AERONAUTES, 369 
Regarding the birds of Inscription Rock, there can, as we have already said, be 
hardly a doubt, for both Dr. Coues? and Mr. Henshaw‘ have seen them there, with 
full knowledge of the birds they were observing. We conclude, therefore, that the 
names saratilis and melanoleucus refer to one and the same species. 
The accounts of the habits of this Swift agree in most points, and are in full accord 
concerning the features of the localities in which alone it is to be found: these are 
gorges of the mountains with rocky precipitous sides, in the fissures and clefts of which 
the birds reside. Both Dr. Coues and Mr. Henshaw speak of the abundance of this 
species in Utah, Colorado, New Mexico, and Arizona, and as congregating in suitable 
places where the fissured cliffs afforded them suitable roosting- and breeding-places. 
The presence of A. melanoleucus in Mexico rests upon the rather doubtful evidence 
of two skins in the British Museum 2, said to have come from that country, and the 
statement by Sumichrast ® that he believed he recognized it flying about the mountains 
of Orizaba. There can, however, be little doubt that it is to be found in suitable 
places in Mexico, as in the countries further to the northward. 
In Guatemala we only met with it in one locality, a gorge of the Rio Guacalate 
between the villages of Dnefias and Ciudad Vieja, at an elevation of about 5000 feet 
above sea-level’, a fissured precipice of igneous rock on one side of the valley har- 
bouring a good many individuals. During the daytime some of the birds of this colony 
might usually be seen soaring high in the air over the valley, others would be hidden 
in the crevices of the rock, keeping up a continuous chatter. Every now and then one 
or two would descend from the flock in the air and enter a crevice with the utmost 
rapidity ; again others would dart out and join their companions in their flight. 
Owing to the inaccessibility and narrowness of the fissures frequented by birds of 
this species their nests and eggs have not yet, so far as we know, been obtained. 
Dr. Coues states * that they breed on the face of high perpendicular cliffs, gluing their 
nests to the sides; and, again °, that they were observed evidently nesting in the rocks, 
but he could not say whether they built against the open rocks or in the crevices, 
though they certainly did so upon the face of the cliffs. This account is not clear, 
and it is not fully supported by Mr. Henshaw, who says 4 that on several occasions he 
found colonies breeding in the faces of the cliffs; the inaccessibility of the crevices they 
had chosen for their retreats proved an insurmountable obstacle to any attempt to spy 
out their domestic arrangements. 
Our own observations in Guatemala, which apply to cliffs of apparently much less 
elevation than those visited by Dr. Coues and Mr. Henshaw, lead us to conclude that 
the nests are placed inside the crevices and not against the face of the rock. We 
visited the Guacalate colony in several months of the year (in February, J uly, and 
November), and we never saw any trace of a nest outside a fissure. Debris from inside 
one of the most frequented crevices consisted of feathers and pieces of dry grass, the 
latter probably brought for nest-building. 
BIOL, CENTR.-AMER., Aves, Vol. II., January 1898. AT 
