MACDOUGALL'S TERN. 649 



compressed, acute, that of the middle toe curved in a semi- 

 circle. 



Plumage close, blended, soft ; the feathers broad !"and 

 rounded. Wings very long, narrow, pointed ; primary quills 

 slightly incurved, the first longest ; secondaries short, broad, 

 incurved, rounded. Tail long, very deeply forked, the lateral 

 feathers attenuated, and extending about three inches beyond 

 the tips of the closed wings. 



Bill brownish-black, orange-red at the base. Iris brown. 

 Feet vermilion ; claws blackish-brown. Head above and 

 upper part of hind neck deep black, tinged with greenish- 

 blue ; hind neck and sides of the head white ; fore neck and 

 all the lower parts of a pale roseate hue ; upper parts pale 

 bluish-grey, hind part of back and tail lighter, almost pure 

 white ; the edge of the wings, the tips and inner edges of the 

 quills white, as are their shafts. The outer three primaries 

 greyish-black, with the inner margin white. 



Length to end of tail 15 inches ; extent of wings 29 ; 

 wing from flexure 9j ; tail 7^ ; bill along the ridge 1-j^, along 

 the edge of loAver mandible 2 ; tarsus -j^ ; middle toe -j^ ; its 

 claw -j^. 



Female. — Not distinguishable as to size or colour from 

 the male. 



Habits. — This very elegant and delicately tinted species 

 was first made known by Montagu, and discovered by Dr. 

 Macdougall of Glasgow, who accompanied the specimen sent 

 with a full description and remarks. It was obtained in July, 

 1812, on the Cumbrays, two small flat rocky islands in Mil- 

 ford Bay, in the Firth of Clyde, where it was intermixed in 

 very small proportion with the Common Tern. " The new 

 species," Dr. Macdougall states, " was discerned by the com- 

 parative shortness of wing, whiteness of plumage, and by the 

 elegance and comparative slowness of motion, sweeping along, 

 or resting in the air almost immovable, like some species of 

 the Hawk, and from the size being considerably less than 

 that of Sterna hirundo." Mr. Selby found it breeding in 

 considerable numbers on the Fern Islands. He states that 



