AYES, 419 



with Trihonyx (p. 394\ yet they are distinguished by their long toes 

 from the two first-named genera, and from the last-named by their 

 tarsi beset with hexagonal horny scales. They have also the breast 

 by no means so compressed as in the Macrodactyli, but a powerful 

 form of body. They are large birds of South America, feeding on 

 herbs and the seeds of plants, and forming the transition to the 

 gallinaceous birds. 



a) With the reyion between the base of bill and the orbits unplumed. 

 Chmcna Illig., Gray, Opistolophus Vieill. 



Sp. Palamedea chavaria Temm., Parra Chavaria L., Temm. PI. color. •219, 

 GUER. Iconogr., Ois. PI. 5 7, fig. 3 ; this bird, called Cliauna from its note, 

 is tamed and left to walk with troops of hens and geese, which it pro- 

 tects. — Parra Derhiana, Chauna Dcrbiana Gray, Gen. of Birds, CLXi. ; 

 Columbia. Both species have a tuft of long feathers at the back of the 

 head. 



b) With the region between the base of the bill and the orbits plumed. 



. Palamedea L., Illig., Gray. 



Sp. Palamedea cornuta L., Bdff. PI. cnl. 45, Less. Ornith. PI. 92, fig. i ; 

 in Brasil and Guiana ; this bird has a long and tliin horn on its head in 

 front, but no tuft of feathers. 



Order ITI. GalUmv (L.) s. Easores. 



Feet covered with feathers as far as tlie tarsal joint, tetradac- 

 tylous, more rarely tridactylous, with tarsi covered anteriorly mostly 

 by a double row of transverse scutes. Anterior toes almost always 

 united at the base by membrane; middle toe much longer tlian the 

 lateral (which are often subequal). Claws moderate, somewhat 

 blunt, grooved below. Bill moderate or short, with culmen convex 

 or gibbous; upper mandible with margin deflected, overlapping the 

 lower. Wings mostly short, rounded. Tail with mostly more than 

 twelve feathers. 



Gallinaceous birds. — The breast-bone is truncated in front, forms 

 a narrow bony band on each side of the keel, and is besides, in great 

 part, represented by membrane, with a forked bony piece at the 

 outer margin. T!]ie farcida does not reach the sternum, but is con- 

 nected to it by ligament only. The bones of the arm are short, 

 the upper arm-bone does not reach farther than the crest of the 

 ilium. The spinous processes of the dorsal vertebrse coalesce to 

 form a single lamina. The pelvis is broad and spacious. The crop 

 is large, and the muscular stomach very powerful. 



27—2 



