150 Annals of the South African Museum. 



tusk passes mainly downwards and its base lies just in front of the 

 orbit. 



In the male skull the pineal foramen is slightly farther back along 

 the pai'ietal bar than in the type ; but the relative shapes and sizes of 

 the bones around the foramen remain the same. 



The foramen magnum is large and the post-temporal fossa is seen 

 to be well up on the occipital plate (No. 3352), so that the paroccipital 

 processes are deep and fairly shoi't. 



The only other small species known from the Cistecephalus zone is 

 D. testudirostris. The two species are readily distinguishable at a 

 glance by the natui'e of the beak. D. testudirostris is especially 

 characterised by the strength of the beak and the vertical inclination 

 of the front of the snout. The suborbital bar has its lower border 

 turned abruptly downwards at the level of the middle of the orbit, so 

 that there is a deep portion of the maxilla underlying the front half 

 of the eye. The two species agree in the narrowness of the frontal 

 region compared with the breadth of the parietal bar, in the narrowing 

 of the parietal bar posteriorly and in the possession of an insignificant 

 postfrontal. In D. testudirostris, however, the postorbitals meet above 

 the parietals at the back of the parietal bar, while in D. pygmaeus they 

 don ot. 



D. pygmaeus has a fairly close ally apparently in D. ictidops from 

 the zone below, from which form it might possibly have been derived 

 by the reduction of the postfrontal and slight broadening of the 

 parietal crest. 



Type.Sku\\. (S.A. Mus. Cat. No. 2664.) 



Locality. Duuediu, Beaufort West, C.P. 



Horizon. Lower Beaufort Beds. (Cistecephalus zone.) 



DlCYNODON ROGERSI, Br. <t Htu. 



1917. Broom & Haughton. Ann. S.A. Mus., xii, 5, p. 121 ; figs. 21, 22. 



This form is closely allied to D. kolbei, and for some years the type 

 specimen was considered to be an example of that species. The 

 differences between the two forms are, however, worthy of recognition, 

 and have been given in the paper cited above. 



One half only of the occipital plate is preserved, and the condyle is 

 lacking. The lateral vacuity is at the level of the middle of the rather 

 small foramen magnum. The tabulare is not large. The stapes is 

 short and its outer end is considerably lower than its inner end. 



The lower jaw is very long and comparatively shallow^ 



