Dr. B. Broom — The Palate of Therioclonts. 343 



cm. 



Total length, of the specimen as preserved ... 23 -8 



Length of the symphysis 8*6 



Depth of the ramus opposite the hinder end of the symphysis ... 5-5 



Depth of the ramus beneath m. 2 5*8 



Depth of the ramus beneath m. 3 5*7 



Transverse diameter of the canine alveolus (approximate) _ 2*0 



Antero -posterior diameter of the canine alveolus (approximate) ... * 2-7 



Dimensions of the teeth : 



Length. "Width. 



p.m. 2 23mm. ... 11mm. 



p.m. 3 ... ... ... 26 ,, ... 13 ,, 



p.m. 4 , 26 ,, ... 13 ,, 



m. 1 21 ,, ... 10 „ 



m. 2 28 „ ... 14 „ 



m. 3 34 ,, ... 17 „ 



This animal closely resembles Pterodon dasyuroides, De Blainville, 

 described and figured in detail by Filhol and Gervais, and may be 

 referred to the same genus. On the other hand, its large size 

 entitles it to specific distinction, and the name Pterodon africanus 

 may be suggested for it. 



IT. — On the Structure of the Palate in the Primitive 

 Theriodonts. 



By R. Broom, M.D., B.Sc, C.M.Z.S. 



FOE some years it has appeared to me that in the Order Therio- 

 dontia as generally accepted there were included a number of 

 forms not at all nearly related to the typical genus, Oalesauriis, and 

 in a number of papers I have referred to these as ' Primitive Therio- 

 donts.' The best known genera are ^lurosaurus and Ictidosuclms, 

 but as in neither of these have the details of palatal structure been 

 very clearly made out, it has been impossible to say how far they 

 differed from the typical Theriodonts. 



Having recently, at the request of Mr. W. L. Sclater, made an 

 examination of some of the reptilian fossil remains in the South 

 African Museum, I came across one or two interesting small Therio- 

 dont skulls that had been for many years in the Museum. These 

 will be described in detail in the Annals of the Museum ; but as 

 one of the skulls, when developed, shows the almost perfect palate, 

 I have thought it advisable to issue this short note on the subject, as 

 the discovery fills a most important gap in our knowledge. 



The little, skull which bears some resemblance to jElurosaurus 

 I have named Scylacosaurus Sdateri. While there is nothing 

 remarkable about the structure of the skull as viewed from above or 

 the sides, the dentition is interesting. In each premaxillary bone 

 there are six incisors, of which the last is very small. Each 

 maxillary has a large tooth near the front, which is evidently 

 a canine. It is not, however, the first of the maxillai-y teeth, as in 

 front of it, and undoubtedly implanted in the maxillary bone, is 

 a small pointed tooth. I regard this minute tooth as the 1st canine 

 and the large tooth as the 2nd canine. There is evidence of a third 



