Tribe BRACHYPTERI. 

 Family COLYMB ID AE.' 



Ch. — Bill more or less long and compressed ; the nostrils are linear or rounded, and situated in a lateral groove ; tail rudimen- 

 tary or short ; tarsi much compressed ; anterior 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. 



Tlie species are remarkable for their powers of swimming and diving; their ease and grace- 

 fulness on the water is in strong contrast with their awkwardness on land. 



The following are the characters of the two sub-families, Cohjmhinae and Podicipinae : 



CoLYMBiNAE. — Bill long, rather strong, much compressed, with the point acute ; nostrils basal, 

 linear ; tarsi much comi^ressed ; toes long and webs full ; tail short ; lores feathered. 



Podicipinae. — Bill generally long and rather slender, comi)ressed 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 COLYMBINAE.— The Divers proper. 



Ch. — Bill about the length of the head, rather stout, much compressed, and acute ; nostrils basal, linear and pervious ; winga 

 of medium size, narrow aud 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 recognised by authors. 



COLYMB OS, Linnaeus. 



Co!i/m6us, Linn. Syst. Nat. 1735. Type C. areticus. 



As the character of the sub-family include those of the single genus Colymhus, it is not neces- 

 sary 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 solitary in their habits, keen 

 sighted, and very difficult of approach ; their flight is strong, rapid, and direct. 

 The species of this genus have the following characters : 



Bill strong, compressed, nearly straight, a groove on the under mandible, continued from 

 the junction of the crura to near the point; head and neck dark bluish green, a small 

 patch of white feathers on the throat in front, also a larger one on each side of the 



neck c. glacialis. 



Bill rather strong, much like that of the above species, but smaller and without the 

 groove underneath ; head and neck bluish grey, a large space of purplish black on the 



front part of the neck C. areticus. 



Bill not so strong as in either of the above named species. Adult plumage not 



known G. pacificus. 



Bill straight and slender ; head and neck clear light bluish grey, hind neck marked with 

 white and greenish black, on the fore part of the neck is a large patch of dark reddish 



l^rown (7. septentrionalis. 



^ Prepared by Mr. George N. Lawrence, of New York. 



