1916] Chandler: Structure of Feathers 307 



(6) Proximals of outer vane with tapering base, and very long, 

 heavy pennulum, with slender, wavy, or curved barbicels basally, 

 and usually both dorsal and ventral barbicels on greater part of 

 its tip ; 



(7) Body feathers, especially on breast, with highly developed 

 flexules on both distal and proximal barbules; 



(8) Down barbules of moderate length, either with rather long 

 prongs, longer near base of barbule {Diomedea and Fuffinus), or 

 with an even series of moderately developed prongs {Oceanodroma 

 and Pelecanoides) . 



4. Order CICONIIFORMES 



Under this large group are included four suborders, and as all 

 the members of the group have little in common as regards their 

 feather structure, it will be more convenient to deal with each sub- 

 order separately. The suborders are as follows: (1) Steganopodes, 

 including all the water birds with fully webbed feet; (2) Ardeae, 

 including herons and bitterns; (3) Ciconiae, the storks and ibises; 

 and (4) Phoenicopteri, or flamingoes. 



I. Suborder Steganopodes 

 Plates 18, 19 

 This suborder contains a rather heterogeneous assemblage of 

 water birds, which, although probably all with the possible excep- 

 tion of the Phaethontidae more closely related to each other than 

 to any other birds and therefore forming a natural group, are very 

 diverse, different members of it being probably near the line of 

 descent of various more specialized groups. In all of them the 

 plumules are evenly distributed over the entire body, and the after- 

 shaft is absent in most genera, but a minute one is present in 

 Fregata. 



a) Phalacocorax penicillatus 



(1) Remex 



Remiges highly developed but not as much so as in Diomedea. 

 Shaft considerably broader than deep except at superior umbilicus, 

 with narrow ventral groove often nearly obsolete ; no fine striations 

 on side of shaft as continuations of attachments of barbs, as 

 there are in most birds. Barbs set about 20 per centimeter, almost 

 equal on both vanes, very narrow, with only slight, translucent 

 ventral ridge. 



Inner vane. — About 40 barbules per millimeter on distal vanule, 



