OF NEW ENGLAND. 257 



sion of an introductory paragraph, relative to tlie Rusty Blaclc- 

 birds and tlicir distribution.) 



(c). As is well known, the animals belonging (or indige- 

 nous) to a country constitute its fauna. But, in a large country 

 like North America, it has been found that different districts 

 (bounded by isotheral lines) are inhabited by distinct groups 

 of birds, or ornithological faunce. In New England there are 

 two faunce, the Canadian and Alleghanian, which are chiefly 

 separated by the approximate latitude of 44°, or the isotheral 

 line of G5°. This line is just to the southward of Mount Des- 

 ert and the White Mountains. Most species belong to several 

 faunae, but not, as a rule, to merely a part of any one. There 

 are several Alleghanian species, however, who have not been 

 found, so far as I know, to the northward of Massachusetts. 

 On the other hand, several Canadian species have been known 

 to breed in this State, chiefly, I believe, along water-courses 

 (such as the Nashua Valley), or along mountain-ranges. Birds 

 may often be detained or prevented from reaching their usual 

 summer-homes, and therefore obliged to remain in a warmer 

 climate, especially in the case of young birds who do not 

 breed. Some species arc distributed in an exceptional man- 

 ner ; thus the Red-bellied Nuthatches are common summer- 

 residents in the Canadian district, and breed in the Carolinian 

 fauna, but not in southern New England. I have likewise 

 observed that the Great Crested Fl3^catchers are more common 

 among the White Mountains than in Eastern Massachusetts. 

 The Long-billed M-arsh Wren, moreover, has been found in 

 Greenland. During the migrations, especially in autumn, 

 birds frequently wander several hundred miles from their usual 

 habitat, and, even in summer, mny occur to the northward of 

 their usual range. Several kinds have even crossed the At- 

 lantic, being driven to sea by winds, and afterwards alighting 

 on ships. Finally in the list of wanderers are to be included 

 escaped cage-birds.^'' 



Tlie Rusty Blackbirds pass the summer in northern New 



«'Iu the appendix is a list of tlic species belonging to oiiv two fuunce. 

 18 



