94 



CHAEADEIUS. 



The subgenus iEoiALOPHiLus must be diagnosed as : — 



Chauadrii having all the following characters : white axillaries ; no hind toe ; white 

 belly ; but no dark subterminal band across the tail. 



Subgenus PLUVIALIS. 



Diagnosis of Charadrii aut axillaribus baud albis ; aut balluce parvo ; aut caud4 fasciata ; aut abdomine magna 

 subgenus. macum nigr^ ornato. 



True 

 Plovers. 



Dotterels. 



Subgeneric 

 characters. 



The Plovers and Dotterels form a subgeneric group of birds belonging to the genus 

 Charadrius, which are easily diagnosed from their congeners. It would, however, be 

 unwise to place them in a separate genus, as it is very probable that some of the characters 

 of the group denote analogy rather than affinity. 



The true Plovers are characterized by their barred tails, though in the young in first 

 plumage the bars are only indicated by spots on the margin. They also present a sHght 

 structural difference from their allies ; the hexagonal scales on the tarsus are reticulated 

 more minutely and in a slightly different way, but the great variations in the scutellations 

 of the tarsus in this genus suggest that it is not a character of much importance. The 

 fact that in breeding-dress the underparts are black may be of more significance, though 

 this is more or less the case with many of the Dotterels. 



The Dotterels form a somewhat heterogeneous assemblage, but have so many characters 

 in common with the true Plovers, that it is most convenient to class them together. 



The group so constituted forms a subgenus Pluvialis, containing 10 species. Of these 

 five differ from all other species of the genus Charadrius in having coloured axillaries. One 

 of the five has a hind toe, a character also found in three other species which are included in 

 this subgenus on that account, but have white axillaries. Two others of the five species 

 which have coloured axillaries have also barred tails, a character shared by a fourth species 

 with white axillaries. Another of the species having coloured axillaries has also a dark patch 

 on the belly, which is found at all ages and seasons, and in both sexes, a character shared by 

 the fifth species with white axillaries, and in the breeding-season by four other species. 



When we consider that none of these characters are possessed by any species 

 belonging to the other two subgenera into which we have divided the genus Charadrius, 

 and that the four sections are linked together by other characters, the Dotterels and 

 Plovers regarded as one subgenus do not seem quite so heterogeneous as they at first sight 

 appear. 



