18 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 75 



I must confess that I can see no practical utility in making races 

 of forms distant geographically because of resemblances in plumage. 

 It is in some cases positively misleading and obscures fundamental 

 differences. Two forms of the same genus that are widely separated 

 and differ quite markedly, even though there are certain resemblances, 

 may have had quite different origins or have come from a common 

 ancestor now extinct." For all practical purposes they are now spe- 

 cies, with their own set of forms or not as the case may be. Species, 

 at least in tire case of land birds, should have more or less of a 

 continuous distribution. Birds of the same genus widely separated 

 geographically and easily distinguished had best be treated as species, 

 even though they may resemble some distant form; the resemblance 

 is covered by the genus. 



COLLOCALIA VESTITA AEROPHILA Oberholser 



Collocalia fuciphaga aerophila Oberholsek, Proc. U. S. Nat. Mus., vol. 42, 

 1912, p. 16 (Siaba Bay, Nias Island). — Chasen and Kloss, Ibis, 1926, 

 p. 283. 



One male and two females, Sipora. 



These have been compared with the type of aerophila. They have 

 a slight greenish gloss on the wings not seen in the type, but I can 

 detect no other differences, and as the Nias bird was described from 

 a single specimen it may not represent the form typically. A single 

 female in the Museum from Simalur Island has the wing a duller, 

 almost glossless black and the sides of the face lighter than aerophila. 

 It has been referred to C vestita vestifa by Oberholser,^*' but this 

 disposition of it I am inclined to doubt is the correct one. I have been 

 unable to find the male specimen from the same island mentioned 

 in the paper cited. 



COLLOCALIA LINCHI OBERHOLSERI Stresemann 



Collocalia Unchi oierholseri Stbesemann, Nov. Zool., vol. 19, 1912, p. 348 

 (North Pagi Island).— Chasen and Kloss, Ibis, 1926, p. 283. 



Two females, Sipora. 



These two specimens have shorter wings than any in the typical 

 series from North Pagi Island, consisting of two males, one female, 

 and two unsexed birds. The two males measure: Wing, 104, 106.5; 

 tail, 43, 43. The female : Wing, 107.5 ; tail, 41. The two unsexed : 

 Wing, 105, 106; tail, 42.5, 42.5. The two females, Sipora: Wing, 95, 

 103 ; tail, 41, 40. There appear to be no constant differences in color. 

 With a larger series from Sipora the supposed difference in the 

 length of wing would probably disappear. 



*> Proc. U. S. Nat. Mus., vol. 42, 1912, p. 16. 



