SUBFAM. IX. Erismaturiné. 
The birds composing this subfamily inhabit the great 
lakes of Australia, Tropical America, South Africa, and in one 
instance South-East Europe; they have short, spiny tails, and 
are possessed of extraordinary powers of diving, being known 
asthe Lake Ducks. Four genera are enumerated by Salvadori, 
as composing this subfamily, Zalasstornis, Nomonyx, Ertsma- 
tura, Biztura. The Erismaturine may be recognised by very 
marked peculiarities. The bill is higher than it is broad, the 
feet large, with the hind toe lobated, the outer toe equal to the 
middle. The wings are short, depriving these birds of any 
great power of flight, consequently the species have not a wide 
geographical range. The stiff, spiny tail feathers, which are not 
covered at the base by the tail-coverts, and are grooved on the 
under side, appear to be used both as a rudder when swimming 
and diving, and as a support when sitting on the ground, the 
legs being placed so far back that the position is penguin-like. 
GENUS ZHALASSIORNIS. 
(Thalasstornis leuconota ). 
One type only is at present recognised, which is confined 
to the Southern parts of Africa. 
GENUS WOMONYX. 
ST. DOMINGO TEAL OR SPINOUS-TAILED DUCK. 
(Nomonyx dominicus). 
This bird, which inhabits Tropical America, including 
the West Indies, is the only representative of the genus. As 
