278 LLOYD’S NATURAL HISTORY. 
Mammals that can by any possibility be included in the Mar. 
supials, are two minute ones from the reputed Triassic rocks 
of North Carolina, one of which has received the name of 
Dromatherium sylvestre. The total number of teeth in the 
lower jaw is fourteen on each side, three of which are incisors, 
one a canine, three premolars, and the remaining seven molars. 
The latter differ from those of all Mammals in which the 
teeth are differentiated into series, in having imperfectly 
divided roots, thus approximating to those of reptiles. The 
premolars are nearly simple cones ; while the molars, as shown 
in Fig. 2 of the diagram on page 274, consist of one main 
cone, with minute accessory cusps on the edges; and it is 
probable that the opposing teeth of the upper and lower jaws 
mutually interlocked, thus displaying another reptilian fea- 
ture. 
Whether this exceedingly primitive creature was really a 
Marsupial may be open to doubt, even if it be a Mammal at 
all. Assuming, however, that, as is probable, it is really 
Mammalian, it may equally weli indicate an Order more nearly 
allied to the Monotremes than to the Marsupials, being, in 
fact, an ancestral type of the former. Our information is, 
however, at present far too meagre to admit of anything de- 
finite being said on this point. 
