Soiith African Fossil Reptiles and Amphibia. 57 



TlTANOSUCHUS DUBIUS, Sp. nOV. 



The portion of mandible on which this species is founded was 

 obtained from the farm Abraham's Kraal in the Prince Albert 

 Division. It is the right ramus, showing four incisors, one canine, 

 and eleven small molars. It differs from T. cloetei in having a 

 more massive symphysis, in being even squarer in the front of the 

 jaw, in the much larger canine and smaller molars differences which 

 appear to warrant the erection of a new species. 



A table showing the teeth measurements in the three known 

 species of Titanosuchus will emphasize their differences : 



T.ferox. T. cloetei. T. dubius. 



First incisor Imperfect 21 x 14 Imperfect 



Interval between i.l and i.2 10 10 9 



Second incisor 21 x 15 18 x 13'5 19 x 14'5 



Interval between z.2 and i.3 10 11 4 



Third incisor 20 x 12 20 x 14 20 x 15 



Interval between i.3 and z.4 18 8 6 



Fourth incisor 23x17 18x14 16-5x13 



Interval between iA and c ? 9 5 



Canine 50x35 30x26 47x20 



Four molars occupy 40 30 



Eleven molars occupy 107 



[All these measurements are in millimetres.] 



It will be seen that the incisors are set much closer together in 

 this new form, although on the whole their size does not differ 

 appreciably from those of T. cloetei. The canine is narrower and 

 longer. In fact, whereas in T, cloetei it approximates in section to a 

 circle, in the new species it is almost oblong, with one side more than 

 twice the length of the other. 



The molars are small and circular in section. A line drawn along 

 the inner side of the molars just touches the canine, and is also 

 tangential to the inner surface of the 4th incisor. 



If a line be drawn across the front of the jaw at right angles to 

 the symphysis, the back of the canine lies 76 mm. from it, and the 

 back of the 4th molar 111 mm. ; whereas in T. cloetei the figures for 

 the same measurements are 67 mm. and 116 mm. respectively. 



