214 "GIANTS' BONES" IN PATAGONIA CHAP. 



the formula is the same as in Typotlierium. The animal seems 

 to have had nails rather than hoofs. The thumb was opposable. 

 The fibula is fused below with the tibia, whereas in the last 

 genus these two bones are quite separate from each other. 



SUB-ORDER 5. TOXODONTIA 



The group Toxodontia, 1 like so many others, is exceedingly 

 hard to define. " Nor are its limits any easier to mark out than 

 many others of the groups of Ungulates. It will be best perhaps 

 to give an account of Toxodon, and of a few types which seem to 

 lie near it in the system, and then to indicate how far they 

 resemble or depart in structure from other Ungulates. Toxodon 

 itself is known from complete skeletons. It lived in Argentina 

 during the " Pampean " period, which seems to be of the Pleistocene 

 age. A large number of species, however, have been described, some 

 of which seem to go farther back in time, and to have existed 

 during the Miocene period further south in Patagonia. 



The size of this creature was about that of a large Ehinoceros ; 

 it has a bulky body and a large head, which was borne low 

 down, on account of the bending downwards of the anterior 

 vertebrae ; in this aspect the figures of the skeletons recall 

 Glyptodon and similar Edentates. The beast was discovered by 

 Darwin, and originally described by Owen. " During his (Mr. 

 Darwin's) sojourn in Banda Oriental," writes the Eev. H. 

 Hutchinson, " having heard of some ' giants' bones ' at a farm- 

 house on the Sarandis, a small stream entering the Kio Negro, 

 he rode there, and purchased for the sum of eighteenpence the 

 skull which has been described by Sir E. Owen. The people at 

 the farm-house told Mr. Darwin that the remains were exposed 

 by a flood having washed down part of a bank of earth. When 

 found, the head was quite perfect, but the boys knocked the teeth 

 out with stones, and then set up the head as a mark to throw 

 at." The whole of the Pampean area is a valley of dry bones, 

 and the remains of Toxodon are abundant there. The skull of 

 Toxodon is not unlike that of a horse in general aspect ; but the 

 orbit is not separated from the temporal fossa. The premaxillae 

 are furnished above with a slight protuberance directed towards 

 1 Cope, American Naturalist, xxxi. 1897, p. 485. 



