374 



U. S. r. E. E. EXP. AND SUEVEYS ZOOLOGY — GENEBAL EEPOET. 



Sub-Family SITTINAE. 



SITTA, Linnaeus. 



Silta, LiNKAEDs, Syst Nat. 1735. (Agassiz.) 



Ch.— Bill subulate, acutely pointed, compressed, about as long as the head; culmen and commissure nearly straight ; 

 gonys convex and ascending; nostrils covered by a tuft of bristles directed forward. Tarsi stout, scutellate, about equal to tlie 

 middle toe, much shorter than the hinder, the claw of which is half the total length. Outer lateral toe much longer than 

 inner, and nearly equal to the middle. Tail very short, broad, and nearly even ; the feathers soft and truncate. Wings reach- 

 ing nearly to the end of the tail, long and acute, the first primary one-third of (or less) the third, or longest. 



This genus differs from Sittella in having the bill entire, not notched, the tail longer, &c. 

 There are several species in the United States, which may be arranged as follows : 



a. Croton black. 



Pure white beneath. Bill stout S. carolinensis. 



Similar. Bill slender S. aculeata. 



Brownish rusty beneath, a black stripe through the eye S. canadensis. 



h. Crown not Hack. 



Crown light brown. Hind toe much longer than the middle one S. pusilla. 



Crown greenish plumbeous. Hind toe about equal to the middle one ..S. pygmaea. 



Comparative measurements of species. 



SITTA CAROLINENSIS, Gmelin, 



White-bellied Nuthatch. 



Silla europaca, var. y, carolinensis, Gmei.in, I, 1788, 440. 



Sitla carolinensis, Latham, Ind. Orn. I, 1790, 262.— Wilsok, Am. Orn. 1, 1808, 40 ; pi.— Bon. Obs. Wils. 1825.— In. 

 List 1838.— 1b. Conspectus, 1850, 227.- Nuttall, Man. I, 1832, 581.— Aud. Orn. Biog. II, 

 1834, 299 : V, 1839, 473 ; pi. 152.— Ib. Birds Amcr. IV, 1842, 175 ; pi. 247. 

 Silla mclanocephala, Vieillot, Gal. I, 1834, 171 ; pi. clxxi. 



gp. Cii. Above ashy blue. Top of head and neck black. Under parts and sidea of head to a short distance above the oyo 



white. Under tail covcrlH and tibial feathers brown ; concealed prinmricH white. Bill stout. 

 Length, about G inches ; wing, about 3;. 

 //lib.— Eastern North America to the high contra! plains. West of this replaced by S. acukala. 



