346 AVES. 



light blue colour and a stony hardness, almost as large as its 

 head. It is blackj the lower part of the belly and the tip of the 

 tail, white. It lays its eggs on the ground. Its original habitat 

 is not exactly known. The trachea descends externally along 

 the right side to behind the sternum, where it inclines to the 

 left, and ascends to enter the thorax, through the fourchette. All 

 its rings are compressed. 



There is another species, which, instead of the tubercle on 

 the beak, has a red salient crest. The belly and tip of the tail 

 are chesnut colour. It is the true Mittu of Marcgrave; Ourax 

 niittu, Tern. Col. 153; Crax galeata, Lath.j Crax tomentosa^ Spix, 

 Ixiii.(l) 



Penelope, Merr. 



The Guans or Yacous(2) have a slenderer beak than the Hoccos; 

 the circumference of the eyes is naked, as well as the under part of 

 the throat, which is generally susceptible of being inflated. 



Several varieties of colour are found also among these birds, 

 between which it is very difficult to establish specific limits. 

 Those w^hich have a tuft are sometimes of various shades of 

 brown or bronze Penelope jacupema^ Mer. II, xij sometimes 

 spotted on the breast Penelope cristata, L., Edw. 13;(3) some- 

 times black, with the same spots, and more or less white on 

 the tuft and coverts of the wings Penelope leucolophos, Merr. 

 II, xii, or Pen. cumanensis, Gm.j Jacq. Beytr. pi. 10; Bajon, 

 Cay. J pi. 5, or Pen.jacutinga, Spix, pi. Ixx. Some of them are 

 intermediate between these two extremes, Pen. pipile, Jacq. 

 Beytr. pi. xi. 



The trachea, at least in the first, descends under the skin far 

 behind the posterior edge of the sternum, ascends, is again 

 flexed, and then continues its course towards the fourchette, 

 through which, as usual, it gains access to the lungs. A spe- 

 cies almost without crest. 



Pen. marail, Enl. 338, Vieill. Gal. 198, greenish-black, with 



(1) Add, Crax tuberosa, Sp. LXVII, a; Cr. uramutum. Id., LXII. N.B. The 

 Chacamely Buff. [Crax vociferans) founded on a vague indication of Hernandez, cap. 

 XLI, is not authentic. Sonnini even thinks it may be the Falco vulturinus. The 

 Caracara of Buff, and Dutertre is the Agami (Psophia). 



(2) Gouan and Yacou are the names of these birds in Guiana and Brazil. That 

 of Penehpe, given to them by Merrem, designated among the Greeks a species of 

 Duck, which, according to them, had saved the wife of Ulysses from drowning 

 when a child. 



(3) The P. jacuaza, jacucaca, jacupeba, jacubcmba, guttata, and arra man, of 

 Spix, LXVIII LXX V, closely approach the P. cristata, if they are not mere vari- 

 eties of it. The P. marail, Vieill, Gal., 198, corresponds most with the jacupeba. 



