INTRODUCTION. 5 1 



ing the objections of that naturalist, and describing 

 in detail the characters, not only of the fossil ex- 

 amined by Cuvier, but likewise of some others since 

 discovered also at Stonesfield. These remains con- 

 sist of two portions of the lower jaw of an animal 

 to which Mr. Owen applied the name Thylacothe- 

 rium Prevostii, and a ramus of a lower jaw differ- 

 ing from these, on which he founds his genus Phas- 

 colotherium, using for the species the name Buck- 

 land^ originally given by Mr. Broderip in his paper 

 on the fragment published in the third volume of 

 the Zoological Journal. The Stonesfield fossils 

 under consideration, in the opinion of Mr. Owen, 

 furnish the types of two new genera of Marsupial 

 animals intermediate between the existing Sarco- 

 phagous and Entomoenophagous groups. The Pkas- 

 colotherium " presents the same numerical dental 

 formula, apparently, as in the Thylacinus and 

 Phascogcde ; but, if another incisor existed in each 

 ramus of the lower jaw, as seems to be indicated by 

 the fossil, then the dentition will agree with that of 

 the genus Didelphys. Incisors, Ji or 4-4 ; canines, 

 j'.j ; praemolares, ; ; molares, J.'l." The incisors 

 and canines are separated by vacant interspaces, and 

 occupy a large proportion of the dental series : the 

 true molares resemble those of Thylacinus, The 

 Thylacotkerium "presents eleven molars on each 

 side of the lower jaw, which resemble, in structure 

 and close arrangement, those of Phascogale and 

 Didelphys, while they are intermediate in their pro- 



