50 



ZOOLOGY OF THE VOYAGE OF THE BEAGLE. 





a deep gray at the base, black at the apex, and narrowly annulated with 

 deep yellow near the apex ; on the throat and belly they are of a paler gray 

 at the base, and grayish white at the apex. The ears are well clothed with 

 brown hairs both within and without, and are for the most part hidden by 

 the long fur of the head. The hairs covering the upper side of the feet are 

 of a palish ashy-brown colour, and the fleshy portion appears to have been 

 brown. The tail is well clothed with hairs, so that the scales are scarcely 

 visible ; on the upper side of the tail the hairs are brownish-black, and on 

 the under side, they are dirty white. The incisors are very slender ; those 

 of the upper jaw are of a very pale yellow colour, and those of the lower 

 are white, or nearly so. The muzzle is slender, and pointed. 



Length from nose to root of tail 



of tail 

 from nose to base of ears 



In. Lines 

 4 9 



2 8 



1 



2 



Length of tarsus (claws included) 



of ear . . . 



In. Lines 



11 

 3 



Habitat, Chonos Archipelago, {December.) 



a 



and 



This mouse is considerably larger than Mus Musculus, and the great length 

 and density of its fur, causes it to appear much stouter in its proportions ; its 

 colouring is darker, the tips of the hairs being much more narrowly annulated 

 with yellow than in that species. The very small size of the ears will serve to 

 distinguish the present animal from its congeners — Mus longipilis, M. Renggeri, 

 M. arenicola, &c. 



* 



The molar teeth of the upper jaw are figured in Plate 34. fig. 8, 

 fig. 8, b, represents the middle and last molars of the lower jaw. 



" Inhabited a very small island, covered with thick forest, in the central part 

 of the Chonos Archipelago." — D. 



A mouse obtained on the islets adjoining the east coast of Chiloe (where 

 Mr. Darwin says it was common) differs from the above in being a little smaller, 

 the tail is rather longer, and the ears are a trifle larger. In the feet, claws, 

 colouring and character of the fur it agrees, and likewise in the pale colour and 

 slenderness of the incisors. Its dimensions are as follows : — 



Length from nose to root of tail 



of tail 



of tarsus (claws included) 



In. Lines 

 4 



3 



10 



Lcnoth from nose to ear 



of ear 



In. Lines 



o ioi 



4 



I have not the means of satisfying myself whether this be a distinct species 

 or not : but I think it is not. 



