4 MAMMALS OF PENNSYLVANU AND NEW JERSEY. 



therm showing a normal mean temperature of six hottest consecutive weeks 

 of 64.4 degrees; of the Transition zone, ditto, 71.6 degrees; of the Upper 

 Austral, 78.8 degrees. The northern limits of the Transition and Upper 

 Austral zones are defined by the sum of normal, mean daily temperatures 

 for the year above 43 degrees, which is 10,000 degrees for the Transition 

 and 11,500 for the Upper Austral. 



In the case of rare or exterminated species a series of records of their 

 historic or more recent occurrence in the various parts of the two states is 

 given by counties. These have been condensed and summarized from an 

 extended correspondence with observers, historians, scientific students, trap- 

 pers, furriers and sportsmen, some of whom, very old men, have since died, 

 and their valuable knowledge of pioneer conditions in our Hmits would 

 have largely gone with them had it not been thus recorded. 



The habits and economic relations of most of the species are touched 

 upon ; those of greater interest, because so little known, as popularly mis- 

 judged or now exterminated, are more fully treated. In this connection it 

 may be stated that there is only one species of vative mouse in Pennsylvania 

 and New Jersey, namely, the mole mouse, underground meadow mouse, 

 or pine vole, M. pinetorum. whose food habits may be said to be so noxious 

 as to make its extermination a desideratum. Moles, shrews and common 

 meadow mice are greatly misunderstood even by those who profess to study 

 them from an economic point of view. The status of the rapacious carnivora 

 — skunks, weasels, minks, coons, bears, wild cats, foxes, etc. — which still form 

 a large part of the living population of our forests, deserves as thorough 

 study as has been recently given by the United States Department of Agri- 

 culture to rapacious birds. From the researches of Dr. Warren in Penn- 

 sylvania along this line we may predict that the popular verdict on these 

 vagabonds will in many cases be found faulty. The commercial importance 

 of many so-called "injurious" mammals, which yield either food or furs 

 to man, is far greater than many realize. For instance the trade, and conse- 

 quent profits, arising from the trapping of muskrats in the Delaware Valley 

 alone amounts to many thousands of dollars annually, and offsets a hundred 

 fold their destruction of dikes, dams, forage crops or grain. The bodies 

 of these muskrats are rarely wasted, being so prized in Cumberland Co., 

 New Jersey, as to have a standard market value of five to eight cents each. 



The Cetacea, or Whales and Dolphins, generally ignored in mammal 

 study because of the confusion so long existing as to their character, 

 identity and habits, have been given special attention, forming as they do, 

 such a numerous representation in the waters of New Jersey. No less 

 than eighteen species of these leviathans, ranging in length from 5 to 80 

 feet, wander to or now exist off our shores, some of the largest entering 

 tidewater as far inland as Trenton. Nine additional extinct whales roamed 



