76 ME. C. W. ANDREWS ON THE SKULL AND 



The Pubis. (Plate XVI. fig. 2, pu.) 

 The pubis is probably imperfectly preserved ; all that now remains is a slender rod 

 of bone arising beneath the middle point of the acetabulum, and running back and 

 terminating against the inner side of the styliform process of the ischium, thus closing 

 an obturator foramen as above mentioned. Whether when complete it extended further 

 back in the usual way cannot be determined. 



Comparison with the Pelvis of other Birds. 



Comparison of this pelvis with that of the Ratitse shows at once that Phororhacos 

 certainly does not belong to that group, though it may have been, and probably was, 

 " Ratite " in the strict sense of the term. It is true that in its length, narrowness, and 

 the large development of the supra-trochanteric processes there is some similarity 

 to the pelves of Dromcms and Struthio, a similarity which, no doubt, is merely the 

 consequence of adaptive modification due to a like mode of progression. On the other 

 hand, in essential points of structure, such as the form and relations of the ischia and 

 pubes to each other and to the ilia, the structure of the " synsacrum," particularly 

 in the distinctive form of the two true sacrals and in the form of the renal fossae, the 

 pelvis in the fossil is very different from that of any Struthious bird. In Apteryx alone 

 the sacrum shows slight points of similarity. 



Among the Carinate birds the pelves which show most resemblance in general outline 

 to the fossil are those of the Grebes and Hesperornis ; but in both of these the pre- 

 acetabular portions of the ilia do not unite with the spines of the " sacrals " to form an 

 ilio-neural crest, but remain separated from them by a considerable interval, while, on 

 the other hand, the postacetabular portions approach one another very closely, and 

 may even unite in the middle dorsal line; the exact reverse is the case in Phororhacos 

 and most other birds. 



To the pelves of the Cranes and Rails the similarity is in many ways remarkable, and 

 probably indicates a real relationship with those birds. The form and character of 

 the renal fossse, particularly the peculiar pocket-like prolongations of the posterior 

 fossse, and the general structure of the " synsacrum," especially the distinctness of the 

 true sacrals, are almost identical with those described in the fossil. One difference, 

 however, must be pointed out, viz. that while in Phororhacos the postacetabular region 

 is the longer, in nearly all the Gruiformes the reverse is the case. In Fulica, however, 

 the post- and pre-acetabular regions are of nearly equal length, and in Cariama the 

 postacetabular portion is the longer, as in Phororhacos. 



The pelvis of Cariama is also similar in the form of its posterior border, the presence 

 of prominent supra-trochanteric processes, and, so far as can be ascertained, in the 

 relations of the pubes. It has, however, a well-developed pelvic escutcheon, the whole 

 postacetabular region being relatively wider than in Phororhacos. On the whole, so 

 far as the pelvis is concerned, I see no reason for changing the opinion expressed in a 



