THE GREAT NORTHERN DIVER. 555 
Famiry COLYMBID. Tue 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, Colymbine and Podi- 
cipine ; — 
CotymBin&. —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. ; 
Popicipin.&. — Bill generally long and yather 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 Cotympinz.— 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 vs. 
Colymbus, Linnxus, Syst. Nat. (1785). (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, Linneus. Syst. Nat., Y. (1766) 221. Wils. Am. Orn., IX. 
(1824) 84. Nutt. Man., II. (1834) 518. Atd. Im. Biog., IV. (1838) 43. Jb., Birds 
. Am., VIL. (1844) 282. 
