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VI. — On Some New Primitive Theriodonts in the Soutli African 

 MnscAim.—By E. Broom, M.D., B.Sc, C.M.Z.S. 



(Plates XVII., XVIII.) 



A.T the request of the director, Mr. W. L. Sclater, I recently made 

 an examination of a series of reptilian fossils that had been for many 

 years in the South African Museum, but which had never l)een 

 critically examined. The most interesting of the specimens are 

 imperfect portions of five skulls of primitive Theriodonts. These 

 are not only important as belonging to three new genera, but from 

 their throwing much new light on the structure of this interesting 

 group of fossil reptiles. 



SCYLACOSAUEUS SCLATERI, g. et sp. nov. 



The best preserved of the specimens is the anterior two-thirds of 

 the skull of a moderate-sized reptile. The lower jaw is absent and 

 the skull broken across immediately behind the orbits. All the 

 anterior portion of the skull, however, is in fair preservation, and 

 thovigh the matrix is exceedingly hard the specimen has been suffi- 

 ciently developed to show most of the details of structure. 



In its general proportions the skull is distinctly fox-like, the snout 

 being long and narrow. The nostrils are practically terminal and 

 have been separated by the ascending processes of the premaxillaries. 

 The orbits are round, and are directed upwards and outwards and 

 slightly forwards. 



The nasal bones are practically perfect. They are long and 

 narrow, and are rather broader in front than behind. Laterally 

 they articulate with the premaxillaries and the maxillaries ; and 

 posteriorly with the frontals and prefrontals. 



The premaxillaries are rather small. Each supports six incisor 

 teeth. The outer border of each nostril is formed by a process of 

 the premaxillary which passes up between the maxillary and the 



