AVES- 



LARID^. 



217 



Clupeilarus verreauxi, Bp. Compt. Rend, xliii. p. 770 (1856: Chile). 

 Lams vocifenis, Burm. La Plata Reis. II. p. 518 (1861 : Buenos Ayres: 



Montevideo) ; C. Burm. An. Mus. Nac. Buenos Aires, III. part X. p. 



248 (1888: Coast of Patagonia and Falkland Islands). 



Fig 



General description. 



Size. — Adult male (breeding). Total 

 length, about 23 inches. 



Wing, 16.5 inches. 



Tail, 7.1 inches. 



Tarsus, 2.4 inches. 



Culmen, 2.25 inches. 



The female is appreciably smaller than the 

 male. 



Color. — Adult male (breeding). General 

 color, white with a black or slaty black man- 

 tle and wings. 



Head : Entirely white. 



Neck: White. 



Back: Mantle and lower back slaty black, 

 coverts white. 



Wing: In general color like the mantle. Upper wing coverts slaty 

 black. The scapulars and all of the secondaries slaty black with broad 

 white tips, which together form a conspicuous alar bar. The primaries 

 are black, broadly tipped with white, and vary in decoration and amount 

 of white with the age of the individual as follows : Very mature birds 

 have the first primary white for about two inches apically, with only a 

 hair line of black next to the shaft. The second primary shows a white 

 mirror, siibapically, which is most extensive on the inner web. Ordinary 

 adults have the white apical region of the first primary modified to a sub- 

 apical mirror; the second primary being decorated as in older birds. 

 Still younger adult birds have only the first primary decorated luith a 

 white mirror, the second primary being black with a broad white tip like the 

 third. In all of these phases, the third primary is black with a broad white 

 tip. The fourth primary begins to show a greyish or white "wedge" on 

 the inner web. This increases in extent until on the seventh primary it 



Lams dominicanus. Adult. Pro- 

 file of head. Bill from above. 

 From specimens procured by the 

 Princeton Expeditions. About ^ 

 natural size. 



Rump and upper tail 



