ANSERES ANAS 133 



cornuta). The result of the last union was a rather remarka-ble- 

 hird, figured in the Proceedings of the Zoological Society (1859, 

 pi. 158), hardly resembling either of the parents and possessing 

 dusky-grey flanks somewhat reminding one of the Australian species 

 (Casarca tadornoides). 



Grant and Seimund found the nest of this species in the hole 

 of an Ant bear or Porcupine on the veld ; the clutch is from eight 

 to ten eggs. The colour is creamy-white and the measurements 

 25 to 2-0 x 1-8 to 1-9. Whitehead states that an officer told him 

 that he had found a nest among the rocks above the river near 

 Aliwal North. It is also generally stated that the young when 

 hatched are carried down to the water by the female on her back. 



Genus VII. ANAS. 



Type. ' 

 Anas, Linn., Syst. Nat. i, p. 194 (1766) A. boschas. 



Bill moderate, about as long as the head, culmen nearly straight, 

 sides nearly parallel, perhaps slightly broadening towards the tip ; 

 nail not prominent ; wing long and pointed with a conspicuous 

 metallic green and blue speculum, formed by the outer secondaries ; 

 tail rather short and graduated, of from sixteen to twenty feathers, 

 which are sometimes stiff and narrow ; tarsus shorter than the 

 middle and outer toes, about equal to the inner one, with a row of 

 transverse shields in front ; hind toe narrowly lobed ; plumage 

 generally mottled. 



Authorities are at considerable differences as regards the limits 

 of this cosmopolitan genus ; Salvador! and Sharpe include only 

 seventeen species, while Eeichenow, putting together several genera 

 recognised by the former authors, considers that fifty-one species 

 should be assigned to the genus. 



For convenience of reference a key is here given of the five 

 species of South African Ducks included in the genus in its wider 

 significance ; these are all resident birds ; none of the European 

 migratory forms extend their winter range so far south. 



Key of the Species. 

 A. Larger, wing 8 to 13. 



a. Speculum green and black. 



a 1 . Bill yellow, with black on the culmen, 



legs black A. undulata, p. 184. 



