18S1.] THE SURVEY OF H.M.S. 'aLERT.' 5 



The tail is very long and but scantily haired ; on the upperside 

 the scales are grey and the hairs dark reddish brown, on the lower 

 the scales are pale yellow and the hairs white ; along the centre of 

 the underside, however, there is a distinct narrow line of dark- 

 brown hairs, contrasting with the white ones on either side. 



The ears possess, at about one third the height of the inner 

 margin, a small projecting lobule, which seems to be present in many 

 species of this genus, and to be well worthy of notice, as being 

 very constant in the species in which it is found. The foot-pads 

 are small but distinct, and the surface of the palms and the distal 

 half of the soles are coarsely granulated, as shown in the woodcut. 



The skull is that of a typical Hesperomys, but shows only a very 

 faint trace of the supraorbital ridges supposed to be characteristic 

 of the subgenus Calomys, to which, however, the species undoubtedly 

 belongs, as proved by its long tail and murine form. 



The following are the dimensions of the two spirit specimens, 

 both of which are adult males : — 



a. b. 



inches, inches. 



Length of head and body 4 3 4*2 



tail 6-4 G-1 



„ head I "4 



„ ear 0*.t5 0-.t3 



„ hind foot without claws .... 1'3 1"22 

 Distance from muzzle to ear-oridce 108 



Measurements of skull of 5 : — 



inch. 



Length 12 



Breadth 0-G5 



Breadth between orbits 0'16 



Length of nasals 0'4 



„ lower jaw, from condyle to tip of incisors . . 0*76 



The species to which H. copping eri appears most nearly allied are 

 H. lutescens. Gay ', and H. jihilipini, Landb.", both from Chili. 

 The first, however, is much larger, being 5'7 inches in length, while 

 its tail is only as long as the trunk. Moreover the skull, as figured 

 by Gay, possesses strong supraorbital ridges, while our three 

 specimens of II. coppiiigeri, as stated above, show but little trace of 

 them. H. philippii, though somewhat similar in size and colour, 

 may be readily distinguished by the extreme shortness of its tarsus 

 (0-8 in.) ; and by the character of its fur, which is described as being 

 short and fine, while that of H. coppingeri, as mentioned above, is 

 particularly long and soft. 



6. Hesperomys (Habrothrix) xanthorhinus, Waterh. 



A skin from Monteith Bay, and a specimen in spirit from Sandy 

 Point. 



' Hist. Chile, i. p. 118 ; Atlas, pi. vii. fig. 2. 

 2 Wiegiii. Ai-chiv, 1858, i. p. 80. ^ 



