PLOVERS. 49 



Order XII. CHARADRIIFORMES. PLOVER-TRIBE. 



The birds included in this Order present great variety in size, shape, [Cases 

 and coloration, and it is interesting to notice that these differences are 

 generally traceable to peculiar methods of feeding. Though a few 

 species frequent arid plains, they are essentially birds of the fen and of 

 the sea-shore, or haunt the banks of streams and desolate marshes, feeding 

 on worms, small shell-fish, and Crustacea. For the capture of these the 

 beak and legs have become modified in many ways. A considerable 

 number of species exhibit conspicuous changes in the coloration of the 

 plumage, adopting a distinct summer and winter dress ; others undergo 

 but little seasonal change. The richly coloured eggs do not ordinarily 

 exceed four in number, and are deposited in a slight hollow in the 

 ground with little or no preparation in the form of a nest. The young 

 are quite active when hatched and clothed in a thick covering of 

 beautifully patterned down, the colour of which is more or less deter- 

 mined by the surroundings amid which they are hatched. 



Family I. DROMADID^E. CRAB-PLOVERS. 



On the floor of this Case, on the right-hand side, we find the sole [Case 27.") 

 representative of this very aberrant and remarkable family, which 

 inhabits the coast-land and sandy islands of India, Arabia, and East 

 Africa. The nesting habits differ entirely from those of every other 

 member of this order, for the Crab-plover (Dramas ardeola) (463) 

 breeds in deep burrows excavated in the sand-hills and lays a single 

 large white egg. The young are covered with greyish down and, like 

 young petrels, remain in the burrows during the day. 



Family II. CHIONIDIDJE. SHEATHBILLS. 



The Sheathbills, of which three species are known, form another very [Case 27.] 

 aberrant family, inhabiting the islands adjacent to the southern extre- 

 mity of South America and in the South Atlantic Ocean. The base 

 of the bill is covered with a saddle-shaped horny sheath, the cheeks are 

 naked, covered with wattles in Chionis alba (464), and the wings are 

 armed with spurs. The habits of the Lesser Sheathbill (Chionarckus 

 minor) (465) are described as resembling in some respects those of 

 pigeons, while in their gait and flight they closely resemble Ptarmigan. 

 The rough nest of dried plant-stems is made in a hollow among the 

 rocks or occasionally in a Petrel's burrow, and contains two or three 

 eggs thickly spotted and mottled with purplish-red. 



