THE HOATZINS. 2j9 



Sexes similar in plumage. 



An elongate crest of rather stiff-shafted feathers sides of 

 the head mostly naked. 



Tail composed of ten feathers, elongate and rounded ; the 

 middle pair considerably longer than the outer pair. 



First primary flight-feather much shorter than the second, 

 which is shorter than the tenth ; sixth to eighth longest. 



Fifth secondary quill present. 



Tarsus with reticulated scales, shorter than the middle toe 

 and claw. 



I. THE HOATZIN. OPISTHOCOMUS HOAZIN. 



Phasianus hoaziti^ Miill. S. N. Suppl. p. 125 (I'j'jG). 



Crested Pheasa7it^ Latham, Gen, Syn. ii. pt. ii. p. 720, pi. Ixlv. 



Phasianus cn'staiiis, Gmel. S. N. i. pt. ii. p. 741 (1788). 



Opisthoco?mis hoatzin^ Steph. in Shaw's Gen. Zool. xi. p. 193 

 (1819). 



Opisthocomiis cristaius^ L'Herminier, C. R. v. p. 433 (1837); 

 G. R. Gray, Gen. B. ii. p. 396, pi. xcvii. (1845); Huxley, 

 P. Z. S. 1867, pp. 435, 460, 1868, p. 304 [skeleton], fig. 4, 

 pi. xcviii. (1845) ; Cabanis, J. f. O. 1870, p. 318, pi. i. fig. 3 

 [egg]; Perrin, Trans. Z. S. ix. p. 353, pis. 63-66 (1875); 

 Garrod, P. Z. S. 1879, p. 109 [anatomy] ; Quelch, Ibis, 

 1890, p. 327 [habits]; Parker, Trans. Zool. Soc. xiii. pp. 

 43-86, pis. vii.-x. (1891); Gadow, P. R. Irish. Ac. (3) ii. 

 p. 147, pis. vii. viii. (1892). 



Opisthocomus hoazin, Ogilvie-Grant, Cat. B. Brit. AIus. xxii. 



p. 524(1893). 



{Plate XL.) 

 Adult Male and Temale. — General colour above dark brown 



glossed with olive ; fore part of the head reddish-brown ; long 



crest-feathers mostly dark brown ; feathers on the back of the 



neck and mantle similar, but the former with buff and the latter 



with white shaft-stripes ; the shoulder-feathers and wing-coverts 



either margined or tipped with white ; quills chestnut-brown ; 



s 2 



