172

148

From that type the present fossil differs in its greater breadth and thickness in propor-
tion to its length, and especially in the greater strength and outward extension of the
condyle for the innermost of the anteriorly directed toes (Pl. CVI. figs. 5,6,ii) ; the shaft
of this composite bone is rather more twisted on its axis, with a greater inclination of
the stem of the condyle (ii) backward. The 'entocondylar cavity' (ib. fig. 5,a) is some-
what deeper and larger than the ectocondylar one (b) ; the intercondylar tubercle (c) is
large, but little elevated. The ectocalcaneal process (ib. fig. 6, s) is a strong and pro-
minent subquadrate plate of bone. The entocalcaneal process (ib. ib. r) is, as usual in
Raptores, of smaller size. The intervening calcaneal groove or channel (ib. ib. u) is of
great depth and width. Into the wide and deep antinterosseal depression (ib. fig. 5, i) open
the entinterosseous and ectinterosseous canals. The small hinder orifice of the latter
remnant of the primitive interspace between the ecto- and mesometatarsal elements is
shown in fig. 6, at m. The ectinterosseous groove is continued down a short way below
this orifice. A strong tuberosity (fig. 5 , n) marks the insertion of the tendon of the
'tibialis anticus'. The entogastrocnemial ridge (g) is continued from the entocalcaneal
process nearly halfway down the shaft of the metatarsus. The ectogastrocnemial ridge
(x) and the postinterosseous ridge (y) are well developed. The intermuscular ridges on
the fore part of the shaft (fig. 5) are equally well marked ; the entometatarsal ridge is
shown at g, the ectometatarsal ridge at k. A long groove (o) for the 'adductor digiti
externi' deepens as it leads to the foramen (p), through which the tendon of that small
muscle glided to the interspace between the meso- and ectotrochleae. A strong osseous
bridge (ib. fig. 6, q) divides the upper and hinder orifice (p') from the intertrochlear
outlet of the tendinal canal. The depth and extent of the surface for the ligamentous
attachment of the innermost and backwardly directed metatarsal (i) bespeak the strength
of the toe opposing the forwardly directed digits (ii & iii) in the grasping actions. The
ectotrochlea (iv) is, transversely , rather narrower than usual relatively to the other
trochleae ; but it is or equal antero-posterior extent. The least circumference of the
shaft of the metatarsal of Harpagornis moorei is 2 inches ; the breadth of the two
extremities and the length of the bone are shown in Pl. CVI.

Among the more characteristic evidences of the present extinct gigantic Raptorial
are certain claw-bones (ungual phalanges). Assuming this ungual phalanx (Pl. CVII.
fig. 7) to correspond with the one which is commonly the largest in diurnal Raptores,
viz that which supports the back toe (digit i), a second somewhat smaller claw-bone,
discovered at the same time and place, and differing only in a slight inferiority of size,
may well be a claw-bone of the toe iii. Subsequently a third ungual phalanx was
discovered in another part of the Glenmark swamp, of rather less length than the
second, but of equal size of basal articulation, and with it the penultimate phalanx of
the same toe. On the assumption that the largest claw-bone (Pl. CVII. fig. 7) was that
of the 'hallux', or hind toe (i), it may be compared with the homologous bone in the
Great Wedge-tailed Eagle of Australia ( Aquila cuneicaudata of Brehm) or the Bold