Tribe BRACHYPTERI. 

 FamilyCOLYMBIDAE.^ 



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, fjee, with a hanging lobe ; claws broad, depressed, buried in the body. 



The species are remarkable for tbeir 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, Oolymhinae and Fodicipinae : 



CoLYMBiNA-B. — 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. 



PoDiciPiNAB. — 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 COLYMBINAE.— The Divers proper. 



Ch. — 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 recognised by authors. 



COLYMBUS, Linnaeus. 



Colynibus, Linn. Syst. Nat. 1735. Type C. arcticus. 



As the character of the sub-family include those of the single genus Colyrribus, 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 , G. arcticus. 



Bill not HO 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 



brown G, septentrionalis. 



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



