174 BULLETIN 15 5, UNITED STATES NATIONAL MUSEUM 



at present known. The two adult males taken have the wing 296 

 and 300 mm. respectively, and the female has the wing 299 mm. 

 Measurements of birds examined from the Antilles indicate vaguely 

 two groups of individuals, one with the wing ranging from 293 to 

 305 mm. and the other from 312 to 331 mm. There is however no 

 definite break between the two so that there is no clear support of 

 the contention that there is a North American continental race dis- 

 tinguished by larger size, particularly since some of the large birds 

 from the West Indies and Bahamas are taken at dates when migrants 

 should have retreated north to their nesting grounds. The matter 

 is discussed by Dwight 60 and Wetmore 61 who agree that the present 

 evidence does not substantiate claim for two forms. The question 

 can be settled only with adequate series of breeding birds from the 

 Bahamas and West Indies. 



In breeding dress the laughing gull has the entire head except 

 for the white ej^elids dark sooty gray, the back gray, the ends of the 

 wings black and the rest of the plumage white. In winter dress 

 the head is more or less mottled with white, the white being ex- 

 tensive in birds of the year. It can be confused only with the royal 

 tern from which it differs always in smaller bill which is dull reddish 

 in life, and the extensive black in the wing. 



Subfamily Sterninae 



GELOCHELIDON NILOTICA ARANEA (Wilson) 



GUIL-BILIED TERN 



Sterna aranea Wilson, Amer. Ornith., vol. 8, 1814, p. 143, pi. 72, fig. 6 (Cape 

 May, New Jersey). 



Oelochelidon nilotica aranea, Danforth, Auk, 1929, p. 365 (recorded). 



Migrant ; status uncertain. 



The only records for the gull-billed tern are those of a pair taken 

 by Abbott near Fond Parisien on the Etang Saumatre May 5, 1920, 

 and of birds recorded by Danforth, who found four at Etang Mira- 

 goane July 22, twenty-five at Les Salines July 30, five at Monte 

 Cristi August 5 (where one was taken), and four at Stroites, Gonave 

 Island July 17, 1927 (reported by Emlen). The species is known to 

 breed on Cuba and some of the Bahama Islands. The birds noted 

 on Hispaniola may have been in migration to some other point of 

 there may be a breeding colony about the salt lakes in the Cul-de-Sac 

 region. 



60 Bull. Amer. Mus. Nat. Hist., vol. 52, Dec. 31, 1925, pp. 266-267. 



61 New York Acad. Sci., Scient. Surv. Porto Rico and Virgin Islands, vol. 9, 1927, pp, 

 378-379. 



