1916] Chandler: Structure of Feathers 369 



narrow, pith more than a single cell in thickness, the vanules placed 

 at a low level on sides, so that rami are as high above as below 

 the attachment of barbules. Ventral ridge narrow and inconspicu- 

 ous. Distal and proximal vanules with about 30 and 22 barbules 

 per millimeter respectively. 



Inner vane. — Distal darhules (pi. 31, fig. 78a) short and broad, 

 about 0.25 by 0.05 mm., the ventral contour sinuate, and ventral 

 teeth small and fingerlike. Pennulum about as long as base, but 

 very frequently broken off just distal to booklets. Hooklets mod- 

 erately long and slender, progressively increasing in length. Ven- 

 tral cilia straight, inflexible, and subequal in size, the first two 

 slightly longer and closer together on account of crowding together 

 of cells. Dorsal cilia rudimentary, except proximal 2 or 3, which 

 are enlarged and lobate, especially on more distal portion of barb. 

 Proximal barbules (pi. 31, fig. 785) relatively large, the base about 

 0.55 by 0.05 mm. ; ventral teeth short, triangular and inconspicuous ; 

 pennulum a little shorter than base, and considerably flattened for 

 most of its length. 



Outer vane. — Distal harhules very similar to those of inner vane, 

 except that dorsal cilia are entirely absent, and hooklets are 

 usually 6 in number. Pennulum has some tendency to break off 

 distal to hooklets. Proximal harhules on outer part of barb (pi. 31, 

 fig. 78c), with relatively small, slender base, and long pennulum 

 with a well-developed series of ventral cilia which are strongly 

 hooked and reminiscent of the Galli in their high development. 



(2) Other Feathers 



Back feathers characterized by long narrow base of distal bar- 

 bules (0.36 by 0.035 mm.) with small, fingerlike ventral teeth, and 

 reduced barbicels, very much as in the Cuculiformes, the hooklets 

 usually 3 in number, but not pronged. Proximal barbules exceed- 

 ingly slender, the base about 0.55 mm. by 0.03 mm., ventral teeth 

 short and pointed, 4 or 5 in number, pennulum somewhat shorter 

 than base and fiattened, but not as much so as in remiges. Breast 

 feathers of same type, but barbicels of distal barbules more re- 

 duced, the cilia being small and the hooklets only two in number, 

 but frequently pronged. Proximals as in back feathers. 



h) Other Types 



Momotidae. — Remiges in Momotus strikingly similar to Coracias 

 in all details of structure, the pennula of the proximal barbules 

 slightly broader and more jagged in outline on account of rudi- 

 mentary 6 ac/i; ward-projecting barbicels. Body feathers with more 

 reduced barbicels than in Coracias, often, especially on outer half 

 of barbs, reduced to mere undifferentiated filaments. 



Meropidae. — M crops viridis like Coracias, but proximal barbules 

 on terminal half of barbs of outer vane more slender, with fewer 

 and less well-developed barbicels. 



