1002 HTDROCUELIDON LEUCOPTEEA. 



uests in the delta of the Nile, and southwards along this river to Wady-Halfa. It has been obtained at 

 Kordofan and on the Bed Sea, and is a straggler to the Blue and White Nile. 

 It has once occurred in America at Wisconsin. 



Habits. — Like the last species, this Marsh-Tern is generally met with about iidand waters, about which 

 it flies with a rapid, graceful, and buoyant flight, and feeds on insects; water-beetles, small fish, larvre, and 

 worms. It consorts in flocks sometimes of considerable number, and associates with the Marsh-Tern, which 

 it excels, however, in the swiftness of its flight. The adult mentioned above passed my boat in Koddiyar Bay 

 at great speed, the black under wing-coverts and white shoulders being very noticeable. It is said to perch 

 on stakes and elevated objects, like the common Marsh-Tern. Yon Heuglin observes that they are courageous 

 birds, and do not ordinarily display much shyness ; he found them feeding on flies, cockroaches, and other 

 insects, and states that they are usually very fat. Naumann has observed them picking insects off the ears 

 of grain. 



Nidification, — This species breeds in marshes, building a nest of reeds and rushes on floating vegetation, 

 and lays in May and June. Its eggs are usually three in number, but sometimes four. A series which I 

 have had the pleasure of examining in Mr. Saunders's collection vary considerably in ground-colour, being 

 buff, brownish buff, pale buff stone-, and pale stone-colour, with a slight olivaceous tint, and are somewhat 

 pointed at the small end for Tern's eggs ; they are very boldly blotched and clouded, some at the large end 

 and some on the middle of the shell, with deep sepia or black-brown, and there are numerous smaller markings 

 of the same, under which are the usual light blots of grey of different shades. Examples measure — E34 bv 

 1-0, 1 35 by 0-99, 137 by 101 inch. 



Genus STERNA. 



Bill varied as regards stoutness ; typically long and straight, with the gonys straight and 

 lengthened ; in some stouter and slightly curved throughout. Tail much forked, the lateral 

 feathers lengthened in the breeding-season. Feet generally more fully webbed than in Hydro- 

 chelidon. 



Head changing to black in the summer. 



