188 BRITISH BIRDS. 
Genus PROGNE. 
The genus Progne was established in 1826 by Boie, in the ‘ Isis’ for 
that year (p. 971), for the reception of the Purple Martin, which thus 
became the type. The birds in this genus may be distinguished by having 
the nostrils opening upwards and exposed, without any internal overhanging 
membrane. Some of the species have a metallic gloss on the feathers of 
the upper parts, whilst others are uniform brown. It is impossible to 
state how many species there are in this genus, many Swallows pre- 
senting characters intermediate between it and Hirundo. On the widest 
estimate the number of species would be between thirty and forty, which 
are confined to the Nearctic, Neotropical, and Ethiopian Regions. The 
narrowest estimate would reduce the number of species to four, belonging 
to the Nearctic and Neotropical Regions only. The sole representative of 
this genus in Europe is the Purple Martin, which is supposed on more than 
one occasion to have accidentally strayed as far as the British Islands. 
It is not known that the species of this genus differ from those of 
Hirundo in habits, food, or nidification. 
