90 ALLIED TERN. 



between thirty-six and forty-four grains. There are two 

 principal varieties with I'espect to colour. A. — White 

 or greenish white, with coarse spots, sometimes 

 scattered, sometimes arranged in groups. The centre 

 of each spot is violet grey or blackish grey, which 

 colour passes into a beautiful chesnut brown and 

 dark brown towards the periphery; the edges are 

 generally burnt brown. These eggs resemble those of 

 Cephus grylle, (the Black Guillemot.) B. — Yellowish, 

 sometimes with a reddish shade, dotted and striolated; 

 the darkest points, dots, and streaks are black brown 

 or brownish red; the margin of the spots 'shining 

 brown or red. In one specimen bluish grey spots 

 form a zone round the base, with many flourishes. 

 All the eggs, held against the light, are transparent 

 yellowish green. Some of the eggs much resemble 

 those of the Sandwich Tern, ^^S'. cantiaca,) but they 

 are all distinguished by the more variegated colouration, 

 the smaller size, and the different structure, characterized 

 by shallow serrated pores, and by finely-granulated 

 rounded tubercles, which render some parts of the 

 shell rather rough." 



Male and female in breeding plumage have the 

 forehead, vertex, and occiput of a deep black; nape 

 silvery white; top of the body bluish ash, like the 

 Sandwich Tern; lower part of the body, front and 

 sides of the neck, and cheeks of a silvery white; wing 

 coverts like the back; primaries of a velvety ash, 

 bordered on their inner webs with white; tail bluish 

 ash, darker than the wing coverts, with the most lateral 

 quill on each side of a velvety ash; beak yellow; feet 

 black. — (Degland.) 



Male and female in winter. — Forehead and half of 

 vertex anteriorly white; the other half and the occiput 



