32 
ALLENS NATURALIST'S LIBRARY. 
Egg'S. — Ground-colour varying from whiti.sh stone-colour to 
clay-brown, the markings being reddish-brown or black, and 
varying in character from small spots, streaks, and lines or 
scratches, to larger spots or small blotches;, never confluent, 
and equally distributed over the surface of the egg ; the under- 
lying spots of purplish-grey distinctly indicated, but seldom 
equalling the overlying markings in prominence. Axis, i’7S- 
1-95 inch ; diam. 1-25-1 -35. 
VI. THE SOOTY TERN. STERNA EULIGINOSA. 
Sterna fultginosa, Gm. Syst. Nat. i. p. 605 (17S8); Dresser, 
13. Eur. viii. p. 307, pi. 587 (1S77) ; B. O. U. List Brit. B. 
p. 183 (1883); Saunders, ed. Yarrell’s Brit. B. iii. p. 562 
(1884) ; Seebohm, Hist. Brit. B. iii. p. 292 (1885) ; 
Saunders, Man. Brit. B. p. 637 (1889) ; id. Cat. B. Brit. 
Mus. XXV. p. 106 (1896). 
Adult Male. — Similar to S. anmstheta, but more uniformly 
sooty-black above, the light mantle not being emphasized, and 
thus the black crown is scarcely darker than the remainder of 
the upper surface ; the quills blackish, with a dark ashy 
“wedge ”011 the inner web of the primaries, not white as in 
A. anmstheta ; “bill and feet black, with a slightly reddish tinge ” 
{Saunders). Total length, 14-5 inches; culmen, 1-65; wing, 
ii'o; tail, 5'8; tarsus, 0-85. 
Adidt Female. — Similar to the male. Total length, 15-5 inches; 
wing, ir-6. 
Adult in ■yiTiuter Plumage. — Only distinguishable from the 
summer plumage by having white flecks on the lores and 
crown {Saunders). 
Nestling. — Mottled above with dusky-blackish and sandy- 
buff, intermixed with a good deal of white on the back and 
rump ; under surface of body whitish, the cheeks and sides of 
the face like the back. As the young bird increases in size, 
the down is replaced by blackish feathers which have sandy- 
rufous or white tips, those on the scapular-plumes being con- 
spicuously white. The under surface of the body is white, 
but the sides of the face are like the crown and are similarly 
mottled. 
