PROFESSOR OWEN ON THE GENUS DINORNIS. 153 
subcompressed and produced, as if slightly bent, backward. The upper articular sur- 
face is convex from before backward, almost flat transversely. The head of the bone 
is flattened on the inner side; almost flat, but a little convex, on the outer side: the 
fore-and-aft dimension of this end of the bone is 2 inches 9 lines; the transverse dia- 
meter is 1 inch 3 lines. Below the head the bone assumes a trihedral form with the 
sides convex, gradually tapering and blending into a shape, elliptic in transverse section, 
and ending in a point about 9 inches above the ankle-joint. The outer surface of the 
shaft of the fibula is impressed by two oblong rough surfaces for the insertion of muscles, 
the upper one 2 inches 9 lines in length. The inner part, which is ridge-like, dividing 
the fore from the back surface of the bone, presents a rough surface, r, 7’, with a median 
interruption, for the ligamentous attachment of the bone to the fibular ridge of the tibia. 
Metatarsus of Dinornis elephantopus. 
Comparative dimensions of the Metatarse of 
D.giganteus’. D.robustus*. D.elephantopus*. D.crassus. 
in. lines. in. lines in. lines. in. lines. 
LGR Sonc cose ooumcQonobannoUaDS RC 18 6 ey 9 3 Shas 
Transverse breadth of proximal end...... 4 3 4 6 4 5 3 3 
Ditto ditto distaltend yrs.) aie 4 bh 8) 5 64 ch et) 
Wieastdittorotishatty erst etaiye ene) piers ele 3} 20 BG iL et) 
Fore-and-aft breadth of proximal end... . ow, i2 3 2 2 10 25, 
Circumference of ditto. We) (0) Ry) 12 O os 
Least circumference of shaft .......... Gi a3 a3 G6 4 6 
Breadth of middle trochlea............ si) 273) Ooh?) paar) 
Length, following the curve .......... 5. 9 5 4 5. 38 4 0 
I had, hitherto, regarded the metatarse of Dinornis crassus, described and figured 
in the ‘ Zoological Transactions,’ vol. iii. pl. 48. figs. 4 & 5, as presenting the most 
extraordinary form and proportions of all the restored species of huge wingless birds of 
New Zealand ; but it is strikingly surpassed in robustness and in great relative breadth 
and thickness by the same bone of the present species (Pl. XLIV. fig. 1), which chiefly 
on that account 1 have proposed to name elephantopus. Only in the great Maccaws 
and Penguins do the proportions of the metatarsus resemble those in this most robust- 
legged of birds; but the Parrot-tribe present those peculiar modifications of the distal 
trochlez, with the strong articulation for the back toe, which relate to the Scansorial 
modifications of the bird’s foot ; and the Penguins associate with their broad and short 
metatarsus a characteristic retention of much of the primitive separation of the three 
constituent bones. In Dinornis elephantopus these elements have become as com- 
pletely coalesced as in any other species, and the general characters of both proximal 
and distal ends accord with those in previously described species. Ona more special 
1 Trans. Zool. Soc. vol. iii. pl. 27. fig. 1. 2 Tb. vol. iv. pl. 1. > Jb. vol. iv. pl. 46. 
