1863.] DR. p. L. SCLATER ON A NEW AFRICAN SWIFT. 205 



7. On a New Spine-tailed Swift from Western Africa. 

 By p. L. Sclater, M.A., Ph.D., F.R.S., etc., Secretary 

 TO THE Society. 



(Plate XIV. fig. 2.) 



While examining the American Swifts of the genus Chcetura in 

 the British Museum, Mr. G. R. Gray kindly called my attention to 

 two African species of the same genus, which have hitherto been 

 confounded together. These are the Chcetura sabini, described by 

 Dr. Gray in Griffith's edition of Cuvier's 'Animal Kingdom,' and 

 the species called Chcetura sabini by Mr. Cassin in his ' List of the 

 Birds collected by M. Du Chaillu on the Rivers Camma and Ogobai.' 



The latter bird is obviously distinct from the former, as will ap- 

 pear by the following characters, and may be called Chcetura cas- 

 sini : — 



(1.) Ch^tura sabini. 



Chcetura sabini, Gray, Griff. An. K. ii. p. 70; Hartl. Orn. W. 

 Afr. p. 25. 



Chcetura bicolor. Gray, Zool. Misc. p. 7. 

 Pallene leucopygia, Boie, Isis, 1844, p. 168. 

 Acanthylis bicolor, Strickl. P. Z. S. 1844, p. 99. 



Nigra : uropygio, caudee tectricibus superioribus et inferioribus 

 et ventre cum crisso albis : tectricum caudalium sup. et inf. 

 plumarum rachidibus nigris. 

 Long, tota 4*0, alee 50, caudse 1*5 poll, et dec. Angl. 

 Hab. Sierra Leone (Sabine) ; Fernando Po (Fraser). 

 In this smaller species the tail is wholly black ; and the whole of 

 the upper and under tail-coverts are pure white, with black shafts to 

 the feathers. 



(2.) Ch^tura cassini, sp. nov. (PI. XIV. fig. 2.) 

 "Chcetura sabinei," Cassin, Proc. Acad. Sc. Phil. 1859, p. 33. 



Nigra : uropygii fascia angusta et corpore subtus albis ; pectore 

 fuliginoso : pectoris et gulce plumarum, rachidibus nigi'is. 



Long, tota 4-8, alae 6'3, caudse 1*2. 



Hab. Gaboon (Dm Chaillu). 



In this species the upper tail-coverts are black, crossed by a nar- 

 row white bar, which extends through and is partially observable on 

 the rectrices. The size is much larger than in Chcetura sabini, the 

 bird being represented in the accompanying plate two-thirds of its 

 natural dimensions. 



