572 



Dr. C. W. Andrews on a Theropodoua 



process unites with the pubis in a sliojhtly convex surface. 

 Beliind flie acetabulum the ilium unites with the iscliium, 

 but the details of the suture are not clear. The posterior 

 fragment of the right ilium { p.l.) narrows gradually towards 

 its posterior end, which is gently convex^ being some- 

 what thickened and roughened for the attachment of a 

 muscle, probably the ilio-caudal. The outer surface is 

 concave from above downwards, while on the inner face 

 there is a thickened and downwardly-reflected flange running 

 down from the postero-superior angle to the base of the 

 ischial process. The inner face of this flange is roughened, 

 and no doubt united with the posterior part of the sacrum. 



Fisr. 1. 



Pelvis of Sarcosaurus luoodi from tlie left side, partly restored from the 

 ri^ht side. \ nat. size, acet., acetabulum ; a.l., anterior lobe 

 of ilium; /., foramen in (?) ilium; isc, ischium; o.n., obturator 

 notch ; p-L, posterior lobe of ilium ; p.n., preacetabular notch ; 

 p.p., pubic process of ilium ; pu., pubis ; s., suture between ilium 

 and pubis. 



The Pubis (fig. 1). — The proximal ends of both pubes are 

 preserved, that of the right side being the more complete. 

 This bone, which seems to liave been larger in proportion to 

 the ilium than in later forms, unites to the pubic process of 

 the ilium in a slightly concave suture ; below this it bears 

 on its posterior face a triangular surface, which forms the 

 anterior wall of the acetabulum [acet.) ; beneatJi this again 

 there is a short process, separated from the acetabulum Ijy 

 a distinct notch and curving backwards to unite with the 

 pubic process of the ischium in a flat suture^ triangular iu 



