362 GEOGRAPHICAL AND GEOLOGICAL DISTRIBUTION. 



whose range formerly extended southward to Virginia (and pos- 

 sibly also to Kentucky), is now largely restricted to its northern 

 habitat, although it is still found in certain portions of the State 

 of Pennsylvania. According to Dr. Allen it is but rarely met with 

 in New England south of Central Maine and Northern New Hamp- 

 shire. The western variety (E. dorsatus, var. epixanthus) occupies 

 the western half of the continent, ranging between Alaska and the 

 Mexican frontier. The greater number of the South American 

 species are included in the genus Cercolabes, tree-porcupine, whose 

 combined range extends from Paraguay to Mexico; Chaetomys sub- 

 spinosus inhabits the warmer parts of Brazil. Of the Old World 

 forms the best known is the crested or common porcupine (Hystrix 

 cristata), whose home is the Mediterranean districts of both Europe 

 and Africa, with some considerable reaches of territory also in the 

 western part of the latter continent. In South Africa this species 

 is replaced by Hystrix Africfe-australis, and in India by the hairy- 

 nosed porcupine (H. leucura), which is found from the Himalayas 

 to the extreme south of the peninsula. Other species of the genus 

 Hystrix and of the brush-tailed porcupines (Atherura) are distrib- 

 uted over the Oriental realm from Nepaul to Borneo ; a species of 

 atherure is also found in Western Africa. 



The last division of the rodents, the rabbit-forms or lagomorphs, 

 embraces the rabbits or hares, and the pikas (Lagomys), small 

 Guinea-pig-like animals which are restricted almost wholly to the 

 elevated mountain districts (11,000 to 15,000 feet) of Northern and 

 Central Asia, with a single species found in Southeastern Europe, 

 and another, Lagomys princeps, in the Rocky Mountain region of 

 the Western United States and Canada. The rabbits and hares 

 (Lepus) include some twenty or more species, which are almost 

 entirely confined to the Northern Hemisphere, where they occupy 

 very nearly the whole of North America and Eurasia, and also 

 Northern Africa. A single species (Lepus Brasiliensis) is found in 

 South America, while several are known from South Africa, al- 

 though in the vast interior of the last-named continent the genus 

 does not appear to be represented. The distribution of the prin- 

 cipal American species has already been discussed in the general 

 consideration of the North American fauna. Only one of these, 

 the polar or Arctic hare (Lepus glacialis or timidus), whose range 

 extends over Greenland and the Barren Grounds to the Arctic 



