244 



CUKSOKIUS. 



CURSORIUS BICINCTUS GRACILIS. 



FISCHER'S COURSER. 



Diagnosis. Cursorius bicinctus colore isabellino : magnitudine minore : gula, vix striata. 



Variations. 



This local race appears completely to intergrade with the typical form, both in size and 

 colour. 



Synonymy. Cursorius gracilis, Fischer § Reichenow, Journ Orn. 1884, p. 178. 



Cursorius bicinctus gracilis (Fisch. fy Reich.), Seebohm, Ibis, 1886, p. 118. 



Literature. Plates.- — Unfigured. 



Habits.— Lort Phillips, Ibis, 1885, p. 416. 

 Eggs. — Unknown. 



Geographi- 

 cal distribu- 

 tion. 



Subspecifie 

 characters. 



Fischer's Chestnut-winged Courser was discovered by the traveller whose name it 

 bears in Masai-Land in Equatorial East Africa (Fischer, Joum. Orn. 1884, p. 178), and 

 was afterwards procured by the same intrepid explorer in Usukuma, south of Lake Victoria 

 Nyanza (Reichenow, Journ. Orn. 1887, p. 46). It has recently been procured to the 

 north-east by Mr. E. Lort Phillips in Somali-Land (Shelley, Ibis, 1885, p. 416). Like 

 Hartlaub's Courser it is slightly smaller than the typical form, but varies from it in colour 

 in the opposite direction. The buff shade is so rich that it approaches pale chestnut, and 

 the white of the upper tail-coverts is suffused with buff. On the other hand, it resembles 

 Hartlaub's Courser in having the dark shaft-lines on the throat less distinct, becoming 

 almost obsolete on the upper throat. 



Levaillant's Courser varies in length of wing from the carpal joint from 6" 5 to 5"7 inch, 

 whilst the same measurements of Fischer's Courser vary from 5" 7 to 5 - l inch. The tarsus 

 of the former race varies from 2 - 3 to 2'0 inch, and that of the latter from 2 - to 1"S inch. 



In the colour of the secondaries, which in this genus vary remarkably wherever a 

 specific difference is to be found, the three forms of Chestnut-winged Courser almost 

 exactly resemble each other. 



