598 SWALLOW TRIBE. 



and a little hooked at the point. Nostrils basal, oblong, behind 

 partly closed by a membrane, and covered by the advancing feathers 

 of the frontlet. Tongue short, bifid. Feet short, and slender ; middle 

 toe longer than the subequal lateral ones, united with the outer to 

 the first articulation, middle toe-nail largest. First priynanj longest. 

 Tail of 12 feathers, and generally forked. 



These birds are remarkable for their sociability, living generally in 

 families, constructing their nests together, and often rendering mu- 

 tual assistance in its formation ; they also assemble and migrate in 

 large flocks. Some build in hollow trees, barns, out-buildings, chim- 

 neys, and even on the ground, or the larger branches of trees ; the ex- 

 ternal part of the nest is fortified with hardening materials, the interi- 

 or lined with soft substances. Constantly paired, they rear several 

 broods in the season, and unite in the labor of rearing the young. 

 They frequent watery places in pursuit of winged insects, which 

 they take with agility, swimming as it were in the air j they likewise 

 skim over the svirface of waters, and drink and bathe even without 

 alighting, the air being almost their peculiar element. In fair weath- 

 er they delight to ascend into the elevated regions of the atmos- 

 phere ; but previous to rain, which they thus prognosticate, they 

 lower their flight, and at length sail near the surface of the earth. 

 They inhabit every region, and moult once a year, in the depth of 

 our winter, and while in their tropical asylum. 



PURPLE MARTIN. 



{Hir undo purpurea, L. WiLsojf, v. p. 58. pi. 39. fig. 1. and 2. Aud. 

 pi. 22. Orn. i. p. 115. Phil. Museum, No. 2645, 2646.) 



Sp. Charact. — Dark bluish-purple, and glossy; wings and forked 

 tail brownish-black. — Female and young bluish-brown ; belly 

 whitish. 



According to the progress of the season in the very 

 different climates of the United States, is measured the 

 arrival of this welcome messenger of spring. Around the 

 city of New Orleans, for example, the Purple Martin is 

 seen from the 1st to the 9th of February. At the Falls 

 of the Ohio they are not seen before the middle of March, 

 and do not arrive in the vicinity of Philadelphia until the 

 first week in April ; on the 25th of that month or later, 



