16 R. W. SHUFELDT, 
evidence that there is in it no inclination even to extend to — or 
join with — the end of the sphenotie process of the same side of 
the skull. This is also pretty much the case in Branta c. hutchinsi 
and in others of that genus; while in some ofthe swans, as in Olor 
and Cygnus, the case is different. In these the enormous inferior 
process of the lacrymal extends far back toward the long, stout 
sphenotie process, but fails to reach it by quite an interval (Pl. 7 
Fig. 40). 
The inclination of the apices of the two processes to again join 
is seen in anserine forms, in no way particularly related to Dendro- 
ceygna, as in Cereopsis and Chloephaga hybrida, but not in Chloephaga 
poliocephala (Fig. 11, Pl. 3, and Fig. 35, Pl. 6). 
Among the ducks, the osseous ring is nearly completed by the 
uniting of the two apophyses aforesaid, in such species as Olangula 
islandica, the true teals (Querguedula), and quite frequently in the 
skulls of the mallard (Anas platyrhynchos) (No. 17537, U. S. Nation. 
Mus. 3). Indeed, it is in species of the genus Anas that the in- 
clination to meet, on the part of these two processes, seems to be 
most evident, and the least so in the genus Chen, in so far as true 
geese are concerned. 
In all Anatidae, the zygoma or infraorbital bar is an 
almost straight, delicate rod of bone, of a size in proportion to the 
skull to which it belongs. Its maxillary extremity is more slender 
than its quadrato-jugal portion, while the entire rod is much flattened 
from side to side, and generally develops a small, triangular, spine- 
like elevation on its upper edge, opposite the descending process of 
the lacrymal. Such ducks as Mareca americana, and Oidemia per- 
spieillata have a zygoma of extremely delicate proportions.. This is 
also true of the ducks in the genus Aix, including Aix galericulata. 
In passing, I may say that not only the skull, but the entire skeleton 
of Aix is quite different from the skeleton in Dendrocygna; while 
at the same time the skull in Aix sponsa agrees, in all particulars, 
with the skull of Aix galericulata, except in the matter of size, — 
the latter being about one-third smaller than it is in the Wood 
Duck; so that breeding in trees, on the part of different genera 
among the Anatidae, has in no way any weight in determining 
nearness of relationship. 
As to the morphology ofthe superior mandible in Dendro- 
cygna autumnalıs, and its appearance on a lateral view, we could 
have nothing better to demonstrate it than the illustration of it 
