SCIENTIFIC RESULTS FROM THE MAMMAL SURVEY. 63 



tail long, more than 120 

 per cent, of head and body 

 length. 



a^ Dorsal colour rufous ; 

 hair of belly rough with 

 rusty tinge ... ... R. rattus nifescens, 



Gray. 

 R. raitus nemoralis, 

 Blyth. 

 h'. Dorsal colour rarely ru- 

 fous ; bellies without 

 rusty tinge. 

 a\ Backs grey or brown ; 

 belly light grey to 

 dusky, rough or 



smooth R. rattus alexandrinus , 



Geoff. 

 b\ Back black; belly 

 bluish gi'cy, sleek 



haired R. rattus rattus, 



Linnaeus. 



1. Rattus rattus, Linnasus. 



A brief reference to the history of this species in Europe will 

 greatly facilitate both the presentation and the understanding of 

 the Indian facts. Mus rattus, Linneeus [Syst. JSat., 10th ed., 

 1758, p. Q\), was described from Upsala, Sweden and based upon 

 the well known Black Rat. At or a little before the date when 

 Linnaeus wrote, this animal was the common house rat of Europe, 

 but later it was almost completely replaced by the Brown Rat 

 (^R. norvegicus, Berkenhout). T^-pical /?. rattus is characterized 

 externally by its dusky coloration, its back being usually black 

 and its underparts of a dark brownish grey or slate. In 1803, 

 Geoffrey (Cat. Mamyn. Mas. Nat. cV Hist. Nat. Paris, p. 192) named 

 his Mus alexandrinus from Alexandria, Egypt ; and in 1812, he 

 gave a full description and figure (Descr. de lEgypte, Hist. Nat. 

 II., p. 735 ; Atlas PI. V, fig. 1). From the latter account it is 

 evident that Mus alexandrinus is a rat in which the back is buffy 

 brown, this colour brightening gradually on the flanks to pass 

 insensibly into the whitish or yellowish grey of the underparts. In 

 1814, Rafinesque (Prec. des Decouv. et Trav. Somiologiques, p. 13) 

 described his " MwscwZms frugivorus", from Sicily ; 'and in 1825, 

 Savi (Nuovo Giorn. dei Letterati, Pisa, X, p. 74) re-described the 

 same form from Pisa, Italy, under the name of Mus tedorum. This 

 Sicilian and Italian rat is brown above as in ahxandrinus, but it 

 possesses a softer coat, and the fur of its underparts is of a pure 



