Cu. I] OF THE DODO. 105 
the fossa for the IZ. flexor brevis pollicis; this surface gives attachment to the ligament of the great tibio-meta- 
tarsal sesamoid fibro-cartilage, which some have regarded, but improperly, as a tarsal element. Anterior to 
it is a narrow triangular tract, with the base above; the apex is roughened for the insertion of the 
internal lateral ligament, and is prolonged into the ridge-like inner border. Beneath the anterior and 
internal angle is the oblique oval prominent tubercle, for the insertion of a ligamentous band, binding down 
the tendon of the I. extensor communis digitorum ; internally, it is attached to a short rough ridge, along 
the inner margin of the anterior concavity, separated from the preceding by a groove leading upwards and 
outwards, and impressing the anterior edge of the internal condyloid fossa, as it rises into the intercondyloid 
tubercle. 
The smooth rounded upper border of the calcaneal ridge (ento-caleaneal process) projects backwards 
from the centre of the posterior border, and is raised in the middle into a slight convexity. The posterior 
angle of the ridge is expanded and flattened into an irregularly triangular rough plate (calcaneal tuberosity), 
with the base above, extendmg mwards and overhanging the internal muscular fossa, while the apex 
protrudes beyond the edge of the buttress; it gives attachment to the tendon of the MW. gastrocnemius. 
Beneath the upper margin of the ento-calcaneal process, internally, is a curved oblong concavity, separated 
by a sharp ridge from the inner muscular fossa: it probably lodges an Haversian gland. The ecto-calcaneal 
process is formed by a short, thick plate (one line and two-thirds wide) projecting backwards, nearly 
midway between the internal process and the external edge; its free extremity is expanded and broadly 
grooved ; from the inner lip of the furrow, an osseous bridge passes inwards to join the calcaneal ridge, 
converting the space between these processes into a canal (calcaneal canal), three lines in diameter above, 
and seven lines and a half long; below, it contracts slightly, and its inferior orifice is prolonged into a 
short triangular groove on the calcaneal ridge. This canal transmits the tendon of the MW. flewor perforans 
digitorum. The deep groove posterior to it, between the calcaneal process and the outer lip of the 
ecto-calcaneal furrow, is closed in the recent state by a fibro-cartilagmous bridge; it gives passage to the 
tendon of the IZ. flexor indicis perforatus anteriorly, and to that of the IZ. flexor indicis perforans et perfo- 
ratus posteriorly. The deep channel for the tendon of the Fleaor perforans pollicis,furrows the outer surface 
of the ecto-calcaneal process, and is overhung by the projecting outer lp of its groove, from which a 
fibro-cartilaginous bridge extends, in the recent state, to a short faint ridge on the posterior surface of 
the external and outer angle of the proximal extremity; the groove is thus converted into a canal. 
External to the ridge just mentioned, is a short and shallow groove lined with synovial cartilage, over which 
plays the tendon of the Peroneus medius (Cuv.), as it proceeds to join the perforated tendon of the middle toe. 
These grooves diminish in height from within outwards. In the recent state a broad shallow groove 
extends from the outer border of the calcaneal tuberosity to the slightly projecting edge of the external 
wall of the canal for the tendon of the perforating flexor of the hind toe; its floor is formed externally by 
the fibro-cartilaginous roof of that canal, centrally by the groove on the ecto-calcaneal process, and internally 
by the fibro-cartilaginous roof of the canal transmitting the perforated tendons of the inner toe; it is con- 
verted by the attachment of the fascia to its margins into a canal, which transmits most anteriorly the 
tendon of the Flexor medi perforatus, and posteriorly, that of the Mexor medit perforans et perforatms, and 
of the Mexor annularis perforatus, the former being internal, and the latter external. 
Viewed from below, the izferior extremity presents the trochlee arranged transversely, so as to form a 
small segment of a large circle; seen from before, the inferior surfaces of the two inner trochlee he in the 
same curve, while that of the outer is elevated four lines above the external margin of the middle one, and 
is nearly on the same transverse plane as the internal inter-trochlear notch. The elevation of the outer 
trochlea, and the abbreviation of the corresponding toe, renders the foot more adapted for progression. The 
