14 R. W. SaureLor, 
a more or less distinet process. This latter process is quite insieni- 
ficant in Dendrocygna; sometimes entirely absent, as in Anas platy- 
rhynchos, to become a very prominent spur in such species as Tachyeres 
cinereus, and still more of a one in the Pacific Eider (Somateria 
v-nigra). 
In the Old-squaw (Harelda hyemalis) both the postero-superior 
process of a lacrymal and the descending one are rather long and 
delicately constructed, especially the latter (Figs. 28 and 29, Pl. 5; 
Figs. 60 and 61, Pl. 9. Cygninae have the postero-inferior pro- 
cess of a lacrymal expanded into a considerable plate of bone, which 
affords not a little protection to the soft parts lying between it and 
the ethmoid (Fig. 40, Pl. 7). 
In all the Anatidae, in so far as I have examined their 
skulls (various species of some 33 genera of them), the squamosal 
process is, in nearly every species, quite aborted, and if present, 
a mere insignificant little spine (Anas rubripes, No. 1606, Coll. U. 8. 
Nation. Mus.); on the other hand, the sphenoticor post-frontal 
process is invariably developed to a greater or less degree. This 
may be well appreciated by a study of the lateral views of the. 
skulls of ducks, geese and swans on a number of the Plates of the 
present memoir. 
As I have elsewhere pointed out, however, in. Dendrocygna — 
in so far as they have been examined by me — a very unusual 
condition obtains: the well-developed, inferior process of the lacrymal 
is carried backwards to meet the apex of the produced sphenotic 
process, to extensively and thoroughly coossify with it at the center 
of the lower periphery of what now forms a complete orbital ring.') 
This condition is clearly shown in Fig. 12, Pl. 3; in Fig. 44, Pl. 8, 
and it may be compared with the skulls of other ducks, geese and 
swans on the Plates.?) 
1) SHUFELDT, R. W., Osteology of Birds, in: Mus. Bull. 130. 
N. Y. State Mus. Albany, 1909, p, 311, 312, Fig. 39. Also, in: Proc. 
Acad. nat. Sc. Philadelphia 1898, p. 489—-499. Through an error, the 
lateral process of the skull, which extended forward to meet the lacrymal, 
was said to be the „squamosal“, which is not the case, it being the 
sphenotic, as correctly set forth above (see PARKER & BETTANY 
Morphology of the Skull, London 1877, p. 254, fig. 72 pf). 
2) Eyron, T. C., Osteologia avium, p. 207, London 1867, and the 
Supplement, London 1869. Unnumbered Plate of Dendrocygna areuata 
(sic!) (arcuata?). All that this author says in reference to the skull of 
D. arcuata is given in a line and a half of text, thus: „Cranium. 
