38 BIRDS OF LA PLATA 
up in the sky from so many throats, the concert has 
a very charming effect, and is in harmony with the 
shadowy morning twilight. 
BANK-MARTIN 
Atticora cyanoleuca 
Above dark glossy blue; quills and tail-feathers black ; cheeks and 
under surface pure white; sides of the neck blue, descending in a 
half-crescent on the sides of the chest; length 4.7 inches. 
Tuis diminutive dark-plumaged species is the small- 
est of our Hirundines. In Buenos Ayres they appear 
early in September, arriving before the Martins, but 
preceded by the Common Swallow. They are bank- 
birds, breeding in forsaken holes and burrows, for 
they never bore into the earth themselves, and are 
consequently not much seen about the habitations of 
man. They sometimes find their breeding-holes in 
the banks of streams, or, in cultivated districts, in the 
sides of ditches, and even down in wells. But if in 
such sites alone fit receptacles for their eggs were met 
with, the species, instead of one of the commonest, 
would be rare indeed with us; for on the level 
pampas most of the water-courses have marshy 
borders, or at most but low and gently sloping 
banks. But the burrowing habits of two other 
animals—the Vizcacha (Lagostomus trichodactylus), 
the common large rodent of the pampas, and the 
curious little bird called Minera (Geositta cunicu- 
