184 IIURID^. 



toes as usual, have been separated as Alactaga, Gray, one species of which, 

 Alaetaga indica, Gray, inhabits Afghanistan, and its habits have been 

 described by Hutton. Most of the jerboas are from Africa, a few from 

 Central Asia. They make most surprising jumps. 



Sub-Fam. Murinje, Rats and Mice. 



Incisors compressed laterally, the lower ones acuminate, awl-shaped; 



3 3 



molars, ^ — - ; rooted, uniformly covered by enamel, the anterior one of 

 o — o 



each series the largest, the posterior the smallest ; the upper molars shelve 

 somewhat backwards, the lower ones forwards. Pore-feet with 4 wide-set 

 toes, and a hallucar unguiculate wart ; hind-feet with 5 toes. Tail usually 

 long and thinly clad or nude, short, and hairy in a few. Cosmopolite. 



This comprises the true rats and mice. Mr. Blyth, just before his 

 departure from India, wrote a valuable memoir on the rats and mice of 

 India, which has been my chief guide in treating of these little animals. 

 Much yet remains to be done in elucidating this group, and determining 

 the value of many of Mr. Hodgson's species. 



Gen. Gerbillus, P. Cuvier. 



CImt. — Upper incisors grooved ; molars equably enamelled with trans- 

 verse ridges, forming when worn oval figures. Ears oval. Head length- 

 ened and somewhat pointed ; hinder tarsus and toes elongated. Tail 

 long, hairy, with a tuft of hair at the tip. 



These field rats have small fore limbs and well developed hinder limbs. 

 Their form is somewhat slender and their eyes are large. They are ex- 

 traordinarily agile, and form extensive burrows in plains, especially in 

 sandy districts, and also in sand hills, but not generally in cultivated fields. 

 They are found in Africa and Asia. 



170. Gerbillus indicus. 



Dipiis apnd Hardwicke, Lin. Tr,, VIII. pi. 7. — 111. Ind. Zool. — Blyth, 

 Cat. p. 110.* — Elliot, Cat. 32. — G. HardwicHt, Gray, and G. Cuvieri, 

 Watbrhouse. — Huma mus, H., «'. e., Antelope rat. — Jhenhi indur, Sansc. 

 and Bengal. — Fen yelha, of Waddurs. — Tel yelka of the Yanadees. — 

 Billa ilei, Can. 



* The printer has playetl euch prftiikfl with the subsequent numberB n Bljiib's Catalogue, that 

 henceforth I will only cite the page. 



