58 CLASS I. ORDER V. 



5 on each side ; in lower jaw 4 : having collar 

 bones. 



SCIURUS, (squirrel,) incisors in upper jaw 

 wedge-form, in lower jaw sharp; grinders 5 on 

 each side in upper jaw, 4 in lower jaw ; having 

 collarbones ; tail spreading towards each side in 

 most species. 



HYSTRIX, (porcupine,) incisors 2, both in up- 

 per and under jaw, obliquely cut ; grinders 8 ; 

 body covered with spines intermixed with hair ; 

 4 toes to each fore foot, 5 to each hind foot. 



LEPUS, (hare, rabbit,) incisors 2 above and 2 

 below, the upper pair duplicate; two small in- 

 terior ones standing behind the exterior. 



CAVIA, (guinea-pig, india-pig,) incisors 2. 

 wedge-form ; grinders 8 ; toes 4 or 5 to each fore 

 foot, to each hind foot 3 to 5 ; tail none or very 

 short ; collar bones, none. 



ORDER 5. EDENTATA. 



Having no incisors, and having hoof-like nails* 



BRADIPUS, (sloth,) cutting teeth none in either 

 jaw ; canine teeth obtuse, single, longer than the 

 grinders placed opposite ; grinders 5 on each side, 

 obtuse ; fore legs much longer than the hind ones r 

 claws very long 



MEGATHERIUM, (extinct genus,) teeth flat-top- 

 ped ; forelegs equal iu length to both head and 

 neck 5 claws long. Intermediate in character be- 

 tween Bradypus and Dasypus. 



DASYPUS, (armadillo,) grinders several, without 

 either the cutting or canme teeth ; body coated 

 with a shelly armour, divided into zones. 



MYRMECOPHAGA, (ant-eater,) teeth none; tongue 

 cylindric, extensile ; mouth lengthened into some- 

 what tubular form ; body covered with hair* 



