GEffEBA AKD SPECIES. 141 



Geoffroyi. Bourc. et Muls. Ann. de 

 Lyons, torn. vii. p. 37. 

 This species will most probably be hereafter 



! regarded as the type of a new genus, its present 



i position being merely provisional. 



We must here observe, that the Prince of 

 Canino separates the species cyanotis, thalas- 

 sinus, AnaiSy iolata, corruscans, Delphince, and 

 Geoffroyi from the genus Petasophora* and places 

 them in a genus which he terms Colibri. But 

 we agree with Mr. Gould in his opinion, that 

 the type of the genus Colibri is the Ruby-throat 

 of North America, the Trochilus colubris of Lin- 

 naeus, and that the term should not be applied 

 to the foregoing species, even granting the ne- 

 cessity of their removal from the genus Petaso- 

 phora. We very much question the propriety 

 of splitting up genera ad infinitum on trifling 

 data as variable as they are non-arrestive to the 

 eye, except it be hypercritically microscopic. 

 Let this system be carried out, and the genera 

 will become almost as multitudinous as are the 

 species. We have yet to search for a rule on 

 which alone a genus ought to be substantially 

 founded. But, in the making of genera, every 

 one seems to follow his own caprice. 

 We now pass to the genus Heliothrix. 



G-enus HELIOTHBIX, Boie. (Les Jacobines, 

 Less. Colibri) in part, Spix.) 



The species of this genus are pre-eminently 





