THE GROUP OP EDENTATES. lOi) 



Still there is one feature in connection with the dentition 

 exhibited by the whole of these so-called edentates ; and 

 this is, that teeth in the front of the jaws, corresponding 

 to the incisors of other mammals, are totally absent. 

 Instead, therefore, of being described as edentates, or 

 toothless mammals, these creatures ought rather to have 

 been named aprotodonts, or incisorless mammals. After 

 all, however, it is not much consequence what is the projjer 

 meaning of a name, so long as we know the sense in 

 which it is used, and there is accordingly no real objection 

 to the employment of the term edentates, which has 

 obtained the almost universal sanction of zoologists. 



In addition to this total absence of front teeth, the 

 edentates are further characterized by the circumstance 

 that all their teeth (when they possess any) show no trace 

 of the hard layer of enamel which is so characteristic and 

 essential a constituent of those of other mammals ; these 

 teeth at no period of life forming roots, but continually 

 growing from below. Moreover, in nearly all the eden- 

 tates there is never any set of milk-teeth developed, 

 although, unfortunately, this cannot be taken as a charac- 

 teristic of the order, since such teeth occur in one of the 

 armadillos, a,nd also in the animal represented in our 

 fourth figure. 



Premising that the edentates are quite distinct from the 

 marsupials and egg-laying mammals, we may say, then, 

 that the only features by which they can be collectively 

 characterized are the want of front teeth, and the absence 

 of enamel on those of the cheek series, while in certain 

 rare instances they may be utterly devoid of teeth. Such 

 characters, it must be confessed, are by no means of first 

 importance. 



The mammals thus associated by these negative charac- 

 teristics, are now chiefly confined to the southern hemi- 

 sphere, and include the sloths, anteaters, and armadillos 

 of South America, the pangolins, or scaly anteaters of 

 south-eastern Asia and Africa, and the aard-varks of 

 Africa ; the true anteaters and pangolins being those in 

 which teeth are wanting. In past times they were also 

 represented by the gigantic megathere, and a number of 



