488 THE AGE OF MAMMALS 



north of Arkansas, shows that the cUmate was of a northerly type similar 

 to that of the forested regions of British Columbia. With the exception of 

 the musk ox — which, it must be remembered, formerly had a more south- 

 erly range than at present — it is certainly in no sense a tundra or arctic 

 fauna. The assemblage, nevertheless, indicates the crowding southward of 

 northerly forms, such as may have occurred during the advance of the great 

 ice sheet. There is no evidence of the existence here at this time of Mega- 

 lonyx, or Mylodon, of the tapir, mammoth, or mastodon. It would not be 

 safe, however, to assume from this evidence that the tapir, mammoth, and 

 mastodon were extinct in all other parts of the American continent at the 

 time. The only four now extinct genera which give an ancient character 

 to this fauna are the saber-tooth tiger, above mentioned, an extinct species 

 of horse (E. scotti ?), an extinct genus and species of peccary (Mylohyus), 

 and the extinct genus of skunk (Brachyprotoma) , three species of which are 

 found in the Port Kennedy Cave. 



The condition of the bones and the association and predominance of 

 certain forms indicate that this fissure was the home of several contem- 

 poraneous species which preyed on still others and brought their remains 

 into it. Cats and bears probably inhabited parts of this cavern, dragging 

 in peccaries and deer; weasels occupied runways in the rock, which are filled 

 with remains of mice, rabbits, and wood rats. Shrew and mice bones were 

 probably introduced largely by owls, which may have lived on the ledges of 

 the fissure. The fauna is typically that of a forest region, with open glades, 

 similar to the present conditions of the same region in Arkansas. There 

 are five species of shrews, three of which are now extinct, a mole, two bats, 

 one living and three extinct species of skunk. Other mustelines are the 

 fisher marten (Mustela pennanti), the mink (Putorius vison), and the weasel. 

 The gray wolf (C. occidentalis) was accompanied by the red fox (Vulpes 

 fulvus f), and the gray fox (Urocyon sp.). The raccoon (Procyon lotor) 

 was abundant. We observe the black bear {U. americanus) , but, as in the 

 Samwel Cave of California, there is no evidence of the giant South American 

 bear which is found in all the earlier Pleistocene deposits of the Megalonyx 

 Zone. Among the cats are lynxes and pumas, beside two species of the 

 extinct saber-tooth (Smilodontopsis troglodytes, S. conardi). 



Among the larger Herbivora both the mule deer (Odocoileus hemionus) 

 and the white-tailed deer (0. virginianus) are recorded, as well as the wapiti 

 (C. canadensis) and the extinct genus and species of musk ox {Symbos ous- 

 tralis) . It is noteworthy that the peccary is not of the existing southwestern 

 type (Dvcotyles torqiiatus), but belongs to the genus (Mylohyus) character- 

 istic of the Megalonyx Zone. 



The small rodent fauna is that of the present forested regions of the 

 Rocky Mountain area. 



Canadian deposits. — The Iroquois Beach deposits (Fig. 194, 2) are con- 

 sidered by Canadian geologists of post-Glacial age. They contain numerous 



