THE TREE OR ROOF RAT 6oi 



Status : — The status of this sub-species has been discussed above 

 under the species. The semi-alexandrines which appeared in the 

 course of de I'lsle's breeding experiments (see p. 595) seem to represent 

 this form, which may have arisen in the first place as a Mendelian 

 mutation. By most writers it is considered as a mere intermediate 

 between true rattus and the next sub-species, and it is the principal 

 foundation of the statement, commonly found in books, that all inter- 

 mediate stages can be found between the two extremes. As already 

 mentioned, we have found occasional difficulty in separating dark 

 specimens from true rattus, but we have not experienced any in 

 distinguishing alexandrinus from frugivorus. 



(3.) The Tree or Roof Rat. 



Epimys rattus frugivorus, Rafinesque. 



1814. MUSCULUS FRUGIVORUS, C. S. Rafinesque-Schmaltz, Precis des D^couv. et 



Trav. Somiologiques, 13 ; described from Sicily. 

 1825. Mus TEcrORUM, G. Savi, Nuovo Giorn. de'Letterati, Pisa, x., 74 ; described 



from Pisa, Italy. 

 1827. Myoxus sicuLiE, Lesson, Man. de Micromamm., 274 (substitute for Musculus 



frugivorus, Rafinesque). 

 1839. Mus ALEXANDRINUS, E. de Selys-Longchamps, Etudes de Micromamm., 



54 (in part) j Blasius (in part) ; de I'lsle. 

 1841. Mus SYLVESTRIS, Pictet, Mdm. Soc. Phys. et d'Hist. Nat, Genive, ix., 153; 



described from near Geneva, Switzerland (the name an alternative for leucogaster, 



Pictet). 

 1841. Mus leucogaster, Pictet, op. cit., 154. 

 1841. Mus nemoralis, E. de Selys-Longchamps, Atti delta seconda Riunione 



degli Scienziati Ital., Torino, 1840, 247 (an accidental substitute for sylvestris, 



Pictet). 

 1845. Mus picteti, Schinz, Synops. Mamm., ii., 142 (substitute for leucogaster, 



Pictet). 

 1905. Mus rattus alexandrinus, J. G. Millais, Mamm. of Great Britain, ii., 



205 (in part) ; (sub-genus Epimys) Trouessart (in part). 

 1909. Mus rattus tectorum, J. L. Bonhote, Proc. Zool. Soc, London, 1909, 



794, and 1910, 652. 

 1912. Epimys rattus alexandrinus, G. S. Miller, Cat. Mamm. West Europe, 



854 (in part). 



Synonsnny : — The present form, differing widely in appearance from 

 E. r. rattus, has naturally attracted far more attention than the other 

 wild-coloured sub-species, E. r. alexandrinus. By most recent writers 

 it has been confounded with alexandrinus, but, as shown above, the 

 latter name must be restricted to the form which, having a dusky 

 belly, has been regarded generally as a mere gradation between the 

 present sub-species and typical rattus. Savi's well-known name, 

 VOL. IL 2 Q 



