100 ANOMODONTIA. 



being in both instances referred without any proviso to 

 Deuterosaurus. Since the specimen (fig. 19) was figured 

 the lower surface of the root has been cut and polished ; 

 and thus exhibits the compressed pulp-cavity, and the 



Pig. 19. 



? Deuterosaurus biarmicus. — Lateral aspect of an incisive tooth, wanting the 

 lower portion of the root; from the Upper Permian of Kargalinsk, 

 Orenburg. £. 



concentric layers of dentine noticed by Eichwald. Similar 

 teeth are figured by Eichwald in his ' Lethaea Uossica,' 

 pi. lviii. fig. 3, and also by Trautschold in the i Mem. Ac. 

 Imp. Nat. Moscou,' vol. xv. pt. i. pi. vii. figs. 3-5. 



Presented by W. H. Twelvetrees, Esq., 1882. 



Genus non det. 



R. 304. The crown of a tusk ; from the Upper Permian of Karga- 

 (Fig.) linsk, near Orenburg, Russia. Described and figured by 

 Twelvetrees in the e Geol. Mag.' dec. ii. vol. ix. p. 338, 

 pi. viii. fig. 3, as the tooth of a Dinosaur. This specimen 

 is laterally compressed and has serrated edges, and thus 

 resembles the tusks of Lyeosaurus ; it is smaller and more 

 slender than the tusks of the skull referred by Eichwald 

 to Deuterosaurus. 



Presented by W. H. Twelvetrees, Esq., 1882. 



Family DIADECTID^E. 



Dentition of an herbivorous type, the cheek-teeth (fig. 20) being 

 transversely elongated, with oval crowns, divided into flattened and 

 subequal moieties by a median vertical ridge at right angles to the 



