Extinct Birds from Patagonia. 9 



Chauna and Cathartes the neck is exceedingly short and 

 stout, and the distal extremity slightly expanded. In all the 

 Ratitae this bone is considerably stouter in proportion to its 

 length and differs in other respects. 



The tibio-tarsus of Phororhacos is about twice as long as 

 the femur, and is straight and slender. The distal condyles 

 are subeqnal and the intercondylar groove is shallow. The 

 bridge over the groove for the extensor tendons lies towards 

 the inner border of the bone and is somewhat oblique. In 

 Cariama the tibio-tarsus is more slender and is more than 

 twice the length of the femur. The extensor bridge is some- 

 what less oblique, and the intercondylar groove is shallower 

 than in the fossil. The crest for the attachment of the 

 fibula (not shown at all in the figure of the fossil) is pro- 

 minent. The tibia is considerably diflFerent at its lower end 

 from that of Gasioinis, in whi(;h the bridge is median, the 

 groove deep, and the lower end as a whole somewhat inflected, 

 closely resembling that of an Anserine bird. In all the 

 Ratitse the intercondylar groove is shallow, and except in the 

 Dinornithidae the extensor bi idge is wanting. In some of the 

 smaller members of the latter genus the resemblance to the 

 fossil is considerable. 



The metatarsus and, indeed, the tibia also of Phororhacos 

 have already been compared with the corresponding bones 

 in the Ratites and in some of the Carinates by Dr. Gadow. 

 Here it will be sufficient to mention that in the structure of 

 the hypotarsus and in the arrangement of the distal trochlese 

 it agrees in some respects with Cariama. In this bird, how- 

 ever, the bone as a whole is more slender than in Phororhacos. 

 The latter, in the whole sti'ucture of the limb, differs widely 

 from Hesperornis and Colymbus, to which the form of the 

 pelvis might lead one to expect some similarity. From 

 Cathartes and the Tinamou there are also great differences. 

 The digits of Phororhacos are provided with powerful hooked 

 claws unlike those found in any of the Ratita3. 



The coracoid (fig, 4, b, p. 10) is remarkably long and slender. 

 In general form it resembles that of some Gallinaceous birds ; 

 in any case it is quite unlike that of any of the Ratitse, in 



