VI PREFACE. 



cates that the relationship between Cadurcotherium and the 

 Astrapotheria is closer than suggested on page 82. Hence there 

 is further evidence that South America received its Tertiary 

 ungulates by way of Africa. The extinct Patagonian birds 

 Phororhachis and Brontornis appear, according to Mr C. W. 

 Andrews, to be nearly allied to the existing South American 

 seriema (Cariama), and since Filholornis, of the French Phos- 

 phorites, has been shown by Prof. A. Milne-Edwards to be 

 related to the hoatzin (Opisthocomus), it would seem that all 

 these peculiar South American types of birds have a history 

 somewhat similar to that of the extinct ungulates of the same 

 region. 



R. LYDEKKER. 



HARPENDEN, 



June ist, 1896. 



