Tribe BRACHYPTERI, 
Family COLYMBIDAE: 
Cx.—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. 
The species are remarkable for their powers of swimming and diving; their ease and erace- 
I g $5 g 
fulness on the water is in strong contrast with their awkwardness on land. 
The following are the characters of the two sub-families, Colymbinae and Podicipinae: 
fo} >) ey 
CotymBinaE.—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. 
Poprcreinaz.—Bill generally long and rather slender, compressed and pointed: nostrils 
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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. 
Cu.—Bill about the length of the head, rather stout, much compressed, and acute ; nostrils basal, linear and pervious ; wings 
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. 
COLYMBUS, Linnaeus. 
Colymbus, Linn. Syst. Nat. 1735. Type C. areticus. 
As the character of the sub-family include those of the single genus Colymbus, 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 
FRE socninosro gt abincocteshec eg ndeet oc See. ACRE EET HER REPS 7 7 AOL e a 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 ............... SPiasiiscuatesesesanerer: ssisece lesaseartecscootseseeOs ANCLICUS, 
Bill not so strong as in either of the above named species. Adult plumage not 
STN O WIL ae se ce su na nen eee Seance SMM etc. cs eck iccs SOO SOREDOOOO stesso. DACHICUS. 
Bill straight and slender; head and neck clear light bluish gréy, hind neck marked with 
_white and greenish black, on the fore part of the neck is a large patch of dark reddish 
UO Willi catae seeatisrotaees eutatseaccins ot csbea reer etry. <cesaivw'saxageceddacencen eons ...C. septentrionalis. 
1 Prepared by Mr. George N. Lawrence, of New York. 
