MARSH GULL-BILLED TERN. 667 



inch ; tarsus short, anteriorly scutellate ; toes slender, the 

 first extremely small, the third longest, the fourth consider- 

 ably shorter ; interdigital membranes emarginate, the inner 

 more deeply ; claws little arched, compressed, very slender, 

 that of the middle toe much larger, and having its inner 

 edge thin and dilated. 



Plumage soft, blended. Wings very long, narrow, 

 pointed ; primary quills tapering to an obtuse point ; secon- 

 dary short, incurvate, obliquely rounded, the inner web pro- 

 jecting beyond the outer. Tail of moderate length, forked, 

 the lateral feathers tapering to a narrow, but obtuse point. 



Bill and feet black. Upper part of the head and part of 

 the hind-neck deep black ; sides of the head and a line mar- 

 gining the base of the upper mandible, fore-neck, and all the 

 lower parts white ; upper parts pale greyish-blue ; the tail 

 of a paler tint, its outer feathers nearly white ; primary 

 quills hoary on the outer web, deep grey on the inner, 

 lighter toward the base. 



Length to end of tail 14^ inches ; extent of wings 34 ; 

 wing from flexure 12 ; tail 5 ; bill along the ridge 1^, along 

 the edge of lower mandible 2^ ; tarsus 1^ ; middle toe -f^, 

 its claw -^. 



Female. — The female is similar to the male, and scarcely 

 differs in size. 



Habits. — This species, which was first distinguished and 

 characterized by Montagu, from specimens obtained on the 

 coast of Sussex, has only in a very few instances been found 

 in England, where there have thus been few or no oppor- 

 tunities of observing its habits. It is said by M. Temminck 

 and others to inhabit marshes and the borders of lakes ; to 

 be common in Hungary and the confines of Turkey ; and to 

 have been met with in various parts of Europe, in India and 

 its islands, as well as in America, from Brazil to the southern 

 United States. The ornithologists of the latter country have 

 given the best account of its habits. Mr. Audubon's state- 

 ment, some particulars omitted, is as follows : — 



" The Marsh Tern is pretty abundant about the salt 



