650 GEOLOGICAL SURVEY OF THE TERRITORIES. 
panding below for the trochlez for the phalanges. For its upper half 
and posteriorly, ranging below the calcaneal process, it develops a sharp 
vertical crest, that gradually subsides below. 
The anterior aspect of the shaft is faintly grooved longitudinally, 
and where it dies out below, just above the notch between the third and 
fourth terminal trochlez, we observe a minute perforating foramen for 
the anterior tibial artery. Upon the inner margin of the shaft below 
there is the well-marked though shallow facet for the os metatarsale acces- 
sorium. This diminutive bone is, as usual, slung to the tarso-metatar- 
sus by a ligament, articulating beyond with the hallux. It represents 
the first metatarsal, and has all the appearances of one of the larger-sized 
phalangeal segments, divided obliquely through the shaft, with the cut 
surface closed in and forming the articular surface for the tarso-meta- 
tarsus. Its position, in situ, is figuredin Pl. IV, Fig.44. The lower and 
expanded end of the tarso-metatarsus, bearing the trochlez of the re- 
maining phalanges, is further conspicuous for the marked manner in 
which the bone is compressed antero-posteriorly, causing the trochlear 
ends to be placed side by side, transversely. The middle one is the 
largest and grooved entirely round, the one for the second toe being 
slightly the higher and bent a little outwards; finally, the fourth is the 
smallest. Slit-like spaces among these “ processes” completely divide 
them. 
The joints of the toes are arranged upon the most common plan, and, 
we believe, upon the general rule for all Oscines ; 7. e., the hallux pos- 
sesses two phalanges, second toe three, third toe four, and the outer and 
last toe five. 
These joints are not impressed with anything particularly remarkable, 
beyond what is found in them among the class generally. Their verti- 
cally cleft and anterior extremities articulate with the joint beyond, 
which is diminished in size and articulates in like manner with the next 
anterior segment. 
The claws are grooved laterally, and show a process at their proximal 
and lower aspects. 
A glance at Pl. IV, Fig. 22, will be sufficient to satisfy ourselves that 
the great length of the claw of the hind toe sometimes seen in Hremo- 
phila, and always characteristic, is due almost entirely to the growth of 
oe horny theca that encases it, and not to the length of the osseous 
claw. 
In the figure just referred to, the hallux, with the first metatarsal, has 
been drawn backwards in the skeleton, not only to show the os meta- 
tarsale accessorium, but also a sesamoid, of no mean size, that is found 
on its outer side, an ossicle that betrays its possessor and declares the 
habit he has of spending a good share of his time upon the ground. 
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