374 PALEONTOLOGY. 





The proofs of the abundant mammalian inhabitants of the 

 eocene continent were first obtained by Cuvier from the fos- 

 silized remains in the deposits that fill the enormous Parisian 

 excavation of the chalk. But the forms which that great 

 anatomist restored were all new and strange, specifically, and 

 for the most part generically, distinct from all known existing 

 quadrupeds. By these restorations the naturalist was first 

 made acquainted with the aquatic cloven-hoofed Anoplothere, 

 and with its light and graceful congeners, the Dichobunes 

 and Xiphodon, with the great Palseotheres, which may be 

 likened to hornless rhinoceroses, with the more tapiroicl 

 Lophiodon, with the large peccari-like Chceropotamus, and 

 with about a score of other genera and species of placental 

 Mammalia. 



Almost the sole exception to the generic distinction of 

 these eocene forms from modern ones was yielded by the 

 opossum of Montmartre (Didelphis Gypsorum, fig. 134) ; and 

 what made this discovery the more remarkable was the fact 

 that all the known existing species of that marsupial genus 

 are now confined to America, and the greater part to the 

 southern division of that continent. An opossum appears 

 to have been associated with the Hyracotherium in the 

 eocene sand of Suffolk ; where likewise, a porcine beast with 

 tusks like ordinary canines (Chceropotamus), and some remains 

 of a monkey (Eopithecus), have been found. With respect to 

 the Didelphis Gypsorum, its generic relations were deduced 

 from characters of the lower jaw and teeth ; but these were 

 associated with other parts of the skeleton in the same block 

 of stone. When Cuvier expressed his convictions of the 

 opossum-nature of the fossil from the parts first examined, 

 his scientific associates were incredulous. He invited them, 

 therefore, to witness a crucial test. On the slab containing 

 the jaws and teeth, the outline of the back part of the pelvis 

 was also exposed, the fore part being buried in the matrix. 



