ON OPISTHOCOMUS CRIST ATUS. 173 



feet have no spurs. There is an atrophied nail on the top 

 of the thumb and finger. 



The length of the bird is about twenty four inches , in- 

 cluding the long tail, which is half this length. The bill, 

 dark brown , is broad , short and conical , with the tip of 

 the upper maxilla slightly bent, and with black hairs at 

 the base : the nostrils are round. The eyes , brick-red , have 

 black eye-lashes; the skin round them and on the neck 

 is light blue , and immediately round the eye and on the 

 sides of the head it is almost naked having only black 

 hairs and small feathers here and there. The head is crest- 

 ed with Ions narrow stififish feathers that have a fawn 

 coloured base and black tip. The front of neck and top 

 of chest is fawn coloured: the back of neck and back is 

 greenish brown , the feathers on the back of neck having 

 a fawn coloured centre , and those on the back a fawn co- 

 loured margin. The wings are rounded , the primaries are 

 nut-brown with a grey tip; the secondaries, tertiaries and 

 wing-covers are greenish brown, the latter having fawn 

 coloured tips, those on the thumb having their outer 

 half fawn colour. The tail is greenish brown , tipped with 

 fawn ; the centre feathers being the longest. The rump , 

 thighs and sides of body are a nut-brown. The feet are 

 the same colour as the bill and have long toes and claws. 



The voice is only a hiss. 



The female is slightly duller in colour than the male. 



There is every probability that these birds ruminate. 



I have mentioned nothing about the circulation as I 

 have not yet worked it out to my satisfaction. 



New Amsterdam, Berbice, British Guyana. 



Notes from tbie Leyden Museum, Vol. X. 



