1906.] NATURAL SCIENCES OF PHILADELPHIA. 193 



feathers ; but these have hardly bearing on the question, for they without 

 much doubt belong to Collocalia unicolor amelis. The present form is 

 said to occur in the western Himalaya Mountains, but careful compari- 

 son of a satisfactory series from this locality with typical examples 

 from southern India would possibly show subspecific differences. Im- 

 mature birds of Collocalia unicolor are rather darker, more sooty than 

 adults, both above and below, 



Collocalia unicolor amelis subsp. nov. 



Chars, subsp. — Similar to Collocalia unicolor unicolor, but less brown- 

 ish and less uniform above, the rump usually appreciably paler than 

 the back, the pileiun decidedly darker; lower surface rather less brown- 

 ish and less uniform, the throat usually decidedly lighter than the 

 abdomen; lining of wing darker; tail usually rather less deeply 

 emarginate. 



Geographical distribution. — Philippine Islands; Island of Guam; 

 ? Celebes; ? Louisiade Archipelago. 



Description.— Type, adult male, No. 189,931 U. S. N. M. ; Irisan, Ben- 

 guet, Luzon, Philippine Islands, May 19, 1903; R. C. McGregor and A. 

 Celestino. Upper parts dark sooty brown with a greenish tinge and 

 but little gloss, the head darker, the rump slightly paler; wings and tail 

 darker than the back — blackish brown with a greenish sheen, the inner 

 webs of the wing-quills dull and paler brown; lower surface grayish 

 brown, darkest on the lower tail-coverts, palest on the throat and 

 jugulum; lining of wing blackish brown. "Iris brown, bill and claws 

 black; legs dark reddish brown." 



Several specimens of this new form, identified as Collocalia white- 

 headi, were some time since received from the Philippine Museum by 

 the U. S. National Museum. Notwithstanding the similarity of pro- 

 portions (including the forking of the tail), the very great difference 

 in size renders it easily distinguishable from C. whiteheadi on even 

 superficial examination. From Collocalia francica and other light- 

 rumped species Collocalia unicolor amelis is at once to be separated 

 by its lack of the whitish band on the rump. Its nearest relative 

 is, of course, Collocalia unicolor unicolor of southern India, from 

 which, though similar in size, it differs as above mentioned ; but com- 

 parison of a series of each of these forms shows none^of the characters 

 to be quite constant, hence amelis must rank as a subspecies. The 

 tarsi in C. u. amelis are entirely devoid of feathers, therefore no special 

 comparison is really necessary with Collocalia fuciphaga and its allies, 

 except for specimens of fuciphaga that have accidentally lost the tarsal 

 13 



