676 Dii. u. nu(X)M on tui-: stuuctuue ov tuk skull 



consisting of littlo more than the roots of the teeth. In 1903 I 

 maile an imperfect ilentary in the South African IMuseum the 

 type of a new species of IHtanosuchns, ui\fler the name 2\ cloetc/i. 

 It dilfers in size from Owen's species, but otherwise appeal's to 

 agree sutliciently closely to make it seem safer to keep it pro- 

 visionally in the same genus. In 1915 I laugh ton added a third 

 species, 7', diobiits, which also difl'ers considerably in size from 

 Owen's species, and less markedly from T. cloetei. Haugh ton's 

 specimen came from Abraham's Kraal, and had also been dis- 

 covered by Mr. van der Byl. The type of T. cloetei is registered 

 as coming from " Gamka River." As Abraham's Ivi-aal is on 

 the Givmka Hiver, it is not improbable that Haughton's type and 

 mine came from the same farm, and in any case they are likely 

 to have come from the same horizon. This new jaw discovered 

 by Mr. van der Byl is so near to 2\ cloetei that I think it safest 

 to refer it to this species. T. dubiiis is pi-obably a synonym, the 

 difi'erences being such as might be accounted for by difference of 

 age or sex. 



Mandible o/Titanosuchus cloetei Broom. 



The mandible discovered by Mr. van der Byl is nearly perfect, 

 but broken into ten portions. Six small portions are mitsing, 

 but four of these are quite unimportant. The two others result 

 in the loss of the contact of the articular region of the jaw with 

 the front part, but so little is missing that the jaw can be 

 completely restored with practical certainty. The Avhole jaw 

 measures in length 565 mm., and, as will be seen from the figures 

 given, the depth is so little in comparison to the length that the 

 jaw appears slender. In reality it is quite a powerful jaw. 



The dentition consists of four incisors, one canine, and a series 

 of 15 molars. The incisors, though the crowns are not satis- 

 factorily preserved, are manifestly of the typical Dinocephalian 

 type. The four together occupy a space of about 84 mm. The 

 canine is rounded, and measures at the base of the crown 29 mn:.. 

 by 28 mm. The 15 inolars measure 149 mm. None of the 

 cx'owns of the molars are well preserved, but from poitions pre- 

 served it is manifest that they- have been flattened with, on 

 the inner side, vertical striie at the base. The anterior and 

 posterior edges are curved somewhat outwards and have a few 

 coarse serrations. There is clear evidence of dental succession 

 at least as far as the 10th molar. 



The dentary forms more tluvn half of the outer side of the jaw, 

 but only about a third of the inner side. In front it is fairly 

 massive to support the powerful incisors and canine. There is a 

 large symphysis. There is no coronoid process. 



The splenial is an exceptionally long splint of bone which 

 fonns nearly the whole of the lower half of the inner face of tlie 

 front half of the jaw. It forms a small part of the symphysis. 

 Its relations with the other bones will be best inideistood from 

 the sections given. 



