SKELETON OF PHOKORHACOS 1NFLATUS. 77 



former paper J , that Cariama is probably a not very remote modern representative of the 

 extinct type. 



From the Birds of Prey the chief points of difference are, that in them the post- 

 acetabular region is very short and is deflected, and there is no ilio-caudal process to 

 the ilium. In Serpentarius, however, the first two of these characters are much less 

 marked, and in this respect, therefore, it approaches the fossil, these characters being 

 probably merely correlated with the fact that it is a much better walker than the other 

 Accipitrine birds. 



In the Storks the pre-acetabular portions of the ilia meet at a very obtuse angle, 

 the postacetabular region is very wide, and there are no recesses to the post-renal fossae. 

 In the Herons these fossae, though present in some, are small, the ilio-neural canals 

 are widely open behind, and the pelvic escutcheon is wide; certain Galliformes, 

 e. g. Phasianus and Francolinus, in which renal pockets are present, differ from the 

 fossil in much the same respect. 



In the account of the skull some points of similarity with that of the Albatross were 

 referred to, but in the pelvis no similarity whatever can be detected. Among the more 

 notable differences may be mentioned the complete absence of pocket-like extensions of 

 the renal fosses, almost complete absence of supra-trochanteric processes, the backward 

 prolongation of the ischia and their mode of union with the ilia, and the indistinctness 

 of the true sacral vertebras. 



Ameghino, in his manuscript catalogue, distinctly states that this pelvis and other 



bones were found associated with the skull above described, and formed part of one 



individual ; and if this is the case, as there is no reason to doubt, the structure of 



the pelvis seems completely toj.outweigh whatever evidence of relationship with the 



Albatrosses may be found in the skull. 



The dimensions of the pelvis are : — 



cm. 



Extreme length 41;5 



Length of ilium 41"0 



Longitudinal diameter of ischiadic foramen 6"8 



Vertical diameter of ischiadic foramen 3 - 7 



Length of obturator foramen 2'5 



Greatest height from hsemal ridge of sacrum to top of iliac crest . . . 10"5 



Width at anti-trochanters 11'2 



„ at supra-trochanteric crests 10*6 



„ between upper edges of acetabula . 4 - 5 



„ (least) behind supra-trochanteric crests . 6'3 



„ (least) pre-acetabular region .... 3'5 



„ centrum of first fused " sacral " vertebra 3 - 3 



Length of " synsacrum " 36"5 



1 'The Ibis,' 1896, p. 1 ; see also ' Science Progress,' vol. v. (1896) p. 398. 



