308 



RODENTIA . 



MURID.^,. 



MURID^. 



BROWN RAT. 



NORWAY RAT. 



Mus decumanus. (Pall.) 



Specific Character. — Greyish-brown above, whitish beneath; ears one-tliird 

 the length of the head; tail shorter than the body. 



Mus decumanus, Pallas, Glir. p. 91. Gmel. Syst. Nat. Linn. I. p. 127. 



Desmar. Mammal p. 473, sp. 473. Flem. Brit. An. 



p. 20. Jenyns, Brit. Yert. p. 32. Blas. Wirbelt. Deutscb. 



I. p. 313. 

 ,, norvegicus, Brisson, Reg. An. p. 173. Erxleb. Syst. p. 381, 1. 

 Surmulot, Bcffon, Hist. Nat. VIII. p. 206, t. xxvii. Fr. Cuvier, 



Mammal. I. 

 Norioay Raf, Penn. Brit. Zool. I. p. 115. Shaw, Gen. Zool. II. p. 51, 



t. cxxx. 



The geographical distribution of animals, although a 

 subject of great interest, and one which has of late years 

 occupied the attention of many eminent zoologists, is 

 not yet sufficiently understood to furnish any very well- 

 defined laws, either with reference on the one hand to 



