254 



white, buffy ochreous, or dark buff blotched and spotted with various shades of brown, black, 

 and violet-grey. 



Sterna hirundo, the type of the genus, has the bill about as long as the head, nearly 

 straight, slender, compressed, tapering to the point, which is elongated and acute, the ridge of 

 the upper mandible gradually curved, and the lower mandible with the junction of the crura 

 median, scarcely prominent ; nostrils large, elongated, linear, basal ; wings very long, pointed, 

 the first quill longest ; tail deeply forked ; legs short, slender, the tibia bare for some distance ; 

 tarsus scutellate ; hind toe small, elevated ; anterior toes small, joined by emarginate webs ; claws 

 compressed, acute, curved, that on the middle toe larger than the rest, and having the inner 

 edge slightly dilated. 



