MUSEUM OF COMPARATIVE ZOOLOGY. 407 



perate zone, and the term Sub/rigid District may be very properly 

 applied to that district of which this fauna forms the eastern portion. 

 The zone corresponding with the Canadian Fauna may in like manner 

 be termed the Cold-temperate District; that corresponding with the 

 Alle^hanian Fanua the Subtemperate District; that corresponding 

 with the Carolinian Fauna the Temperate District; and that corre- 

 sponding with the Louisianian Fauna the Warm-temperate District; 

 the Floridian Fauna in like manner corresponding with the Subtorrid 

 District, or with Dana's subtorrid zone. Each of these districts is 

 distinguished, in contradistinction from the faunae, by species which 

 range across the continent, while the districts are distinguished from 

 each other by the same kind of difference as has been shown above to 

 characterize the several fauna3 among themselves. 



5. Ox the Geographical Range of the Species. 



The preceding tables, while serving to characterize the ornithological 

 faunae of Eastern North America, indicate only very obscurely the range 

 of the species. The following tables have hence been prepared in order 

 to show more clearly the hreeding range, and also the winter quarters, of 

 those species whose distribution in the breeding season is tolerably 

 known. For this purpose the birds occurring iu the Eastern Province 

 of the North American region have been grouped, according to their 

 geographical distribution, into the following classes, beginning with those 

 which have the widest breeding range : I. Cosmopolitan Species. 

 II. Circitmpolar Species. III. Species which range across the whole 

 breadth of the North American Temperate Region. IV. Species limited 

 in longitude to the Eastern Province of this region. The birds of the 

 Eastern Province are further subdivided according to the range of the 

 species in the breeding season in latitude.* 



* In a preliminary notice like the present it has been found impracticable to give the 

 authorities in detail on which the generalizations given in the following synopsis have 

 been based. The list of papers given in the Appendix serve in a general way to 

 indicate the principal sources from which information has been derived. It is 

 believed, however, that the limits assigned each species will be found in the main 

 correct, though in many cases the accessible data have been quite too few to 

 be satisfactory. The generalizations are given, of course, as a representation of our 

 present knowledge of the subject rather than as final. The polar and equatorial limits of 

 the migratory range of the species varies, as is well known, more or less in different years, 

 according to the season. It is also somewhat different on the coast from what it is in 



