24 



Genus III.— AGELAIUS, Swains. MARSH-BLACKBIRD. 



Bill shorter than the head, stout, straight, conical, tapering to an acute 

 point; upper mandible with the dorsal line straight, slightly convex at the 

 base, the ridge flattened toward the base, where it forms a short tapering 

 process on the forehead, the sides rounded, the edges inflected, the tip a little 

 depressed; lower mandible with the angle short and wide, the sides convex 

 at the base, toward the end rounded, the edges involute, the tip acute; the 

 gap-line ascending at the base, afterwards direct. Nostrils basal, oval, with 

 a small operculum. Head ovate, of moderate size; neck short; body mode- 

 rately stout. Feet of ordinary length, rather stout; tarsus compressed, with 

 seven anterior scutella; toes rather large, the first much stronger, the outer a 

 little shorter than the inner, and adherent at the base. Claws long, little 

 arched, compressed, laterally grooved, very acute. Plumage soft and blended, 

 glossy in the males. Wings of moderate length, with the outer four quills 

 nearly equal. Tail rather long, rounded. Roof of the upper mandible with 

 three longitudinal ridges; tongue tapering to a horny, flattened, slightly 

 emarginate tip; oesophagus wide, considerably dilated about the middle; 

 stomach roundish, muscular; intestine short and of moderate width; coeca 

 very small, cloaca oblong. 



YELLOW-HEADED TROOPIAL. 



•f Ageeaius xanthocephalus, Bonap. 



PLATE CCXIII.— Male, Female, and Young. 



This species was first made known as an inhabitant of North America 

 by the naturalists of Major Long's expedition to the Rocky Mountains. 

 According to Dr. Richardson, "the species ranges in summer to about the 

 fifty-eighth parallel," but has not been found to the eastward of the Missis- 



