CHAP. Ill ZOOLOGICAL REGION^ 49 



hares, all very similar to those of the Eastern Hemisphere, 

 and several hardly distinguishable. Even the bison or 

 " buffalo '' of the prairies, once so abundant and character- 

 istic, is a close ally of the now almost extinct '' aurochs '' of 

 Lithuania. Here, then, we undoubtedly find a very close 

 resemblance between the two regions, and if this were all, 

 we should have great difficulty in separating them. But 

 along with these, we find another set of mammals, not 

 quite so conspicuous but nevertheless very important. We 

 have first, three peculiar genera of moles, one of which, the 

 star-nosed mole, is a most extraordinary creature, quite un- 

 like anything else. Then there are three genera of the 

 weasel family, including the well-known skunk (Mephitis), 

 all quite different from Eastern forms. Then we come to 

 a peculiar family of carnivora, the racoons, very distinct 

 from anything in Europe or Asia ; and in the Kocky 

 Mountains we find the prong-horn antelope (Antilocapra) 

 and the mountain goat of the trappers (Aplocerus), both 

 peculiar genera. Coming to the rodents we find that the 

 mice of America differ in some dental peculiarities from 

 those of the rest of the world, and thus form several 

 distinct genera ; the jumping mouse (Xapus) is a peculiar 

 form of the jerboa family, and then we come to the 

 pouched rats (Geomyidae), a very curious family consisting 

 of four genera and nineteen species, peculiar to North 

 America, though not confined to the Nearctic region. The 

 prairie dogs (Cynomys), the tree porcupine (Erethizon), the 

 curious sewellel (Haploodon), and the opossum (Didelphys) 

 complete the list of peculiar mammalia which distinguish 

 the northern region of the new world from that of the old. 

 We must add to these peculiarities some remarkable 

 deficiencies. The Nearctic region has no hedgehogs, nor 

 wild pigs, nor dormice, and only one wild sheep in the 

 Rocky Mountains as against twenty species of sheep and 

 goats in the Palaearctic region. 



In birds also the similarities to our own familiar songsters 

 first strike us, though the differences are perhaps really 

 greater than in the quadrupeds. We see thrushes and wrens, 

 tits and finches, and what seem to be warblers and 

 flycatchers and starlings in abundance ; but a closer exam- 

 ination shows the ornithologist that what he took for the 



