American Dipper 477 



if not all the work of building. The eggs, four or five 

 in number, are pure white, and rather pointed at one end. 

 The time of nesting of the Dipper is rather irregular. 

 Gale found fresh eggs from early in May until the middle 

 of June ; Drew found one nest with four hatched young, 

 and another nest yet unfinished on the same date — June 

 19th in San Juan co. — while Dille gives the first week in 

 June as a good average date for fresh eggs. 



Family MIMID^E. 



Rather large birds with considerable external re- 

 semblance to the Thrushes, with a bill of variable size 

 and shape, but always with conspicuous rictal bristles ; 

 wing short and rounded, shorter than or only just 

 exceeding the tail ; outer primary never very small, 

 usually about half the length of the next ; tarsus stout 

 and adapted to walking. 



This family, containing the Mocking-birds, Thrashers 

 and their allies, is confined -to America. 

 Key of the Genera. 



A. Tail slightly shorter than the wing and nearly even ; breast 



spotted. Oroscoptes, p. 477. 



B. Tail always longer than the wing and distinctly graduated. 



a. Culinen shorter than the middle toe without claw, 

 a^ With a good deal of white on the wings and tail. 



Mimus, p. 479. 

 b^ Without any white on the wings and tail. 



Dumetella, p. 481. 



b. Culmen always exceeding the middle toe and without claw. 



Toxostoma, p. 482. 



Genus OROSCOPTES. 



Bill moderate, not hooked or curved except at the tip, shorter than 

 the head ; rictal bristles well developed ; wing and tail apjjroximately 

 equal, the latter even or very slightly graduated ; outer primary hardly 

 half the length of the next ; plumage thrush-like, dull brown with 

 spotted under-parts. 



One species only. 



