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, booklets, 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 booklets, 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) Galli, including the megapodes, curassows, 

 pheasants, partridges, turkeys, etc.; (3) Turnices, including the, 

 Hemipodes of the Old World; and (4) Opisthocomi, to which 

 belongs only the peculiar Hoactzin of South America. 



