260 
Mr. O. Salvin on the 
raise an hypothesis on this subject upon the facts that I have, 
up till now, collected, but merely state the numbers, and wait 
for further investigations. 
v / 1. Phaethornis adolphi. 
Coban, Vera Paz. November 15th. 
Though not common about Coban, this species seems pretty 
generally dispersed. Like many others, it feeds among the 
Salvia. To a practised ear its presence may be detected by the 
peculiar hum of the wings. This at once warns the collector 
to look out sharply among the lower branches and flowers, 
which are well searched by this bird, while the upper shoots of 
the bush are comparatively neglected. At Yzabal, w T here P. 
adolphi abounds, its habits somewhat differ. This is probably 
owing to the very different nature of the plants from which it 
takes its food, rather than to any other cause. If the females 
are to be distinguished from the males by their yellower throat, 
the ratio of the sexes is two females to seven males. 
/ 2. Campylopterus delattrii. 
Coban, Vera Paz. November 1859. 
The large size and showy tail of this Humming-bird make it 
one of the most conspicuous when on the w r ing. It is common 
at Coban, feeding among the Salvia. It is said also to be found 
in the Volcan de Puego, but I have not yet met with it. The 
females of this species are most abundant, their ratio to the males 
being as five to two. C . delattrii is not nearly so shy as its 
congener, C. rufus . 
/ 3. Campylopterus pampa. 
Coban. November. 
A single female specimen only was brought to me while at 
Coban. 
4. Petasopiiora thalassina. 
Volcan de Puego. September 6tli. 
The barrancos of the Volcano are favourite resorts of this 
species. 
Duenas, September 15th. A specimen obtained on this day 
is the only one I have seen out on the llano, as the bird is 
usually found in the dense forest. 
