109

87

thicker and stronger bones, and yet has more signs of immaturity. We in a like manner
associate together f7, f8, f17, as not varying beyond a line from the length of eight
inches.

In the first four femora, f1, f2, f3, f12, enumerated in the table, there is a more
regular gradation of size. The left femur, f12, is eleven inches, and the shaft of a
right femur, f4, so precisely corresponds in circumference and other proportions as to
leave no doubt as to their similarity in length, and render it highly probable that they
belonged to the same bird. The femora f2 and f 3 were 13 inches in length;
and the shaft f1 indicates a femur of at least sixteen inches in length.

In an Ostrich the circumference of the femur, of the tibia, and of the metatarsus is
respectively five inches three lines, four inches three lines, and three inches seven lines.
In an Emeu the circumference of the same bones is respctively three inches seven lines,
three inches four lines, and three inches.

From these analogies we may conclude that the shaft of the femur f1, with a cir-
cumference of seven inches and three lines, may have belonged to a Dinornis with the
largest tibia whose circumference is six inches six lines, and with the tarso-metatarsal
bone whose circumference is five inches six lines, the proportionate thicknesses of
these bones to each other being intermediate in their degrees to those presented by the
same bones in the Ostrich and the Emeu. It must be remembered that the relative
length of the femur and metatarsus is very different in the Dinornis from that in existing
Struthionidæ, the Apteryx excepted; but, according to the above collocation of the
femur, tibia and tarso-metatarsus of the largest Dinornis, the tarso-metatarsus exceeds
the femur in length by 2½ inches in this species, which I have named Dinornis giganteus.
the femur f2 presents a similar correspondence with the tibia t2; but is excess of
length over the tarso-metatarsus m3 renders it very improbable that they could belong
to the same species, especially when the difference in their circumference is added,
that of the femur being six inches one line, that of the metatarsus four inches three
lines; besides, the distal articulation of the tibia t2 is obviously too large for the arti-
culation of the metatarsus m3. The femur f12 offers the required correspondence
with the metatarsus m3 of the Dinornis struthoides, which exceeds the length of that
femur by one inch, and is consequently but a little shorter in proportion than in the
largest species.

The tarso-metatarsus is proportionally still shorter in the third species (Dinornis didi-
formis), to which I refer the femora f7, f8, f17, the tibiæ t3, t4, t5, t8, t9, t10, and
the tarso-metatarsal bones m4, m5, m6. The tibia, according to this allocation, being,
like that of the gigantic Donornis, little more than twice the length of the femur, we
may with great probability associate the shaft of the tibia, which, when restored, gives
a length of twenty-five inches, with the femur of the Dinornis struthoides, measuring
eleven inches in length.

The proportions of the three principal bones of the leg in the Ostrich, the Emeu, the