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ON THE AFFINITIES OF TRITYLODON. 



By E. Broom, M.D. 



(Bead November 30, 1904.) 



Tritylodon longcevus was described in 1884 by Owen* from an 

 imperfect skull submitted to him by Dr. Exton, the Curator of the 

 Bloemfontein Museum. The specimen is stated to have been found 

 at " Thaba-chou, Basutoland." Unfortunately there is some doubt 

 about this locality, as no place of this name is to be found on any of 

 the recent maps of Basutoland. There is a mountain south of 

 Morija called Thaba-tsueu, which may be the locality. There is, of 

 course, the well-known locality in the Orange Eiver Colony, Tha- 

 ba'Nchu, but this is hardly likely to be the spot, as Dr. Exton, who 

 submitted the specimen to Owen, was present at the meeting of the 

 Geological Society at which the paper describing the specimen was 

 read, and is not likely to have allowed the statement that the speci- 

 men came from Basutoland to have passed without correction, if 

 wrong. It is further highly probable that the name of the locality 

 was given by Dr. Exton, who, of course, would be well aware that 

 Thaba 'Nchu was not part of Basutoland in 1883. The importance 

 of the determination of the locality lies in the fact that the whole of 

 Basutoland belongs to the Stormberg age, and is of much more 

 recent date than the Upper Beaufort beds of Aliwal North and 

 Burghersdorp, which have yielded the Theriodonts. While the latter 

 are believed to be Upper Triassic, the former are most probably 

 Lower Jurassic. 



Owen described the specimen as the remains of a Mammal, and 

 pointed out a large number of features which seemed to confirm this 

 view, among others the striking resemblance of the teeth to those of 

 Stereognathus ; and this view has had the support of a number of 



* E.Owen, "On the Skull and Dentition of a Triassic Mammal (Tritylodon 

 longcevus, Owen) from South Africa." Q.J.G.S., vol. xl., 1884, p. 146. 



