DIPLOSPOSTDYLIDJE. 175 



smaller size ; the length of the median line of the skull being 0,040. 

 The skull does not narrow very markedly towards the muzzle, 

 which is blunt. Other examples are required to show whether the 

 inferior size of the undermentioned specimens as compared with 

 the type of M. stowei is a good specific character. 

 Hob. South Africa. 



R. 510. The skull ; from the Karoo system of Tafelberg, Queens- 

 (Fig.) town district. The type ; figured by Owen in his ' Cat. 

 Toss. Pept. S. Africa,' pi. xx. figs. 13, 14, and 17-20 ; 

 and also by Zittel in his ' Handbuch der Palasontologie,' 

 1 Abth. iii. Band, 2 Lief. p. 397, fig. 387. Compared 

 with the figure of the type skull of M. stowei in the 

 ' Quart. Journ. Greol. Soc' vol. xv. pi. xxi., and allowing 

 for the imperfect parietal region of the latter, the two 

 agree exactly in contour. 



Presented by W. G. Ather stone, Esq., M.D. 



E. 510 a. An imperfect skull, attached to a mass of matrix ; from 

 Tafelberg. The width of the interorbital bar would 

 appear to be owing to the effects of crushing. 



Presented by W. G. Atherstone, Esq., M.D. 



Family DIPLOSPONDYLID.E l . 



Vertebrae (at least in the caudal region) of the embolomerous 

 type 2 . A ventral armour. 



This family is a provisional one, since it has been suggested that 

 the embolomerous and rhachitomous types of vertebral structure may 

 occur in different parts of the column of the same form 3 . The type 

 genus Diplospondylus, Lydekker 4 , of the Permian of Bohemia, is 

 very imperfectly known, but the cranial bones are not pitted, and 

 the limb-bones are penetrated by a number of nutrient foramina. 



Genus CRICOTUS, Cope 5 . • 



Skull (fig. 42) long and triangular, with a narrow muzzle, and 

 the ovoid orbits situated in the hinder half; cranial bones sculptured, 

 with a lyra. No postarticular process to the mandible. Vertebral 



1 =Diplovertcbnd<e, Fritscb. 2 See p. 140. 



3 See Fritsch, Fauna der Gaskoble, vol. ii. p. 4. 



4 Geol. Mag. dec. iii. vol. vi. p. 325 (188!)).— To replace the hybrid Diplo- 

 vertebron, Fritsch. 



5 Proc. Ac. Nat. Sci. Philad. 1875, p. 405. 



