338 



ALCIDiE, AUKS. GEN. 315. 



lo' 



middle toe and claw 1|. Central America, AA^est Indies and 

 Mexico, Texas, Southern Colorado, Lower California. Sylbeocydus domi- 

 nicus CouES, I. c. 232 dominicus. 



315. Genus PODILYMBUS Lesson. 



ul Pied-billed Grebe. Dab-chick. Dipper. Diedapper. Water-ivilch. 

 Length 12-14; wing about 5; bill 1 or less; tarsus IJ. Adult: bill 

 bluish, dusky on the ridge, encircled with a black bar; throat with a long 

 black patch ; u^Dper parts blackish-brown ; primaries ashy-brown, secondaries 

 ashy and white ; lower parts silky-white, more or less mottled or obscured 

 with dusky ; the lower neck in front, fore breast and sides, washed with 

 rusty. Young: lacking the throat patch and peculiar marks of the bill, 

 otherwise not ijarticularly different; in a very early plumage with the head 

 curiously striped. N. Am., very abundant. Nutt., ii, 259; Aud., vii, 

 324, pi. 483; Lawk, in Bd., 898 podiceps. 



Family ALCIDiE. Auks. 



Feet three-toed, palmate. Bill horny, non-lamellate, of extremelj- variable shape, 

 often euriouslj' appendaged ; nostrils variable, but not tubular. Wings and tail 

 short ; tarsi shorter than the middle toe and claw. Form heavy, thickset. 



Birds of this family will be immediately recognized by the foregoing circum- 

 stances, taken in connection with general pygopodous characters. Agreeing closely 



m essential respects, they differ among 

 themselves to a remarkable degree in the 

 form of the bill, with every genus and 

 almost every species ; this organ frequently 

 assuming an odd shape, developing horny 

 piocesses, showing various ridges and 

 Inrrows, or being brilliantly colored. It 

 IS the rule that anj' soft part that may be 

 observed on the bill will finally become 

 hard, or form an outgrowth, or both; and 

 such processes, in some cases at least, are 

 temporary, appearing only during the 

 111 ceding season. The bill, besides, varies 

 oicatly with age, in size and shape, often 

 showing at first little trace of its adult 

 character. In gen. 316-7 the bill is high, 

 compressed, with curved vertical colored 

 grooves, the nostrils densel}' feathered ; in 

 318-23, the feathers are remote from the 

 nostrils, and the bill reaches its maximum 

 of diversitj' and singularit}^ of contour ; 

 in the rest, the bill is of simpler shape, 

 usually coiiico-elongate, with more or less 

 pcrfcctljr feathered nostrils. The general coloration is simple ; but many species 

 develop very remarkable frontal or lateral crests ; the sexes are alike ; the 

 young different ; seasonal changes are almost always strongly marked. 



Fig. 215. tiieat Auk. 



