202 MARBTTPIALIA. 



M. 1951. The imperfect, cranium ; from the Karoo series of Basuto- 

 (%.) land, South Africa. This is the type and only known 

 specimen, and is described and figured by Owen in the 

 ' Quart. Journ. Geol. Soc.' vol. xl. p. 146, pi. vi. figs. 1-7, 

 and also by Cope in the ' Amer. Nat.' vol. xviii. p. 688, 

 fig. 2 ; the latter figure being reproduced in the accom- 

 panying woodcut. 

 By exchange with the Bloemfontein Museum, South Africa, 1884. 



Fig. 34. 



Tritylodon longeevus. Oral (a) and frontal (b), aspects of the cranium ; from 

 the Karoo series of of Basuto-land. . (From the ' Ainer. Nat.') 



Family BOLODONTID^. 



Upper true molars numerous and antero-posteriorly elongated, 

 with a deep median groove, bordered by two antero-posterior ridges 

 surmounted by blunt tubercles ; the upper premolars with tricuspid 

 non-secant crowns. The serial position of the family is provisional, 

 but it is probably allied to the three preceding ones \ 



Genus MICROLESTES, Plieninger 2 . 

 Syn. Hypsiprymnopsis, Dawkina 8 . 



Owen recognizes three equally minute species, viz. M. antiquus, 

 Plieninger, from the Upper Trias (Keuper) of Stuttgart ; M . rhceticus, 



1 Marsh (Amer. Journ. 1887, p. 329) places Bolodon in the Plagiaulacida, in 

 which Osborn (MS.) includes Microkstes. The former, as the best-known genus, 

 is made the type of the family. 



Jahrcsh. Ver. Nat. Wiirtt. vol. iii. p. 164 (1847). 



8 Quart. Journ. Geol. Soc. vol. xx. p. 406 (1864). 



