2g6 



NATURAL SCIENCE. 



May, 



in which the power of flight had been lost. From the Ratitae they 

 also differ widely in the relative proportions of the head and body, for 

 in the struthious birds the head is in all cases extremely small in 

 comparison with the whole bulk of the body, while in Phororhacos it 

 is proportionately very large. Probably the Shoe-billed Stork 

 (Balaniceps) gives the best idea of these proportions in Phororhacos ; 

 the two are, however, in no way related, and the shape of their heads 

 is quite different. 



The bones of the fore-limb were all very short, but at the same 

 time stout and strong, so that although these birds were almost 

 certainly incapable of flight, they still possessed, for some purpose or 

 other, a powerful wing. The pelvis has been to some extent crushed, 

 so that the extreme narrowness of its post-acetabular region, as 

 shown in Ameghino's figure, is somewhat exaggerated. All the 

 bones of the hind-limb are known in this species, so that the height 

 of the bird at the middle of the pelvis can be estimated to have been 

 less than i metre. The skull is 34 cm. (about 13^ inches) long. 



Skull of Phororhacos inflatus, Ameghino. One-fourth natural size. 



(After Ameghino.) 



As to the affinities of these birds there is still much doubt. It is 

 clearly impossible to regard them as struthious, and their great 

 specialisation renders it very difficult to ascertain their place among 

 the Carinatse. In a recent paper in The Ibis, Mr. C. W. Andrews has 

 suggested that their nearest living ally is that curious South American 

 bird the Cariama [Dicholophtis), which, though much resembling the 

 Secretary-bird, is now usually regarded as a very aberrant crane. 

 To this, in some respects, as for example in the structure of the 

 metatarsus, the resemblance of Phororhacos is very great. If this 

 surmise be correct, it is a matter of some interest to find that some of 

 the birds, like many of the mammals, now living in South America, 

 have extinct representatives of gigantic size and a high degree of 

 specialisation. 



Prosser on Permian Problems. 



Considerable doubt has prevailed as to the relations of the 

 Permian beds in the Western States of America, if, indeed, the 



