PTILOGONYS. 411 
Tail longer than wings, somewhat fan-shaped, nearly even in type, the slight 
emargination greater than the rounding (in caudatus much graduated, with 
central feathers prolonged). Feathers broad, the outer webs very narrow. 
Wings pointed, although the outer feathers are much graduated; Ist quill 
not half the 2d, which is shorter, the 3d rather longer, than secondaries ; 5th 
and 6th longest; Ist, 2d, and 3d attenuated and acuminate at end. 
Bill short, much depressed, hooked and notched at both tips; gape wide 
and deep; commissure straight; culmen for terminal half and short gonys 
considerably curved. Nostrils oval, bordered above and behind by mem- 
brane, the frontal feathers reaching not quite to the posterior margin ; rictal 
bristles distinct, but moderate. 
Legs weak; tarsi very short, less than middle toe and claw, with strongly 
marked rough scutelle (seven) anteriorly, one or two divisions on the lower 
part of sides. Outer toe rather longer than inner, and reaching just beyond 
base of middle claw. Hind claw considerably longer than middle. Basal 
joint of middle toe adherent for almost its whole length to one and a half 
joints of outer; internally for basal half of length to basal half of first joint 
of inner. 
P. caudatus, very similar otherwise, differs remarkably in structure of tail, 
which is cuneate and nearly one and a half times the length of the wing; 
the two central feathers greatly prolonged and tapering gently to a rounded 
narrow tip, the other feathers graduate from these to the outermost. 
Ptilogonys differs from Myiadestes in more compact plumage ; 
a shorter, broader, thicker bill; the frontal feathers much less 
bristly ; the nostrils broader and more exposed, with a greater ex- 
tent of naked membrane behind them. ‘The legs are shorter, but 
stouter ; tarsus much shorter and roughly scutellate, not smooth ; the 
claws thicker and more curved ; the hinder considerably larger than 
the middle. Nearly the whole extent of basal joint of middle toe 
is adherent externally, not the half only; internally adherent for 
half to the basal half of first joint of inner, which in M/yiadestes are 
divided to base. The wing is much more graduated; the third quill 
having the relationship to the longer ones that the second has in 
Myiadestes, The tail lacks the deep emargination of Myiadestes ; 
the lateral feathers are of equal width to near the end, or even 
wider, instead of becoming narrower. 
There has been much diversity among writers in the spelling of 
the name of this genus, Mr. Swainson, its author, having himself 
written it very differently, His first rendering of the name, how- 
ever—Ptilogonys—is more nearly correct than the subsequent ones, 
as compounded of wraov and yo, or feathered knee, in allusion to 
the tuft of cottony feathers on the tibie. 
The two known species of Péilogonys are quite similar in colora- 
tion, but differ markedly in shape of tail, which in one is even, in 
the other greatly cuneate. The characters are as follows :— 
