THE EOCENE OF EUROPE AND NORTH AMERICA 115 



England are found locusts (Robinin), figs (Ficus), tulip trees (Liriodendron), 

 and GrevUlea, a proteaceous plant now confined to Australia.' The marine 

 and estuarine plastic clays of this formation also contain remains of Cro~ 

 codilus and of the giant bird Gadornis. 



Prevailing The remains of mammals are very scarce. In the 



Mammals Soissons deposits (6) are found three very important and 

 Coryphodonts distinctive forms, namely, the two heavy-bodied ungulate 

 Hyracotheres coryphodons C. eocenus, C. oweni, the former described in 

 (Horses) 1846 by Owen, the latter by Hebert ten years later. An 



Lophiodonts equally significant form from the Lignites de Soissons is 

 Palaeonictids the odd-toed or perissodactyl ungulate Lophiodon larteti, 

 which Filhol regarded as the ancestor of the true heavy- 

 bodied lophiodonts.^ Among the carnivorous mammals is the creodont 

 Palceonictis gigantea (from Muirancourt, Oise, 8), a member of the Palse- 

 onictidae, a family of cat-like, short-faced creodonts, which also appear for 

 the first time in the Wasatch of the Rocky Mountains {Palceonictis occiden- 

 talis). In the Soissonais of Europe has also been found a large mesonychid 

 creodont, Pachycena botdei. Both at Meudon and in the upper deposits 

 near Cernay are found the bones of Coryphodon oweni. This sparsely 

 known mammalian fauna of Europe has its complete counterpart in the 

 Rocky Mountain region. 



From the Upper Cernay deposits near Rheims (seep. 100) (sables et argiles 

 ligniteuses) is also recorded a femur (length .390) of Coryphodon oweni 

 Hebert identical in size with the typical specimen found at Meudon. 



Ypresian Life 



Lower Ypresian formations. — The Ypresian stage is named from Ypres, 

 Flanders. It is typified by the famous estuarine formation of the London 

 Clay (166 m.), which is also the type of the Etage Londinien of Mayer- 

 Eymar, a formation containing several important primitive mammals and 

 marine molluscs, which prove that this is on a higher level than the Sparna- 

 eian. Exposures are at Heme Bay, Kent (18), Kyson (19), Harwich, Essex 

 (20). Of the same age are the plant deposits of the Isle of Sheppey (21), 

 near the mouth of the Thames, and the marine deposits of Pourcy (22) near 

 Rheims. (See map, p. 102). 



The mammals of the London Clay include the amblypod Coryphodon 

 eocenus, also a small mammal Platychcerops { = Miolophus) , an animal often 

 compared with but certainly not related to the tillodont Eslhonyx of the 

 Rocky Mountain region; it is of the size of the marten (Mustela) and of 



* Gardner, British Eocene Flora, Palceont. Soc, p. 29, quoted by A. Goikie in A Text- 

 Book of Geology, London, 1893. 



^ Deperet, C, Les Transforniations dii Monde animal (Paris, 1007), traces the evolu- 

 tion of the four phyla of lophiodonts from the Upper Ypresian stage (pp. 206-208). 



