riCATHARTES GYMNOCEPHALUS 159 



altitude where the nesting place is, they commence to con 

 struct or repair their nest, which is placed in a fissure in 

 the rocks or in a cave, or else amongst ruins and huildings 

 where the.y are not likely to he interfered with. The exterior 

 portion of the nest, which is a large and bulky structure, is 

 composed of twigs, grasses and roots, worked together and 

 intermixed with lichens and mosses ; and the inside lining 

 is composed of leaves, hair and fine roots. The eggs, from 

 four to five in number, are incubated by both male and female 

 in turn, the term of incubation being about eighteen or nine- 

 teen days. The eggs are creamy white, or with a greenish 

 tinge, with underlying faint purplish marking and surface 

 spots and blotches of brown, and measure about I'A X 1"0. 



Genus IV. PYCATHARTES. 



Head naked ; bill grey or blackish, culraen about the length of the 

 head or middle toe with claw ; nostrils rounded and opening at the end of 

 a groove half-way between tlie forehead and tip of bill. Wing short and 

 somewhat rounded ; primaries 5, G and 7, the longest. Tail long and 

 rounded, generally longer than the wing. Tarsi and feet greyish, the 

 former rather long, much longer than the culmen. 



Type. 



Picathartes, Less. Man. Orn. 1828, p. 374 .... P. rjumnocephalus. 



The genus is confined to "West Africa and comprises two species, and 

 these are, apparently, restricted to the highland forests. 



Picathartes gymnocephalus. 



Corvus gymnocephalus, Temm. PI. Col. p. 55, pi. 327 (1825). 



Picathartes gymnocephalus, Ussher, Ibis, 1874, p. 67, pi. 2 Denhera ; 

 Sharpe, Cat. B. M. iii. p. 141 (1877) ; Shelley, B. Afr. I. No. 042 

 (189C) ; Eeichen. Yog. Afr. ii. p. 644, pi. 11, fig. 2 (1903). 



Achdt. Head bare and bright yellow, with a roundish black patch on 

 each side of back of head ; back, wings and tail slaty grey, with the quills 

 browner ; chin bare and bright yellow ; neck and under parts covered with 

 silky white feathers. Iris dark brown ; bill and legs slate colour. Total 



