THE TREE OR ROOF RAT 601 
Status :—The status of this sub-species has been discussed above 
under the species. The sezz-alerandrines which appeared in the 
course of de I’Isle’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 ra¢fws 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 vaétwus, but we have not experienced any in 
distinguishing alevandrinus from frugivorus. 
(3.) THE TREE OR ROOF Rat. 
Lpimys ratius frugivorus, Rafinesque. 
1814. MUSCULUS FRUGIVORUS, C., S. Rafinesque-Schmaltz, Precis des Découv. et 
Trav. Somiologigques, 13 ; described from Sicily. 
1825. MUS TECTORUM, G. Savi, Wuovo Giorn. de’ Letterati, Pisa, x.. 74; described 
from Pisa, Italy. 
1827, MYOXUS SICUL&, Lesson, Man. de Micromamm., 274 (substitute for MWusculus 
Srugivorus, Rafinesque). 
1839. MUS ALEXANDRINUS, E. de Selys-Longchamps, Etudes de Micromamm., 
54 (in part) ; Blasius (in part) ; de V’Isle. 
1841. MUS SYLVESTRIS, Pictet, Mém. Soc. Phys. et d’Hist. Nat., Généve, ix., 153; 
described from near Geneva, Switzerland (the name an alternative for leucogaster, 
Pictet). 
1841. MUS LEUCOGASTER, Pictet, of. cit, 154. 
1841. MUS NEMORALIS, E. de Selys-Longchamps, A‘# della seconda Riunione 
degli Sctenziati Ital., Torino, 1840, 247 (an accidental substitute for sylvestris, 
Pictet). 
1845. MUS PICTETI, Schinz, Synops. Mamm., ii., 142 (substitute for /excogaster, 
Pictet). 
1905. MUS RATTUS ALEXANDRINUS, J. G. Millais, Mamm. of Great Britain, ii., 
205 (in part) ; (sub-genus Zfzmys) 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). 
Synonymy :—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 a/exandrinus, 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 vattus. Savi’s well-known name, 
VOL. IL 2Q 
