GRALLATORES. HJEMATOPUS. 199 



directed forwards, and united at their base by a membrane, 

 that is prolonged, and margins them. Nails strong, broad, 

 slightly falcate, and semi- acute. Wings of mean length, 

 with the first quill-feather the longest. 



Plumage close, firm, and adpressed. General contour ro- 

 bust. 



The species hitherto described of this well-marked genus, 

 although not numerous, are distributed over a wide geo- 

 graphical range, one or more of them being found in almost 

 every quarter and climate of the globe. They dwell on the 

 shores of the ocean, subsisting entirely on marine animals, 

 such as molluscous shell fish, Crustacea, &c., to detach and 

 obtain which their strong wedge-shaped bill is admirably 

 adapted. Their habits are more aquatic than the other 

 groups of the family, indicated indeed by the membranes 

 that unite and border their toes, and which conformation (as 

 I have before remarked) preserves the connexion with the 

 aquatic groups of the other families. They are thus enabled 

 to swim with ease, and which they occasionally do, when 

 passing from one feeding spot to another, where the water is 

 too deep to admit of wading. During the winter, and whilst 

 performing their migratory movements, they associate in 

 large flocks ; but on the approach of spring, they separate 

 and pair. They are subject to a double moult, but not in- 

 ducing any striking difference of colour. They are birds of 

 a compact robust form, with a thick and muscular neck, 

 well adapted to support the bill as a powerful lever in de- 

 taching patellae, &c. from the rocks, or for wrenching open 

 the shells of the bivalve molluscae. Their flight is strong 

 and steady, and can be sustained for a long time. They 

 breed on the shingle of the sea-coasts, and lay invariably 

 four eggs. 



