CTPSELtJS MELBA 31 



present daj', to judge from the effects of its action on the hard rocks 

 forming its banks. 



The nests of the two species, C. affinis galilejensis and C. urbica, 

 which seemed to be intermingled together, were placed at the top of 

 the cave, where it commenced to arch over, and at a height of about 

 forty feet from the ground. Apparently the two species were living 

 in perfect harmony with each other. 



CYPSELUS MELBA (Linnajus). 

 ALPINE SWIFT. 



Hirundo melba, Linn. Syst. Nat. i, p. 345 (1766). 



Cypselus melba, Illiger, Prodromns, p. 230 (1811) ; Loche, E.rpl. Sci. 



Alg. Ois. ii, p. 98 (1867) ; Koenig, J. f. 0. 1888, p. 165; id. J.f. 0. 



1892, p. 360; Whitaker, Ibis, 18M, Tp.'95. 

 Micropus melba, Hartert, Cat. Birds, Brit. Mies, xvi, p. 438. 

 Cypselus alpinus, Malherbe, Cat. Rais. d'Ois. Alg. p. 18 (1846). 

 Apus melba, Etianger, J.f. 0. 1899, p. 513. 



Description. — Adult male, spring, from Ain-Ehorab, Central Tunisia. 



Above pale mouse-grey, with a faint metallic lustre, darker on the quills 

 and tail ; most of the feathers with paler fringes ; chin, throat and abdomen 

 pare white ; pectoral band, flanks, crissum and under tail-coverts mouse- 

 grey, margined with whitish. 



Iris and bill very dark brown, feet livid brown. 



Total length SoO inches, wing 8-60, culmen from gape -90, tarsus -60. 



Adult female similar to the male. 



Observations. — Specimens vary slightly in shade of colour, two in my 

 collection from South Tunisia, being rather paler than the generality of these 

 birds, but I cannot say whether this difference is constant in a large series, 

 and in any case it is extremely slight. Herr v. Tsehusi has, however, 

 recently described a bird of this species from Tunisia as a new form under 

 the name of Apxis melba tuneti (Orn. Jahrb. sv. Heft 4, p. 123). 



The Alpine Swift occurs commonly in Tunisia as a regular summer 

 migrant, arriving together with the other species of Swifts, towards 

 the end of March, or the beginning of April, and leaving again on the 



