4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I45 



resembled Rieffer's hummingbird in color pattern, they were so 

 much larger, especially in bulk of body and total length, and also 

 SO much darker colored, that they were examples of an unknown 

 form. From careful examination the dififerences are of such a nature 

 that they must be considered as representative of a distinct species. 

 This is named for Charles O. Handley, Jr., in recognition of his 

 continuing interest in the avifauna during his field work concerned 

 with the mammals of Panama. 



The five birds taken by Dr. Handley were preserved in formalin 

 and were prepared as skins by Mrs. Roxie Laybourne on their arrival 

 at the U. S. National Museum. Their much greater size was obvious, 

 but to make certain that the color differences were not due to the 

 preservative I placed a recently taken study skin of Amasilia tzacatl 

 t.zacatl in the same fluid in which the hummingbirds from Isla 

 Escudo de Veraguas had been received. When dried after a month 

 of such immersion this specimen showed no change of any kind. 

 It is interesting to record that in this skin, and in the larger relative 

 here described, the feathers along the side of the neck when wet 

 were metallic reddish purple, a color that disappeared completely as 

 the specimens dried. 



Anmcilia tzacatl as a species maintains uniform size, within the 

 usual limits of individual variation, throughout a vast area from 

 eastern Mexico, Central America, and Colombia to western Ecuador 

 and western Venezuela. The only variation apparent is in a buffy 

 wash on the abdomen in that part of the population found in south- 

 western Colombia and Ecuador on which birds of that section are 

 separated as a geographic race under the name A. t. jucunda. It has 

 been noted above that the bird of Isla Escudo de Veraguas com- 

 pared with tzacatl differs in decidedly darker coloration and in much 

 larger size. It is clearly evident that the island group is of a stock 

 similar to that of the mainland, so that on first consideration it 

 would appear that they should be related as subspecies. The color 

 differences, while considerable, would not militate against this. But 

 the size difference in terms of bulk of body of the island bird is 

 so much greater — over 50 percent more than that of the mainland 

 group — with its complete isolation, make it reasonable to regard 

 handlcyi as a separate species. 



As stated in my earlier paper (Wetmore, 1959, pp. 3-4) it is 

 probable that the island had connection with the mainland during the 

 fluctuations in sea level of Pleistocene time so that the present 

 inhabitants among birds and mammals may have come to it during 



