1916] Chandler: Structure of Feathers 337 
plainly indicated by other features in their anatomy, and is made 
rather easy, even taking into consideration the structure of their 
feathers, on account of the intermediate condition of Gypogeranus, 
the Accipitres must be regarded as derivatives of a Steganopode- 
like bird. Yet in the form of the ventral cilia of the proximal bar- 
bules, and of ventral teeth, hooklets, and dorsal cilia of the distals, 
they come very close to the Galli. The down of some resembles 
that of the Steganopodes while that of others, e. g., Falco sparverius, 
resembles that of some Coraciiformes. However, all of these points 
of resemblances are features which could easily be conceived of as 
having been developed more than once, and it seems best to regard 
the Accipitres as derivatives of the Steganopodes through the 
Cathartae and Gypogerani. 
e) Summary 
The Accipitres are characterized as follows: 
(1) Distal barbules of inner vane of remiges with relatively large 
base, lobate ventral teeth, 5 hooklets, slender filamentous ventral cilia, 
and slender dorsal cilia, the basal ones spinelike ; pennulum frequently 
much longer than base. 
(2) Distals of outer vane with shorter base, and relatively shorter 
pennulum with shorter cells, making a brushlike series of ventral cilia. 
(3) Proximals of inner vane with relatively small base, short 
pointed ventral teeth and moderately long pennulum. 
(4) Proximals of outer vane, on distal half of barb, with well- 
developed series of hooklike ventral cilia. 
(5) Body feathers differing from remiges only in simplification, 
and slender form of barbules. 
(6) Down barbules very fine and slender, the nodes more or less 
enlarged, sometimes pigmented. 
7. Order GALLIFORMES 
Plate 24 
Comprising a very large assemblage of the so-called ‘‘game- 
birds,’’ the present order is subdivided into four suborders as fol- 
lows: (1) Mesaenatides, represented only by the kagu or mesite 
of Madagascar; (2) Gall, including the megapodes, curassows, 
pheasants, partridges, turkeys, etc.; (8) Turnices, including the 
Hemipodes of the Old World; and (4) Opisthocomi, to which 
belongs only the peculiar Hoactzin of South America. 
