LEPORID^— LEPCS TIMIDUS. 289 



I am unable to find any characters, either in the skulls or skins, by 

 which L. " glacialis" auct. can be distinguished from the L. "variabilis'' 

 auct. (= L. timidus Linn., 1766), and I find that a similar difficulty has been 

 encountered by other authors. Brown says, " It is difficult (indeed almost 

 impossible) to give characters whereby this species can be separated from 

 the Lepus variabilis of Europe when the former is in its summer dress ; and 

 the skull presents equal difficulties. I have, however, preferred to look upon 

 it as nominally distinct, though I really believe that it is only a climatic 

 variety of L. variabilis, Pallas." * Lilljeborg also quotes Blasius as finding no 

 difference of importance between L " glacialis'' and L. variabilis, either in 

 skins or skulls.f 



The earlier writers considered them identical, and in their accounts of 

 L. variabilis usually spoke of it as inhabiting Greenland and the arctic por- 

 tions of America as well as the northern parts of Europe and Asia. 



The American animal was first regarded as specifically distinct from the 

 European by Dr. Leach, in 1819, when he distinguished the American form 

 first as L. arcticus, and later in the same work as L. glacialis. His specimens 

 were from the shores of Baffin's Bay In 1824, Captain Sabine (Appendix to 

 Captain Parry's First Voyage) gave a detailed enumeration of its supposed 

 distinctive characters, he believing the American form to be the larger, with 

 proportionally longer ears, and the incisors more curved than in the European. 

 These alleged differences, however, are such as disappear in the comparison 

 of large series of each, being either simply individual peculiarities or differ- 

 ences due to the latitude of the locality. In accordance with the well estab- 

 lished law of variation in size with locality (viz., decrease in size with 

 decrease of latitude), specimens from the far north are considerably larger 

 than those from more southern localities Hence American specimens from 

 the arctic regions are much larger than specimens from the Scottish High- 

 lands or from Southern Scandinavia, as well as much larger than Newfound- 

 land specimens. On the other hand, specimens from Lapland are as large as 

 those from Greenland and the arctic shores of America, while the Scottish 

 and Scandinavian specimens scarcely differ in size from those from New- 

 foundland and the shores of the Great Slave Lake. 



The actual differences between the European and American forms, 

 judging from the limited material before me, seem, as already stated, to be 



* Brown (R.), Proc. Zool. Soc. Lond., 1868, 351. t Faun. Sver. och Norges, i, 422. 



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