146 CLASS MAMMALIA. 



The Gerboas are found represented in an upright posture 

 on the models of Cyrenaica. 



Under the name of Mus Jaculus, Pallas has joined three 

 animals, differing in size, and the proportion of certain 

 parts, but strongly resembling in the disposition of their 

 colours, their general forms, the tuft of hair at the tail, and 

 other particulars. He even says himself, that in many re- 

 spects they may be considered as forming distinct species ; 

 and M. de Blainville has divided them, under the name of 

 Mongul Gerboa, Brachyura, and Little Gerboa. 



Samuel Gmelin published a genuine species of Gerboa, 

 under the name of Cuniculus Pumilio Saliens, and Alac- 

 taga, which last word, in the language of the Mongul Tar- 

 tars, signifies variegated colt. This Gerboa resembled, in 

 all respects, the Mus Jaculus of Pallas, of the large variety, 

 except in the hind feet, which, according to Gmelin, have 

 but four toes, while the Mus Jaculus of Pallas has five. It 

 seems probable, however, that Gmelin was mistaken in 

 reckoning the toes, and did not perceive the internal, or 

 fifth toe. This is particularly the opinion of the Baron, as 

 our readers must have seen. 



We shall describe this animal under the name of Alac- 

 taga alone, the great variety of Pallas, and in the two others 

 we shall follow M. de Blainville, without exactly subscrib- 

 ing to his opinion of distinct species. 



This animal is about the size of the common squirrel, and 

 not that of the rabbit, which the name Cuniculus, adopted 

 by Gmelin, would lead us to believe. It differs from the 

 Gerbo by the number of toes on the hinder feet ; the Gerbo 

 having but three, and the Alactaga five. In this relation it 

 approaches the two other varieties of the Mus Jaculus of 

 Pallas, of which we shall speak hereafter. 



The fur is very soft and pliant, of a yellowish fawn over 

 the body, but varied with a grayish brown towards the 

 Crupper- The muzzle is white towards its extremity, and 



