520 PROFESSOR OWEN ON THE 
between the anterior and posterior parts of the so divided ectocondylar surface 
(fig. 13,0, %). A difference of colour and of texture indicates that the articular cartilage 
was not continued upon the flat triangular intercondylar facet (ib. d). The extreme 
transverse extent of the proximal articular surface is 1 inch 6 lines; the extreme fore- 
and-aft extent of that surface is 9 lines. In Pezophaps minor (ib. fig. 12) these dimen- 
sions give | inch 3 lines and 7} lines respectively. 
The side of the entocondylar division of the proximal end is traversed by three longi- 
tudinal ridges. The anterior, beginning by a slight rise of the articular border, extends 
along the inner (tibial) side of the entometatarsal about one third of the way down; it is 
the “ entometatarsal ridge” (fig. 4, ¢, e). The second ridge begins at the highest part of 
the entocondylar border, and subsides after a downward course of two thirds of an inch; 
it is the “entocondylar” ridge (f'). The third ridge begins at the back part of the 
entocondylar border, makes a curve as it descends toward the inner side of the entometa- 
tarsal, but descends before attaining that side, and is continued downward two thirds of 
the length of that metatarsal as the ‘‘ entogastrocnemial” ridge (fig. 4, g). The second 
short ridge (7), in some specimens, joins the third to form the entogastrocnemial 
ridge. The fore part of the entocondylar expansion shows two or three oblong 
tuberosities, in the same transverse line, the outermost of which (fig. 3, h) extends 
down as a short ridge and forms part of the inner boundary of the “ anterior interosseous 
depression (7). 
This, which is due to the retrogression of the head of the mesometatarsal (111), is 
bounded above by the part of the confluent epiphysis developing the imtercondylar 
tuberosity (¢); its sides are formed by the more advanced proximal ends of the ento- (11) 
and ecto- (1v) metatarsals, the latter bone defining that side of the fossa by a ridge or 
ridge-like angle continued into the ‘‘ ectometatarsal ridge” (4), which descends inclining - 
to the outer side of the lower part of the ectometatarsal (1v). Into the antinterosseal 
depression (7) open the two fore-and-aft canals between the upper ends of the meta- 
tarsals, that (7) between the ento- and meso-metatarsal being the largest ; it is vertically 
elliptical, 53 lines by 23 lines in diameter. The canal between the meso- and ecto- 
metatarsals opens into the fossa by a vertical slit (fig. 3, m), two lines long and two thirds 
of a line wide. Below the larger foramen is a rough surface (n) for the insertion of 
the “tibialis anticus;” it does not project. The interosseous depression (¢) gradually 
shallows and contracts as it descends, or as the middle metatarsal advances into line 
with the outer and inner ones, the boundaries being defined by low narrow antinter- 
osseal ridges, which, midway down the shaft, diverge as they descend, the outer one 
(fig 3,0) terminating in the groove leading to the lower interosseal canal (p) between 
the meso- (111) and ecto- (iv) metatarsals. The anterior orifice of this canal (fig. 3, p) 
is vertically oblong, about 13 of a line in width; the posterior orifice (fig. 2, p') is 
minute and circular. The bar or bridge of bone (ib. g), from the neck of the ecto- 
trochlea (1v) to that of the mesotrochlea (111), converts the remaining interspace behind 
