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Genus VI.— PHAETON, Linn. TROPIC BIRD. 



Bill as long as the head, stout, very much compressed, slightly curved, 

 tapering, acute, opening to beneath the eye; upper mandible with the dorsal 

 line slightly arched, the ridge narrow, rounded, the sides sloping and slightly 

 convex at the base, nearly erect towards the end, the edges sharp, direct, 

 irregularly broken, the tip acuminate; nasal groove short, near the ridge; 

 lower mandible with the angle long, and extremely narrow, the dorsal line 

 straight and ascending, the sides erect and slightly convex, the tip acuminate. 

 Nostrils basal, linear, very small. Head rather large, ovate; neck short and 

 thick; body rather full. Feet very short; tibia bare for a considerable 

 space; tarsus extremely short, roundish, covered with small round scales; 

 toes rather small, placed in the same plane, and connected by reticulated 

 webs; first very small, third a little longer than fourth, all scutellate above. 

 Claws small, arched, compressed, rather sharp, that of the third toe with a 

 thin entire inner edge. Plumage soft, blended, on the back rather compact. 

 Wings long, acute, the first quill longest. Tail of twelve feathers, tapering, 

 the two middle feathers extremely elongated, narrow, and tapering. This 

 genus appears to be intermediate between Sula and Sterna. 



