166 BIRDS THROUGH AN OPERA-GLASS. 
of our common swallows, being dead grayish-brown 
above and white below, with a band of grayish- 
brown across the breast, so that vanity does not 
interfere with their underground life. 
LI. 
EAVE SWALLOW; CLIFF SWALLOW. 
THE cliff swallow is the common swallow that 
we constantly see on telegraph wires and about 
barns in company with the barn swallow. It is 
easy enough to distinguish between them, because 
the tail of the eave, instead of being deeply forked, 
is almost square ; its back, instead of being glossy 
steel-blue, is dull blackish, and it also lacks the 
steel-blue collar. 
The nest of the cliff swallow is “a gourd or 
retort-shaped structure composed of pellets of mud 
mixed with a few straws and lined with soft feath- 
ers, attached to the face of overhanging cliffs or 
underneath the eaves of buildings.” 
ie 
CROSSBILLS. 
In November, 1887, one of the commonest sounds 
heard on my walks was an odd metallic kimp, 
kimp, kimp, coming from a flock of crossbills far 
