BIRDS OF AMERICA. 



Genus III.— TACHYPETES, Vieill. FRIGATE-BIRD. 



Bill longer than the head, strong, hroader than high, unless towards the 

 curved extremity; upper mandible with its dorsal line slightly concave, at 

 the tip decurved, its ridge broad and nearly flat at the base, narrowed and 

 more convex towards the end, the sides separated from the ridge by a narrow 

 groove, convex, the edges sharp, direct, irregularly jagged, with a promi- 

 nence at the commencement of the curve at the elongated, compressed, 

 tapering, decurved point; lower mandible with the angle extremely long, 

 narrow, the membrane bare and dilatable into a small pouch, the very short 

 dorsal line decurved, the sides erect at the base, convex in the rest of their 

 extent, the edges sharp, much inflected, irregularly jagged, at the tip narrow 

 and decurved. Nostrils basal, linear, inconspicuous. Head of moderate size, 

 oblong; neck of moderate length, stout; body rather slender. Feet very 

 short, stout; tibia very short; tarsus extremely short, feathered; toes all 

 placed in the same plane, and connected by short deeply emarginate webs, 

 which run out narrow along the sides, scutellate above, first small, second 

 shorter than fourth, third much longer. Claws strong, compressed, curved, 

 acute, that of the third toe long, with the inner edge pectinate. Plumage 

 compact, glossy; feathers of the head, neck, and back, lanceolate. Wings 

 extremely long, pointed, the first quill longest; the rest rapidly diminishing; 

 secondaries very short, the inner long and tapering. Tail very long, deeply 

 forked, of twelve feathers. Tongue exceedingly small, fleshy, flattened; 

 oesophagus very wide; proventricular glands forming a complete belt; sto- 

 mach very small, roundish, its muscular coat thin, the inner soft and corru- 

 gated; no pyloric lobe; intestine of moderate length; coeca extremely small; 

 cloaca globular. 



Vol. VII. 2 



