626 



SYLOCHELIDON CASPIA. THE CASPIAN 

 STRONG-BILLED-TERN. 



Sterna caspia. Lath. Ind. Ornith. LI. 803. 



Ilirondelle-de-mer Tchegrava. Sterna caspia. Tcmm. Man. d'Ornith. 



II. 733. 

 Caspian Tern. Sterna caspia. Solby, Illustr. Brit. Ornith. 463. 

 Sterna caspia. Jen. Brit. Vert. Aiiim. 264. 

 Sylochelidon oaspia. Bonap. Comp. List, 62. 



Bill vermilion ; tarsus an inch and tico-thirds long ; feet 

 black; tail short, forked. In winter, the forehead and -part 

 of the croivn white, the hind part of the head black. In 

 summer, all the upper and hind parts of the head black. 

 Plumage white; back and icing -coverts bluish ■ grey ; tail of a 

 paler tint ; quills greijish-broum. 



Several specimens of this, the largest European species 

 of its family, have of late years been obtained in England. 

 1 have not seen any of them, however, and am therefore 

 obliged to describe it from foreign sources. 



Adult in Si'mmrr. — Bill rather longer than the head, 

 stout, compressed, tapering, pointed. Feet rather small ; 

 the tibia bare for nearly an inch ; the tarsus little com- 

 pressed ; the interdigital membranes with the margin con- 

 cave ; the claws rather long, arcuate, compressed, acute. 

 The plumage soft and mostly blended ; the wings very long, 

 extending far beyond the forked tail, which is of moderate 

 length. 



Bill vermilion, the tip paler. Feet black. All the upper 

 part of the head and the nape deep black ; sides of the head, 

 neck all round, and all the lower parts pure white. Back, 



