AVES. 533 



Opisthocomus cristatus. — The Hoatzin. Plate xxxvii**. fig. 7. White 

 abovo and black beneath ; head with a \u\ig somewhat pendulous crest ; a 

 naked rufous space round the eyes; wings with two paler bands; tail 

 wedge-shaped; with a fillet of yellow. Twenty- two inches long. Inhabits 

 Guiana. 



Genus 2.— BUCEROS.— iinn^Ms. 



Generic Character.— Bill large, long, convex ; curved from the base ; 

 edges serrated, with a large horny protuberance near the base of the upper 

 mandible rising into a crest; nostrils behind the base of the bill, covered by 

 a membrane; legs robust, short; lateral toes equal; the external one 

 united to the second joint ; first three quills graduated, the fourth or fifth 

 longest. 



Buceros 7nonoceros.— The Malabar Hornbill. Plate xxix. fig. 1. Black 

 above, extending to the bottom of thejugulum; breast and thighs white; 

 middle tail feathers black, external feathers white ; bill pale yellow ; horny 

 crest black in front and yellow behind. Two feet long. Inhabits Malabar. 



Genus 3.— PRIONITES.— /ffig-er. 



Generic Character.— Bill strong, hard, middle-sized, convex above, and 

 hooked towards its point, where it is compressed ; edges of the mandibles 

 serrated; nostrils lateral, oblique, situated at the base of the bill, open, but 

 partially covered by feathers ; toes lateral, unequal, the internal one being 

 very short, joined at its base; the external united to the second joint; wings 

 short ; the first three quills graduated, the fourth and fifth longest. 



Prionites ruficapillus. — The Red-Headed Saw-Bill. Plate xxvi*. fig. 6. 

 Head reddish-brown, back and wings brownish-green ; primaries and tail 

 verdigris-colour, greenish above; abdomen ferruginous; a black patch 

 around the eyes; bill horn-colour. Fourteen inches long. Inhabits Pa. 

 raguay. 



Genus ^.—CO'R.WS.—Linneeus. 



Generic Character.— Bill thick, straight at its base, slightly bent to- 

 wards the point ; nostrils concealed by reflected bristly feathers ; legs and 

 feet plaited ; feet with three toes before and one behind, divided, the tar- 

 sus longer than the middle toe ; wings pointed, the fourth quill being the 

 longest. 



Corvus coj'ax— The Raven. Plate xxviii. fig. 5. De^icribed, vol. iii. p. ISn. 



Corvus cornix.—The Hooded Crow. Plate xxviii. fig. 6. Described, vol. 

 iii. p. 155. 



Corvus monedula.— The Jack-Daw. Plate xxviii. fig. 7. Described, vol. 

 iii. p. 157. 



Gemts 5.—G AnRUl.VS.— Vieillot. 



Generic Character. — Bill of medium size, robust, edges thin and cutting, 

 beset with setaceous feathers at its base, pointing outwards ; upper mandi- 

 ble hollow, and curved towards the point : nostrils hid by basal feathers ; 

 tarsus annulated : middle toes attached from the base of the exterior, but 

 completely separated from the interior toe ; wings of medium length ; bas- 

 tard feathers short, rounded at their extremities ; the three first remiges 



