365 



1587- The shaft of a left metatarsal bone of corresponding dimensions with the 

 preceding ; a section has been removed from the proximal end, showing 

 the confluence of the originally distinct juxtaposed walls of the three me- 

 tatarsals, and the coarse cancellous structure in the centre of each. 



1588. The left tarso-metatarsal bone of the Dinornis didiformis: this specimen 

 measures seven inches ten lines in length ; it is in other respects iden- 

 tical in character with the preceding bones Nos. 1585, 1586, and appears 

 to indicate a sexual superiority of size. 



Presented by William Cotton, Esq., F. R.S. 



1589. A phalanx, apparently the second of the middle toe, of the Dinornis 

 struthoides : it is three inches and a half long and one inch and a half 

 broad across the proximal joint. This does not present the median 

 vertical ridge which the corresponding groove in the articular surface of 

 the metatarsal indicates the proximal phalanx to possess, and it appears 

 therefore to be a second phalanx, which, as in the middle toe of the 

 Ostrich, would then differ from the first phalanx in the equable conca- 

 vity of the proximal articular surface. In the second or outer toe of 

 the Ostrich the median eminence is wanting on the proximal end of the 

 first phalanx, but the want of symmetry in that bone shows that it 

 cannot be the analogue of the phalanx of the Dinornis in question, 

 which is almost quite symmetrical. From this character it may be 

 referred to the middle toe : compared with the second phalanx of that 

 toe in a full-grown Ostrich, it is relatively longer, less depressed or flat- 

 tened, the depth of the bone being equal to its breadth except at the 

 distal articulation, which nevertheless is much less expanded and de- 

 pressed than in the Ostrich. In this bird the length of the second 

 phalanx of the middle toe is two inches and a quarter, the breadth of the 

 distal end is one inch and a half, and its depth at the middle of the 

 bone eight lines. In the phalanx of the Dinornis the breadth of the 

 distal end is one inch and a quarter, its depth at the middle ten lines. 

 The size of the phalanx of the Dinornis, regarded as the second of the 

 middle toe, agrees well with that of the tarso-metatarsal of the Dinornis 

 struthoides. 



