with the description of a new Species. 325 



(2.) S. Leucodon, Herm. — The collection contains two adult 

 and four immature individuals of this species. In the adult 

 the upper middle incisors are rather less curved than those of 

 the S. Araneus last described, and with the spur behind less 

 developed. They are quite separate throughout their whole 

 length in one of the specimens, but in contact at their tips in 

 the other. The second and third lateral incisors above are 

 also smaller in relation to the first. The lower middle incisors 

 are long and slightly recurved. The snout is of the same form 

 as in the last species, but its proportions a little different, the 

 distance from the ear to the eye being one-third less. This is 

 in consequence of the upper margin of the auricle being 

 brought rather more forward. The head does not appear so 

 full or large, the crown between the ears being more depressed. 

 The feet are similar, but the tubercles on the soles somewhat 

 smaller. The tail is shorter, and less tapering at the extre- 

 mity ; the long scattered hairs more numerous. The colours 

 are considerably darker above and paler beneath ; that of the 

 upper parts is very deep reddish brown, that of the under 

 pure silvery grey ; the two are separated on the sides by a 

 tolerably well-marked line. 



In the young individuals of this species the teeth are not all 

 apparent, the lateral incisors being still invested with the skin 

 of the periosteum. The middle incisors are much shorter than 

 in the adult *. The snout also is more obtuse, and in three 

 of the specimens the distance from the ear to the eye is rela- 

 tively greater. In the fourth, however, the proportion of this 

 part is the same as in the adult, showing that too great stress 

 must not be laid upon this character. The colours are ex- 

 actly similar. 



Dimensions of the two adult specimens. 



(i.) 



In. Lin. 



Length of the head and body 3 



I of the tail 1 2 



of the hind foot G 



■ of the fore foot 4 



of the ears l£ 



From ear to eye 2 



to the end of the snout 8 



In. Lin. 



2 9 



1 3^ 



6i 



4 



1A 



74 



* I have already noticed the peculiarities of the teeth in these youno- spe- 

 cimens in a former memoir, See Ann. of Nat. Hist., vol. i. p t 427, 



