136 ZOOLOGICAL GEoGKAPHY. [part hi. 



celebrated for its power of ejectiug a terribly offensive liquid, the 

 odour of which is almost intolerable. The skunks are nocturnal 

 animals, and are generally marked, as in the species represented, 

 with conspicuous bands and patches of white. This enables 

 them to be easily seen at night, and thus serves to warn larger 

 animals not to attack them. To the left is the curious little 

 jumping mouse {Jaculus hudsonius), the American representative 

 of the I'aliearctic jerboa. Climbing up a tree on the left is the 

 tree porcupine {Erethizon dorsatiis), belonging to the family Cer- 

 colabidcE, which represents, on the American continent, the por- 

 cupines of the Old World. In the background is the elk or 

 moose (Alces americanus), perhaps identical with the European 

 elk, and the most striking inhabitant of the northern forests of 

 America, as the bison is of the prairies. 



Birds. — Although the Canadian sub-region possesses very few 

 resident birds, the numbers which breed in it are perhaps greater 

 than in the other sub-regions, because a large number of circum- 

 polar species are found here exclusively. From a comparison of 

 Mr. Allen's tables it appears, that more than 200 species are 

 regular migrants to Canada in the breeding season, and nearly 

 half of these are land-birds. Among them are to be found a 

 considerable number of genera of the American families Tyran- 

 nidie and Mniotiltidas, as well as the American genera Sialia, 

 Progne, Vireo, Gistothorus, Junco, Pipilo, ZonotricMa, Spizdla, 

 Melospi^a, Molothrtts, Agelmus, Cyanura, Sphyrapicus, and many 

 others ; so that the ornithology of these northern regions is still 

 mainly Nearctic in character. Besides these, it has such specially 

 northern forms as Surnia (Strigid?e) ; Picoides (Picidse) ; Pinicola 

 (Fringillidce) ; as well as Leucosiicte, Plectroplianes, Perisoreus, 

 and Lagopus, which extend further south, especially in the middle 

 sub-region. No less than 212 species of birds have been col- 

 lected in the new United States territory of Alaska (formerly 

 Russian America), where a humming-bird (Sclasphorus rvfiis) 

 breeds. The great majority of these are typically American, 

 including such forms as Colaptes, Helminnwphaga, Siurus, Den- 

 drccca, Myiodiodes, Passercubcs, ZonotricJiia, Junco, S^nzella, 

 Melospizpa, Passerella, Scoleophagas, Pediocetes, and Bonasa; 



