318 University of California Publications in Zoology fVoL. 13 



(4) Breast feathers with flexules developed on terminal por- 

 tion of barbs of breast feathers. 



(5) Down smooth and filamentous, little if any over 1 mm. long. 



II. Suborder Ciconi.xe 

 PI. 20, Figs. 23-27 

 Constituting the second suborder of the Ciconiiformes are the 

 storks and ibises, which, together with the Ardeae, form a compact 

 and well-defined group. Although the typical Ardeae are readily 

 distinguishable from typical Cicon^ae, there are a number of more 

 or less intermediate forms which make their characterization by 

 other characters as well as by epiphyology very difficult. Ex- 

 cluding Balaenieeps and Scopus, which combine characters of both 

 groups, the Ciconiae are distinguished from the Ardeae by the fol- 

 lowing characteristics: (1) absence of powder down, (2) even 

 distribution of plumules in both pterylae and apteria, and (3) 

 feathered lores. The aftershaft is very variable, being present, 

 rudimentary, or absent in different genera. 



a) Mycteria americana 



(1) Remex 



Shaft stout and square, about as deep as wide, with broad, V- 

 shaped ventral groove, and fine striations on sides where barbules 

 are attached. Rami not greatly deepened at junction with shaft 

 but deeper than usual in Steganopodes. Pith cells more than a 

 single layer thick, and ventral edge of rami of both outer and inner 

 vanes without villi. Distal vanule with barbules greatly outnum- 

 bering those of proximal vanule, the barbules about 40 per milli- 

 meter on former, only 18 per millimeter on latter, this difference ac- 

 companied by great difference of angle of insertion of barbules on 

 ramus. 



Inner vane. — Distal harhules (pi. 20, fig. 23a) small relative to 

 proximals; base of moderate size, about 0.35 by 0.05 mm., with 

 fairly large, lobate ventral teeth, frequently blunt and slightly 

 incised at tip ; pennulum characterized by stout heavy form ; 

 booklets numerous, 6 or 7 in number, moderately stout, and pro- 

 gressively increasing a great deal in length ; ventral cilia rather 

 poorly developed, present all the way to tip of pennulum, straight, 

 and appressed to barbule ; basal dorsal cilia stout, blunt, and spine- 

 like, well separated from each other, the first one always the largest ; 

 usually three such stout barbicels developed, the following ones 

 becoming more and more like the ventral ones. Proximal barbules 

 (pi. 20, fig. 23&) with very large bases, about 0.7 mm. long by 0.07 

 mm. wide with a series of broad, triangular ventral teeth projecting 

 very little beyond the ventral contour of barbule ; pennulum re- 



