AXIAL SKELETON OF THE PELECANID^. 331 



and terminal portion of the pygostyle. This most anterior portion represents, more or 

 less completely, at its preaxial end the characters of the forty-second vertebra. 



The Pelvis. 



The pelvis of the adult consists of fifteen or sixteen vertebrae with the ossa 

 innominata. Compared with that of Struthio and the other Struthionidse it presents 

 many contrasts (Plate LIX. figs. 1-3). 



Preaxially viewed, the ilia fm-m a much less steep arch (approximate dorsad at a 

 more obtuse angle) than in any of the Struthionidse (than even in Dromceus) ; and the 

 ilium, thus seen, is concave on each side. It differs from Struthio and Bhea in that 

 the pubis and ischia respectively simply diverge ventrad. 



Fostaxially viewed, it diff"ers from the pelvis of all the Struthionidae in the wide 

 (transversely extended) and dorsally flattened postaxial ends of the ilia ; the ilia not 

 being laterally compressed and flattened against the sides of the vertebrae included 

 between their most postaxial parts. 



Laterally viewed, the acetabula are seen to be a little preaxiad of the antero-posterior 

 middle of the pelvis, measured from the preaxial end of the ilium to the postaxial end of 

 the pubis. The pelvis differs from that of all the Struthionidee in that (1) the ilium {il) 

 is less vertically expanded in front of the acetabulum, (2) that it is relatively more 

 vertically expanded behind the acetabulum, (3) that the ischium (i) is, at its distal end, 

 largely united with the ischium. Moreover the ischium extends postaxially beyond 

 the ilium more than in any of the Struthionidse, except Struthio and Ehea, but about 

 as much as in Struthio, though not nearly so much so as in Bhea. 



The pubis (;;) extends postaxiad of the ischium much more than in any of the 

 Struthionidse, except Struthio, which is so exceptional in its family in this respect. 

 The pubis is curved as in Struthio, but scarcely ever approximates at its tip to its 

 fellow of the opposite side. The obturator-foramen is long and narrow, and shaped 

 much as in Struthio, except that its anterior part is not divided off", that division being 

 here only indicated by a rudimentary intertrochanteric process of the ischium, which 

 does not nearly attain the pubis (Plate LIX. fig. 2, j9s). 



In this respect Pelecanus differs from all the Struthionidse, except Apteryx and 

 Dinornis. The pubis has no opposite corresponding process, or a mere rudiment of such. 



There is no ilio-pectineal process, by which Pelecanus diSeis from all the existing 

 Struthionidse, if not from Binornis also. 



No process extends ventrad from the mid ventral margin of the pubis. 



The antero-posterior diameter of the pelvis is rather more than twice its dorso- ventral 

 dimension. 



There is an oval sacro-sciatic foramen. There is no such foramen in any of the 

 Struthionidse, except in Ehea and sometimes in Casvarius. 



VOL. z. — PART VII. No. 3. — August \st, 187S. 2 z 



