18:1 PROCEEDINGS OF THE ACADEMY OP [April, 



entire lower surface dark brownish gray; upper parts more brownish, 

 the light rump band decidedly less conspicuous. 



Wing, 130-137; tail, 50-56; exposed culmen, 6; tarsus 12-12.5 mm. 



Type locality.— Fort Mouat, South Andaman Island, Andaman 

 Islands. 



Geographical distribution.— Sonthern Tenasserim to Lower Siam and 

 Perak, Malay Peninsula; Mergui Archipelago; accidental(?) on South 

 Andaman Island. 



The large size, feathered tarsi, light brownish rump band with dark 

 shaft lines, and the conspicuously darker mesial lines of the lower 

 surface, which last are present in only a few forms of CoZZocaha, 'suffic- 

 iently distinguish this very strongly characterized species. An adult 

 female taken by Dr. W. L. Abbott on September 5, 1896, at Trong, 

 Lower Siam, proves its occurrence in that region. 



Collocalia ocista sp. nov. 



Chars, sp. — Similar to Collocalia leucophaeae, but tarsi feathered ; 

 slightly smaller, except the tail which is longer ; upper surface, includ- 

 ing wings and tail, darker, more blackish (less brownish), and on head 

 and back as well as elsewhere with a decided greenish metallic gloss; 

 lower parts more grayish. 



Geographical distribution. — Marquesas and Society Islands. 



Description. — Type, adult female; Nukahiva Island, Marquesas 

 Islands, September 16, 1899; Charles H. Townsend. Upper surface 

 almost uniform dark sooty brown, slightly deeper on the pileum, a 

 little lighter on the rump — neither of these differences very noticeable 

 — and everywhere with a greenish metallic sheen; wings and tail darker, 

 more blackish, with a bluish or purplish metallic gloss, the wing-coverts 

 slightly more greenish, the innermost secondaries and inner margins of 

 the quills, at least basally, lighter and more brownish — about the same 

 color as the back; sides of head clove brown almost as dark as the 

 crown, the lores quite so, the loral feathers with lighter brown bases; 

 lower parts nearly uniform deep brownish gray, only the chin and 

 longest under tail-coverts somewhat darker; lining of wing clove brown. 



This new and very interesting bird is superficially so much like 

 Collocalia leucophaea, with the type of which it has been compared, 

 that a specimen in the Academy of Natural Sciences, Philadelphia, 

 collected long ago in the Marquesas Islands, and presented by Dr. 

 Gambel, was so labelled ; but the species may readily be separated by 

 the characters above given. It is fully as dark below as C. leucophaea, 

 and like that species is peculiar in possessing light brown bases to the 



