100 Annals of the South African Museum. 



Ornithosuchus and Erpetosuclms the pretnaxilla is entire, and forms 

 an anterior border to the external nares, and Broom has considered 

 that the bone in Euparkeria was similar. Of the fact that in this 

 type the nostril was terminal and open I think there can be no 

 doubt. Dr. du Toit, who partially developed the front of the snout 

 before the fossil came into my hands, informs me that no bone was 

 broken away save a tiny fragment from the outer edge of the left 

 nasal ; and in the specimen as it is now displayed there is no sign of 

 any anterior vertical portion of the premaxilla. 



There is no septomaxillary present on the face. 



The antorbital vacuity is large, and is sunken in the face, having 

 borders which make an oblique angle with the sides of the face. 

 The whole of the lower and anterior borders is formed by the 

 maxilla, which extends back only so far as the front of the orbit- 

 not nearly so far as in Euparkeria. The maxilla carried about 

 12 teeth, of which 8 are preserved on the right side. Unfortunately, 

 not one possesses the crown ; but a small tooth in the lower jaw 

 shows serrations on the anterior border similar to those of the 

 carnivorous Dinosaurs. The teeth are flattened laterally, and vary 

 considerably in size. The first maxillary tooth has an antero- 

 posterior diameter of just over 1 mm. ; the probable 6th, which 

 is the largest, has a diameter at the gum of 7 '5 mm. The teeth do 

 not increase or decrease regularly in size from front to back of 

 the jaw, but are variable. 



The surface of the maxilla is plentifully supplied with grooves and 

 small foramina for blood-vessels. 



The nasal is an extremely long bone forming the upper surface of 

 the skull from the tip of the snout nearly to the plane of the front 

 of the orbit. It forms none of the posterior border of the nostril. 

 The greatest width across the pair of bones is 20 mm. at the back 

 while the length is about 88 mm. 



The lachrymal forms the whole of the upper border and most 

 of the posterior border of the antorbital vacuity, besides forming 

 the larger part of the anterior orbital border. 



The prefrontal is a small bone lying between the frontal, nasal, 

 and lachrymal. Below it has a lobe-like extension articulating with 

 the lachrymal, so that it forms about 18 mm. of the orbital border ; 

 but its width throughout most of its length is only about 6 mm. 



I can see no evidence of a postfroutal. Even if one be present, 

 the frontal is still peculiar in that it passes back to form part of the 

 anterior border of the upper temporal fossa, separating the post- 

 orbital from the parietal. The interorbital region has a median 



