PODIClPIDiC, GEEBES. 725 



Family PODIOIPID.E : Grebes. 



Bill of variable length, much longer or shorter than head ; culmen asually about • 

 straight, sometimes a little concave, or quite convex, especially at the end. Commis- 

 sure nearly straight, but more or less'correspondiDg with the carve of the culmeu, 

 usually sinuate at base. Under outline of bill in general convex, -with slight gonydeiil 

 augle or none. Sides of bill more or less striate. Nasal fossiB well marked, the nostrils 

 near their termination. Nostrils line.ar and pervious (broader in P(jdH//m6Ms), upper 

 edge straight, not lobed. Frontal extension of feathers considerable, and usually 

 antias run still fnrther into the nasal fossa. A groove along the symphysis of the man- 

 dible extends often nearly to tlio tip. Eyes far forward, with a loral strip of bare skin 

 running thence to base of upper mandible, very narrow in the typical forms, broader 

 in Tacliyhaptcs and Podilymhus. Head usually adorned in the breeding season with 

 variously lengthened colored crests or rufi's ; when these are ^\anting the frontal feath- 

 ers may be bristly. Neck usually long, slender, and sinuous. Plnmage thick and com- 

 pact, smoothly imbricated above, below of a peculiar smooth, satiny texture. ^Yings 

 short bnt ample, very concavo-convex; primaries eleven* narrow, somewhat falcate, 

 graduated, the three or four outer ones attenuate on one or both webs; secondaries 

 short and broad; tortials very long, hiding the rest of the quills when the wing is 

 closed. Bastard quills unusually long, their tips reaching over half way to the ends 

 of the primaries. Greater coverts also very long. Tail rudimentary, represented by 

 a tnft of downy featbers.t Characters of the feet peculiar; for in other lobe-footed 

 birds, as Phalaropes and Coots, the Jobation is of a different character. Tarsi exceed- 

 ingly compressed, with only a slightly thickened tract within which the tendons pass. 

 Front edge a single smooth row of overlapping, the hinder serrate, with a double row 

 of pointed scales ; sides regularly transversely scntellate, as are the upper surfaces of 

 the toes, the latter being inferiorly reticulate with an edging of pectinated scales. 

 Toes flattened out and further widened with broad lobes, especially wide toward the 

 end, and at base connected for a varying distance by interdigital webs. Hind too 

 highly elevated, broadly lobate, free. Claws short, broad, flat, obtuse, of squarish 

 shape ; that of the hallux minute. Tarsus no longer or much shorter than the middle 

 toe and claw ; outer toe usually rather longer than the middle ; the inner the shortest 

 of the anterior ones. 



This is a very natural group of numerous closely-related species. Extremes of form 

 may be.seen in Podiceps occidcnialis and Podilt/ntbus podiceps. There are but two strongly 

 marked genera, though many have been instituted. These genera, one of which has 

 several subdivisions, may be defined as follows, to include all the subgenera found in 

 North America : 



Analysis ofXortli American gen'yra and. subgcnei'a. 



A. Bill slender or only moderately stout, paragnathous, acute. Nostrils 

 narrow or linear. Loral bare strip narrow. Frontal feathers normal. 

 Tarsus generally but little, if any, shorter than the middle toe^at 

 least three-fourths as long. Semipalmation of toes moderate. 

 Lobe of hallux broad. Usually with conspicuous crests or ruff's 

 , during the breeding season Podiceps. 



1. Bill longer than head, extremely slender an 1 acute. Tarsus 



equal to the middle toe and claw. Crests and ruffs slight. 



Large J^climo^jhonis. 



2. Bill not longer than bead, moderately stout. Tarsus shorter 



than middle toe and claw. Crests and ruffs decided. Size 



over 10 inches. Podiceps. 



3. Bill much shorter than head, not two-thirds the tarsus, quite 



stout. Tnrsus about three-fourths the middle toe. Outer 

 and middle toes equal. No decided crests or ruff's. Small ; 

 length 10 inches or less Taclujlaples. 



* A greater number than have been shown to occur in orher birds, with few excep- 

 tions. The same number is stated to occur among Phasianidw. 



t"The tail of the Grebes is usually described as a small tuft of feathers, but on 

 carefully removing the coverts and downy parts the tail may be satisfactorily traced. 

 In this species [P. aistatusj there are fourteen feathers ; on each side seven, arranged in 

 a semicircular manner. The two middle feathers are separated to the distance of about 

 OEe-twelfth, and the two outer or lateral approach each other below, leaving an interval 

 of about the same space. When the feathers are broken across their bases, which they 

 frequently are, there is thus produced an appearance of a small circular tuft. Wheiu 

 perfect, they are about IJ inches long, and arched, with loose barbs, downy at their 

 extremity." (Auduhon.) 



