StJPPLEMENT. 307 



m. 2 ; from the Phosphorites of Caylux (Tarn-et Garonne), 

 Prance. Purchased, 1885. 



M. 2355. Fragment of a smaller left maxilla, provisionally referred 

 to this species ^ ; from Caylux. The specimen shows 

 pm. 3 and pm- 4 . Purchased, 1885. 



M. 2356. Fragment of the left maxiUa of an immature individual, 

 provisionally referred to this species ; from Caylux. The 

 alveoli of the milk-teeth and the germs of pm. 3 and pm. 4 

 are shown. Purchased, 1885. 



M. 2357. Part of the left ramus of the mandible, containing the 

 last five cheek-teeth ; from Caylux. Purchased, 1885. 



HI. 2358. Part of the left ramus of the mandible, showing pm. 3, 

 pm. 4, and m. 1 ; from Caylux. Purchased, 1885. 



M. 2359. Hinder portion of the right ramus of a smaller mandible, 

 provisionally referred to this species ; from Caylux. The 

 last true molar is shown. Purchased, 1885. 



M. 2359 a, The imperfect left ramus of the mandible, exhibiting the 

 symphysis ; from Caylux. Purchased, 1885. 



Family PROVIVERRID^ \ 



Distinguished from the Hycenodontidce by the greater development 

 of the inner tubercle of the upper true molars, and the presence 

 of an inner cusp to the blade of the lower true molars (fig. 46) ^. 

 The latter resemble the corresponding teeth of Dasyurus, and 

 also m. 1 of the Viverridce and Cynodictis ; and it is thus not im- 

 probable that the present group is derived from early marsupials 

 which had four premolars ; and that the Viverridce and Cynodictis 

 are themselves descended from forms allied to the present. In the 

 one instance the chief dental modification would be the reduction ia 

 the number of incisors and true molars ; and in the other the dif- 

 ferentiation of pm. 4 and m. 1 into carnassials, and the assumption of 

 a more or less completely tubercular character by the cheek-teeth 

 behind the two mentioned. 



^ The cheek-teeth of smaller individuals of this species cannot apparently be 

 distinguished from those of P. biincisivus, Filhol. 



2 Formed by Schlosser in the 'Morphol. Jahrb.' vol. xii. p. 293 (1886), to su- 

 persede the LeptictidcB of Cope (Amer. Nat. vol. xviii. p. 347 [1884]), of which 

 the type genus is referred to the Insectivora. 



^ The instances of the Canince and Dasi/urid(8 suggest that this character 

 need not be of more than generic value. 



x2 



