Mam . Class ifica tio n. 13 



divided into Seven Families. 



1. Ttie Phascolomydce (Wombat) present, in ttie arrange- 

 ment of the teeth, a considerable resemblance to the Rodentia. 

 2. The Macropidce are at once distinguished by their exceed- 

 ingly long and powerful hind legs with elongated feet, resting 

 with their whole sole upon the ground ; and forelegs very 

 short. 3. The Phalangistidcc have all a large thumb, so 

 separated from the other digits that it seems to be directed 

 backward, as in birds ; it has no nail, and the two following 

 fingers are joined by the skin as far as the last phalanx ; from 

 this [circumstance they have derived the family name. The 

 three preceding families feed chiefly on plants ; the next four 

 on flesh or insects. 4. In the PeramelidcE the form of the 

 molars would seem to agree with those of the order Insecti- 

 vora : in structure of hind legs they approach the Macropidae. 

 5. The Didelphidoe are remarkable as alone of all the Marsu- 

 pials possessing eight incisors in the lower jaw. 6. The 

 Myrmecohiidce are distinguished from all other Marsupials 

 by the great number of teeth, viz. fifty-two. 7. The family 

 of the Dasyuridce includes the largest of the rapacious Mar- 

 supials. 



XY. The Order MO:^OTEEMATA (iiovoq, single ; rpr^na, 

 orifice) is so called in reference to the single excretory and 

 generative outlet found in the three species comprised in it, 

 which however is not peculiar to them among Mammalia. 

 The members of this Order show most distinctly, in all their 

 characters, a relationship to the Oviparous Yertebrata, and 

 have been termed Ornithodelphia. 



