1922.] On certain (.'haracters in (luiradriine (jenera. 475 



XXVIII. — On the Si(jnijicance of certain Characters in some 

 Charadriine genera, icith a provisional classijicaiion of the 

 Order Charadriiformos. By Percy R. Loave, M.B.U.U. 



(Plate YI. & Text-figures 10-12.) 



I PROPOSE to deal first with what might l)e called the 

 '• Golden-Plover Associatiou/' an assemblage coni|trised of 

 the following species and subspecies : — 



The Golden Plover, Fluvialis apricarius a/>ricariiis {L.). 

 The British Golden Plover, 1^. aj>ricarius orcophilns 



Meinertz. 

 The American Golden Plover, P. doniinicns dominicus 



(Miiller). 

 The Pacific Golden Plover, 1\ dominicus falviis . 



(Gmelin). 

 The Grey Plover^ Squatarola sqnatarola scjuatarola 



(Linn.). 

 The American Grey Plover, S. squatarola c/jnosura' 



Thayer & Bangs. 



Considered as a single association, this Plover-group would 

 appear to be admirably specialised, as far as colour-pattern 

 is concerned, for the regions which may be said to be its 

 typical home — viz., the Tundras of the Old World ;ind 

 the Barren-orounds of the New. In the Tundras one of 

 the most characteristic features of the flora is the lichen 

 known as Reindeer Moss (Cladonia rangiferina) , while in 

 the Barren-grounds true mosses are met with. On the face 

 of it, nothing could seem to be more admirably adapted to 

 such a floral background than the colour-pattern of the 

 dorsal surface of the adult or nestling of any of the above- 

 mentioned species or subspecies ; indeed, some might be 

 inclined to quote it as a wonderful illustration of the direct 

 evolutionary iuflucmce of the immediate tundral environ- 

 ment aided by natural selection. 



We may pause, however, to reflect that, firstl}', this 

 iinmediate environment on the nesting-grounds of these 



