476 FTJKTHEK EVIDENCE OE ENDOTHIODON BATHY8T0MA. 



32. On Ffkther Evidence of Endothiodon bathystoma {Owen) 

 from OuDB Klooe in the Nieuvtv^eldt Mountains, Cape Colony. 

 By H. G. Seeley, Esq., F.R.S., E.G.S., Professor of Geography 

 and Lecturer on Geology in King's College, London. (Eead 

 May 25tli, 1892.) 



I am indebted to Mr. Thomas Bain, Geologist and Irrigation Officer 

 to the Government of Cape Colony, for two bones collected by him 

 in the Oude Kloof, a picturesque mountain-valley which traverses 

 the Nieuwveldt range north of Tamboer, on the road towards 

 Fraserburg. 



The remains consist of the left ramus of the mandible, which is 

 almost complete, and what I regard as the left squamosal bone under- 

 lapped by the malar in front, but fractured at both ends, so that only 

 the external zygomatic bar is preserved. Small as the cranial frag- 

 ment is, it is important as showing that the back of the head pro- 

 bably conformed to the type of skull seen in some of the Dicyno- 

 donts. The skull was as large as that of Dicynodon leoniceps. 



The Zygomatic Bar. 



The longitudinal squamosal bar is 20 centim. long, compressed 

 from side to side and flattened, with the superior border convex in 

 length. The convexity is most marked in the hinder part, where 

 the edge of the bone is about 0*75 centim. thick and rounded, and 

 the depth of the bone in front of its hinder termination is 6*25 

 centim. A wide shallow concavity extends along the external 

 surface, and appears to be defined inferiorly by a rugose condition 

 of the bone. Anteriorly the depth of the bar is a little less, but 

 its thickness augments ; this is due to the strong malar bone, 

 2*5 centim. thick, which forms its infero-anterior border, and ex- 

 tends behind the thin, external, zygomatic prolongation forward 

 of the squamosal. 



The inferior margin of the bar appears to be concave in length 

 to the abrupt angle where the descending bar (if it was developed) 

 is broken away, so that the bone has a depth of only 8J centim. 

 from the superior border. This descending bar, so characteristic of 

 all Dicynodonts and absent from Theriodonts and the Placodontia, 

 if present would support Sir Bichard Owen's judgment in regarding 

 Endothiodon as affiliated to Oudenodon} 



The Lower Jaw. 



The left ramus of the mandible, as preserved, is 30 centim. long, 

 but has apparently lost about 2-5 centim. from the anterior 

 extremity. It is nearly straight, with a slight inward inflection at 



* Quart. Journ. Geol. Soc. vol. xxxv. (1879) p. 657. 



