Fauna and Stratigraphy of the Stormberg Series. 



The second sacral rib is missing; but it is apparent that the base 

 of the third sacral rib is larger than the second, and the second than 

 the first. Distally the sacral ribs are fused to form one long surface 

 for the support of the ilium. The base of the first lies on the anterior 

 part of the centrum just below the neural arch and only covers a 

 small part of the body; that of the third occupies at least half of 

 the anterior half of the body and extends up to the strong transverse 

 process. Inferiorly the proximal part of this rib is strong and rounded ; 

 superiorly it thins considerably and then widens out to meet the 

 under side of the fairly wide, horizontal, and backwardly directed 

 transverse process. The anterior face of the rib is thus fairly strongly 

 concave, the posterior face also being concave, but less so. The first 

 rib is essentially of the same character, but is much smaller. 



Of the zygapophyses only the prezygapophysis of the first vertebra 

 is well seen. It is strong with a flat upper surface facing somewhat 

 inwards. The first postzygapophysis is closely fixed to the prezyga- 

 pophysis of the second vertebra. 



The neural canal is high and narrow. The neural spines are higher 

 than the centra, thin, broader above than below, and slightly back- 

 wardly directed. 



Ilium. The left ilium lacks only the posterior process, which is 

 present in the type of the genus. 



The anterior spine is short and sharp, its lower border rounded and 

 fairly thick, its upper border sharp and thin. Its lower border is 

 straight. The preacetabular process is long and strong, widest at the 

 end. In cross-section it is triangular, the apex of the triangle - 

 formed of an obtuse angle - being on the outer side of the bone. 

 The upper half of the process has a strong sharp ridge on its outer 

 edge, which ridge gradually becomes less pronounced as it continues 

 round the acetabular border until it disappears altogether just behind 

 the mid-point of the upper border of the acetabulum. 



The postacetabular process is short and broad, its inner surface 

 flat, its outer surface broadly rounded. The hinder border is concave. 



The body of the bone thins away rapidly above the acetabulum, 

 and the upper border is bent inwards between the anterior and 

 posterior spines. 



The acetabulum is high and narrow. More than half of it is formed 

 by the ilium. 



Ischium. The expanded proximal portion of each ischium is 

 preserved. The surface for articulation with the pubis is long and 

 narrows below; both it and the iliac surface are thickened. The 

 hinder surface of the bone is thickened and carries a longitudinal 



