REPTILKS FROM SOUTH AFllTCA. 1075 



known. The deiitaiy foi-ms about lialf of the jaw, l)ut owing to 

 a slender backward process which rests on the surangular it forms 

 about 1^ of the upper horder. 



The splenial is slender. T'he angular forms the lai-ger pai-t of 

 the outer side of the posterior part of the jaw, and the slender 

 surangular the upper thii'd. The articular, which has two con- 

 caVities for the quadrate, is a powerful bone which in front fits 

 in between the angular and surangular on the inner side of the 

 jaw. 



The teeth are imperfectly known, but appear to be very similai- 

 to those of Delpliinognathus and Eccasaiirus. This type closely 

 resembles the tooth figured by Twelvetrees and Seeley as the 

 tooth of D enter osaur us, and if these authors are right in regarding 

 that tooth as belonging to ])euterosuurus, there can be no doubt 

 that Beicterosaurus is a Dinocephalian closely allied to South 

 African forms. 



Suborder A N o M o D o x x i A. 



DivELURODOX WHAiTSi, gcn. et sp. n. (PI. LXIII. figs. 6 & 7.) 



This beautiful little Endothiodont skull was discovered by the 

 Rev. J. H. Whaits on the Beaufort West Commonage. It 

 is fairly complete, but the matrix is so hard that no development 

 has been attempted. Fortunately, the skidl was discovered broken 

 into quite a number of scraps, and, but for this, it would have 

 been regarded as belonging to a small species of Dicynodon. 

 The lower jaw w^as, however, broken across obliquely and the 

 fracture revealed the presence of a series of molars. A second 

 very badly weathered S2:>ecimen appears to me to belong to the 

 same species. 



The total length of the skull is 83 mm. From the beak to the 

 front of the orbit is only 22 mm., and to the back of the orbit 

 41 mm., so that the orbit is entirely in the front half of the skull. 

 The greatest width of the skull at the back part is about 50 mm. 

 The parietal region measures 19 mm. across its narrowest part, and 

 the frontal region is only 13 mm. acioss. Owing to the foi-wai-d 

 position of the orbits the facial pai-t is I'elatively small and also 

 narrow. The tusks are typically Dicynodont, but owing to the 

 premaxillaries being veiy small, j^laced more forward than in 

 Dicynodon. 



The molars are aiTangecl in a- row like those of Endothiodon 

 uniseries Owen, but a second i-eplacing set is seen developing on 

 the inner side of the fiuictional teeth. Thei'O are probably about 

 8 teeth in use in each jaw. The crowns are not displayed in any 

 of the teeth of the type specimen, but in the second .specimen a 

 large part of one crown is seen. It is long and slender and has 

 coarse serrations on the anterior and posterior borders. In this 

 the teeth agree with those of Endothiodon, and difter from those 

 of Pristerockm and Opisthocieitodon. 



