

122 MAMMALIA. GLIRES. 



flat spines on the back ; tail nearly as long as the body, scaly and 

 black. Isle of Trinity, Gulf of Mexico Mam. 313. 



Gen. 100. DIPUS, Cuv. Geoff. Gmel. 



Incisors , canines g-g, molars f-f or \-\ = 16 or 18. Mo- 

 lars simple, with tuberculous crowns ; eyes large ; ears long, 

 pointed ; posterior extremities much elongated, with the num- 

 ber of toes variable, but having only one metatarsal bone ; tail 

 very long, tufted. 



These singular animals, approaching something in form to the Kangaroo, but 

 very different in other particulars, were formerly supposed to walk solely upon their 

 hind-feet ; but subsequent observation has proved this to be wrong. They usually 

 walk on all-fours, but when alarmed endeavour to escape by prodigious leaps, spring- 

 ing from their hind-feeet by the assistance of their tail, their fore-feet being pressed 

 close to their breast on these occasions. 



D. maximus, Blainv. The Great Jerboa. Fur bright gray above, 

 with a black line over each eye, uniting on the forehead ; four 

 toes on the fore-feet, and three on those behind. Size of a rabbit. 



D. gerboa, Desm. (Musjaculus, Lin.) The Jerboa. Fur bright 

 fawn-colour above, white underneath ; tail tufted ; three toes on 

 the hind-feet, the middle one longest. About six inches long. 

 Barbary, Egypt, &c. Shaw, ii. pi. 157. 



D.jaculus, Desm. (Musjaculus, Pall.) Pale fawn-coloured above, 

 white below ; muzzle white, and a white band across the buttocks ; 

 five toes on the hind-feet ; ears long. Seven inches long. Tar- 

 tary Shaw, ii. pi. 158. 



D. brachyurus, Desm. Pale fawn-coloured above, white below ; 

 a white crescent-shaped spot on the buttocks ; muzzle white at 

 its extremity, brown above ; tail and limbs thick ; ears short ; 

 hind-feet pentadactyle. Four inches and a-half long. Siberia. 



D. minutus, Desm. Fur pale yellowish gray, whitish underneath ; 

 the extremities and transverse stripe on the buttocks white ; hind- 

 feet pentadactyle. Four inches long. Shores of the Caspian sea. 



Gen. 101 . GERBILLUS, Desm. F. Cuv. 



Incisors f, canines g-g, molars - =16. Molars tubercu- 

 lous ; posterior extremities very long, with five toes, each 

 with its proper metatarsal bone ; tail long, covered with hair. 



G. tamariscinus, Desm. (Mus tamariscinus, Pall.) Fur grayish yel- 

 low above, white below ; tail nearly as long as the body, annu- 

 lated with brown. Six inches and a-half long. Shores of the 

 Caspian Sea Shaw, ii. pi. 160. 



G. meridianus, Desm. (Mus longipes, Lin.) Fur grayish fawn- 

 colour above, white below, with a central line of red brown on 

 the belly. Body four inches long. Deserts near the Caspian 

 Sea Shaw, ii. pi. 160. 



G. Indicus, Desm. Fur chestnut above, sprinkled with small brown 



