CLASS I. ORDER IV. 57 



inferior 8, the two middle ones broader and very 

 short ; canine teeth long ; grinders denticulated ;- 

 tongue ciliated with papillae ; teats (in most spe- 

 cies) contained in an abdominal pouch. 



MACROPUS, (kanguroo,) front teeth in upper 

 jaw 6, (in young ones 8,) emarginated ; in lower 

 jaws 2, very large, long, sharp, and pointed for- 

 ward ; grinders 5 on each side, both iti upper 

 and lower jaw, distant from the other teeth ; fore 

 legs very short ; hind legs very long ; the female 

 having an abdominal pouch. 



ORDER 4. ARRQSQRES. 



Having incisors in both jaws and no cuspidate 

 teeth ; toes with nails ; feeding almost wholly on 

 vegetable substances. They are the proper gnaiv- 

 crs. 



CASTOR, (beaver,) iRcisors in the upper jaw 

 truncated and excavated with a transverse angle j- 

 in the lower jaw transverse at the tips ; grinders 

 on each side 4 ; tail long, depressed and scaly ; 

 lias collar bones. 



Mus, (rat, mouse,) upper incisors wedge-form ; 

 grinders 3 on each side, rarely 2 ; having collar 

 bones. 



MYOXUS, (dormouse,) incisors 2, upper wedge- 

 form, lower compressed ; grinders 4 in each jaw ; 

 vibrissffi long ; tail cylindric, villose, thicker to- 

 wards the end ; legs of equal length ; 4 toes to 

 each fore foot. 



DIPUS, (long-foot mouse,) incisors 2 above and 

 2 below ; fore legs very short, hind legs very long : 

 having collar bones. 



ARCTOMYS, (rat-bear,) incisors 2 in each jaw, 

 strong, sharp, wedge-form 5 grinders in upper jaw 



