1897.] NATURAL SCIENCES OF PHILADELPHIA. 205 



named above show but slight departure from the typical Alleghen- 

 ian scenery with which the traveller from Harrisburg to Pittsburg 

 becomes familiar in his westward route along the Juniata River. 

 The whole country is more or less crowded with parallel ranges of 

 mountains running northeast and southwest, much broken by coves 

 and cross valleys whose numerous streams empty, with the exception 

 of those of Cambria and Somerset Counties, into the Susquehanna. 



The character of the Alleghenies over this wide area conforms 

 closely to the continuous ridged type of parallel chains rising in long, 

 flat-topped ranges, which rarely present a peak or dome to relieve 

 their rounded, monotonous outlines. Their average height is about 

 1,200 feet, though an elevation of over 2,000 feet is reached in some 

 localities. With the exception of Sullivan County, nearly the entire 

 region treated in this paper is devoid of lakes, lying as it does almost 

 wholly south of the southern border of the great terminal moraine. 



Owing to deforesting and burning of the timber over the whole 

 region, the character, not only of the existing flora, but in greater or 

 less degree of the climate and fauna of the country, is more or less 

 altered from the conditions of 100 years ago. 



While this has resulted in the extinction of certain forms of rep- 

 tiles, birds and mammals from their place in the fauna of Pennsylva- 

 nia, it has not so affected the smaller mammalia, which continue to 

 find in isolated places the necessary life environment. 



Such places it has been the author's endeavor to search out and 

 thoroughly explore, in order to supplement our historic knowledge 

 of the larger exterminated species with reliable facts regarding those 

 whose subterranean and retiring habits, or restricted range, have 

 enabled them to escape the older methods of research. 



Central Pennsylvania, with the exception of the lowlands of the 

 Susquehanna below Sunbury and a large part of the Counties of 

 Adams, York, Cumberland and Franklin in the south, is dominated 

 principally by the semi-boreal climate, fauna and flora which Dr. 

 Allen has fittingly named "Alleghenian," as contrasted with the 

 colder "Canadian " of the north and the warmer Carolinian of the 

 south. In the intermediate region between these last we find the 

 most puzzling gradations of animal and plant forms. On the high- 

 est elevations, however, faunal distinctions are well marked and 

 in strong contrast with those of the southern lowlands. The most 

 boreal environment encountered in my investigations was at Eagles- 

 mere, in Sullivan County, the only place in which the typical 



