MOLOTHRUS. — CHRYSOMUS. 565 



According to Beebe (Our Search for a Wilderness, p. 125), 

 "most o£ the Cassiques feed usually in flocks, sometimes of great 

 size. In the deep bush of the interior it is the habit of birds of 

 many species to search together for food following a set route, 

 and keeping closely to their time schedule." 



Genus CHRYSOMUS Swains. 



Chrysomus Swainson, Classif. B. ii. p. 274, 1837. Type C ictero- 

 cephalui (Linn.). 



Fig. 205. — Chrysomus icterobepltalus. 



This, genus is distinguished by the peculiar shape of the bill, 

 which is sharply pointed and compfessed, and the sides of the lower 

 mandible involute ; its width at the base is about equal to half the 

 length of the exposed culmen. The wing is rounded, the second, 

 third, and fourth primaries longest and equal, and the first inter- 

 mediate in dength between the fourth and fifth. The tail is 

 slightly rounded at the tip and about three-fourths the length of 

 the wing. The tarsus exceeds the length of the exposed culmen 

 by about one-third. Coloration : male and female different. 



704. Chrysomus ioterooephalus. 



Yellow-headed Marsh-bibd. 



Oriolvs icterocephalus Linn. Syst. Nat. i. p. 163, 1766 (Cayana). 

 Chrysomus icterocephalus Cab. in Schom.b. Eeis. Guain. iii. p. 681, 



1848. 

 Agelaus icterocephalus Selater, Cat. B. Brit. Mus. xi. p. 345, 1885 



(Georgetown). 

 Xanthosomus icterocephala Lloyd Price, Timehri (2) v. pp. 64, 65, 1891 



(nesting habits ; Quelch, t. c. p. 87 (Georgetown). 

 Agelaius icterocephalus Beebe, Our Search for a Wilderness, p. 351, 



1910 ; Brabourne & Chubb, B. S. Amer. i. p. 436, no. 4484, 1912. 



Adult male. Crown of head, sides of face, throat, and neck all 



