308 , BIRDS. PALMIPEDES. 



Gen. 1. CEREOPSIS, Lath. 



Bill very short, strong, almost as deep at the base as long, co- 

 vered by a cere prolonged towards the point, which is arch- 

 ed and truncated ; nostrils very large, in the middle of the 

 bill, open ; tarsus longer than the middle toe ; hind toe long, 

 jointed on the posterior part of the tarsus ; toes palmated, 

 with deeply notched membranes ; claws thick and strong ; 

 wing-coverts almost as long as the wings. 



C. Novce Hollandice, Tern. Plumage ashy-gray ; brownish above, 

 with some of the wing-coverts spotted with black. 39 inches 

 long. Inhabits New Holland. Shaw, xii. pi. 44. 



Gen. 2. CHIONIS, Forst. Vaginalis, Lath. 



Bill strong, hard, conico-convex, compressed, inclined towards 

 the point ; base of the upper mandible half covered by a 

 moveable corneous sheath, with longitudinal furrows; nos- 

 trils marginal, in the middle of the bill, on the border of the 

 corneous substance ; naked part of the tibise small ; toes with 

 a rudimentary border ; the middle and exterior ones semipal- 

 mated, the anterior united only at the base; wings tuberculated. 



C. Forsteri, Tern. Sheath-bill. Plumage snowy white ; knob at 

 the head of the wings blackish ; bill black at the base, the ap- 

 pendage or sheath yellowish ; papillae on the face orange. 15 to 

 18 inches long. Inhabits New Zealand Shaw, xii. 281. 



Gen. 3. RHYNCHOPS, Lin. 



Bill long, straight, flattened into a blade, truncated at the apex ; 

 upper mandible much shorter than the under ; nostrils late- 

 ral, marginal, remote from the base ; legs slender ; tarsus 

 longer than the middle toe ; the fore toes united by a mem- 

 brane ; hind toe jointed on the tarsus ; tail forked, and short- 

 er than the wings. 



R. nigra, Lin. Black Skimmer or Cut- water. Blackish above ; 



white beneath ; wings with a transverse white band ; legs red. 



18 to 20 inches long. Asia and America Shaw, xiii. pi. 16. 



This bird is ever on the wing, sweeping the surface of the water, and dipping in 

 its bill, or at least the under mandible, to scoop out the smaller fishes on which 

 it feeds. In stormy -weather it frequents the shores, and subsists on shell-fish. 



R. flavirostris, Vieill. Body above ashy brown, beneath white ; 

 bill yellow ; legs brown. Inhabits Senegal. Shaw, xiii. 138. 



Gen. 4. STERNA, Lin. 



Bill as long as, or longer than the head, almost straight, com- 

 pressed, slender, edged, and pointed ; mandibles of equal 

 length, the upper slightly sloping towards the tip ; nostrils 

 in the middle of the bill, longitudinally cleft, and pervious ; 



