612 GEOLOGICAL SURVEY OF THE TERRITORIES. 
side of the shaft of the bone, at junction of upper and middle thirds, to 
turn upon itself, so as to be projected upwards, forwards, and a little 
outwards, terminating with an elliptical facet for articulation with the 
clavicle. The upper border of this process is concave lengthwise and 
articulates throughout its extent with the inferior margin of the acro- 
mial process of the. scapula. The lower and thin edge of the coraco- 
clavicular process tends obliquely downwards, to be lost on the inner 
surface of the shaft of the bone near its middle. The outer wall of the 
anterior groove is formed by the coracoid itself, the process just de- 
scribed being really nothing more than a wing-like extension forming 
the inner boundary of the groove in this bird; it terminates above both 
clavicle and scapula in a rounded, tuberous head. Below this head, an- 
teriorly and still more inwardly, the coracoid affords a vertical, elongated 
facet for the clavicle, while behind, looking a little outward, is the con- 
cave elliptical facet that constitutes about one-third of the glenoid cav- 
ity for the humerus, internal to which, and running first directly up- 
wards, then making a right angle and continuing forwards, a little 
upwards, and outwards, the last direction being the upper margin of 
the coraco-clavicular process, is another facet, for the scapula. Behind 
and below, this bone displays one or two lines and depressions, bound- 
aries of muscular attachments. In the middle of the anterior groove, 
opposite the base of the coraco-clavicular process, the shaft of the bone 
is perforated; this perforation is elliptical lengthwise with the shaft, and 
passes directly through to make its appearance on the posterior convex 
surface just below the scapula. This foramen transmits a branch of 
that cervical nerve coming from between the twelfth and thirteenth cer- 
vical vertebre. This nerve branch, after passing through the bone, is 
distributed to the under surface of the pectoralis minor muscle, and its 
filaments ascend among its fibres. This foramen is observable also in 
other Owls, as Bubo virginianus, and in some of the diurnal Raptores, as 
in Accipiter cooperi; in very many birds it is absent. The scapula pre- 
sents little that is unusual in that bone among the class generally. It 
lends the additional two-thirds of articular surface to form the glenoid 
cavity with the coracoid; internal to this the acromion process extends 
forwards, touching the coracoid as described, and having a limited bear- 
ing on the clavicle. Posteriorly its blade-like length is produced, ex- 
panding, turning slightly outwards to terminate in an obliquely trun- 
cate extremity, with its point over the second dorso-pleurapophysial 
interspace. 
What.the scapula Jacks in interest is amply made up by the changes 
observed in the last bone of the group, the clavicle. This element is 
broad above, much compressed from side to side throughout; it spans 
the anterior groove of the coracoid and touches the scapula as described 
above, rapidly diminishing in size as it is produced downwards and in- 
wards by a gentle curve towards the fellow of the opposite side. The 
upper extremities in adult birds are separated by an average distance 
of 2.3 centimetres. If the sternum pointed to feebleness of flight in 
this little Owl, it is still further carried out by the ill-developed clavicles, 
which constitute that arch in birds, where they are thoroughly and - 
firmly united below, that assists to resist the pressure of the humeri when 
the wings are depressed in flight, and send them back to their former 
position after the completion of the action. In examining again PI. I, 
which represents the skeleton of an old male, we find this bone to be 
simply a pointed styliform process; in other individuals, and adults too, 
it does not even attain the length here shown; but, as if to bid defiance 
to all law or invariable rule governing it, we again find in very young 
