New Species of Propappus, and Pose of Pareiasaurian Limbs. 327 



acetabulum to the most anterior part of the iliac crest is 190 ram. 

 The narrowest part of the ilium is 65 mm. 



The acetabulum is large, and but for a marked development of the 

 upper iliac border and of the ischial border would be rather shallow. 

 Its greatest width is 115 mm., and its vertical measurement 95 mm. 

 The three bones forming it are so completely anchylosed that their 

 limits cannot be with certainty determined. 



The pubis and ischium are so completely anchylosed that no trace 

 of the dividing suture can be detected, and the bones of the two 

 sides are likewise completely anchylosed along the symphysis. The 

 bones are massive, and represent a somewhat specialised modification 

 of the plate-like type. 



The pubis is considerably longer vertically than antero-posteriorly. 

 From the anterior part of the symphysis to the point where it 

 probably unites with the ilium is about 170 mm. The greatest 

 antero-posterior measurement is probably not more than 100 mm. 

 There is a large pubic foramen situated as shown in the figure. As 

 the bone lies in the body the pubic canal passes almost directly 

 upwards. The outer half of the front edge of the pubis is much 

 thickened and bent downwards and forwards, and I think there 

 is little doubt that it supported a prepubic cartilage. This surface 

 for the cartilage measures about 90 mm. in length, and varies from 

 20 to 30 mm. in width. The lower end of the surface rises abruptly 

 from the inner part of the anterior border of the pubis. 



The ischium measures about 180 mm. by about 135 mm., and but 

 for the great vertical depth would be practically of the plate-like 

 type. The symphysis is very thick. In the pubic region it reaches 

 a thickness of 68 mm., but becoming thinner in the ischial region 

 it averages about 55 mm., and at the posterior part of the ischium it 

 is only about 35 mm. 



Femur. 



The right is preserved in perfect condition. It resembles pretty 

 closely the femur of Propappus omocratus, but differs from that of 

 Pareiasaurus serridcns in a number of important features. It agrees 

 with the femur of Propappus omocratus in having the axis of the 

 upper third of the bone making an angle with the lower part of 

 the shaft of about 45. It also agrees with it, and differs from that 

 of Pareiasaurus in having the middle of the shaft constricted and 

 nearly round. And lastly, it agrees with the femur of Propappus 

 omocratus in that the trochanter minor is directed backwards and 

 outwards, so that a deep concavity is formed between it and the 



