124 HAVELL S TERN. 



less robust, in having the bill a little longer and much more slender, its 

 height at the angle being ||, whereas in that species it is ^ ; in ha- 

 ving the tarsus shorter and much more slender, the feet yellow instead 

 of being black, the claws more slender, and the tail more deeply forked. 



The figure in the plate, which is that of an adult bird yet in its 

 winter plumage, has the lateral tail-feathers obliquely truncate, but 

 this was caused by accident, for these feathers in my other specimens 

 run to a narrow point. My specimens from the Texas are also in their 

 winter plumage. One of them is coloured as above ; but the other is 

 a young bird, which may here be described. 



The bill is somewhat shorter and more tinged with brown ; the 

 lower parts, the rump, the outer web of the lateral tail-feathers and the 

 sides of the neck are white ; the wings as in the adult, but the prima- 

 ries internally margined with white, and the secondaries tipped with 

 the same ; the upper part of the head, and the rest of the upper parts, 

 are light yellowish-brown, intermixed with greyish-blue, and there is 

 the same black band on the side of the head as in the adult. 



