8 Mr. D. G. Elliot on some 



Columbia and Bolivia respectively. Besides the ^'eat diffi- 

 culty ot" recognizing more than one species by size (for there 

 is absolutely no change of colour or brilliancy in the plumage 

 to warrant any specific rank being granted to more than one 

 form) , there is the geographical distribution of the species. If 

 three species are to be accepted, we find that L. splendens in 

 the north is separated from L. otero in Bolivia by L. grata 

 of Columbia, and that the last two become mingled toge- 

 tlier in Bolivia — not at all a probable state of things for 

 really distinct species. As in many groups of Humming- 

 birds, a variability in size of bill and length of wing, and 

 perhaps also of tail, is discernible ; but if these, unsup- 

 ported by other more important characters, are to be accepted 

 as always denoting distinct species, much confusion is certain 

 to be the resvilt, and no limit can be fixed beyond which any 

 naturalist, possessed with keen sight and enthusiastic appre- 

 ciation of minute difference, may not go. It may, however, 

 be advanced, with much probability, that there is only one 

 species of those birds consigned to the genus Leadbeatera, 

 whose range extends from Venezuela, through Columbia, into 

 Bolivia, being somewhat variable in the size of the bills of indi- 

 viduals from some localities, though it is almost certain that 

 a large series of specimens would yield a regular series of in- 

 termediate measurements. I do not see that Bonaparte had 

 any reason for taking this bird out of the genus Heliodoxa, 

 and, therefore, have not adopted his term. 



Lexjcippus leucogaster. 



Trochilus leucogaster, Tschudi, Consp. Av. inWiegm. Archiv, 

 1844, p. 297. 



Trochilus chiono g aster , Tsch. Faun. Peruan. p. 247, t. 22. 

 fig. 2. 



Leucippus chionogaster, Gould, Intr. Troch. p. 150, sp. 321. 



Trochilus ( ?) hypoleucus, Gould, P. Z. S. 1846, p. 90, 



sp. 16. 



Leucippus pallidus, Tacz. P. Z. S. 1874, p. 542. 



Hab. Peru and Bolivia. 



This species, first procured by Tschudi in Peru, has received 



