J86 COLYMBUS. 



drawn forward to give the stroke, and, with the 

 thin edge of the tarsus, thus offers a very slight re- 

 sistance. The food is entirely fish taken by diving. 

 The number of species is limited, and they are 

 confined chiefly to northern and tempe -ate clmates. 

 The generic characters of this form arc, 



GEN. COLYMBUS, Linnceus. Generic characters. 

 Bill long, straight, pointed, strong, tomia 

 smooth, lower outline of mandible curved, but 

 showing little or no angle ; nostrils basal, late- 

 ral, linear ; wings short, accuminated, feathers 

 in structure stiff, first and second quills longest ; 

 tail short, rounded; legs placed far behind, tarsi 

 much compressed, feet large, amply webbed, 

 outer toe longest, nails broad and flat, hallux 

 articulated inside the tarsus, lobe small. 



Types. C.glacialiS) arcticus^ &c. Europe, Asia, 

 America. 



Note. Habits peculiarly aquatic, maritime; breed 

 inland ; a marked summer plumage, lost in 

 winter. 



