Mr. P. L. Sclater on the known Species o/Sitta. 311 



western form as Sitta aculeata *; but Prof. Baird states that its 

 " only appreciable difference " is the " much slenderer bill.^^ I 

 have no eastern examples in my collection, but I have Mexican 

 skins from Jalapa and Oaxaca. These have the bill decidedly 

 shorter and perhaps a trifle stouter than a Californian skin 

 kindly furnished to me by Prof. Baird, but do not quite agree 

 with one another, the Oaxacan bird having the shortest of the 

 two. Prof. Baird says that specimens from Washington Terri- 

 tory are also intermediate. 



10. Sitta canadensis, Linn. 



This little species, which, except in size and its black head, 

 reminds us of the group of Sitta europaa, has also a wide range, 

 but does not go nearly so far south as the last, not apparently 

 reaching Mexico, or even Texas. It seems, on the other hand, 

 to wander very far north ; for a specimen in the British Museum 

 is marked as having been obtained by Dr. Rae in Repulse Bay, 

 on the south side of Melville Peninsula, lat. 66° N. Sitta cana- 

 densis is common in Canada and all across the Rocky Mountains 

 to British Columbia, numerous specimens having been obtained 

 by Mr. Lord during the " Boundary ^^ Survey. Prof. Baird 

 registers specimens from various parts of California. 



11. Sitta pusilla, Lath. 



This little species appears to be confined to the southern 

 Atlantic States of North America, — South Carolina and Georgia 

 being its head-quarters. 



13. Sitta pygmcea, Vigors. 



Sitta pygmcKa represents the last species on the western coast, 

 where it ranges as far north as Washington Territory. De- 

 scending southwards it gradually extends eastwards, as is the 

 case with many other Californian species, and pervades the 

 table-land of Mexico. I have never had an opportunity of 

 comparing my example from Xalapa (collected by De Oca) with 

 north-western specimens, but I have little doubt as to their 

 identity. 



* Proc. Acad. Phil. 1856, p. 254. 



