38 
Messrs. Salvin and Sclater 
gutture lactesccnti-albo, ventre imo crissoque obscurioribus, 
nigricantioribus: rostro nigro, pedibus plumbeis: long, 
tota 4*3, alre 4*6, caudae 2*4, tarsi 0*45. 
Had . in Mexico et Guatemala. 
An imperfect specimen from Coban transmitted by Salvin 
seems to be referable to this species, of which I have taken the 
characters from two skins obtained by M. H. dc Saussure in 
Mexico. The bird is nearly allied to two South American 
species, Chcetura spinicauda and C. poliura , but is immediately 
distinguishable by its pure white throat, passing into smoky 
brown on the belly. In C. spinicauda the throat is also whitish, 
but the belly is of a bluish ash-colour, and the uropyginmis 
pale cinereous. In the present bird the uropygium and tail- 
cpverts arc of a pale smoky brown, like the belly. 
It is probable that this Swift may be the Chcetura vauxi (Baird, 
Report, p. 145) of Western North America, of which I have 
never seen specimens. It seems to agree with the figure of that 
bird, given in the 10th volume of the Pacific R. R. Reports' 
ph 18.—P. L. S. 
Pam. TROCHILIM. 
54. Phaethornis adolphi, Gould: sp. 177. 
Ibis is one of the commonest species of the family about 
A zabal, and, I think, one of the most restless and active of them 
that I have yet met with. It searches the flowers growing from 
the ground to the height of about four or five feet. 
55. Campylopterus rufus (Less.) : sp. 178. 
I saw only one example of this species at Duenas last year. Now* 
it is abundant in all parts, and instead of being one of the rarest 
is one of the most familiar species. There seems to be a slight 
difference in the notes of all the humming-birds that have come 
under my observation, which is more especially noticeable when 
several species frequent the same place. The call-note—if such 
ru fus is very distinct from those of Thaumastura 
henicuj Amazilia arsinoe , and Cyanomyia cyanucephala , all of 
u hich are in their turn distinguishable one from another; but 
these differences, perceptible as they are to the ear, are not 
capable of being rendered intelligible in writing. It appears 
