THE DlilTERS. 
327 
permeates all their bones^ with the exception of the pha- 
langes of the toes, and even passes under the skin of the 
breast, which is only attached to the muscles of the body by 
some scattered connecting pillars. This structure is also 
met with in the tropic birds, and must give them great ad- 
ditional buoyancy. 
The Darters {Plotus) have a very long neck and small 
head, from which they have acquired one of their names, 
that of Snake-birds.^^ They are exceedingly shy, and, 
when approached, plunge into the water, leaving as little 
agitation on its surface as that occasioned by an eel. It is 
a widely distributed genus, — species being found in North 
and South America, in India, in Australia, and one (P. Le- 
vaillantii) seems to occur in various parts of Africa. 
Colonel Sykes says that the Indian species, Flotus mela- 
nogaster, the Black-bellied Darter (Plate XX. fig. 2), can 
swim with the whole of its body under water ; its long neck, 
ending in a small head, alone being visible, and strongly 
resembling a snake. Mr. Gould, who found a new species 
in Australia {P, Novce-IIoUandid), says that it dives with 
the greatest ease to the bottom of the deepest pools, and 
that it generally swims with a considerable portion of its 
body above the surface of the water ; but immediately on 
