MUS SETIFER. 



the posterior extremities the three intermediate toes are largest ; they are robust, 

 and nearly of equal length ; the outer and inner toes are smaller ; the latter is consi- 

 derably removed from the others, and admits a more lateral motion. Underneath, 

 the feet are naked, and provided with prominent tubercles. 



The body is posteriorly lengthened towards the uropygium or vent, affording 

 thus a conical base to the root of the tail. This organ is nearly cylindrical, and 

 very gradually attenuated to an obtuse point : it is covered' with numerous delicate 

 membranaceous rings ; the disposition of these is regular in the highest degree ; they 

 are made up of oblong scales, placed in close contact, so as to exhibit the appearance 

 of rings with crenulated margins, in which the separate squamae are not perceptible. 

 The tail is more naked than that of the Mus decumanus ; a few short delicate hairs 

 arise, in very small tufts of two or three, from the scales composing the rings. 



The colour of our animal is dark brown above, and grayish underneath. The 

 tint is more uniform than in the common Brown Rat. The separate hairs are gray, 

 or tawny, at the base, and dark at the extremity, by which a slight variegation is 

 produced on the surface. The covering is throughout rough and bristly ; the hairs 

 are short on the head and on the under parts generally, and they are here supplied 

 with a little down at the base ; among these, the rigid hairs or bristles, which give a 

 character to our animal, are copiously scattered; they have an oblique direction 

 on the back and the adjoining portions of the sides ; they are here nearly an inch 

 long ; but on the rump they increase in length and in substance ; their direction is 

 more regular, and they constitute a lax covering about the posterior parts, which 

 projects considerably beyond the body, and terminates in an abrupt manner. 



Several points of agreement between the Mus setifer and the Mus decumanus, 

 or Brown Rat, have already been enumerated: in my comparisons with other 

 species of this genus, I have had the assistance only of figures and descriptions. 

 Besides the peculiar rough and bristly character of its hair, our animal differs from 

 the Brown Rat in the extraordinary size of its ears, in the strength of its front 

 teeth, in the comparative nakedness of the tail, and in several minuter particulars 

 in its form and proportions, which, although not easily expressed by words, become 

 obvious by comparison. Among other Indian Rats the Mus giganteus and the 

 Mus perchal have some affinity to it. The former is carefully described by General 

 Hardwicke, in the Vllth Volume of the Linnean Transactions ; and detailed draw- 

 ings, accompanied with notices as to its size, have been received at the Honourable 



