518 PROFESSOR OWEN ON THE 
The atrophy of wings had not proceeded so far in the extinct Ground-Dove of 
Rodriguez as in the larger species of the Mauritius. ‘The constituents of the scapular 
arch—scapula (pl. 19, figs. 97-99, N.) and coracoid (ib. figs. 76-79 )—are absolutely larger, 
or are relatively thicker or broader (pl. 19, figs. 132, 133) in Pezophaps than in Didus; 
and the same difference of proportion prevails in the humerus, radius, and ulna. The 
expansion of the distal end of the scapula in Pezophaps makes the general curve of the 
upper and anterior border slightly concave; in Didus, beyond the proximal concavity 
of the curve of that border, it runs straight to near the distal end, towards which it 
curves, convexly, as in Pezophaps. ‘The absence of any example of confluence of scapula 
and coracoid in the rich series of specimens possessed by Messrs. Newton of these bones 
(thirty-six of scapula, twenty-seven of coracoid) in the bird of Rodriguez, indicates a 
more habitual and powerful use of the appendage of the arch than was exercised by 
Didus. 
The bones of the manus of the latter bird are still unknown; the desire to obtain 
such is increased since the discovery that the metacarpus of Pezophaps has, on the 
- radial border, a large subspherical knob resembling a tumour, and compared by its 
describers to a callus-like mass of diseased bone. Its repetition, however, in all the 
perfect specimens, its association with a similar outgrowth from the radial border of 
the distal end of the radius in the larger examples of that bone, supposed by Messrs. 
Newton to be of the male Solitaire, and the notice of the same structure in the living 
bird by Leguat’, show it to be normal in Pezophaps, though, when fully developed, 
perhaps sexual. Such tumefaction of the metacarpus has not been noticed in any of 
the accounts or figures of the living Dodo, and it may well be one of the marks of 
distinction between the Solitaire and Dodo. I should not be disposed, however, to 
assign to the metacarpal knob a higher than specific value. 
In Didus and Pezophaps the metatarsal bone presents, besides difference of proportions 
illustrated in a paper by Strickland? and in the joint work of Strickland and Melville’, 
differences of structure, which I fix at a like value. As the characters afforded by the 
articular extremities of the metatarsal of Pezophaps are obscured, more or less, by the 
stalagmitic incrustation of the bones figured in pl. 15 of ‘Dodo and its Kindred,’ I 
believe that the subjects of Pl. LX VI. of the present paper may not be deemed super- 
flous or be unacceptable. 
The metatarsus of Pezophaps is represented by bones of different dimensions, but may 
be said to be, as Strickland recognized them to be, “large” and ‘‘ small,” the variations 
in these two categories ranging within narrow limits. ‘The two nearly perfect speci- 
mens, a right and left, presented by Professor Newton to the British Museum, are of 
1 «The bone of their wing grows greater towards the extremity, and forms a little round mass under the 
feathers, as big as a musket ball.” Quoted by Messrs. Newton at p. 350 of their memoir. 
2 Trans. Zool. Soc. vol. iv. p. 187, pl. 55. 
3 «Todo and its Kindred,’ 4to, 1848, pls. 11 & 15. 
