostrils concealed by feathers. Other differences will be found mentioned under 

 the respective genera. 



PoLioPTiLiNAE. — Bill slender, elongated, distinctly notched ; nostrils not covered by bristly 

 feathers, but exposed ; nostrils elongated. 



Parixae. — Bill short, conical, without indication of notch ; nostrils rounded, completely 

 concealed by elongated bristly feathers directed forwards. 



POLIOPTILA, Sclater. 



Polioptila, Sclater, Pr. Zool. Soc. 1855, 11. Type Molacilta caeruUa. 



CuUcivora, Swainson, Class. Birds, II, 1837, 243. Type C. alricapilla. Not CuUcivora (type stenura) ofSwainson's 

 Zool. Jour, lir, 1827,359. 



Ch. — Bill slender, attenuated, but depressed at the base; nearly as long as the head, distinctly notched at the tip, and 

 provided with moderate rictal bristles. Nostrils rather elongated, not concealed, but anterior to the frontal feathers. Tarsi 

 longer than the middle toe, distinctly seutellate ; the toes small ; the hinder one scarcely longer than the lateral ; its claw 

 scarcely longer than the middle. Outer lateral toe longer than the inner. First primary about one-third the longest ; second 

 equal to the seventli. Tjil a little longer than the wings, moderately graduated ; the feathers rounded. 



The species all lead color above ; white beneath, and to a greater or less extent on the exterior of the tail, the rest of which 

 Is black . Size very small . 



Two species of this interesting genus are now known to belong to the United States in 

 addition to the one described by Wilson and Audubon. 



Synopsis of species. 



Two outer tail feathers entirely white. A narrow frontal line, extending back over the eye, 

 black F. caerulea. 



Outer tail feather, with the whole of the outer web (only) white. No black on the forehead, 

 but a stripe over the eye above one of whitish P. plumbea. 



Edge only of outer web of outer tail feather white. Entire top of head from the bill black. 



P. melanura. 



