1889] A Disputed Pedigree. 353 



*' Fauna of the Outer Hebrides," inclined to rank it as a 

 species, but far more closely related to the Brown (Mus 

 decumanus) than to the English Black Rat. Mr. Thoma . 

 Southwell, disputing this conclusion (" Zool.," Sept. 1889), 

 thought it was probably a cross between the two. Ulti- 

 mately ("Zool.," Jan. 1891) Messrs. Eagle Clarke and 

 Barrett-Hamilton published, as the result of an exhaustive 

 inquiry, the conclusion, since generally subscribed to, that 

 the " Irish Black Rat " is a melanistic variety of Mus de- 

 cumanus, the common Brown Rat. 



2 A 



