622 STERNIN^. 



colours. The females are coloured like the males, but the 

 young are mottled with brown. 



These birds are remarkable for their very buoyant, 

 bounding, and gliding flight. They feed on small fishes 

 and Crustacea, seeking their food chiefly along the shores of 

 the ocean ; some, however, subsist on insects, which they 

 obtain on fresh water. They nestle on the ground, some- 

 times in bushes, laying from two to four spotted eggs. The 

 young, covered with down, soon walk, but generally remain 

 about their birthplace until able to fly. 



The genera are Rhynchops, Megalopterus, Sylochelidon, 

 Gelochelidon, Sterna, Hydrochelidon, and some others not 

 well defined. 



SYNOPSIS OF TEE BRITISH GENERA AND SPECIES. 



GENUS I. SYLOCHELIDON. STRONG-BILLED-TERN. 



Bill nearly straight, compressed, tapering, stout, with 

 the edges sharp, and the tip elongated and pointed ; the 

 upper mandible with its outline gently arcuate, the lower 

 with the junction of the crura beyond the middle and 

 slightly prominent ; legs short, slender ; anterior toes small ; 

 wings very long and acuminate ; tail forked. 



1. Sylochelidon Caspia. Caspian Strong-hilled Tern. 

 Tarsus an inch and two-thirds long ; bill vermilion ; feet 

 black; tail short. 



GENUS II. STERNA. TERN. 



Bill about the length of the head, nearly straight, slender, 

 compressed, tapering, with the edges sharp, and the tip 

 elongated and pointed ; the upper mandible Avith its outline 

 gently arcuate, the lower with the junction of the crura 

 medial, scarcely prominent ; legs very short, slender ; anterior 

 toes small, their membranes eraarginate ; wings very long 

 and acuminate ; tail forked. 



