38 Transactions of the South African Philosophical Society. 



number of Diapsidan characters not hitherto known in the Synap- 

 sidan phylum. The divergence from the TherocephaHans is too great 

 to allow of its being placed in that suborder, and it seems necessary 

 to make it the type of a new suborder of the Therapsida, for which 

 I propose the name Deomasaueia. 



Aenogn4thus paevidens, g. et sp. nov. 



From the same locality as the skeleton of Galechirus Mr. Scholtz 

 obtained an interesting dentary bone, which belongs to a new 

 Therocephalian genus, for which I propose the above name. The 

 specimen is the right dentary of an animal about the size of a 

 small fox, and is in fair preservation, though much of the coronoid 

 process is missing. The ramus is long and slender, and the anterior 

 end is rotated slightly outwards, giving the appearance when viewed 

 from the side of a bulbous end. This terminal portion is markedly 

 convex and pitted. There are no teeth preserved in it, and it is 

 doubtful whether any have been present. The alveolar margin is 

 apparently grooved, but there is no distinct evidence of tooth 

 sockets. Behind the dilated portion there is a part of the ramus con- 

 taining 10 small pointed teeth. These are rounded, with no serrations, 

 and have enamel on the tips. The last of the 10 is smaller than 

 the others. Further back there is a portion of the ramus without 

 teeth, and then it gradually expands and curves upwards to form 

 the coronoid process. The dentary has an angle, as in most Thero- 

 cephalians. The coronoid process is narrow but thick, and has 

 probably been of considerable length. 



The following are some of the principal measurements : — 



Length from front to angle 31 mm. 



Depth at posterior molar 14 



Depth at anterior molar 15*5 



Length of molar series 22 



There is only one known form to which this jaw has close affinity 

 — the Therocephalian described by me some years ago under the 

 name Ictidosuchus primcevus. It resembles it in being long and 

 slender, in having a series of small pointed molars, and in having 

 apparently no incisors. It differs in having the angle much more 

 marked and in having the end of the jaw dilated. Though it cannot 

 belong to the same genus, it probably belongs to the same family. 

 Another form which may be related to it is TJieriodcsvius pliylarclms, 

 described by Seeley from the fore limb. As nothing is known of 

 the head, it is impossible to say much about its affinities. Ictido- 



