THE GREAT NORTHERN DIVER. 555 



FAMILY COLYMBID^E. THE DIVERS. 



Bill more or less long and compressed; the nostrils are linear or rounded, and 

 situated in a lateral groove ; tail rudimentary or short ; tarsi much compressed ; an- 

 terior toes long, with the interdigital membrane more or less full, the outer longest; 

 hind toe short, free, with a hanging lobe ; claws broad, depressed, buried in the 

 body. 



The species are remarkable for their powers of swimming and diving : their ease 

 and gracefulness on the water is in strong contrast with their awkwardness on land, 



The following are the characters of the two sub-families, Colymbince and Podi- 

 cipince ; 



COLYMBIX.E. Bill long, rather strong, much compressed, with the point acute; 

 nostrils basal, linear; tarsi much compressed; toes long and webs full; tail short; 

 lores feathered. 



PomciPiNjE. Bill generally long and rather slender, compressed and pointed; 

 nostrils situated in a groove, oblong and narrow ; tarsi compressed ; toes long and 

 broadly lobed ; tail wanting, or very rudimentary ; lores naked. 



Sub-Family COLYMBINJE. The Loons. 



Bill about the length of the head, rather stout, much compressed, and acute ; 

 nostrils basal, linear, and pervious; wings of medium size, narrow and pointed, first 

 quill the longest, reaching far beyond the scapulars; tail short and rounded; tarsi 

 very much compressed; entire tarsi and base of toes reticulated; toes long, the 

 anterior ones united by regular webs, the claw of the middle twice as long as broad ; 

 hind toe short, edged with a narrow membrane. 



These birds excel all others in their rapidity of diving, and the great progress 

 they are able to make under water. Only one genus in this sub-family is recognized 

 by authors. 



COLYMBUS, LINN^US. 



Colymbus, LINN^US, Syst. Nat. (1735). (Type C. articus.) 



As the characters of the sub-family include those of the single genus Colymbus, it 

 is not necessary to repeat them. 



They are abundant during summer in the high northern latitudes, both on the 

 seacoast and on inland lakes ; in winter, they migrate to the South. They are soli- 

 tary in their habits, keen-sighted, and very difficult of approach : their flight is 

 strong, rapid, and direct. 



COLYMBUS TORQUATUS. Briinnich. 

 The Great Northern Diver ; the Loon. 



Colymbus glacialis, Linnaeus. Syst. Nat., I. (1766) 221. Wils. Am. Orn., IX. 

 (1824) 84. Nutt. Man., II. (1834) 513. Aud. Orn. Biog., IV. (1838) 43. lb., Birds 

 Am., VII. (1844) 282. 



