Vol. 56.] SKELETON OF EURrCARPTJS OWENI. 327 



value consists in indicating the form and size of the head, which is 

 a little less than a quarter of the length of the drawing ; and thus 

 agrees with the measurement of the Murray specimen, within a 

 tenth of an inch. 



The shape of the head as drawn was previously unknown. The 

 discoverer differentiated it by means of the expanded form of the 

 nose. This character was then and is still unknown in the genus 

 Dicynodon. It is found to some extent in all Theriodontia, although 

 the transverse constriction behind the canine teeth is more marked 

 in Gomphodontia than in other Theriodonts. There is no direct 

 evidence that the skull possessed Theriodont dentition, but the molar 

 teeth might be hidden, and the sketch may imply that the roots of 

 the canine teeth are seen in the lower jaw (fig. 1). The only group 

 of Theriodonts known from the Dicynodon-beda is the Lycosauria ; 

 and it is probable that Eurycarpus may be referred to that group. A 

 peculiar feature of the sketch is the concave anterior extremity of 

 the nose. 



The Vertebral Column. (PI. XXI, v.) 



The vertebrae are mostly in close order, with only very small 

 displacements in their continuity. There may have been seven 

 cervical vertebrae. Six appear to be indicated in Mr. Bain's original 

 slab, by the short strong neural spines, which are not unlike those 

 seen in Tropidostoma Dunni. The forms of the cervical vertebrae are 

 not shown. 



There are eleven dorsal vertebrae which support long ribs. They 

 are succeeded by five vertebrae with short ribs. The hindermost of 

 these terminates 1J inches in advance of the head of the femur. 

 The total length of this part of the vertebral column, comprising 

 fourteen vertebrae, is 16 inches. According to Mr. Bain's memorandum 

 this would leave 3^ inches for the sacrum and early caudal vertebrae 

 which he indicated. This suggests a short sacrum, with not more 

 than two or three vertebrae. 



The depth from the summit of the neural arch to the base 

 of the centrum is 1| inches, with but little variation down the 

 length of the dorsal region ; and this is in harmony with the skeletons 

 already known of Anomodonts, such as Cynognathus, Deuterosaurus, 

 Procoloplion, and Pareiasaurus. 



The front of the centrum appears to be a little wider than the 

 back. The greatest width of an early dorsal vertebra in front is 

 -fa inch measured over the neural arch. The front margin of 

 the articular surface of the centrum is a little thicker than the 

 hinder margin. The articular faces of the centra are flattened 

 or very slightly concave, but they are very imperfectly exposed. 

 The length of the ventral surface of the dorsal vertebrae is T 6 - inch 

 in the front part of the back, but in its lower part they are slightly 

 longer. The inferior margins of eight dorsal vertebrae are clearly 

 seen, and they show no indication of intercentral ossifications such as 

 have been described in Cynognathus and Pareiasaurus. 



