CHAP. XV.] 
THE NEARCTIC REGION. 
135 
americanus), and the ground dove ( Chamcepelia passerina). The 
most regular visitants are a kingfisher ( Geryle alcyon), the wood- 
wagtail ( Siurus noveboracensis), the rice-bird ( [Doliehonyx oryzivo- 
rus), and a moorhen ( Gallinula galeata). Besides the American 
species, four European birds have been taken at the Bermudas : 
Saxicola oenanthe, Alauda arvensis (perhaps introduced), Crex 
pratensis, and Scolopax gallinago. 
A common American lizard, Plestiodon longirostris , is the only 
land reptile found on the islands. 
IV. The Sub-Arctic or Canadian Sub-region. 
This sub-region serves to connect together the other three, 
since they all merge gradually into it; while, to the north it 
passes into the circumpolar zone which is common to the Palce- 
arctic and Nearctic regions. The greater portion of it is an exten- 
sive forest-district, mostly of coniferse; and where these cease 
towards the north, barren wastes extend to the polar ocean. It 
possesses several northern or arctic forms of Mammalia, such as 
the glutton, lemming, reindeer, and elk, which barely enter the 
more southern sub-regions ; as well as the polar bear and arctic 
fox ; but it also has some peculiar forms, and many of the most 
characteristic Nearctic types. The remarkable musk-sheep 
(Ovibos) is confined to this sub-region, ranging over a con- 
siderable extent of country north of the forests, as well as 
Greenland. It has been extinct in Europe and Asia since the 
Post-pliocene epoch. Such purely Nearctic genera as Procyon, 
Latax, Erethizon, Jaculus , Fiber , Thomomys , and Hesperomys , 
abound, many of them ranging to the shores of Hudson’s Bay 
and the barren wastes of northern Labrador. Others, such as 
Blarina , Gondylura, and Mephitis, are found only in Nova Scotia 
and various parts of Canada. About 20 species of Mammalia 
seem to be peculiar to this sub-region. 
Plate XX. Illustrating the Zoology of Canada. — We have 
here a group of Mammalia characteristic of Canada and the 
colder parts of the United States. Conspicuous in the fore- 
ground is the skunk (. Mephitis mephitica), belonging to a genus 
of the weasel family found only in America. This animal is 
