232 



COLYMBUS. DIVER. 



Generic Character. 



Rostrum capite longior, rec- 

 tum, validum, fere cylin- 

 dricum, compressum, acu- 

 tiore ; mandibula superiore 

 inferiore longiore. 



Nares basales, laterales, con- 

 cavae, membrana semi- 

 clausse. 



Pedes tetradactyli, medio- 

 cres, dig'iti antici longissi- 

 rai toto palmati; pollcx 

 brevis pinnatus ; ungues 

 depress!. 



Cauda brevis. 



Beak longer than the head, 

 straight, strong, nearly 

 cylindrical, compressed, 

 acute ; the upper mandible 

 longer than the lower. 



Nostrils basal, lateral, con- 

 cave, half-closed by a mem- 

 brane. 



Legs four- toed, mediocral, 

 the anterior toes very long 

 and wholly webbed ; the 

 hinder toe short and web- 

 bed ; the claws depressed. 



Tail short. 



COLYMBUS. Ray, Linn., Gmel., Lath., Cuv., Temm. 

 MERGUS. Briss. 

 EUDYTES. Illig. 



x\.T once distinguished from the following genus 

 by the presence of the hinder toe; and from the 

 Grebes and Podose by the palmated feet. All the 

 species inhabit the northern regions, and live almost 

 continually upon the water, diving and swimming 



