~) 
1916] Chandler: Structure of Feathers 32 
with any other Ciconiae, and in the third they are intermediate 
between the Ciconiae and the Anseres. 
5. Order ANSERIFORMES 
Pl. 21, Figs. 28-31 
Comprising the two suborders Anseres and Palamedeae, this order 
is characterized by the uniform distribution of plumules, and 
the absence or rudimentary condition of the aftershaft. The Pala- 
medeae are further characterized by the total absence of apteria, 
a condition found elsewhere only in the Sphenisciformes among 
carinate birds. Since in the finer structure of their feathers the 
two suborders have little in common, it will be more advantageous 
to take them up separately. 
I. Suborder ANSERES 
Pl. 21, Fig. 28-30 
a) Anas platyrhynchos 
(1) Remex 
Calamus unusually long, being considerably over one-third length 
of quill in primaries. This elongation is a very constant and char- 
acteristic feature. Shaft about as broad as deep, with broad, shal- 
low ventral groove. Rami with rather broad attachment to shaft, 
especially on outer vane, and differing from all other birds except 
a few gallinaceous species, in the enormous development of ventral 
ridge into a broad, thin, filmlike expansion on the basal one-third 
to two-thirds of the barb, reaching over and adhering to the 
adjacent ramus in front of it, producing a very conspicuous 
macroscopic effect on lower side of feather, where the portion of 
feather plate involved has a shiny, glazed appearance. Plate 21, 
ficure 28a, represents proximal portion of barb from inner vane 
of a primary, showing expanded ventral edge with filmy expanded 
ventral ridge ending abruptly. On outer vane, rami further char- 
acterized by dense villi (pl. 21, fig. 28b). Distal and proximal 
vanules with barbules not as different in size as in Ciconiae but 
distals outnumbering proximals nearly as much as in latter group; 
about 42 distals and 23 proximals per millimeter on a barb from 
inner vane of primary. 
Inner vane——Distal barbules (pl. 21, fig. 28c) relatively large 
for size of feather, base about 0.27 by 0.042 mm., extremely thin 
and filmy, pigment usually absent below line of nuclei, although this 
area is wider than usual; ventral teeth lobate but not blunt or 
truneate at end, being drawn out more or less into slender points. 
Hooklets exceedingly slender and delicate, with their hooked tips 
somewhat enlarged, usually 6 or 7 of them, progressively and 
regularly becoming longer; ventral cilia long, slender, and not 
