80 PLOCEID^ AMBLYOSPIZA 



frequently build in a tree that is already occupied by the nest of an 

 eagle or vulture, possibly because the proximity of their powerful 

 neighbours affords them protection against the attacks of monkeys 

 and snakes. Generally from four to seven pairs of the Buffalo 

 Weaver Bird unite to build a common nest of closely interwoven 

 sticks and thorny twigs, oval openings being left here and there 

 which are afterwards lined with dry grass and used both as nesting 

 and roosting places. The collective nest, which measures three or 

 four feet across, is repaired and added to from time to time and 

 often lasts for many years. As many as six of the larger nests may 

 be sometimes seen in a single tree, each inhabited by as many pairs 

 of birds. The eggs, laid on the Limpopo in December, are three 

 or four in number, greyish-white streaked and marbled with several 

 shades of grey and brown. They measure about 112 X 0-90. 



Genus VI. AMBLYOSPIZA. 



Type. 

 Amblyospiza, Sundev. (Efvers, 1850, p. 98 A. albifrons. 



Bill very massive and deep, cone-shaped ; the culmen flattened 

 at the base, arched, ridged, with a narrow but deep groove on 

 each side near the base, extending backwards on the forehead 

 beyond the middle of the eye ; nostrils basal, lateral and rounded, 

 partly concealed by frontal plumes. Wings moderate, rounded, 

 the first quill small, the fourth and fifth longest. Tail graduated. 

 Tarsi robust, strongly scutellated anteriorly ; toes long and strong, 

 the outer two about equal, the hinder longer ; claws long and 

 curved. 



This genus contains five species of African Weaver Birds ; one 

 only occurs in Eastern South Africa and ranges into Nyasaland. 



40. Amblyospiza albifrons. Thick-billed Weaver Bird. 



Pyrrhula albifrons, Vigors, P. Z. 8., 1831, p. 92. 



Pyrenestes frontalis, Smith, III. Zool. S. Afr. 1840, pis. 61, 62; 



Layard, B. S. Afr. p. 191 (1867). 

 Amblyospiza albifrons, Sundev. OEfv. K. Vet.-Ak Forh. Stockholm, 



1850, p. 98 ; Sharpe, ed. Layard s B. S. Afr. pp. 449, 848 (1884) ; 



id. Cat. B. M. xiii, p. 501 (1890) ; Shelley B. Afr. i, p. 33 (1896). 



Description. Adult male in summer. Above, crown and back 

 chocolate-brown, the rump and upper tail-coverts blacker, most 



