1906.] NATURAL SCIENCES OF PHILADELPHIA. 203 



white or whitish in contrast to most of the remaining more or less 

 deeply brownish lower parts; under tail-coverts like the back; lining 

 of the wing rather more brownish. 



Wing, 86-96; tail, 38-42; exposed culmen, 3.5; tarsus, 9-9.5 mm. 



Type locality. — Philippine Islands. 



Geographical distribution. — Philippine Islafids. 



This very distinct species differs markedly from all the preceding 

 forms with unfeathered tarsi in its small size, deeply blackish upper 

 surface, white abdomen, and peculiar white rump band. It is super- 

 ficially very similar to Collocalia leucopygia, but aside from the lack of 

 tarsal feathers is easily distinguished from that species by its more 

 greenish upper surface, broad blackish tips to the white feathers of the 

 rump band ; and more extensively blackish lower tail-coverts. There 

 is considerable variation in the wing-length of C. troglodytes, but this 

 does not seem to be correlated with different geographical areas. 



The species has been obtained on the following islands of the Philip- 

 pine archipelago: Mindanao, Palawan, Siquijor, Cebu, Masbate, Negros, 

 Guimaras, Panay, Romblon, Sibuyan, Mindoro, Luzon, Marinduque, 

 Samar, Leyte, and Ticao. 



Collocalia uropypialis Gray. 



Collocalia uropygialis Gray, Ann. and Mag. Nat. Hist., ser. 3, XVII, 1S66> 

 p. 123. 



Chars, sp. — Similar to Collocalia troglodytes, but rather larger; feath- 

 ers of the white band on the rump without blackish shafts or tips ; most 

 of the rectrices usually with white spots on the basal portion of inner 

 webs; some of the under wing-coverts and lower tail-coverts with 

 whitish tips or margins. 



Wing, 89-99; tail, 38-44; tarsus, 7 mm. 



Type locality. — Aneiteum Island, New Hebrides Islands. 



Geographical distribution. — New Caledonia and New Hebrides 

 Islands. 



Readily distinguished from all the other light-rumped forms of the 

 genus by the white spots on the tail-feathers; with the remaining 

 species it needs no special comparison. 

 Collocalia marginata Salvador!. 



Collocalia marginata Salvadori, Atti R. Acad. Sci. Torino, XVII, 1882, p. 



448. 

 Collocalia cebuensis Kutter, Journ. f. Ornith., 1882, p. 171 (Cebu Island, 



Philippine Islands). 



Chars, sp. — Somewhat like Collocalia uropygialis, but larger; rather 

 more greenish above; rump without a white band, but its feathers 

 with conspicuous white edgings; rectrices never with white spots. 



