BIRDS ALLIED TO THE DODO. 195 



No. 17. No. 18. 



inch. lin. inch. lin. 

 Length from lower border of middle trochlea to summit of 



intercondyloid tubercle 58 59 



Transverse diameter of the shaft 06 06 



Antero-posterior diameter of the shaft at the upper portion 



of articular surface for posterior metatarsal 4 4 



Transverse diameter of lower extremity 13^ 1 3| 



Distance from upper border of posterior metatarsal articular 



facet to internal intertrochlear notch 13 1 34 



Length from external trochlea to external condyloid fossa .5 1^ 5 2^ 



Length from internal trochlea to internal condyloid fossa . 5 2J 5 3-^ 



Breadth of upper extremity 12 1 ^i 



Antero-posterior diameter of upper extremity 11 



Projection of ento-calcaneal process 5 



;i 



The tarso-metatarsus is the only bone of the genus Pezophaps (with the exception of 

 the very imperfect fragment of the cranium No. 1) which we are at present able to 

 compare with its corresponding member in the genus Didus. Fortunately also it is one 

 of the most characteristic bones in the ornithic skeleton, presenting peculiarities of 

 structure in each of the orders and families which enable us in most cases to identify 

 with certainty the group of birds to which any example of this bone has belonged. 



On comparing the bones Nos. 17 and 18 with the tarso-metatarsus of the Dodo, de- 

 scribed at p. 102, and figured in plate xi. figs. 1,2,3, 4, 5, 6, of the work above referred 

 to, we are struck at once by the much slenderer proportions of this bone in Pezophaps 

 than in Didus. Although the tarso-metatarsus of the former is longer by 6 lines than 

 the latter, its transverse diameter is one-sixth less. The width of both extremities of 

 the bone is also considerably less in the Pezophaps than in the Didus. 



These differences of proportion all indicate that the Pezophaps was a taller bird, but 

 of lighter weight and more active movements than the Didus — a distinction, to which 

 the historical accounts of the Solitaire and of the Dodo bear ample testimony. 



With the exception, however, of this difference in the proportions of its length and 

 breadth, the entire details of structure are almost identical in the tarso-metatarsus of 

 these two birds. The elaborate description given by Dr. Melville of the tarso-metatarsus 

 of the Dodo (' Dodo and its Kindred,' p. 103) would apply almost word for word to the 

 bones before us, and afford the most convincing proof of their close affinity. There are 

 indeed some very slight modifications of form which distinguish the tarso-metatarsus of 

 the Solitaire from that of the Dodo, which are carefully pointed out by Dr. Melville, 

 loc. cit. p. 1 18, and which I need not now adduce. I may, however, refer to two points, 

 which the perfect state of the specimens Nos. 17 and 18 has now for the first time 



