American Dipper ATT 
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 MIMIDZ. 
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. Culmen shorter than the middle toe without claw. 
al 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 approximately 
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. 
