DIDELPHYS 1 



71 



MARSUPIAL1A 1 



DWELPHIDJE ? 



Fig. 22. 



Outside, nat. size. 



Upper view. 



Inside, nat. size. 



DIDELPH YS ? COLCHESTERI, Owen. 



Didelphys Colchesteri. CHARLESWORTH, Mag. Nat. Hist., 1839, p. 450, fig. 60. 

 Opossum ? LYELL, Annals of Nat. Hist. vol. iv. p. 190. 



THE fossil above figured in three views, though small 

 and not yielding decisive evidence as to its generic rela- 

 tions, forms one of the interesting unequivocal evidences 

 of the Mammalian class, which the careful researches of 

 Mr. Colchester, of Ipswich, have brought to light from the 

 Eocene sand underlying the red-crag at Kyson, near Wood- 

 bridge, Suffolk. 



It consists of a small portion of the right branch of a 

 lower jaw, with one double-rooted premolar tooth and the 

 sockets of two others, and it has been referred by Mr. 

 Charlesworth,* who first described it, to the Opossum 

 genus (Didelphys). He states, " The tooth, in its sym- 

 metrical form, united with the indication of an anterior, 

 as well as posterior heel or talon, does not agree with any 

 species of Didelph with which I have as yet been able 

 to compare it, but I think no doubt can be entertained 

 of the generic or family affinities indicated by the cha- 

 racters which it exhibits. Judging from the empty alveoli 

 on either side, the tooth appears to be the one immedi- 

 ately succeeding the true molars : its posterior tubercle is 



* Loc. cit. 



