368 Prof. S. F, Baird on the Distribution and 



The southern division of the eastern province is also quite 

 well outlined by Prof. Guyot's limits of the cotton-producing 

 region^ although running much further to the north-west in 

 Arkansas and the Indian Territory than there indicated. 



The much greater tendency of the southern birds, or those 

 belonging to the cotton-region, to go northward in the Missis- 

 sippi valley than along the Atlantic slope is explained not only 

 by the ascent there of the isothermal lines, but by the absence 

 of any such obstacle to their journey as is furnished by the 

 Appalachian range. 



The great central plateau region of Prof. Guyot's map corre- 

 sponds quite closely with the middle ornithological province, 

 reaching north to the Saskatchewan and west to the Pacific 

 slope. The close relationship of the western province to the 

 middle is illustrated by the fact that the region of country ex- 

 ceeding 800 feet in height extends quite to the Pacific in most 

 places, leaving only a few narrow borders and perhaps the valley 

 of the San Joaquin and the Tulare Lakes below that level. 



terizes by the presence of certain species during the breeding-season, 

 replacing certain near allies, in what, with Prof. Agassis, we may term 

 the Alleghanian subdivision. Some of the characteristic and more or 

 less parallel species of birds in these two subdivisions he considers to be 

 the following : — 



Allerihanian. Canadian. 



Dendroeca discolor. Dendroeca striata. 



Pipilo erythrophthalmus. Chrysoniitris pinus, 



Spizella socialis. Curvirostra leucoptera. 



Junco hyemalis. 

 Perisoreus canadensis. 

 Picoides arcticus. 

 Tetrao canadensis. 

 The Canadian subprovince includes, especially the higlilands between 

 Hudson Bay and the St. Lawrence waters and across them into Northern 

 Wisconsin, the higher portion of the Adirondack, Green, and White 

 Mountains, Northern Maine, and, according to Prof. Verrill, the coast- 

 region from Mount Desert to the south-eastern part of New Brunswick, 

 including the islands in the Bay of Fundy. Even far to the south the 

 high mountain-regions of the Alleghanies to Georgia have the same fauna, 

 their most characteristic species of bird being the common blue Snow- 

 bird, Junco hyemalis. 



