6 MAMMALS OF PENNSYLVANIA AND NEW JERSEY. 



and New Jersey. If we add to these the 30 species found associated in the 

 fossil state with the others, but which are identical with existing species, we 

 have a list of 91 species of fossil mammalia recorded from Pennsylvania and 

 New Jersey. Comparing this with the list of species native to and recently 

 existing in the two states and which numbers 71 species and 25 subspecies 

 or geographic races, we have the rather extraordinary result of a known 

 extinpt mammalian fauna of two eastern states exceeding their existing- 

 mammal fauna. This is the more noteworthy in that nearly all of the 

 terrestrial extinct species have been found in pleistocene, drift or terrace 

 periods, which are supposed to so closely antedate the present age. In 

 contrast with this I may mention that the known extinct mammalian fauna 

 of New York, as given recently by Miller, only numbers 5 species. Another 

 interesting fact, shown by our list, is the former existence in Pennsylvania, 

 and New Jersey of living species now confined to the Arctic and sub-Arctic 

 faunae of Canada. Of these I may mention the caribou, musk ox, moose,, 

 wolverene and walrus. Of the southern or tropical fossil genera, once very 

 abundant in the Delaware Valley, none of the characteristic Sirenians. 

 giant sloths, shark-toothed dolphins, tapirs, peccaries, mastodons, rhinoceros, 

 or sabre-tooth cats now exist anywhere in the earth. These are two of the 

 many interesting proofs of the Arctic source of Postpliocene extinction. 



It will naturally be asked, " What previous publications have been made 

 regarding the mammalogy of Pennsylvania and New Jersey? " 



The most pretentioas, and in fact the only work relating to the entire 

 state of Pennsylvania is found in much scattered form in Dr. B. H. War- 

 ren's part of the book entitled '•' Diseases and Enemies of Poultry," pub- 

 lished in 1897 by the Pennsylvania Department of Agriculture. In this 

 many mammals are treated at length from the economic standpoint, and 

 incidentally a large amount of valuable information, secured from residents of 

 the state, has been recorded regarding .other species. As a book of general 

 reference, however, or as a list of species of Pennsylvania mammals, the book 

 makes no pretensions. A few local Pennsylvania county lists, almost worse 

 than useless because misleading, "have been inserted in older histories."' 

 The same may be said of the local county literature relating to New Jersey. 

 Dr. C. C. Abbot's list of mammals, published in the appendix to the " Geology 

 of New Jersey" in 1868, is the only one relating to the recent mammalia 

 of that state worthy of mention. It enumerates forty-seven species, about 

 one-half of the number now known. Prof. E. D. Cope's list of extinct New 

 Jersey mammals in the same book includes only twenty species,, nearly all of 

 which were based on specimens from the marl beds. This number, in the 

 light of subsequent discoveries, is nearly doubled. 



Since the studies just summarized were begun, twelve existing species, not 

 previously known to occur in Pennsylvania and New Jersey, have been there 



