Zoological Society. 235 



ment of this uncinated part as in the Vulturida, hut are nearer the 

 lower border of the mandible in the Dodo. 



The resemblance between the skull of the Dodo and that of the 

 Albatros is chiefly in the compression and prolongation of the curved 

 mandibles : there are no traces in the Dodo of the hexagonal space 

 on the upper surface of the cranium of the Albatros, so well defined 

 there by the two supra- occipital ridges behind, the two temporal ridges 

 at the sides, and the two converging posterior boundaries of the supra- 

 orbital glandular fossae in front. There is no sudden depression of 

 the frontal region in the skull of the Albatros ; the nostrils are near 

 the upper surface of the basal third of the beak in the Albatros ; and 

 the Dodo's cranium is thrice as broad in proportion to the breadth 

 of the mid-part of the mandible as in that of the Albatros. 



More satisfactory evidence of the affinities of the Dodo was ob- 

 tained from a comparison of the bones of the foot, which have recently 

 been very skilfully and judiciously exposed by the able Curator of 

 the Ashmolean Museum. 



The tarso-metatarsal bone most resembles in its thickness and 

 general proportions that of the Eagles, especially the great Sea- 

 Eagles (Haliaetus) ; it is much stronger than the tarso-metatarsus of 

 any of the Vulturida, or than that of the Cock, the Crax, or any of 

 the Gallince or existing Strut hionidee; the stronger-footed species of 

 Dinornis most resemble it in the general proportions of the tarso- 

 metatarsus, but greatly differ in the particular configuration of the 

 bone, and in the absence, or feebler indication, as in the subgenus 

 Palapteryx, of the articulation for the metatarsal bone of the back- 

 toe. The relative size of this bone is greater in the Dodo than in 

 any other known bird. The Eagles make the nearest approach to 

 it in this respect ; as also in the shape of the hinder supplemental 

 metatarsal, the breadth of its distal end, and its peculiar twist back- 

 wards and outwards, so as to form a bridge or pulley against which 

 the flexor tendon of the hind-toe plays. This half-twist of the rudi- 

 mental hind-metatarsus is feebly repeated in the Gallirue, but the 

 bone is much less expanded at its lower articular end, especially in 

 the Crax ; whilst the more typical Gallince are further distinguished 

 from the Dodo by their spur. 



The Apteryx is the sole existing Struthious bird which possesses 

 the hind-toe ; but it is very much smaller than in the Dodo, and the 

 supporting metatarsal bone is devoid of the distal twist and expanded 

 trochlea. The upper end of the tarso-metatarsus of the Dodo is re- 

 markable for the great development of its calcaneal process, from 

 which a strong ridge descends, gradually subsiding, half-way down 

 the bone. The posterior surface of the calcaneal process is broad, tri- 

 angular, vertically grooved and perforated at its base. In the Eagle the 

 corresponding calcaneal process is a compressed, subquadrate ridge, 

 whose base of attachment is not much longer than the obtuse end, 

 and this is neither grooved nor perforated. In the Cathartes Cali- 

 fornianus the calcaneal process is thicker than in the Eagle, shaped 

 more like that of the Dodo, with a ridge descending upon the meta- 

 tarsus, but it has a double groove behind. 



R2 



