LARID^, TEENS. GEN. 289-92. 319 



apparently just about that of the gulls. Some twenty "genera" have been imposed 

 upon the terns — three-quarters of these are of no account whatever. 



N. B. Understand ivhite, the pileum blacJe, the quills silvered-dusky with long 

 white stripe, unless the descriptions state otherwise. 



289-92. Genus STERNA Linnaeus. 



* Bill remarkably short, stout and obtuse, hardly or not half as long again as 

 the tarsus. {Gelochelidon.) 

 A'fp^ Gull-billed, ov Marsh Tern. Bill and feet black; mantle pearly grayish- 

 blue, this color extending on the rump and tail ; primaries with the white 

 striioe restricted to their base, their shafts white. Length 13-15 ; extent 

 about 34 ; wing 10-12 ; tail 4, forked only 2 or less, the lateral feathers little 

 narrowed ; tarsi l-li- ; bill 1^. Eastern United States ; apparently not 

 abundant in this country. Europe, etc. S. aranea Wils., viii, 143, pi. 72, 

 f. 6 ; Lawk, in Bd., 859 ; S. anglica Nutt., ii, 269 ; Aud., vii, 81, pi. 430 ; 

 Geloclielidon anglica Coues, Proc. Phila. Acad. 1862, 536. . . anglica. 



** Bill of an ordinary sternine character. 



t Occiput slightly crested. Feet black. Size large. {Thalasseus.) 



X~(o f Caspian Tern. Bill red. Mantle pearly grayish-blue; cap extending 

 below the eyes, but the imder eyelid white ; i^rimaries ivitliout any white 

 band. In winter, black of the cap chiefly restricted to the occiput ; j'oung, 

 with the bill dusky and yellowish, the Imck, wings and tail patched with 

 brown or blackish. Much the largest of the terns ; length 20 or more ; 

 wing 15-17 ; tail 5-6, moderately forked, without narrowed feathers ; bill 

 2^-2|, very stout, f or more deep at base, J wide opposite nostrils ; tarsus 

 If-lf ; middle toe and claw rather less. Arctic America and Europe, S. 

 in winter to the Middle States ; apparently not abundant in this country. 

 Lawr. Ann. Lye. N. Y., 1851, v, 37 ; Coues, /. c. 537 (var. imperator) , aud 



Proc. Essex Inst, v, 308 ; Elliot, pi. 56 caspia. 



D& '■ Royal Tern. Bill orange. INIantle pearly grayish-blue. In winter, bill 

 duller colored; cap mostly restricted to occii)ut : rump and tail shaded with 

 the color of the mantle. Youug, with the crown much like that of the adults 

 iu winter; upper parts without bluish, or this only showing in patches, and 

 variously spotted with dusk}^ Scarcely sliorter than the last, owing to 

 length of tail, but much less bulky; length 18-20; wing 14-15; tail 6-8, 

 deeply forked, with narrowed lateral feathers ; tarsus about IJ, middle toe 

 and claw rather more than less ; bill 2J-2J (in the young sometimes only 

 2^)) J-| deep at base, the gonys about 1 long. Atlantic Coast, U. S., to 

 New York (iatcren-ce) , abundant southerly ; California? S. cayana'NvT:T., 

 ii, 268 ; Aud., vii, 76, pi. 429 ; S. regia Gambel, Proo. Phila. Acad. 1848, 

 128; Lawe. in Bd., 859; Thalasseus regitts Coues, /. c. 538. regia. 



^ t -^ Elegant Tern. Similar to the last ; mantle very pale ; under parts rosy- 

 tinted in high plumage. Smaller and somewhat differently proportioned ; 

 bill much slenderer ; tarsus obviously longer than middle toe and claw. 

 Length about 17 ; wing 12-13 ; tail 6-7 ; bill 2J, under J deep at base, the 

 gonys about IJ long; tarsus rather over 1; middle toe and claw under 1. 



