SPECIES OF RAT IN ENGLAND. 107 



the 3fus Rattus of Gesner, Linnasus, Desmarest, and Fleming, was 

 drawn up after the examination of several specimens : — 



The first and largest was a female, its dimensions were, length 

 of head and body, 7 inches; of head, If inch; of tail, 8 inches. 



Colour cinereous black, on the back and sides, belly, and other 

 under parts of the body paler, a male was observed to be not so dark 

 as the female. The fur is composed of two kinds of hair, as in 

 rats generally, long and short, the long predominates on the back 

 and sides, giving a glossy appearance to this fur, which that of 

 the brown rat wants. The cinereous colour is owing to the 

 admixture of black and white hairs, the white hairs are more 

 numerous on the under parts of the body. 



Nose rather sharp, eyes black round and bright, whiskers black 

 and very long, the longest project as far as, or even beyond, 

 the tips of the ears. Uai^s almost an inch long, large, ovate, 

 expanded, delicate, black and naked, epidermis in minute pave- 

 ment-like spots, l^ail, black, in some round, in others squarish, 

 and has about 180 rings of scaly epidermis, from under cover of 

 these rings project backwards whorls of short stiff black hairs. 

 Mammse, five pairs, two pectoral, the first being placed between 

 the fore legs, the second close to the lower margin of chest. 

 Separated from the pectoral, by a considerable distance, are the 

 other three pairs, of which the middle one is placed very near to 

 the last. The two last lie between the hinder legs, and a very 

 short way in advance of, and external to, the genital orifice. 

 Feet of same colour as body and tail; five toes on both fore and 

 hinder feet; but the thumbs on the fore feet are minute, rudimen- 

 tary, and furnished with a small flattish delicate nail. All the 

 other toes have clav/s. Length of sole, fore foot ii inch; hinder 

 foot, nearly 1^ inch. Five pads on sole of fore^ six on that of 

 hinder foot. Teeth, small, delicate, incisors two, molars six, in 

 each jaw, the anterior molar the largest. Length of skull, 1 -g inch ; 

 of lower jaw, | inch. 



Interior: — Abdomen. Liver, 6-lobed, two lobes much larger 

 than the rest. No gall bladder. 



Pancreas, of considerable size, diffused. Spleen, narrow, thin, 

 H inch long. 



