1916] Chandler: Structure of Feathers 379 



group. The Trochilidae and the suborder Pici, with the exception 

 of the Galbulidae, show such striking likenesses to the Passeriformes 

 that it is difficult to deny their closer alliance to that group than 

 to the Coraciiformes. 



f) Summary 



The Coraciiformes are characterized as follows : 



(1) Plumules more or less suppressed, or confined to apteria. 



(2) Aftershaft variable, being absent, rudimentary or well 

 developed. 



(3) Distal barbules of remiges with bases different in different 

 groups but always with small slender ventral teeth ; pennulum 

 moderate, with usually not over 5 booklets, the ventral cilia mod- 

 erate, straight, usually longer and more conspicuous near tip of 

 pennulum than at its base; dorsal cilia as a rule poorly developed. 

 Exceptions in the relatively stout, blunt ventral teeth of Trochili- 

 dae, the extremely long pennula of Striges and Caprimulgi, and 

 the minute pennula of Trochilidae, the poorly developed ventral 

 cilia in the inner vane of Podargus, in the large number of stout 

 booklets in the outer vane of Bucerotidae, and in the relatively 

 high development of the proximal two dorsal cilia in the Bucer- 

 otidae. 



(4) Proximal barbules of inner vane of remiges usually with 

 slender elongate base, moderate ventral teeth, and rather broad 

 pennulum somewhat shorter than base. Exceptions in short broad 

 bases in Trochilidae, and in greatly elongated pennula in Striges 

 and Caprumulgi. 



(5) Proximal barbules on distal part of barbs of outer vane 

 of remiges with moderately developed series of hooked ventral cilia. 

 Exceptions in enormous talon-like ventral cilia of Ceryle, non- 

 barbicelled pennulum of Bucerotidae and Trochilidae, and weak 

 cilia of trogons, hoopoes and owls. 



(6) Body feathers, where unmodified for color production, mere 

 simplifications of remex type. 



(7) Down always more or less pigmented, with nodes slightly 

 enlarged and inconspicuous in typical coraciid forms, larger and 

 beadlike in Alcedinidae, and almost unnoticeable in Caprimulgi 

 and Cypselidae ; barbules coarse, with prongs at nodes, in Bucero- 

 tidae ; nodes large basally and inconspicuous distally in Striges and 



