862 DR. R. BROOM ON 



published in 1910*. Within the last i'eAV months Mr. Whaits 

 has fortiniately discovered a good skull of Ciorgonops which shows 

 that it has quite a large temporal opening, very similar to that 

 in the present genus. 



In general appearance K>c)/mnognathi(s diiiei's from tlie more 

 typical Therocephalians mainly in having the intertemporal region 

 about as wide as the interorbital. The snout is long, the orbits 

 small, the temporal region fairl}^ wide, and the squamosals more 

 poweifully developed than in most Therocephalians. 



The total length of the skull is, in the type, 305 mm. In a 

 second but much crusheil specimen the length is probably about 

 325 mm. From the front of the snout to the front of the orbit 

 the measurement in the type is 165 mm., and the length of the 

 orbit about 40 mm. The interorbital width in the type is 70 nnn. : 

 in another ^'ery inipei'fect specimen it measures 78 mm., and in a 

 third about 76 mm. The narrowest part of the parietal region 

 measures in one of the lai'ger specimens 78 mm. 



The parietal foramen is situated well back and is 6 nam. in 

 diameter. 



Though the limits of many of the bones cannot clearly be made 

 out, much of the cranial structure can be seen. The bones of the 

 snout seem to agree with those of the better known Thero- 

 cephalians, though the septomaxillary is relatively larger. The 

 jugal is unusually well developed and the postorbital is very large. 

 The pt)stfrontal also seems to be much larger than in any other 

 tvpe hithei'to examined. The squamosal is more massive than in 

 most Therocephalians, and the quadrate is relatively small and 

 largely hidden by the squamosal. The occipital condyle is single. 



The lower jaw is fairly similar to that previously described 

 and ligui'ed in L}/cosuchHS and Aloposaurus. The front of the 

 dentary is very deep and has a well-marked mental process. 

 Posteriorly the dentary has a short corouoid pvoces* and for a 

 considerable distance lies above the angulai-. The sui-angular is 

 much smaller than in other known Therocephalians. 



There are live upper incisors, one large canine and three or four 

 molars. The incisors are long pointed teeth, oval in section, and 

 apparently without serrations. The space occupied by the five 

 incisors in three specimens is 37 mm., 39 mm., and 40 mm. The 

 space between the last incisor and the canine in four specimens is 

 18 mm., 22 mm., 25 mm., and 26 mm. The length of the canine 

 in seven specimens is 16 mm., 18 mm., 20 mm., 20 mm., 20 mm., 

 20 nun., and 21 mm. Behind the canine is a diastema varying from 

 7 mm. to 16 mm., followed by either thi'ee or four molars. The 

 number of molai's apparently depends on age. When three molai-s 

 are present the distance occupied by them is 20 or 21 mm. : when 

 four are present they occupy 25 mm. to 29 mm. 



The dental formula is, i. '] , c. , m. ._ "^ " . 



* " (Miservatious on soino si)efiiiiciis of South African Fossil Rei)tiles iirof^crved in 

 the British Museum." Tr. Koy. Sue. 5>. Afr. vol. ii. pt. 1, 1010, p. 20. 



