266 LAND-BIRDS. 



(bounded by isotberal lines) are inhabited by distinct groups 

 of birds, or ornithological /<:m?i(«. 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 65°. This line is just to the southward of Mount De- 

 sert and the White Mountains.* Most species belong to sev- 

 eral faunce^ 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 Massachu- 

 setts. 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 are distributed in an 

 exceptional manner; 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 Flycatchers 

 are more common among the White Mountains than in east- 

 ern Massachusetts. The Long-billed Marsh Wren, moreover, 

 has been found in Greenland. During the migrations, espe- 

 cially in autumn, birds frequently wander several hundred 

 miles from their usual habitat^ and, even in summer, may 

 occur to the northward of tlieir usual range. Several kinds 

 have even crossed the Atlantic, being driven to sea by winds, 

 and afterwards alighting on ships. Finally in the list of wan- 

 derers are to be included escaped cage-birds. ^^^ 



The Rusty Blackbirds pass the summer in northern New 

 England (chiefly northwestern Maine ?) and in all the coun- 

 tries beyond, except the arctic regions. They winter in the 

 Southern States, where they are frequently met with in large 

 flocks. They reach Massachusetts in March, lingering into 

 April, and return in autumn, when they are most abundant in 



* It should have been mentioned i^'- i„ the appendix is a list of the 



that the Adirondacks belong to the species belonging to our t\vo/aH??OE. 

 Canadian faunal district. [Appendix 

 to first edition, p. 444.] 



