SYNOPSIS OF THE 



Inhabits the shores of the Caspian. 



Obs. Pallas found but three cheek-teeth on each side in 

 the upper jaw in this species ; if this were not accidental, 

 it should constitute a specific character. 



619. 5. Z>. Mrtc2?mw5 (Great Jerboa.) Bright gray above ; 

 a black line over each eye, uniting on the forehead ; v^^hite 

 underneath ; four toes to the fore-feet, and three to those 

 behind. About the size of a moderate Rabbit. 



Dipus Maximus, Blainville. Desmarest, Nouv. Dict.d' His.t, 

 Nat. 



Icon. . 



Habitat uncertain. 



Obs. We have inserted the several species considered as 

 such by M. Desmarest, some of v^hich, it vf\\\ be seen, Dr. 

 Pallas treats as varieties. 



Gerbillus. Desmarest. Incisive teeth f; canines ^^ ; 

 cheek-teeth ||= 16; cheek-teeth tuberculous, the first with three, 

 the second with two, and the third with one tubercle. Ears 

 moderate; fore-feet short, with four toes and the rudiment of 

 a thumb ; the hind legs long, or very long, terminated by five 

 toes, with nails, each with a distinct metatarsus ; tail long, 

 covered with fur. 



Obs. M. Desmarest separated a number of species, here- 

 tofore inserted in several different subdivisions of the Ro- 

 dentia, into one genus, under the name Gerbillus, without, 

 we believe, having examined the teeth of any of the ani- 

 mals he refers to it, except those of the Egyptian species. 

 The Baron admits also the Indian species into Desmarest's 

 genus; but of those then remaining, he says, that having 

 examined the teeth of some of them, he finds some distinct, 

 and others he refers to new groups. 



Frederick Cuvier has restricted the genus, and gives the 



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