TURDIDA. 3 
B. Nostrils linear, in lower edge of nasal membrane. Loral and frontal 
feathers soft and downy, and no bristles or bristly points whatever 
about the mouth. 
Cinclidz. Body very short and broad. Wings short, rounded, and 
concave. 
The American Sylviadz are in some respects very closely related 
to the Savicolidx, but may be distinguished by their much smaller 
size, more slender and depressed bill, more strongly bristled rictus, 
ete. ; on which account they are more strictly * fly-catchers,” taking 
their prey in great part on the wing. 
Of the three families, the Turdidz contain a great variety of forms, 
and exhibit widely different characters, rendering it exceedingly diffi- 
eult to arrange them in any systematic or regular sequence, or to 
accurately define their boundaries. In my work on the Birds of North 
America, I placed the Mocking Thrushes among the Wrens, on ac- 
count of the distinct tarsal scutelle, and other characters. I am 
now, however, inclined to believe, with Dr. Sclater, that their place 
is with the recognized Turdidx; and among other reasons, on the 
ground of their more deeply cleft toes, and greater extension forward 
of frontal feathers. On the other hand, I have included Donacobius 
among the Thrushes, on’ account of the deeply cleft toes ; although, 
as in the Wrens, the open nostrils are considerably in advance of 
the frontal feathers. 
The following synopsis of such American forms of Zurdide as I 
have had the opportunity of examining, may serve to determine the 
genera artificially, even though their natural affinities be somewhat 
violated. Nowhere is it more difficult than here to furnish in linear 
series, trenchant and positive characters which shall at the same 
time express and illastrate their true relationships. Cichlerminia 
and Cinclocerthia, which I have not seen, are placed by Dr. Sclater 
the one between Turdus and Margarops, the other between Aham- 
phocinclus and Harporhynchus. The primary division is into 
Turdine, or species with the tarsi ‘‘ booted,” that is, having all the 
scutelle fused into a continuous plate covering the front of the tarsus 
and extending half way round on the two sides; and Mimine, or 
those with this same anterior half of the tarsus covered by a suc- 
cession of imbricated overlapping scales, usually seven in number. 
In one species of imocichla, placed in the first section, the division 
of the scutellz are appreciable, although they are all fused into one 
plate ; while in the Cat-bird the scutelle, in some specimens (as No. 
20,396), are quite indistinguishable—the leg here being as much 
“booted” as in the true Thrushes ; in others, however, they are per- 
