1901.] AFFINITIES OF UDENODON. 163 



When an endeavour is made to classify the specimens found, one 

 is beset with a number of difficulties. Almost every specimen 

 exhibits some degree of crushing ; and when two skulls of the same 

 species have been crushed in different directions, the appearances 

 would readily make one believe that he was dealing with two 

 species. One skull of Udenodon hain't in my possession has the 

 maxilla of one side so crushed as to give an appearance very like 

 that in the specimen described by Owen (2) as " Udenodon 

 strigiceps." Another difficulty is due to our ignorance of the 

 extent to which differences in specimens may be due to the sex 

 and age. The identification of any specimen therefore must in 

 the meantime be subject to some doubt. 



The following is a list of the specimens which I have found 

 and on which my researches are based : — 



1. An almost complete skull of a small form, which I regard as 



new, and for which I propose the name of Udenodon 

 gracilis (PL XVII. figs. 2 & 3). 



2. An almost perfect skeleton of apparently the same species. 



The skull unfortunately has been so much weathered that 

 it is impossible to decide the species with certainty 

 (PI. XYL). 



3. A lower jaw of possibly the same species. 



4. A fairly good skeleton of Udenodon baini. 



5. A second very imperfect skeleton of presumably the same 



species, but with the head missing. 



6. A moderately complete skull of Udenodon baini, but much 



crushed on one side. 



7. A second imperfect and much crushed skull of the same 



species. 



8. A third imperfect skull, also probably of U. baini. 



9. A moderately complete but somewhat crushed skull of a 



young animal, probably U. megalops. From a much higher 

 stratum than the other specimens. 



10. An imperfect skull of a young animal, apparantly U. greyi. 



11. The posterior portion of a skull referred to Udenodon, but 



possibly belonging to a Dicynodon. 



12. The mandible and front part of snout of a small Udenodon. 



13. Imperfect middle region of a small Udenodon-sknW . 



14. A number of detached portions of mandibles, maxilla?, humeri, 



vertebrae, and other bones referred to Udenodon. 



Of these specimens all have been discovered in the neighbour- 

 hood of Pearston, S. Africa, with the exception of specimen 10, 

 which is from the Bedford district and was kindly presented to 

 me by Mr. 1). D. Prazer, Junr. 



Before beginning an account of the general structure of 

 Udenodon, I think it will be well to give a brief description of 

 specimens 1 and 2. 



The small > k u 1 1 which I take as the type of Udenodon gracilis 

 (I'l. XVII. fig. 2) is somewhal crushed od the right side, and 



11* 



