118 | Animal Life 
Limitations of space 
forbid detailed reference 
to many other more or 
less peculiar types of 
dentition met with in the 
mammalian class, most 
notable among which are 
the degenerate teeth of 
the sloths and armadillos 
of South America—a 
degeneration which has 
culminated in the total 
disappearance of teeth in 
their near relatives the 
anteaters of that conti- 
nent. Enough has, how- 
ever, been said in order 
to illustrate the numerous 
aoe special adaptations of a 
Fig. 17. Side view of the Dentition of the Carpincho, showing x as 
the Grinding-Surfaces of the Molayrs. common type for special 
functions, and likewise to 
demonstrate the general interest of the subject. Not less interesting is the study of 
the various structural modifications presented by the molar teeth of different groups of 
mammals and the manner in which these may be traced to a common type, but it 
is obvious that this could not be attempted in an article which has already largely 
exceeded its proper liunits. 
FOREWORD. 
HE next article in this series will deal with reptiles, the third and fourth with 
fishes. Before these are published there will appear two articles on the subject of 
the Identification of Birds, by Mr. Frank Finn, the first of which will be found in our 
November issue. The Editor believes that the way in which the author has treated 
his subject is unique, both on account of its originality and its simplicity. Several other 
important articles relating to birds are in preparation by the same authority for ANIMAL 
LirE, and the Editor also has pleasure in announcing that he will shortly publish in 
these pages two articles entitled “Traces of Animal Habits,” by Dr. Walter Kidd, in 
which special reference is made to the conclusions which may be deduced from a 
scientific study of the direction and disposition of the hair in mamunals. 
ary 
