494 Mr. N. A. Vicors on the Natural Affinities 
latter character is still further developed in the ensuing genus 
Porphyrio, Briss., where the base of the bill exhibits a considerable 
degree of robustness ; and is also carried on to Fulica, which im- 
mediately adjoins Porphyrio. "The species that compose the true 
Gallinula and Porphyrio may be observed to possess a narrow 
membrane on each side of the toes, which extends along their 
whole length, straight and entire. We thus recognise the gra- 
dual approximation of these genera to the lobated foot of Fulica 
and Podoa, which unite the swimming Faders to the true web- 
footed Natatores. The dilatation of the upper mandible into a flat 
crown upon the forehead, which characterizes the latter groups 
of this family, together with the same length of the toes, is found 
to exist in some species of Parra; and thus we are led back to 
the groups from which we commenced our observations on the 
family. 
We are T to the family of Charadriade, or the three- 
toed Waders, by means of Hæmatopus of Linnæus, which indi- 
cates its affinity to the lobated Fulica of the last division by the 
rudiments of the membrane that extends along the toe. This 
character is sufficiently discernible in the species so frequent on 
our coasts ; butit is so far conspicuous in an Australasian species 
as almost to give its foot the appearance of being perfectly lo- 
bated. This genus by its habits of swimming preserves an affinity 
with the natatorial groups of the preceding family of Rallide ; 
and these again being connected with Phalaropus, which forms 
an extreme genus of the Scolopacide, the whole of the Wading 
Birds that possess the faculty of swimming are brought together 
into one contiguous group. Besides Hematopus, the present 
family consists of Arenariu, Briss., our common Sanderling ; to 
which I feel inclined to add Sfrepsilas, Il., and Vanellus, Briss., 
which have been separated from Tringa and generally assigned 
a place near Arenaria. It is true that | both these genera possess 
a hind 
