Prof. Owen on the Class Mammaiia. ii 
phinus), which have from one hundred to one hundred and 
ninety teeth, yielding the maximum number in the class Mam- 
malia. 
When the teeth are in excessive number, as in the Armadillos 
and Dolphins above cited, they are small, equal, or sub-equal, 
and ee of a simple conical form 
most other mammals particular ‘teeth have special forms for 
spain uses; thus, the front teeth, from being commonly pee 8 
ted to effect the first coarse division of the foo d, have bee 
called cutters or incisors ; and cir back teeth, which complete its 
comminution, grinders or molars; large conical pointed teet 
situated behind sh incisors, ed ndnaptell by being nearer the in- 
sertion of the biting muscles, to act with ‘greater r force, are called 
Polder tearers, ‘acation or more commonly Proven, from being 
we developed 3 in the Dog and other Carniv 
t is peculiar to the class Mammalia to has "teeth implanted i in 
sockets by two or more fangs; but this can only happen to teeth 
of limited growth, and generally characterizes the molars and 
re-molars: perpetually growing teeth require the base to be 
ept simple an iad excavated for the persistent pulp. In 
no mal does anchylosis of the tooth with the 
jaw constitute a sera mode of attachment. Each tooth has 
its peculiar socket, to which it firmly adheres by the close co- 
adaptation of their opposed surfaces, and by the firm adhesion of 
the alveolar periosteum to the organized cement which invests 
the fang or fangs of the tooth. 
True teeth implanted in sockets are confined, in the Mamma- 
lian class, to the maxillary, premaxillary, and mandibular or 
lower maxillary bones, and form a single row in each. They 
may project only from the premaxillary bones, asin the Nar- 
most Bruta (Sloths, Armadillos, Getaarsives} In most Mam- 
mals, teeth are situated in all the bones above mentioned. 
The teeth of the Mammalia usually consist of hard unvascular 
dentine, defended at the erown by an in fears of enamel, and 
every where surrounded by a coat of cem 
The al cement is of extreme sete in Man, Quadru- 
mana sind the terrestrial Carnivora; it is thicker in the Herbiv- 
ora, especially in the complex grinders of the Elephant. 
Vertical folds of enamel and ce ment Picco the crown of 
the tooth in the ruminating and many other Ungulata, and in 
most oe characterizing by their various forms the genera 
of those o 
No Marna’ has more than two sets of teeth. In some spe- 
cies the tooth-matrix does not develop the germ of a second 
