442 PROFESSOR OWEN ON MACROPUS. 
This (ce) is the largest of the three cuneiform bones, extends backward beyond the 
overlapping entocuneiform, and swells out into an expanded quasi-calcaneal process (cé’), 
which is closely united to a similar process of the cuboid. 
There is a large plantar sesamoid (cut, fig. 2), which has a smooth oval flat or feebly 
concave articular surface (ib. a), adapted to the surface, below the grooved process, upon 
the back of the fourth metatarsal (rv.). 
The above description is from a dissection of a full-grown male I. major. 
The cuboides (Pl. LX XXIII. figs. 1, sb & 2, c 6, and figs. 10, 11, 12) equals the 
astragalus in the longest diameter, and exceeds it in thickness and massiveness. It is 
moderately smooth and flat from behind forward, on its upper (rotular) part, but is 
convex across. At the hind proximal part the surface (fig. 11, /), concave in both direc- 
tions but chiefly vertically, is more produced proximally than is the less-concave surface 
(ib. e); these positions correspond to the different levels of the distal calcaneal surfaces 
(ib. figs. 6, 7, 8, e, f) to which they are adapted. ‘The surface e (fig. 11) is produced 
downward and inward (at g) coextensively with the surface g of the calcaneum (fig. 8). 
On the inner tibial side of the bone a narrow strip (fig. 11, 4) is extended from the 
surface f to articulate with the naviculare. The lower (plantar) part of the cuboid 
(fig. 12) is developed into three prominences: the inner one (7), in the form of an oval 
tuberosity, articulates with the neck of the similar tuberosity (¢) of the ectocuneiform 
(fig. 9); the middle tuberosity (fig. 12, &) is coextensive with the length of the cuboid, but 
is deeply grooved at the outer and under part of its origin; the outer prominence (J) 
supports the flat articular surface for the fifth metatarsal. The main part of the ante- 
rior surface of the cuboid is articulated, but immovably, with the base of the great 
(fourth) metatarsal (1v). The outer side of the cuboid (fig. 2, cb) extends downward 
and backward beyond the metatarsal tv, so far as was required to offer an articular surface 
(fig. 12, 7) to the proximal end of the fifth metatarsal (fig. 14). 
Of the metatarsal series of foot-bones the first (or that of the hallux, 1) is suppressed ; 
the second (fig. 1, 11) and third (ib. 111) are filamentary, but almost as long as the fourth 
(1v), which constitutes the chief part of this segment of the foot. 
The second metatarsal (cut, fig. 1, 11) has a proximal expansion of 2 lines diameter, with 
a flat articular surface 1 line in breadth for the corresponding facet at the distal end of 
the entocuneiform (ci). The shaft of the metatarsal soon shrinks to less than a line in 
thickness, but gains slightly in this dimension at its distal half. This rather abruptly 
expands into the convex joint for the first phalanx of the small toe, Pl. LXX XII. fig. 1, 1. 
The third metatarsal (1m) differs in having a longer and more compressed proximal 
end, which articulates with both meso- (em) and ecto- (ce) cuneiform bones, and syn- 
desmotically with a rough facet on the great metatarsal (Iv), which has been the seat 
of confluent ossification in my present subject. In the slenderness of the shaft and 
shape of the distal articulation it agrees with the second metatarsal (11); each of these 
bones is upwards of 5 inches in length. 
