302 BIRDS OF THE REPUBLIC OF PANAMA PART 3 



the material. The single egg, incubated by the female alone, hatched 

 in 25 days. While the group of four all fed the nestling, one male 

 appeared to do the greatest part. Though the nest was inaccessible, 

 when the egg hatched half of the shell was found on the ground 

 below. It was "exceedingly dark with a deep olive ground color rather 

 thickly covered with blackish brown markings." (This is the only 

 note on egg color seen.) The nestling was "covered in buff-colored 

 down." The second nest mentioned was not successful. 



Dr. R. M. Strong (Auk, 1952, pp. 199-200, fig. 1 ) has described 

 the microscopic structure of the throat feathers in the male as chang- 

 ing in appearance in reflected light from red to orange. "This change 

 takes place in the distal exposed portion . . . the feather structure 

 consists of highly-modified, barbuleless barbs. These barbs are 

 flattened and twisted so as to present a maximum surface area for 

 color reflection. Cross-sections reveal features which are unique in 

 my experience. . . . There is an outer layer that is almost too thin 

 to be called a cortex . . . only two to four microns thick. This cortex 

 or cuticle covers a . . . pigmented, central core which has a maximum 

 thickness of about 20 microns . . . when viewed by transmitted light 

 ... is orange red in color." 



Through the extensive range of this species, from northeastern 

 Costa Rica through Central America, and in northern South America 

 to Peru, Bolivia, the Amazon Valley in northern Brazil, and the 

 Guianas. these birds appear uniform in size and color so that no 

 geographic races have been recognized. 



PROCNIAS TRICARUNCULATA (J. and E. Verreaux) : 

 Three-wattled Bellbird, Calandria 



Figures 27 and 28 



Casmarhynchus tricaniiiculatus J. and E. Verreaux, Rev. Mag. Zoo!., ser. 2, 

 vol. 5, May 1853, p. 193. (Bocas del Toro, Panama.) 



Size large, body heavy; male, head white, body chestnut-rufous; 

 female, olive-green above ; underneath yellow streaked with olive- 

 green. 



Description. — Adult male, forehead and loral region bare except for 

 small scattered bristles and small downy feathers ; eyelids also bare 

 except for a line of feathers around edge ; bill broad at base, flattened, 

 with the mouth large, the rictus extended back beneath the eye ; a 

 slender fleshy wattle attached to the corner of the mouth on each 

 side, with a third arising from the base of the bill adjacent to the 

 forehead, all three dangling, pendant over the neck and breast to a 



