BIRDS OF MINNESOTA. 351 
eagles are instantly put to flight by them, and in the words of 
Wilson, ‘‘So well known is this to the lesser birds, that as soon 
as they hear the Martin’s voice engaged in fight, all is alarm 
and consternation. To observe with what spirit and audacity 
this bird dives and sweeps upon, and around the hawk, or the 
eagle, is astonishing. He also bestows an occasional bastinad- 
ing on the Kingbird, when he finds him too near his premises, 
though he will at any time instantly co-operate with him in 
attacking the common enemy.” The value of the Purple Mar- 
tin to the general, or the special agriculturist is so well under- 
stood, and so universally accepted on account of their destructon 
of noxious insects, that for an exception, no argument is needed 
with that class of producers to defend it. It is nearly univer- 
sally distributed over the State. It leaves the whole country 
almost simultaneously between the 20th and 25th of August, in 
company with the White-bellied Swallows. Years of record 
show that they have left the vicinity of Minneapolis on either 
the 23d or 24th of that month. 
Notre. Mr. Washburn when referring to this species in his 
notes gathered on his second trip to the Red river valley says:— 
“This species too, occurs about Mille Lacs, where the farmers 
provide boxes for them. The great majority of them there, 
however, nest with the Gulls on an island called Spirit island 
by the Indians, lying about two miles from the southeastern 
shore of Lake Mille Lacs. Here large numbers lay their eggs 
in the sand,—in the crevices and fissures of the rocks, and 
serve as allies in driving away the ravens and other birds dis- 
posed to prey upon the eggs and young of the gulls.” 
SPECIFIC CHARACTERS. 
Bill strong, short, gape very wide, sides gradually com- 
pressed, culmen and lateral margins arched to tip, and the 
latter inflected, nostrils basal, lateral, open, and rounded; tail 
considerably forked; tarsi shorter than middle toe and claw, 
and about equal to the toe alone; toes long, strong, lateral ones 
equal; closed wings rather longer than the deeply forked tail; 
tarsi and toes naked; color everywhere glossy steel-blue with 
purple and violet reflections. 
Length, 7.30; wing, 5.85; tail, 3.40. 
Habitat, temperate North America. 
PETROCHELIDON LUNIFRONS (Say). (612.) 
CLIFF SWALLOW. 
Nowhere that my personal observation has extended, has 
this species of sparrow been more abundant from about the 
first of May to the 20th of August, than in this northern land. 
