On Some Points in the Structure of the Dicynodont Skull. 341 



allowance is made for some degree of depression of the frontal and 

 parietal regions. But though the outlines are moderately correct, 

 the shading is very unsatisfactory. In Fig. 2 the deep vaulting of 

 the front of the palate is not shown, nor is the deep depression 

 between the anterior parts of the pterygoids brought out, nor 

 the deep furrow between the basioccipital processes. In Fig. 1 

 there is very little attempt to indicate the heights and depths of the 

 specimen. Figs. 3 and 4 are both fairly well drawn, but the shading 

 bad in both, especially in Fig. 3. 



The premaxillary (EM, intermaxillary in the figures) is a large 

 powerful median bone. In all the Dicynodonts the bones of 

 the two sides are anchylosed at a very early period. In front the 

 bone forms a rounded sharp beak. Above a broad powerful 

 internasal process passes up between the nasals and ends in a 

 point as shown in Fig. 1. Underneath the premaxillary forms 

 about two-thirds of the hard palate. Though the suture is not 

 shown in the figures, it begins in the dark mark shown in Fig. 3 

 behind the letter " b " of " broken," and passes almost straight back 

 along the outside of the irregularities believed by Seeley to be 

 teeth. It then passes inwards in front of the irregularity marked 

 "palatine tooth," and ends in the middle line in front of the 

 irregularity marked "tooth," and behind the region marked "teeth 

 lost." I have carefully examined the structures regarded by Seeley 

 as teeth, and am quite satisfied they are merely bony irregularities 

 with no tooth structure. The whole of the hard palate was probably 

 covered by thick epithelium, which was horny in front, and probably 

 most of the snout above was also covered w T ith a horny beak and 

 horny scales. Underneath the great epithelial development the 

 bone in most places is irregular. The nasals, the premaxilla, and 

 much of the external surface of the maxillae have a very rough 



/ 



appearance. In the palate there are patches of what appear to me 

 to be exactly the same style of roughened bone. This rough 

 appearance is seen on the median ridge formed by the premaxilla 

 and on the small part of the ridge formed by the vomer on the pair 

 of ridges in the front part of the premaxillary, on the ridges formed 

 by the lateral margins of the premaxillary, and on the anterior part 

 of the palatines. Though it is customary to speak of the horny 

 beak of the Anomodonts, it is probable that the beak was less horny 

 than in the tortoise or bird, except perhaps just on the margins. 



Both maxillae are in almost perfect preservation ; that of the left 

 side being quite perfect except for the loss of a minute fragment 

 from the caniniform process. The bone forms the greater part of 



