650 Messrs. Sclater and Mackworth-Praed on [Ibis, 



lected at Shendi by Rothschild and Wollaston,so that several 

 writers have considered it to be an abnormal variation. 

 Messrs. Chapman and Lynes have, however, collected a good 

 series of this truly desert form on the banks ol the White Nile 

 from about 50 to 100 miles south of Khartoum, and there 

 can be no doubt of the validity and distinctness of the form. 



We l)elieve that Cisticola deserticolor Wettstein (Anz. 

 Akad. Wien, 1916, no. 13, pp. i;31-135), from 20 kilometres 

 N. of El Obeid, will prove to be identical. 



As the distribution of this and C. c. uropyywlis appears to 

 overlap along the White Nile valley and we have not come 

 across any intermediate lorm, we prefer at present to regard 

 C. aridula as a distinct species. 



Cisticola ruficeps ruficeps. 



Mahirus nijlccps (/retzschmar in Riipp. Atlas, 1826, p. 54, 

 pi. 36 A : Kordofan. 



[B. coll.] 1 Jebel Melbis Apl. Kor. 



This bird is mentioned by Butler (Ibis, 1905, p. 333) as 

 being much paler than the forms from the Nile valley, and 

 obviously represents the true M. ruficeps of Cretzschmar. 

 There is one uther example in the British Museum labelled 

 " Nubia ? Dr. Kotschy ? " 



Cisticola ruficeps scotopter a. (PL X. figs 8-11.) 

 Diyinaca scutuptera ^Sundevall, OEfv. Ak. Porh. 1850, 

 p. 129 : Seunar. 



? Drymceca cinerascens Heuglin, J. f. 0. 1867, p. .^96: 

 Sennar. 



Cisticola floweri Hartert, Bull. B. O. C. xxvii. 1910, p. 12: 

 Sennar. 



Cisticola ruficeps (part) Butler, Ibis, 1905, p. 333, 1908, 

 p. 229, 1909, p. 82. 



[B. coll.] 2 Roseires Apl. Sen. ; 1 Ta.ufikia Apl., 1 Fashoda 

 Jan. U.N.; 1 Chak Chak Feb., 1 Moyen May, E.G.; 

 4 Mongalla summer. 

 [C. & L. coll.] 3 Singa, 2 Kamisa Dec. Sen. ; 14 White 

 Nile from Jebeleia to Bahr el Zeraf Jan. Feb, 



