248 
SYSTEMATIC SYNOPSIS. —PASSEBES— OSCINES. 
ing the yellowish or bnffy suffusion seen in sivainsoni, being thus like the back, or merely 
grayer ; no buff ring around eye breast slightly if at all tinged with yellowish. Rather larger 
than sivainsoni, about equalling mustelinus : length 7.50-8.00; extent 12.50-13.50; wing 
4.00-4.25 ; tail 3.00-3.25 ; bill over 0.50; average dimensions about the maxima of swainsoni. 
Distribution and nesting the same, but breeding range more northerly(?). A weU-marked 
variety, perhaps a distinct species. (A local race has been described as smaller, with the bill 
usually slenderer ; Catskill and White Mts.; T. alicicR hicknelli Eidgw.) 
T. u. swain'soni. (To Wm. Swainson, an English naturalist.) Olive -BACKED Thrush. 
^ 9- Above, clear olivaceous, of exactly the same shade over all the upper parts; below, 
white, strongly shaded with olive-gray on the sides and flanks, the throat, breast, and sides 
of the neck and head strongly tinged with yellowish, the fore parts, excepting the throat, 
marked with numerous large, broad, dusky spots, which extend backward on the breast and 
belly, there rather paler, and more like the olivaceous of the upper parts. Edges of eyelids 
yellowish, forming a strong buff orbital ring ; lores the same. Mouth yellow ; bill blackish, 
the basal half of lower mandible pale ; iris dark brown ; feet pale ashy-brown. Length of 
(^,7.00-7.50; extent 12.00-12.50; Ming 3.75-4.00; tail 2.75-3.00 ; bill 0.50 ; tarsus 1.10. 
9 averaging smaller; length 6.75; extent 11.50-12.00, etc. North America, N. to high 
latitudes, W. to the Rocky Mts., common; migratory; breeds from New England northward. 
Nest in bushes and low trees, thus in situation like that of the wood thrush, but no mud 
in its composition ; eggs unlike those of mustelinuSj fuscescens, and the varieties of unalascco, 
in being freely speckled with different shades of browni on a greenish-blue ground ; size 0.90 X 
0.66; number 4-5. 
2. Subfamily MIMIN/E: Mocking Thrushes. 
Aberrant Turdidm, departing 
from the prime characteristic of 
the family in having the tarsi scu- 
tellate in front (the scutella some- 
times fusing, however, as in the 
catbird), and the 1st primary, 
though short, hardly to be called 
spurious. Wings short and round- 
ed (for this family), about equal 
to the tail only in Oroscoptes ; 2d 
primary shorter than the 6th. 
Tail large and rounded or much 
graduated, usually decidedly longer 
than the wings. Tarsus about 
equal to the middle toe and claw ; 
feet stout, in adaptation to some- 
what terrestrial life. Bill various 
in form, usually longer or at least 
more curved than in the true 
Fig. 119. — Mocking-bird, about I nat. size. (After Wilson.) thrushes; in Harporhijnchus at- 
taining extraordinary length and curvatm-e. Birds much like overgrown wrens (with which 
they have been associated by some) ; distinguished chiefly by greater size, different nostrils 
and rictal bristles, and more deeply-cleft toes. As a group they are rather southern, hardly 
passing beyond the United States : few species reaching even the Middle States, and the max- 
imum development being in Central and South America. They are peculiar to America, 
where they are represented by Oroscoptes, Mimus, Harporhynchus, and five or six related 
