FALCO .ESALON 143 



a certain amount of variation in colour and size Ijetween individuals, 

 but the differences are comparatively slight, and apparently not 

 constant. Brehni's Falco gracilis (Naum. 1856, p. 1'28'2), moreover, 

 does not appear to be a good species, and von Heuglin, alluding to 

 the type specimen which was obtained on the Blue Nile, and is 

 preserved in the Berhn Museum, says it is a typical example of 

 Falco suhhiitco. 



FALCO iESALON, Tunstall. 

 MERLIN. 



Falco aesalon, Tunstall, Oni. Brit. p. 1 (1771); Malherbe, Cat. Rais. 



il'Ois. Al,/. p. 6. (1846). 

 Falco regulus. Sharpe, Cat. Birds Brit. Mits. i, p. 406. 

 iEsalon lithofalco, Locke, E.rpl. Sci. Ahj. Ois. i, p. 63 (1867). 



Description. — Adult male, spring, from Djerba, South Tunisia. 



Forehead whitish ; crown slate-colour, striated with black ; nape and 

 mantle rufous, striated with black; rest of upper plumage bluish-slate, 

 slightly striated with black, and becoming blackish on the quills ; tail with 

 a broad subterminal bar, and five indistinct minor bars ; cbin white ; rest 

 of the underparts white, tinged with rufous, and striped with dark brown ; 

 thighs and crissum rufous. 



Iris brown; bill slate, darker at tip; cere, bare skin round the eyes, 

 and feet yellow. 



Total length 11 inches, wing 8, culmen 0-70, tarsus 1-40. 



Adult female, spring, from Tunis, North Tunisia. 



Forehead whitish ; crown brown, striped with black ; nape whitish, 

 tinged with rufous and striped wiiii brown ; rest of the upper-plumage 

 brown, spotted with pale rufous; tail with six buff-coloured bars; chin 

 white ; rest of underparts white, heavily striped with brown ; thighs and 

 crissum buff. Soft parts as in the male. 



Total length 12 inches, wing 8-50, culmeu 0-75, tarsus 1-50. 



This small Falcon, although nowhere common in the country, is 

 to be met with in Tunisia in the winter months, and during the 

 periods of migration. It is probably more often to be seen in the 

 northern districts of the Kegency, but it also occurs in the south, and 

 I have an example of it, which was obtained on the Island of Djerba. 

 Loche (Expl. Scient. Alg. Ois. i, p. 6.5) says it is resident in Algeria, 



