420 LAREDO 



About the end of May or early in June, 1859, an adult, in 

 nuptial plumage, was shot off Exmouth when associating 

 with a flock of Black-headed Gulls. The bird is preserved 

 in the Exeter Museum (Koss., Ann. & Mag. Nat. Hist., 

 1859, p. 467). 



DESCRIPTIVE CHARACTERS. 



PLUMAGE. Adult male nuptial. Head, jet-black ; small 

 white crescentic patch above the eye and another below ; 

 back and wings, darker ' pearl ' grey than in L. ridibundus ; 

 secondaries, broadly margined with white, forming a con- 

 spicuous wing-bar ; primaries, chiefly whitish, the first six 

 being barred with black; neck, breast, abdomen, and tail, 

 pure white. 



Adult female nuptial. Similar in plumage to the male. 



Adult winter, male and female. Resembles the nuptial 

 plumage, except that the head is streaked with brownish- 

 black. 



Immature, male and female. Head, sides of neck, back, 

 and wings, mottled 'with brown; primaries, brown; secon- 

 daries, brown, broadly edged with white, and bordered with 

 white along the outer webs ; tail, white, banded on its 

 terminal portion with blackish-brown. 



Nes tling . Greyish- white . 



BEAK. Deep yellowish-red at the angle, and banded 

 with black. 



FEET. Olive colour ; webs, orange. 



IKIDES. Very dark brown. 



EGGS. Yellowish-stone colour with large streaks and 

 blotches of brown and black : clutch, three. 



AVERAGE MEASUREMENTS. 



TOTAL LENGTH 26 in. Female smaller. 



WING ... 19 



BEAK 3'25 



TARSO-METATARSUS ... 3' 3 ,, 

 EGG ... ... 2-95 X 2 in. 



