416 Mr. N. A. Vicors on the Natural Affinities 
natural arrangement, cannot be placed in a different family from 
Gallinula, nor Podiceps in a different one from Colymbus. 1t is 
not easy, I must confess, to draw a decided line of partition be- 
tween orders so closely assimilated as the Grallatores and Nata- 
tores. Perhaps the plan most accordant with nature would be 
to divide the above Aquatic Dirds, according as they frequent 
the fresh or inland waters, or generally inhabit the ocean. 
The approaching groups of each division would of course par- 
tially encroach upon the domains of the other; and while the 
extremes of the oceanic birds would be occasionally found in 
inland stations, those of the grallatorial birds would sometimes, 
on the other hand, gain their support from the ocean, but on the 
sea-shore, or not far distant from land. Such a view would 
go far to restore the genera Fulica and Phalaropus, whose sta- 
tion has been so often disputed, to their original place among 
the Waders, where they were arranged by Linnæus. We may 
thus observe, that the family of Grallatores, which approaches 
the Natatores by their swimming habits, will lead on in a 
regular succession from Rallus, Linn., to Gallinula, and Por- 
phyrio, Briss.; thence to Fulica, Linn., and Podoa, IL ; which 
last genus exhibits a striking approach, in the general con- 
struction of its neck, body and tail, to the family of Anatide, 
that forms one of the extremes of the natatorial birds. Some of 
these, on the other hand, as the genus Anser, evince in the length 
of their neck and tarsi and the forward position of their legs, 
together with a greater compression of bill than is found among 
the Anatide in general, a corresponding approach to the Ral- 
lide, or extreme subdivision of the Grallatores. The genus Ce- 
the typical oceanic or true swimming and diving birds, the other to those which barely 
approach them. The system which, without regard to their general structure, unites 
these discordant groups into one, and separates them from all other birds, —merely be- 
cause the webs that border the toes, although not even similar in construction, (for in 
one group they are emarginated, in the other entire) are not united,—is the most arti- 
ficial with which I am acquainted. 
reopsis 
