28 CYPSELID^ TACHOKNIS 



are found clustered together. It also sometimes (like C. caffer) 

 lays its eggs in deserted swallow's nests. The eggs, generally 

 three in number, are white, not glossy, long ovals, measuring 

 0-87 X 0-57." 



Genus II. TACHORNIS. 



Tachornis, Gosse, B. Jamaica, p. 58, pi. 9 (1847) ...T. phoenicobia. 



The birds of this genus differ from the true Swifts in having the 

 toes in pairs, although still all pointing forwards, the first and 

 second form an inner pair, the third and fourth an outer ; toes 

 unfeathered, size small. The nests are always attached to the 



Fig. 15. — Foot of Tachornis parva. x t- 



leaves of palms or, where palms are used for thatching, to the roofs 

 of such huts. The genus is spread over Africa, southern Asia as 

 far as Java and China, and the West India Islands. One species, 

 with a race recognised as a sub-species, is found in Africa and 

 described below. 



390. Tachornis parva. Palm Sivift. 



Cypselus parvus, Licht. Verz. Doubl. p. 58 (1823) ; P. L. Sclater, P. Z. S. 



1865, p. 601 ; Gurney in Andersson's B. Damaraland, p. 48 (1872) ; 



Sliarpe, ed. Laijard's B. S. Afr. p. 94 (1875). 

 Cypselus ambrosiacus, Temm. PI. Col. 460, fig. 2 (1828). 

 Tachornis parva, Hartert, Cat. B. M. xvi, p. 463 (1892) ; Shelley, B. 



Afr. i, p. 107 (1896) ; Hartert, Tierreich, Podarg. p. 81 (1897) ; 



Alexa7idcr, Ibis, 1900, p. 93 [Zambesi Eiver]. 



Description. Adult. — Above and below, mouse-coloured, slightly 

 darker on the wings and tail, which have traces of greenish-metallic 

 gloss ; chin and throat paler than the rest of the under parts with 

 darker shaft lines; tail much forked, the outer rectrices considerably 

 produced and attenuated. 



Iris dark brown ; bill black ; legs and feet brown. 



Length about 7'0 ; wing 5'30 ; tail, central feathers 1"50, lateral 

 feathers 3-80; culmen 0-20 ; tarsus 0-40. 



In the young bird the throat is uniform and all the feathers 

 especially those of the upper surface have rusty edges. 



