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There is still a great amount of uncertainty concerning 

 the distribution and range of our smaller birds, although it 

 is to these that we must chiefly look for the determination of 

 Faunae, but as far as my observations go the following ap- 

 pear to be instances of representation. The Towhee Bunt- 

 ing in the Alleghanian Fauna is represented by the Fox-col- 

 ored Sparrow in the Canadian ; the Grass Sparrow, by the 

 Savannah ; the Song Sparrow, in part by the White-throat- 

 ed ; the Chipping Sparrow, in part by the Tree Sparrow and 

 Blue Snow Bird ; the Pine Warbler, by the Yellow Rump ; 

 the Prairie Warbler, by the Magnolia and Black Poll ; Wil- 

 son's Thrush, by Swainson's Thrush. These are not however 

 given with much confidence, since the observations have not 

 yet been made sufficiently general. Many other more or 

 less doubtful instances might be added, especially among 

 the warblers and flycatchers, but much still remains to be 

 done concerning these very interesting groups. It seems to 

 be well established however that there are two distinct Fau- 

 nae as indicated above. The chief difficulty is to determine 

 their boundaries. To me it seems best to take, as a guide 

 in determining the northern limits of the Alleghanian 

 Fauna, the most southern localities in which those birds pe- 

 culiar to the Canadian Fauna commonly breed. The line 

 thus established seems to separate the two Fauna3 more dis- 

 tinctly than any other. The birds which have been most 

 useful in this investigation, their habits being best known, 

 are the Blue Snow Bird, Pine Finch, Canada Jay, Crossbills, 

 Black-Poll Warbler, and Spruce Partridge. Whenever 

 these breed abundantly in any region it may safely be con- 

 sidered as belonging to the Canadian Fauna. According to 

 this arrangement the Adirondack region of New York, the 

 northern parts of Vermont and New Hampshire, including 

 most of the higher parts of the Green Mountains and all of 

 the White Mountains, and even the summits of the higher 

 Alleghanies, will be included in the Canadian Fauna. But 

 the Alleghanian Fauna will extend northward into some 

 parts of Canada West, about Lake Ontario, and along the 

 valley of the St. Lawrence, perhaps as far as Montreal. In 

 Maine the Canadian Fauna will embrace most of the north- 

 ern portion of the state extending southward as far as the 

 Umbagog Lakes in the western part. Concerning central 

 and northeastern Maine I cannot speak with certainty, but 



