LEUCOPOLIUS. 
synonymy of marginatus appears leucopolius, so that the first-named must be 
accepted, by tautonomy, as the type. The Austrafian ruficapillus is so close 
to marginatus that the latter name was misappHed to it; consequently we 
must use Leucopolius for it and not MgialopTiilus. Gould designated 
cantianus {=alexandrinus) as the type of his genus, and I am unable to 
separate this generically from Leucopolius, so that Gould’s name becomes a 
synonym. 
Now, if the coloration of these birds be criticised, it is at once seen that 
aU the members of the black-billed group can be ranged into series and their 
inter-relationship seems correlated with coloration. Charadrius vociferus 
stands quite alone in size and coloration ; the coloration is somewhat that of 
the “ hiaticula ” group, but the red rump is pecuhar ; the bill is moreover long, 
slender and Pluvialine ; the legs are short but the feet are strong and the tail 
is long and wedge-shaped. There should be no hesitation in admitting its 
generic rank. Next to hiaticula, in the Catalogue of Birds, is placed the 
species placida,^^ but this has a long thin Pluvialine bill though similar in 
coloration to C. hiaticula. Close examination shows it to be very near 
vociferus, having the same long wedge-tail, short legs, strong feet, and Pluvialine 
black bill. It entirely lacks the red rump, however. The majority of the rest 
of the species agree in having the forehead white, black frontal band, and 
the back of the head red or tending to red — and also in size ; the under- 
surface is white, with signs of banding on the breast which agrees with 
locahty. Thus 7narginatus has a ruddy breast which in venusta becomes 
narrowed down to a red band ; pecuarius, though with longer legs and weaker 
feet, has a similar ruddy flush on the under-surface ; the island-form, 
sanctcehelence, has developed into quite a distinct form, being larger with a 
longer bill, and very long legs with long bare portion of the tibia, and slender 
feet. These are aU African. The Austrafian ruficapillus is very like 7narging,tus 
but lacks the ruddy coloration, the under-surface being pure white. 
C. alexandrinus has a black spot on each side of the breast which in 
nivosus appears almost as an interrupted black band ; and in collaris there 
is a distinct black band ; another very distinct island-form seems to have 
originated from collaris and developed into falhlandicus, which is larger and 
has two black bands across the breast, but retains the red on the back of 
the head. All these are American, save alexandrinus which spreads across 
the Old World in the Palsearctic Region. A species in the Moluccas which 
resembles alexandrinus is peroni, but this is peculiar in having a black band 
on the back of the neck, and also looks not unlike a miniature imngolus. 
The Austrafian C. hicinctus, which I have placed in Cirrepidesmus, mimics 
C. falhlandicus in having two bands, but the lower one is brownish-red not 
VOL. m. 
113 
