HAEES. 363 



coast, is common to the Old World, where its range extends 

 over the greater portion of Europe, from Scotland to the Ural 

 Mountains and the Caucasus. Singularly enough, the species ap- 

 pears to be wanting in Scandinavia. The variable hare (L. vari- 

 abilis), which is by many authors considered to be identical with 

 the last, or at best only a varietal race, inhabits Eurasia (from Ire- 

 land to Japan) north of the fifty-fifth parallel of latitude, but reap- 

 pears on the more elevated mountain regions of the south where 

 the climatic conditions are apjiroximately those of the northern 

 lowlands. Thus, we find the animal in the Swiss, Bavarian, and 

 Austrian Alps, in the Pyrenees, and in the Caucasus, although in 

 much or most of the intervening lowland it is completely wanting. 

 Unlike the last species, which in the Alpine region occupies prin- 

 cipally the basal tracts, rarely ascending above 5,500 feet,* the 

 variable hare more properly frequents the elevated summits, up to 

 10, 000 feet or more, and only occasionally descends below the level 

 of 4, 000 feet. The species is wanting in the Jura Mountains. Much 

 uncertainty attaches to the true home of the semi-domesticated rab- 

 bit (Lepus cuniculus), which is at the present time so extensively 

 distributed throughout Europe, and the contiguous parts of Asia 

 and Africa. Until recently supposed to have been introduced 

 from Spain, the discovery of its remains in the Quaternary depos- 

 its north of the Alps would seem to throw considerable doubt upon 

 the accuracy of this hypothesis. 



The most complete analysis of the extinct rodent fauna of the 

 Northern Hemisphere is furnished by Schlosser ("Paleeontograph- 

 ioa," 1884), who recognises about seventy well-characterised species 

 from the Tertiary deposits of Europe alone. Of these the most 

 ancient, or those of the Eocene and Oligocene periods, belong in 

 principal part to types that are either entirely extinct or have their 

 nearest analogues among forms living at the present day in tropical 

 America. Such are the genera Nesokerodon, Theridomys, and 

 Protechimys, from the French phosphorites, the first of which ap- 

 pears to be closely related to the South American cavies, and the 

 last two to the spiny-rats, and more distantly to the chinchillas. 

 The squirrels and dormice are represented by the modern gen- 



* Theobald affirms the presence of the common hare at an altitude of 7,000 

 feet in the Orisons (Fatio, "Faune des Vert^br^s do la Suisse," p. 250). 



