o , NEW YORK STATE MUSEUM 



there is often a peculiar intemiingling of northern and southern forms. 

 Thus, species which are ordinarily regarded as Carolinian may be found 

 breeding side by side with Canadian species, and although the Alleghanian 

 species are the most abundant in those localities, the Transition zone seems 

 to have lost its special character by the Carolinian fauna being joined 

 directly with the Canadian. This effect though noticeable to a certain 

 extent in the Catskill region, as has been shown by Mr Bicknell, is particu- 

 larly evident in western New York as will be seen in the account of the 

 Potter Swamp area. The plateau and lowland of western New York west 

 of the 75th meridian slopes from an altitude of about 2000 feet near the 

 Pennsylvania line to 250 feet on Lake Ontario. Though its slope and 

 drainage is chiefly to the north, the waters of this region reach the sea at 

 such widely diverse points as the Gulf of St Lawrence, New York bay, 

 Delaware bay, Chesapeake bay and the Gulf of Mexico. The plateau 

 region thus is reached by the narrow extension northward of the Delaware, 

 Susquehanna and Alleghany valleys, but at such a high altitude that few 

 southern forms are introdvxced by those routes. There is little or no evi- 

 dence that Carolinian fomis come into western New York by way of the 

 Mohawk valley, bvit the chief influx is from the west by way of southern 

 Ontario, and along the southern shore of Lake Erie, and from the south 

 along the Delaware and Susquehanna valleys. In the Adirondacks and 

 Catskills the Canadian fauna is entirelv surrounded b)- the Alleghanian 

 which ascends all the valleys to the very hearts of those regions. The 

 eastern end of Long Island, cooled by the sea, is mostly Alleghanian in its 

 fauna, but still strongly tinged with the Carolinian. 



The Alleghanian faunal area in New York, though perplexing to map 

 out accurately, certainly includes the greater portion of the State and its 

 birds are the most abundant and well known in all localities from Long 

 Island to the spruce and fir line of the Catskills and Adirondacks. In this 

 area "the chestnut, walnut, oaks, and hickories of the sovith meet and 

 overlap the beech, birch, hemlock, and sugar maple of the north ; the southern 

 mole and cottontail rabbit meet the northern star-nosed and Brewer's 

 moles and varying hare, and the southern bobwhitc, Baltimore oriole, 

 bkiebird, catbird, chewink, thrasher, and wood thrush li\'e in or near the 



