42 R. W. SHUrFELDT, 
pneumatic, — only the coracoids and scapulae being so endowed in 
Branta. 
It will thus be noted that the Anseres vary considerably in 
this respect. 
In Branta canadensis the anterior moiety of the scapula is 
very thick owing to the presence of the pneumatic cavity within 
that division of the blade. Pneumatic foramina, usually single, 
are found at the distal end of the bone, close to the middle of the 
border, and both above and below. The distal apex of the bone is 
squarely truncated, but is more rounded in Olor columbianus. Of 
very much the same proportions and form, the scapula of this swan 
can at once be distinguished from that of the Canada Goose by its 
being completely non-pneumatic, and by the absence of the pneumatic 
foramina. This is a valuable character when we have fossil scapulae 
of swans and geese of various sizes to refer. 
Among the various Anatinae, the scapulae assume a great 
variety of forms, varying with respect to their relative lengths; 
distal terminations; amount of curvature; width and thickness of 
the blade, and morphology of the anterior extremity. 
The scapula in Dendrocygna differs from Branta in being non- 
pneumatic, and in the form of its distal third, differing, in this 
latter particular, from the scapula in Olor. As a matter of fact, 
the scapula of Dendrocygna autumnalis is anatine in character, and, 
in most respects, closely resembles the scapula of such a duck as 
Aix sponsa (No. 18612, Coll. U. S. Nation. Mus.). This should not have 
much weight, however, in so far as affinity is concerned, especially 
when we find a scapula in such a duck as Polystieta stelleri having 
all the characters, apart from mere size, of the bone as we find it 
in Olor columbianus. 
The general form of the coracoid among the Anseres is 
well known to the avian osteologist, and so need not be very 
elaborately described in detail here. Its pneumatic or non-pneumatic 
state in swans, geese and ducks has already been touched upon 
above, and its general form, as it occurs in this group, is well shown 
in Figs. 57, 63, 74, 90, 91, 96 and 108 of the present paper. 
Both in Olor and Branta, the mesial side of the head of the 
scapula (acromium) is produced downward as an osseous veil, 
overhanging the conspicuous group of pneumatic foramina in that 
locality. Posterior to this in Branta there is a deep fossa, at the 
base of which occurs numerous other pneumatic openings. This 
