PROGNE. 



Genus PROGNE Boie. 



329 



Troqne Boie, Isis, 1S2G, p. 971. Type P. furpurca (Linn.), 1700 = 

 F. s/i/j/s (Linn.), 17oS. 



Fig. 131— To show the form of the tail. 



This fjenu? contains tlie largest of the Swallows. The hill is 

 depressed at the base, th« width beint/ about four-fifths the len;>th 

 of the exposed culmen; the nostrils are without any superior mem- 

 brane, rounded, and exposed. The wing is pointed and nearly 

 twice the length of the tail. The feet are strong and the claws 

 sharplv curved ; the middle toe and claw are about one-third longer 

 than tho tarsus. Coloration : male and female similar. 



Ke// to the Species. 



A. Upper s\u-fat'e pur])lisli blue. 



a. Larger, wing more tl)an 1 10 nmi. ; ab- 



domen pniphsli ])lue P. *?^/>/.v, p. 330. 



b. Smaller, wing less than 110 mm.; ab- 



domen white P. cJid/i/I/rti, ]). 331. 



B. Upper surface smoke-brown P. Inpo-K, p. 312. 



