PROFESSOR OWEN ON THE GENUS DINORNIS. 155 
attachment of the rudimental back toe, there is no trace in the metatarse of Dinornis 
elephantopus. 
The form of the articular pulleys for the three toes is shown in PI. XLIV. fig. 3. 
Toe-phalanges of Dinornis elephantopus. 
The bones of the foot I shall compare with those ot Dinornis robustus', to which they 
make the nearest approach in size. 
Equalling, or nearly equalling, the phalanges of that bird in breadth and thickness, 
they differ chiefly in shortness, but in a less degree than the metatarsi differ. 
These proportional characters of the species are best given and easiest appreciated in 
the plates (compare the above-cited Plate I. with Pl. XLIV.). A few minor differences, 
however, may be noticed: the outer portion of the proximal end of the first phalanx of 
the inner toe, 1, 11., is broader in proportion to its fore-and-aft diameter in Dinornis 
elephantopus. The inner portion of the proximal end of the first phalanx of the outer 
toe, 1, Iv., presents the like difference: the general form of that articular surface, fig. 3, 
u. & 1v., is less triangular and more oval in both the specified phalanges of Dinornis 
elephantopus ; the under side being indented as usual in the proximal phalanges of the 
inner and outer toes. 
The modifications in the other phalanges, besides those of size and proportion, are 
not greater or other than might be expected in different species of the same genus. 
Of the very remarkable species of Dinornis based upon the powerfully developed limbs, 
the bones of which are described in the foregoing pages, Mr. Mantell’s collection 
includes five right and eight left femora, three right and four left tibie, nine right and 
fourteen left fibulz, three right and eight left metatarsi ; together with a considerable 
collection of toe-bones, from which, probably, other entire feet might be reconstructed 
in addition to the one of the left foot here exhibited, figured in Plate XLIV.* 
There are also two femora and two metatarsi of an immature bird, apparently, by 
their proportions, from one individual of Dinornis elephantopus, Pl. XLV. fig. 1; to 
which may also belong the proximal end of a tibia, wanting the articular epiphysis. 
The femora, as in other birds, retain the two articular ends, which are simply rougher 
than in the adult, having been covered by a thicker cartilage ; but are not developed 
upon distinct osseous pieces, as in land mammals. 
The proximal epiphysis is wanting in both the immature metatarsi, the left of which 
is figured in P]. XLV. fig. 1, so that they exhibit the separate expanded ends of the three 
constituent bones, as shown in fig. 1,a; which bones terminate in the three prominent 
trochlez below. The length of the femur of this young bird is 11 inches, that of the meta- 
tarse 74 inches. They already present the characteristic robustness of the adult bird. 
2 See Trans. Zool. Soc. vol. iv. pl. 1. 
2 'The bones of the entire right foot of apparently the same individual bird have been determined and restored 
since the above was written. 
