OF ORNITHOLOGY 119 



rigid, spinous, and almost entirely exposed ; the cov- 

 erts nuicli abbreviated. 



B. Bill high at the base, much compressed. The lamellae 



directed backwards as serrations. The upper jaw with two se- 

 ries of teeth on each side ; the lower with one which fits be- 

 tween the others. The nail of the bill compressed, much 

 curved, forming the tip of the bill. Edges of bill nearly 

 parallel. Legs with transverse plates anteriorly. 

 Mergin.e. — Characters as above." 



Most writers do not make the ErismaturinvE a separate 

 sub-ftimilv from the FuLKiUUN.?:, otherwise the above table 

 answers perfectly for our present classification. We shall 

 unite the two into one sub-family, and call it the Fuligu- 

 LiN.E. The family divides itself naturally into the following 

 s?(7j-families : 



Sub-family a CYGNIN2E Swans 



The difference between the Swans and the Geese is easily 

 recognizable. The size of the former, alone, would separate 

 them ; add to this the naked loral spaces and there will be 

 very little difficulty in telling them apart. Swans are still 

 rare in North America, and our species are now reduced to 

 four well-marked and constant forms. There is but a single 

 genus, though writers differ in names ; some calling it Cygnus 

 and some Olor. Whichever form we admit, we must recog- 

 nize the other as an equivalent synonym and not a sub-genus. 

 Sicans appear to resort more to inland and fresh waters than 

 to the sea coasts, and to the extremes of the continent in arc- 

 tic or sub-arctic rather than ordinary temperate regions. 

 Genus, Cygnus or Olo7\ (4 species). 



Sub-family /; ANSERIN-ffi Geese 



The Geese are much better known throughout North Amer- 

 ica than the Sicans. They inhabit all portions of the conti- 

 uent — inland and seaward, north, south, east, and west. The 



