26 BULLETIN 98, UNITED STATES NATIONAL MUSEUM. 



less convex, the culmen much more sharply ridged — almost as in 

 Alcedo and Alcyone — and the gonys more decidedly keeled. The 

 three species above included should therefore be called: 



Therosa argentata (Tweeddale). 



Therosa solitaria (Temminck). 



Therosa cyanopectus (Laf resnaye) . 



Family MICROPODIDAE. 



*MICROPUS SUBFURCATUS (Blyth). 



Cypselus subfurcatus Blyth, Journ. Asiat. Soc. Bengal, vol. 18, August, 1849, 

 p. 807 (Malay Peninsula). 



Recorded from the Anamba Islands by Mr. C. B. Kloss. 1 



COLLOCALIA LOWI (Sharpe). 



Cypselus lowi Sharpe, Proc. Zool. Soc. Lond., 1879, p. 333 (Labuan Island, 

 northern Borneo). 



One adult male from Pulo Riabu, August 22, 1900. Length, 133.5 

 mm.; wing, 134 mm. "Shot out of a flock of nearly a hundred that 

 were hawking along the beach in the evening." The present example 

 has the tail distinctly though not deeply emarginate; but this can 

 be regarded as scarcely more than an individual peculiarity. Indeed, 

 the shape of the tail, as a character used to distinguish Collocalia lowi 

 from Collocalia whiteheadi, is of doubtful value, for some specimens of 

 the latter have the tail almost square, while Collocalia lowi sometimes 

 shows distinct emargination. 



Mr. Erwin Stresemann has recently described 2 as a subspecies 

 of Collocalia lowi the form of Collocalia whiteheadi from Palawan 

 Island which the present writer some years ago indicated as possibly 

 separable. This is a bird with unfeathered tarsi, like Collocalia 

 whiteheadi, and clearly is a subspecies of that species, not of Collocalia 

 lowi, with which it has nothing to do, and should, therefore, stand 

 as Collocalia whiteheadi palawanensis. These two species, Collocalia 

 lowi and Collocalia whiteheadi, are very similar in coloration, as, 

 indeed, are so many of the other distinct species of this difficult 

 genus, but Collocalia lowi is somewhat darker below than both 

 Collocalia whiteheadi whiteheadi and Collocalia whiteheadi palawa- 

 nensis, with more distinct dark shaft streaks and more uniform 

 coloration, the throat not being noticeably lighter than the breast 

 and abdomen, as is the case in both forms of Collocalia whiteheadi. 

 In fact, the most satisfactory means of distinguishing these two 

 species is the difference in the feathering of the tarsi. Thus, to 

 consider Collocalia whiteheadi, a bird with unfeathered tarsi, a sub- 



1 Journ. Straits Branch Roy. Asiatic Soc, No. 41, January, 1904, p. 79. 



2 Collocalia lowi palawancnsis Stresemann, Verhandl. Ornith. Gesells. Bayem, vol. 12, May 15, 1914, 

 p. 10. 



