58 



American. Of these, the birds offer many genera peculiar to North 

 America, while the few Mammalia are of Neotropical genera. The 

 greatest resemblance between the North American and Palaearctic 

 region is seen in the Mammalia. Around the Arctic regions as well as 

 further south, several species, both of Mammalia and Birds, are 

 identical. 



Among Mollusks there is also much resemblance. Anodonta, Vnio, 

 and Succinea are common to both the northern faunae, but have no 

 common species; all three greatly predominate in numbers in North 

 America. The snails of the west coast are very European in character, 

 but there are but few Pupae in the Eegio Nearctica, and no GlaiXsiliae^ and 

 Bulimus is represented by few species. 



II. — NUMBER OF SPECIES. 



The numbers of the Vertebrata found in the Nearctic realm are nearly 

 as follows: 



Mammalia : 



Monotremata 



Marsupialia 1 



Edentata 1 



Rodentia 139 



Insectivora 28 



Chiroptera 23 



Cetacea . . 42 



Sirenia 1 



Hyracoidea ; 



Prohoscidea 



Perissodactyla 



i Omnivora 1 



Artiodactyla ^ 



/ Ruminantia 14 



( Pinnipedia 13 



Carnivora ^ 



/ Fissipedia 46 



Primates 1 



310 



AVES : 



SOscines 306 

 Glamatores 33 



Zygodactyli 36 



Syndactyli 20 



