182 PROCEEDINGS OF THE ACADEMY OF [April, 



e^. — Wing more than 95 mm.; upper surface much 

 brighter. 

 [/. — Upper parts much more bluish or purplish. 

 g. — Larger (wing averaging 104.6 mm.), 



Collocalia linchi cyanoptila. 

 g^. — Smaller (wing averaging 99.2 mm.), 



Collocalia linchi afjinis. 

 /'. — Upper parts much more greenish. 

 g. — Larger (wing 103-105 mm.), 



Collocalia Ihichi linchi. 

 g^. — Smaller (wing 97-101.5 mm.).^ 



h. — Upper surface duller, somewhat less 

 bluish or purplish; size slightly 

 greater, Collocalia linchi isonota. 

 h^. — Upper surface brighter, somewhat 

 more bluish or purplish ; size slightly 

 less, Collocalia linchi elachyptera. 



AERODKAMUS.e subgenus nov. 



Chars, subgen. — Similar in i3roportions to the subgenus Collocalia, 

 but tarsus more or less feathered. 

 Type. — Collocalia innominata Hume. 



Collocalia leucopygia Wallace. 



Collocalia leucopygia Wallace, Proc. Zool. Soc. Lond., 1863, p. 384. 



Chars, sp. — Upper surface dull, slightly sooty black, with a weak 

 metallic gloss, most evident on crown, the rump with a broad white 

 band whose feathers have conspicuous blackish shaft lines ; wings and 

 tail black with some metallic sheen, the latter without white spots ; sides 

 of head and neck clove brown, the loral feathers with white bases; 

 chin and throat brownish gray; remaining lower parts pale grayish 

 anteriorly, becoming brownish on sides of body, and whitish on abdo- 

 men, all the feathers with distinct darker shaft lines; longest under 

 tail-coverts glossy blackish brown; thighs and lining of wdng brownish 

 black. 



Wing, 95-99.5; tail, 45; exposed culmen, 4; tarsus, 8.5 mm. 



Type locality. — New Caledonia. 



Geographical distribution. — Loyalty Islands, New Hebrides Islands, 

 and New Caledonia. 



This species may readily be distinguished from all its congeners with 

 feathered tarsi, excepting Collocalia innominata and C. agnota, by the 

 white band on the rump ; and from all but Collocalia agnota by the 



" arjp, aer; Spafidv, cursare. 



