THE IBIS. 



THIRD SERIES. 



No. XVIII. APRIL 1875. 



IX. — Notes on the Trochilidse. The Genera Chlorostilbon and 

 Panychlora. By D. G. Elliot, F.L.S. &c. 



Of all the known genera of Birds I doubt if there is 

 one whose species ornithologists have found more difficult 

 and perplexing than those treated of in this paper. The 

 reason appears to be, that the variation in colour of the plu- 

 mage, together with that of size in the body and its members, 

 has greatly assisted such Trochilidists as were desirous of de- 

 scribing new species, and who, with perhaps only one specimen 

 upon which to found an opinion, were easily contented to em- 

 ploy these variations as sufficiently characterizing new forms, 

 even though they were frequently infinitesimal in degree. In 

 the articles upon the various species given in this paper, I en- 

 deavour to show how little dependence can be placed upon the 

 different tints and shades of colour as indicating specific value ; 

 and the tables of measurements of a large number of examples 

 from various localities exhibit clearly that size alone is not to 

 be relied upon. I can find recognizable characters for only 

 eleven species ; and I do not see any cause for believing that 

 there are more. Of some described species, however, I have 



6ER. III. VOL. V. ' M 



