52 



been very skilfully and judiciously exposed by the able Curator of 

 the Ashmolean Museum. 



The tarso-metatarsal bone most reserables 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 Gailina or existing Struthionida ; the stronger-footed species of 

 Dinomis 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. 'ITie 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 \vhich 

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

 mentai hind-metatarsus is feebly repeated in the Gailina, but the 

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

 the Crax ; whilst the more typical Gailina 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 

 \vhich 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, subąuadrate ridge, 

 ■vvhose 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 likę that of the Dodo, \vith a ridge descending upon the meta- 

 tarsus, but it has a double grocve behind. 



In the Common Cock the calcaneal process more resembles that 

 in the Dodo than the Vulture's does, but it is not so broad. 



With regard to the first or proximal phalanx of the hind-toe, that 

 of the Halia'ėtus is larger and broader, especially at its base, stronger 

 in proportion to its length, but longer in proportion to the sustaining 

 raetatarsus. 



In the Vultures the proximal phalanx is not only longer in pro- 

 portion to the metatarsus, but is more slender than in the Dodo. 

 The šame bone is edso longer and more slender in proportion to the 

 small supporting metatarsal bone in the Cock, the Crax, and all other 

 Gailina ; in fact, the Dodo is peculiar among Birds for the eąuality 

 of length of the metatarsus and proximal phalanx of the hind-toe. 

 ■VVith regard to the three trochlear extremities of the principai 

 coalesced metatarsals, the middle one in all Gailina is longer in pro- 

 portion than in the Dodo, in \vhich the inner one is nearly as long 



