BIRDS OK NOETH AND MIDDLE AMERICA. 675 



Family CINCLID^. 



THE DIPPERS. 



Aquatic, slender-billed, " ten-primaried " acutiplantar Oscines, with 

 plump body, short tail, short and very concave wings; rather long 

 booted tarsi; plumage very compact, soft, and underlaid with down, 

 and feathers of the anterior portion of the head short and dense, with- 

 out the usual bristly tips, even the rictal bristles being absent. 



Bill much shorter than head, slender, much compressed; culmen 

 nearly straight for most of its length, more or less concave subbasally, 

 the tip rather abruptly decurved; gonys nearlj' straight, ascending 

 terminally, its base forming a distinct angle decidedly anterior to 

 anterior end of nostril; tomia nearly straight, that of the maxilla dis- 

 tinctly notched subterminally, both being sometimes indistinctly ser- 

 rate or nicked for terminal half (except in South American species 

 only?). Nostril very narrow, longitudinal, opening as a narrow slit 

 in the lower edge of the nasal foss^, overhung by a broad membrane- 

 ous operculum; feathering of lores and frontal antiaj not bristly, but 

 soft and dense, the latter advancing on sides of the maxilla to about 

 the middle of the nasal fossae. Rictal bristles obsolete. Wing short, 

 very concave beneath, with tip comparatively long and stiff, the 

 longest primaries exceeding secondaries by more than two-thirds the 

 length of the tarsus; ninth, eighth, and seventh, or eighth, seventh, 

 and sixth, primaries longest, the ninth sometimes nearly equal to 

 eighth, sometimes shorter than fifth, the tenth much less than half, 

 sometimes less than one-third, as long as ninth. Tail decidedly more 

 than half as long as wing, even or slightly rounded, the rectrices 

 broad and rounded at tip. Tarsus decidedly longer than middle toe 

 with claw, more than one-third as long as wing, the aci'otarsium 

 booted, except extreme lower portion; lateral toes equal in length, 

 reaching to penultimate joint of middle toe, their claws falling short 

 of base of middle claw; hallux about as long as lateral toes, but much 

 stouter, its claw much shorter than the digit; basal phalanx of middle 

 toe with its basal half united to outer toe, a little less to inner toe; 

 claw of middle toe with its inner edge more or less produced, some- 

 times slightly nicked or pectinate. Head, neck, and body covered 

 *with down; plumage very dense though soft. 



Coloration. — Colors plain, gray or brown predominating, this never 

 relieved by bars or other conspicuous markings, though parts of the 

 plumage are sometimes squamately marked with darker margins to 

 the feathers; throat and breast, pileum, or part of back sometimes 

 white; sexes alike, but young different in color from adults, being 

 much paler below. 



Widification. — Nest a bulky oven-shaped mass of green moss with 

 opening in one side, placed among rocks near waterfalls, usually in 

 contact with their spray. Eggs immaculate white. 



