616 GEOLOGICAL SURVEY OF THE TERRITORIES. 
langes at its distal end. The first metacarpal is short, and fused with 
the second just anterior to the boundary of the trochlear surface ot os 
magnum; it makes an angle with the shaft of the second metacarpal, 
its extremity being directed upwards. Atits base, close tothe shaft of 
mid-metacarpal, it bears a uniform facette for articulation with the index 
phalanx, a free, three-sided, pointed little bone, about 9 millimetres in 
length. The second metacarpal is straight; its enlarged proximal ex- 
tremity is formed chiefly by the confluent os magnum; its shaft is in- 
clined to be subtrihedral, with its broadest face looking forwards; its 
distal extremity is terminated by a knot-shaped enlargement, that is 
still further enhanced by the confluence with the third metacarpal. It 
bears a digit composed of two phalanges, the proximal one bearing on its 
posterior border, for nearly its entire length, a quadrangular expansion, 
that has a raised margin, leaving asingle concavity radiad; asimilar con- 
cavity occurs on the ulnar side, but is there divided by a ridge, sloping 
downward into two shallow depressions. This little bone somewhat re- 
minds one of a cleaver, with the end of its handle attached to the meta- 
carpus. It supports at its distal extremity the second phalanx of this 
digit, a bone having very much the same appearance and shape as the 
index digit,! only being longer and more pointed. The proximal ends: 
of all the phalangeal segments are more or less expanded, in order to 
support the ample facets of articulation that occur among them, and 
the metacarpus. The third metacarpal is expanded transversely above, 
slender below, where it falls a little beyond the medius after its conflu- 
ence with it. It also has a small, pointed phalanx, freely attached to 
its distal extremity, and lying in that recess formed by the shaft and 
posterior expansion of the first phalanx of the second digit. t a very 
early date, comparatively, in the life of this Owl, ossification is normally 
extended to many of the tendons of important muscles of the antibra- 
chium and pinion. ‘ 
Of the pelvic limb.—The lower extremity is composed of twenty dis- 
tinet segments, including the patella, or just double the number found 
in the pectoral limb. This increase will not surprise us when we recol- 
lect the greater number of small bones devoted to the foot above those 
found in the hand. Its most striking feature, next to those osteological 
characteristics common to the family, is its extreme length, due princi- 
pally to the tibia and tarso-metatarsus. All the bones of the lower 
limb in this species are non-pneumatic. The femur is comparatively of 
good size and strong; articulated in the usual manner, it measures 4 
centimetres in length and 7 millimetres across the condyles at their 
widest part. At the proximal extremity, externally, above the shaft, 
there is a flat and roughened surface, bounded above by the curved 
trochanterian ridge. This surface forms the major part of the great 
trochanter. There is no trochanter minor present. ‘he trochanterian 
ridge is the highest part of the bone, when it is held vertically ; it lies 
in the antero-posterior plane, with the femur in its natural position, the 
bird standing erect ; from it, sloping directly inwards and occupying the 
remainder of the summit between it and the head, is a smooth articu- 
lar facet, broadest externally, merging into the globular head internally. 
1Mr. J. A. Jeffries, in a very interesting article entitled ‘“‘On the Fingers of Birds” 
(Bull. Nutt. Ornith. Club, January, 1881, p.6), endeavors to settle the argument 
upon the homology of this joint. This author says: ‘‘Whetner the metacarpus are 
the I-III or the II-IV has been a mooted question, Rolleston, Huxley, and Gegen- 
baur holding the first view, and Owen, Wyman, Morse, and Coues holding the second 
view.” Ihave always maintained the view expressed by the latter gentlemen men- 
tioned; the fact, however, that the first phalanx of manus in Aves is the homologue of - 
pollex of the pentadactyle limb seems to be gaining ground. 
