228 DR. GAMBEL ON THE BIRDS OF CALIFORNIA, 



THALLASEUS, Boie. 

 175. T. REGIUS, Gamb. 



Sternia regia, Gamb. Proceed. Acad. Nat. Sci., vol. iv. p. 128. 



S. cayana, Aud. PI. 273, Orn. Biog. vol. iii. pi. 505 ; Bonap. ; Giraud, Bd.s. 



Long Island, p. 355 ; 5. cmjana, Lath.? 

 S. erythrorhynchos, De Weid. Bey. Zur. Natur. Brazil? 



Adult male.— Length, 19 inches : extent of wings, 3 ft. 9 in.: length of wing, 15 in. : outer tail feathers, 

 Ih. in. : tarsus, 1 inch and 2-lOths, black: bill bright red, along the ridge 2^ in. : from corner of the 

 mouth, 3i in. : from symphysis to point, beneath, 1 inch : depth at commencement of feathers, 7-lOths 

 inch. 



This noble species, so abundant on our southern coast, has for a lono- time been 

 considered the S. cnyana of Latham, notwithstanding its disparity with his 

 description both in size and colouration. It seems to me that the Cayenne Tern 

 must have been founded upon the immature plumage of one of the yellow-billed 

 species of the Brazilian coast, since described by Lichenstein, probably the 

 S. magjiirostris. 



Young birds of our species would agree pretty well with the erythrorhyncha of 

 Brazil, described by the Prince de Wied, as they are somewhat smaller and less 

 proportioned, yet we hesitate to give it that name, until its identity can positively be 

 proved, particularly as the Terns of that coast are peculiar. 



The representative of the o-egia in the old world, is the S. velox of Riippel, though 

 quite distinct. 



176. T. ELEGANs, Gamb. 



Sterna elegans, Gamb. Proceed. Acad. Nat. Sci. vol. iv. p. 129. 



Adult male.— With the general plumage of S. re^ia : length, 17 in. : of wing, 12^ in. : of outer tail 

 feathers, 6 and 8-lOths in. : tarsus, 1 and 1-lOth in.: middle toe and nail, 1 and 2.1-lOthsin. :bill bright 

 red, along the ridge 2 and 6-lOths in. : from corner of mouth, 3 and 3-lOths in. : from symphysis to 

 point beneath, 1^ in. : depth at commencement of feathers, 5-lOths in. 



This elegant species differs from the former not only in proportions, but in the 

 delicate Ime of the under parts, which are of a satiny cream colour when livino-, but 

 faded very much in the dried specimen. 



The bill is of the same colour as in the regia, and as long, but much more slender ; 

 the prominent angle beneath half an inch farther from the point, and the depth at 

 base two-tenths of an inch less. Wings two and a half inches shorter, but of the 

 same colour in every respect. Legs pure black, the tarsus nearly as long as in the 

 former, but the toes much shorter. Tail long, pure white and deeply forked, whole 



