400 



DUCKS. 



approach of winter. One species, however, is peculiar to New 

 Zealand. They are met with in pairs and in small societies, fre- 

 quenting fresh-water lakes and rivers, but sonic are more espe- 



cnsiatit). 



cially found on the sea-shore. Their food consists principally of 

 small univalve and bivalve mollusca, for which they dive, or seek 

 in the pools left on sand-banks after the tide has receded. 



Sub-Family VII. 

 THE SPINY-TAILED DUCKS. ERISMATURIN.E.* 



General Characteristics. — Bill elevated at the base, and the anterior half much 

 depressed to the tip, which is furnished with a nail ; the wings short and concave, 

 with the ends of the quills incurved ; the tail lengthened, and composed of narrow 

 rigid feathers, which are but slightly protected with coverts both above and below ; 

 the tarsi shorter than the middle toe, and compressed ; the toes lengthened, the 

 anterior ones united by a full web, and the hind toe long and furnished with a 

 broad web. 



The ducks belonging to this sub-family are met with in various 

 parts of both hemispheres. They are peculiarly aquatic birds, 



* ipiGfi-a, erisma, a cause of strife; ovpd, oura, a tcil. 



