AXIAL SKELETON OP THE PELECANID.E. 333 



The parapophyses of the lumbal' vertebrae form together three presacral foramina on 

 each side (fig. 3, s', s^, s^). Postaxiad of this there are no parapophyses, but the wide 

 as well as long (though somewhat longer than wide) subquadi-ate renal fossa appears on 

 each side. 



The parapophyses of the three sacral vertebrae become shorter postaxially. 



Those of the sacro-caudal vertebrae remain of about the same transverse extent as 

 those of the third sacral vertebra. 



There is no fossa on the ventral surface of the ilium towards its postaxial end, any 

 more than there is in any of the Struthionidae ; but there is a wide surface (posterior 

 iliac ventral surface) of ilium extending outwards on each side between the distal ends 

 of the sacro-caudal parapophyses and the outer margin of the ilium (fig. 3, il'). 



The Ilium. 



This bone almost extends to roof over the last dorsal vertebra but one (i. e. the 

 twenty-first vertebra) ; an ossification of fascia connected with it continues onto two or 

 three vertebrae more preaxial. 



Seen laterally, the preacetabular part has its dorsal margin very slightly convex ; its 

 ventral margin is concave in even a less degree than the other is convex. The two 

 margins meet together preaxially. There is no ilio-pectineal process. 



The ilium probably takes about the same share in forming the acetabulum that it 

 takes in Struthio. 



The postacetabular part of the ilium decidedly exceeds in length its preacetabular 

 part. Seen laterally this part is at first very small [i. e. above the sacro-sciatic foramen), 

 but more postaxially it expands dorso-ventrally to join the ischium. 



Seen dorsally this part is widest just behind the antitrochanteric process, whence it 

 narrows postaxially to the hinder end of the sacro-sciatic foramen, and then expands to 

 join the ischium. 



The postaxial end of the ilium develops a large ilio-caudal process [Ic), which is sepa- 

 rated from the sacrum by a narrow notch, and from the postaxial end of the ischium 

 by a much wider notch. 



There is a gluteal ridge (fig. 1, gl) extending along the dorsal edge of the ilium from 

 the preaxial end back to the antitrochanteric process. Just behind and above this 

 process is a small prominence (figs. 1 & 2, st), which may be compared to the supra- 

 trochanteric process of the Struthionidae, and may be here termed the imsttrochanteric 

 process. The ilium has on its ventral surface the siipraacetabular fossa before described. 



The Pubis. 

 This bone is long and very narrow, with a sigmoid curvature, but without any pvomi- 

 nent process. It forms no ankylosis with any other bone postaxial to its origin. It 

 widens (dorso-ventrally) just postaxiad to its ligamentous attachment to the ischium. 



2z2 



