CEEODONTA. 347 



Sarcothraustes ANTiQuus Cope. 



Loc. sup. cit. 

 Plate XXIV e; figs. 19-22. 



The penultimate superior molar has a strong posterior cingulum which 

 commences within the line of the internal bases of the external cusps, and 

 rises into considerable importance behind the internal cusp. There is also 

 an anterior cingulum which does not rise internally, and which is continuous 

 with a strong external basal cingulum. The latter passes round the pos- 

 terior base of the posterior cone, and runs into the posterior branch of the 

 internal V. The posterior cone is smaller than the anterior cone, and its 

 apex is well separated from the latter. The appearance of this tooth is 

 something like that of a carnivorous marsupial. 



The symphysis mandibuli slopes obliquely forwards, and is vmited by 

 coarse suture. The ramus is stout and deep, as compared with the size of 

 the molar teeth. The roots of the teeth are relatively large, especially 

 those of the first two premolars. The crown of the canine is lost. The 

 first premolar points forwards, nearly parallel with the canine, and divergent 

 from the second premolar. The crown of the second premolar is small and 

 subconic, and has a rudimental heel, and no anterior basal tubercle. The 

 first true molar resembles considerably that of Mesonyx. There is a small 

 anterior basal tubercle on the inner side of the principal cusp. The ex- 

 pansion of the heel is transverse only, there being no longitudinal lateral 

 edges or tubercles. The enamel is obsoletely, rather coarsely wrinkled. 

 There are two rather large mental foramina; the posterior below the ante- 

 rior root of the first true molar, and the anterior below the posterior root 

 of the second premolar. 



Measurements. 



M. 



\ auteroposterior externally 01.5 



Diameters of superior M. ii. ^rausverse ! ' 024 



Anteroposterior diameter of base of M. iii 0095 



Auteroposterior diameter base of crown of inferior canine 020 



Length of bases of three inferior premolars 038 



f anteroposterior 019 



Diameters inferior M. i. < transverse 0095 



( vertical OHO 



Depth of ramus at Pm. iii 01520 



Width " " 022 



