I70 



FOSSIL ANTEATERS 



only two toes on the fore- feet. It is to be distinguished, 

 anatomically, from its larger relatives by the complete clavicle, 

 and by the fact that the pterygoids do not meet in the middle 

 line of the skull. The ribs, too, are unusually wide, as in the 

 Whale Neohalaena, and form a bony encasement for the body. 

 It has two small caeca. Of fossil Anteaters but little is known. 

 The most interesting form is Scotaeops, interesting because it has 

 two small back teeth, which are totally lost in its living allies. 

 The huge Patagonian extinct bird PhororJiacos, first known by a 

 lower jaw, was at one time regarded as a member of this group on 

 account of the form and edentulous character of the jaw. 



Fam. 2. Bradypodidae. — The Sloths, genera Brady pus and 



Fia. 96. — Unan, or Two-toed Sloth. Choloepus didudylus. x i. 

 (After Vogt and Specht.) 



Choloepus, come, as already stated, very near to the Anteaters, in 

 spite of their striking difference in appearance. The Sloths are 

 purely arboreal creatures, with strong recurved claws, which serve 



