GEOLOGICAL SOCIETY, 



45 



ture, they resemble those of the B. tridactylus ; they 

 differ in form and in the possession of two radical fangs. 



The teeth of the Megalonyx also consist of three dis- 

 tinct substances ; their general structure bears a close 

 analogy to those of the B. tridactylus ; but complete 

 series of the teeth of this species have not yet been ob- 

 tained. The molars which have been discovered differ 

 from each other in size and form ; their crowns assume, 

 by friction, a form analagous to those of the three-toed 

 sloth. 



