146 THE ZOOLOGIST. 
The birds comprised in the third group have the rump nearly 
the same colour as the mantle and lower back, the crown uniform 
dark brown, with an obscure pale mesial line, and more or less 
distinct bars across the primaries and secondaries. They are 
supposed to represent the birds which emigrated down Baffin’s 
Bay and the chains of American lakes. After the passing away 
of the Glacial Period they seem to have spread westwards to 
Behring Straits, and possibly to East Siberia. Two species 
are known. 
6. NUMENIUS TAHITIENSIS. 
The traces of pale bars on the inner webs of the primaries 
of the Pacific Island Whimbrel effectually prevent its being 
confused with the two smallest Whimbrels, though it agrees 
with them and differs from its nearest ally, the Hudsonian 
Whimbrel, in having the lower breast and belly buff instead 
of white. 
The Pacific Island Whimbrel has occurred on the Sandwich 
Islands, the Society Islands, the Samoan Group, and on some 
other islands of the South Pacific Ocean, where it is probably 
only a winter visitor. A single example has been obtained in 
Alaska, and Taczanowski records it from Kamschatka, which 
are presumably the breeding-grounds of this species. 
7. NUMENIUS HUDSONICUS. 
The Hudsonian Whimbrel is sufficiently distinguished from 
its dark-rumped allies by the whiteness of its lower breast and 
belly, and by the distinctness of the pale bars on the inner webs 
of its primaries. 
It is confined to the Arctic Regions of the American continent 
during the breeding season from Alaska to Greenland, but in 
autumn it migrates southwards across the line, where it has 
been seen as far south as Patagonia. 
The birds comprised in the fourth group may be called 
Plain. winged Whimbrels, and are easily distinguished from all 
their allies by the absence of bars on their primaries and 
secondaries. They appear to represent the birds which 
~ escaped from the Polar ice through Behring Straits, and after- 
