OSTEOLOGY OF THE DODO. 921 
into a vertical “adductor” canal, leading from the anterior orifice of the lower inter- 
osseal canal (p) to the interval between the ecto- and meso-trochlee. The tendon of 
the ‘adductor digiti externi” traverses this canal, to be inserted into the inner side of 
the base of the proximal phalanx of the outer toe. 
The calcaneal process (7, s) is developed from the back part of the head of the meso- 
metatarsal (111) and the part of the proximal epiphysis confluent therewith; it is divided 
into ento- (r) and ecto- (s) calcaneal portions, by the tendinal canal (¢) completed by 
peripheral ossification between those portions; this uniting plate of bone is impressed 
externally by an open shallow tendinal groove (w). The outer part of the ectocalcaneal 
process is impressed by a narrower and deeper tendinal groove. The posterior rough 
and flattened surface of the entocalcaneal process is elongate and contracted below; in 
Pezophaps minor (fig. 6, 7), where alone I have seen it entire, it is 10 lines long by 
34 lines in extreme width. The ectocalcaneal process (ib. s) shows a similar surface, 
7 lines in length and 2 lines in breadth, in Pez. minor. A deep and wide elongate 
channel (fig. 4, v) intervenes between the entogastrocnemial ridge (v) and the calcaneal 
process (7), with its sustaining buttress formed by the back part of the mesometa- 
tarsal; into the upper part of this concavity opens the canal (/) between the ento- and 
meso-metatarsals. The smaller interosseous canal (mm), between the meso- and ecto- 
metatarsals, opens into the shallower depression (fig. 1, w) external to the calcaneal 
prominence. This depression is bounded externally by the ectogastrocnemial ridge (2), 
which describes a slight curve, convex backward, as it descends to terminate on the 
ectotrochlear ridge (fig. 2, z). From the back part of the mesometarsal (fig. 2, 7’), 
which projects in a subtriangular form, a narrow (postinterosseal) ridge (ib. y) is con- 
tinued, which descends for some way outside of and parallel with the one continued 
down from 7’; but at the beginning of the trochlear expanse it bends outward, and 
terminates in the tuberosity, or thicker ridge! (z), at the outer and hinder part of the 
ectotrochlea (iv). The entogastrocnemial ridge* (vy) terminates at the upper border of 
the “hallucial surface” (1). The mid ridge or hind angle of the mesometatarsal (111) 
runs down along the outer side of the hallucial surface, almost subsiding, but seeming 
to be continued by a strong oblique ridge (fig. 2, «), lost upon the back part of 
the neck of the entotrochlea (11). A tendinal groove (fig. 2, 8) extends from the 
upper and outer part of the oblique ridge to or near to the interspace between the 
ento- and meso-trochlee. 
The posttrochlear depression (fig. 2, y), bounded by the oblique ridges (« & z), and 
’ This is mutilated in the specimen figured in Trans. Zool. Soc. vol. iv. pl. 55. fig. 6. 
* The insertions of “the strong ligamentous aponeurosis” formed by the confluence of the tendons of the 
gastrocnemius internus and gastrocnemius externus (Trans. Zool. Soc. vol. iii. p. 294) are represented in pl. 32. 
fig. 2, r, and in fig. 1; also in pl. 35. n***, of that volume, in Aptery« australis. The ridges termed “ gastro- 
cnemial” mark the lines of insertion of this strong aponeurotic sheath for the tendons of the deeper-seated 
muscles, chiefly flexors of the toes. 
VOL. VII.—PART vil. November, 1871. 45 
