218 HYSTRIOIN^. 



The remaining rodents have the clavicle imperfect in many, almost 

 wanting in some. They form two groups, llystricidoi and Leporidce. 



Fam. Hystricid^. 



Clavicles typically imperfect ; the lower angle of the lower jaw acute; 

 usually 4 equal molars on each side with roots. 



This family comprises a large number of rodents of varied form and 

 habits, by far the greater number being from America, and only one sub- 

 family occurring in the Old World. 



Sub-fam. Hystricin.e, Porcupines. 



4—4 



Incisors large, usually coloured, not grooved anteriorly ; molars 



4—4 



in adults, complex, with undulated striae of enamel in the crown; body 

 more or less clad with acuminate spines ; fore-foot tetradactylous, with 

 a very small wart-like thumb ; hind-feet with 4 or 5 toes. 



Porcupines possess clavicles, which, however, are only attached to the 

 sternum, and not to the scapula. The skull is remarkable for the great 

 size of the infra-orbital foramen. They have usually 14 paii-s of ribs. 

 The length of the tail is very various. 



Porcupines are burrowing animals, of strictly nocturnal habits, feeding 

 on roots, fruit, bark, and young shoots. The most typical forms of the 

 sub-family belong to the Old World. 



Gen. Hystrix, Linnseus. 



Char. — Hind-feet with five unguiculate toes ; all the claws stout ; body 

 armed with rigid spines, mixed with some longer flexible ones ; tail very 

 short, with a bundle of open tubes at the end ; muzzle truncated. 



Porcupines are a well-known group, which take their popular name, 

 signifying spiny -pig, from their large size and grunting voice. They are 

 found in the warmer regions of the old continent. The peculiar open 

 tubes of the tail are supported on slender stalks, and they make a 

 rattling noise when shaken. 



204. Hystrix leucura. 



Sykes.— Blytii, Cat. p. 128.— Elliot, Cat. 45.—//. Mrsutirostrls, 

 Bkandt. — //. criatata indica, GuAY, Hakdwicke, 111. Ind. Zool. I, 



