TETTrLODONTID.^. 



201 



pretty evident that Tht/lacoleo, with its three upper incisors, could 

 not have been derived from Triiijlodon, in which there are only two 

 of these teeth ; the same remark being also apx)licable in the case of 

 the Macropodidce. 



Genus TRITYLODON, Owen\ 



Syn. TriglypJius, Fraas 2. 



Dentitk 



-Ij, C/^, Pm.|, M. 



P The diastema is of great 

 length, the first upper incisor is large and scalpriform, and the 

 second small and functionless ; each ridge of the upper cheek-teeth 

 usually carries three subcorneal tubercles. 



Fig. 33. 



^ 



Tdtylodon fraasi, n. sp. Lyd. — Upper molar ; from the Triassic bone-bed near 

 Strasbourg. The central figures are of the natural size, the others f . (From 

 the ' Neues Jahrb.') 



The upper molar from the Triassic bone-bed near Strasbourg (fig. 

 33), figured by Fraas under the name of Trujlijplim, presents no 

 characters by which it can be generically distinguished ^ from Trity- 

 lodon, and may therefore be at least provisionally referred to that 

 genus; but as its smaller size "* indicates its specific distinction, it 

 may be named T. fraasi. 



Tritylodon longsevus, Owen \ 

 This is the type species, and appears to have been somewhat 

 smaller than a liadger. 

 Hab. South Africa. 



1 Quart. Journ. Geol. Soc. vo.. xl. p. 146 (1884). 



2 ' Vor der Silndfluth,' p. 215 (Stuttgart, IS(jG). The name is preoccupied for 

 a genus of Diptera. 



The character mentioned by Neuniajr, Neues Jahrb. 1884, vol. i. p. 



219. 



cannot be regai'ded as of more than -«;pecific value. 



•* It is of too large dimensions to liave been the upper molar o? Miowlestcs, 

 which was probably two-ridged. Loc. cit. 



