382

352

Femur :- In no specimen that has hitherto reached me are the dinornithic modifica-
tions of the femur more definitely and strongly marked than in the present example
(Pls. XLI. & XLI.A), in which the effects of the usual posthumous abrasion are limited
to the articular prominence of the head, and to parts of the margin of the trochanter and
hinder projections of the outer condyle. I propose, therefore, to take the opportunity
of noting the characters more in detail than has been done in previously figured, less
complete, and commonly larger specimens.

The head (a) of the femur, in all the species of Dinornis, is less sessile than in birds
generally ; but the part supporting it has more the character of a neck in the present
species than in Dinornis giganteus 1, in Dinornis casuarinus 2, or in Dinornis maximus 3.
The constriction affects the entire circumference, but is deepest, as usual, anteriorly,
the head being turned rather forward as well as projecting inward ; the axis of the head
and neck also slightly inclines upward. The head forms more than a hemisphere.
From the neck (d), or constriction, the bone rapidly expands to the great trochanter
(f) and shaft. The articular surface is continued from the head upon the anterior
two thirds of the upper part of the trochanter (Pl. XLI. A. fig. 2, c), and is defined
by a linear boundary from the non-articular part. Three surfaces may be noted in
the enormous trochanterian enlargement of this femur - the upper (epitrochanterian)
subdivided as above, the anterior, and the postero-external.

The anterior, or "pretrochanterian," surface (Pl. XLI. fig. 1, g) is bisected by a low
linear ridge (h), which, rising about an inch below the angular summit, passes down-
ward and inward, and subsides (at h') on the inner side of the shaft above the expansion
of the inner condyle.

The pre- meets the post-trochanterian tract at an acute angle (i) ; the latter surface
is transversed vertically by a rough, broad tract, commencing about an inch from the
summit of the trochanter, and gradually approaching the anterior angle as it descends,
below which the ridge bends forward, and terminates in the ectotrochanterian tube-
rosity (Pl. XLI. fig. 1, l).

The rough tract defines a narrow ectotrochanterian surface from the broader post-
trochanterian surface (Pl. XLI. A. fig. 1, m). On this surface are two rough oval shallow
depressions for muscular insertions ; the upper one (Pl. XLI. A. fig. 1, n, for the "ab-
ductor femoris ") is 10 lines below the epitrochanterian ridge, and measures 15 lines by
10 lines : half an inch below and rather in advance of this is the second depression, of
rather smaller size, but with a more irregular surface (ib. ib. o, for the "quadratus
femoris"). From this surface several longitudinal striae descend vertically, and are
continued by one principal linear ridge down the outer side of the shaft to within an
inch of the ectocondylar fossa (ib. k'). A rough tract is continued from the lower
gluteal surface obliquely downward and backward, contracting to the strongly marked
ridge (Pl. XLI. A. fig. 1, p). To this ridge converges an inner less prominent oblique

1 Pl. XXXVI. fig. 1. 2 Pl. XXXVIII. figs. 1, 2. 3 Pl. LXXIX. fig. 1.