Cynanthus bolivianus, Gould. 233 



Total 



length. Wing. Tail. Culmen. 



inches. inches. inches. inch. 



1. 6 ~\ 2| 5 i 



From Bolivia (Buckley) : — 



3. tJ 7 2i 4f £ 



4- c? 6} H 4| | 



o. 6 6* 2i 4| * 



G. rf, Pera .... 6i 2| 4J | 



Mr. Gould's specimen (locality, Ecuador?) : — 



7- 6 6J 2i 4f i 



Another specimen from Baiios, Ecuador (Buckley), lias not 

 the tail fully developed ; so I do not give the measurements ; 

 and two others are females. All the above are adult males 

 in perfect plumage. It will be noticed that none of them 

 has a total length of 8 inches, given by Mr. Gould as the 

 measurement of G. mocoa, the largest being 7^ inches ; and this 

 example, I consider, has an unusually long tail. The make- 

 up of a skin causes a total length to vary sometimes very 

 considerably ; and it should always be mistrusted as indicating 

 a specific character in birds like those of the family Trochi- 

 lidas. The length of wing, as will be seen, is about the same ; 

 while of the tail, the shortest is found in a specimen from 

 Ecuador, as is also the longest. From the foregoing, as well 

 as from my experience in these birds, I do not think that a 

 slight difference in the measurement of any of their parts has 

 any specific value whatever ; and no specimen should be sepa- 

 rated from its fellows as distinct with only a slight difference 

 in size to substantiate its claim. Finding measurements un- 

 profitable, I turned to colour. The " brighter metallic 

 green " being only a comparative distinction from a " bright 

 metallic green " proved to be a very difficult character to 

 seize upon, as the colour of the birds varied in hue and inten- 

 sity as the rays of light fell upon them ; but it was easy to 

 see that all possessed the same colouring, be the metallic hues 

 bright, brighter, or brightest. The single remaining point 

 was that the tail of the Bolivian bird should be more of a 

 brilliant " steel-blue " than " vivid green." If this last 

 should prove to be a stable character, there might be some- 

 thing in it ; but what did the examination show ? That no. 4, 

 from Bolivia, possessed the most brilliant metallic green tail 

 of all the specimens ! ! ; and next to it was no. 5, also from 

 Bolivia; while no. 2, from Ecuador, and no. 1, from Ecuador, 

 exhibited rectrices of the same hues slightly tinged with steel- 



