MAMMALIA. 



/'. Incisors compressed ; one small upper premolar; infra- 

 orbital opening very large and rounded; metatarsal 

 bones greatly elongated ; hind-feet with five digits, of 

 which the first and fifth do not reach the ground ; tail 

 long, cylindrical and tufted. . Alactaga, p. loi. 



b^. One premolar above and below; molars with re-entering 

 enamel folds and semi-rooted; no post-orbital processes to 

 frontals ; mandible with the angular portion springing from 

 the outer side of the bony covering of the lower incisor ; 

 fibula a distinct bone throughout life ; muffle hairy ; fur 

 modified into spines and quills. [=Hystricidae.] 



M. Spines cylindrical ; tail short, covered with spines and 

 hollow quills. . . . . Hystrix, p. 104. 



n^. Spines flattened and channelled ; tail long, scaly, with a 

 tuft of bristles Atheruraj p. 104. 



. Two pairs of incisors above; optic foramina confluent; no 

 alisphenoid canal ; bony palate much reduced ; fibula and 

 tibia anchylosed below and articulating with the calcaneum ; 

 testes always external. [=Duplicidentata.] 



0. Two premolars above and below ; frontals with no post-orbital 

 process ; ears and hind limbs short ; no external tail. 



Lagomys, p. 109. 



o'. Three premolars above, two below ; frontals with two wing- 

 like processes ; ears and hind limbs elongated ; tail short, 

 bushy, and recurved . . . Lepus, p. 112. 



Genus SCIURUS. 



Sciurus, Linnaus Syst. Nat,, I2ih ed., i, p. 56 (1766). 

 Macroxus, Gray Ann. Mag. N. H. (3) xx, p. 275 (1857). 



The Museum collection of the squirrels of the Oriental Region 

 is a very complete one and formed the basis of Anderson's mono- 

 graph of the group in his Anatomical and Zoological Researches. 

 In the Catalogue below Anderson has, except in one or two 

 trifling instances, been followed, though it seems that still further 

 reductions will have to be made in the number of species, more 

 especially in the group of grizzled squirrels. 



The synopsis or key is not intended to apply to geographical 

 varieties of Indian species not found within the limits of the Indian 

 empire, so that the numerous pale varieties of Sciurus bicolor and 

 the curiously coloured varieties of Sciurus ferrugineus, which are 

 none of them found within the limits of the Indian empire, are 

 not included in the key. 



