140 BANK SWALLOW. 
cess of wet, and act as a safeguard against the de- 
predations of birds of prey, a highly necessary 
precaution; the nest, placed on a bare surface of 
rock, unsheltered by even a leaf, is visible to every 
passing plunderer; and further, its form shades 
the sitting bird from the intense heat of the sun. 
Frequently fifteen or twenty nests are piled. 
on one another, their long tubular mud entrances 
sticking out in all directions. It is a pretty 
sight in a houseless country to watch these fea- 
thered masons, always suggestive of home, and 
the familiar martin, that builds its mud-nurseries 
under the eaves of our residences, recalling sad 
though pleasant memories of friends far away, 
perhaps, like I am, watching the mason-birds. 
After nesting-time they abandon the rock with 
their families, and scatter over the prairies, reas- 
sembling, prior to their final start for the south, 
in September; the nesting-time is in June, five 
eggs being usually the number laid. 
Bank Swattow (Cotyle riparia, oir).— 
These arrive at Colville in May and June, but 
somewhat earlier along the coast and at Van- 
couver Island. They are widely distributed, and 
generally frequent the larger river-banks. On 
their first arrival they assemble in immense num- 
bers, sometimes so completely covering a dead 
