284 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 
about half its length, the rectrices (12%) abruptly and conspicuously 
acuminate, with their very rigid shafts twisted and strongly decurved 
subterminally. Tarsus about as long as exposed culmen, less than 
one-fourth as long as wing, slender, distinctly scutellate (enda- 
spidean); middle toe, with claw, shorter than tarsus; outer toe, with 
or without claw, equal to or very slightly longer than middle toe; 
inner toe, without claw, reaching to a little beyond subterminal 
articulation of middle toe; hallux much shorter than inner toe, not 
stouter; middle toe united to outer toe by whole of its first and about 
half of its second phalanx, to inner toe by greater part of its first 
phalanx; anterior claws rather large, very strongly curved and 
acute, that of the hallux slightly curved, as long as or longer than 
the digit. 
Coloration.—Tail-coverts, tail, and remiges chestnut or rufous- 
chestnut; pileum and back olive-brown, the former with narrow 
indistinct streaks of paler; beneath light olive-brown, throat brown- 
ish buff or clay color, the chest sometimes spotted with the same. 
Nidification.—Nests in holes; eggs glossy white. 
Range.—Costa Rica to British Guiana and upper Amazon Valley. 
(Four species. °) 
This genus is distinctly intermediate between Sittasomus and Dendrocincla, and 
I quite agree with Hellmayr that it is more nearly related to the latter than to the 
former; but I can not believe that it is ‘‘perhaps barely separable” from Dendrocincla 
(see Hellmayr, Bull. Brit. Orn. Club, xiv, 1904, 52), the difference in the character 
of the tips of the rectrices (in which character Deconychura is precisely like Glypho- 
rynchus and Sittasomus and very unlike Dendrocincia), even apart from the differ- 
ence in the form of the bill, being, in my opinion, quite sufficient to justify generic 
separation. I have not, however, seen Dendrocincla longicauda Pelzeln, which 
Hellmayr refers to Deconychura, and which may possibly bridge the gap apparently 
separating the two genera as understood by me. 
KEY TO THE SPECIES OF DECONYCHURA.¢ 
a. Rump brown like back (only the upper tail-coverts a bend of 
wing washed with cinnamon-rufous. 
b. Smaller (wing 95-102 in male, 86-90 in female; bill, from rictus, 24-25, 5); 
breast spotted or streaked with buff. (Southwestern Costa Rica and Panamé4.) 
Deconychura typica (p. 285). 
bb. Larger (wing 107-111 in male, 102 in female; bill, from rictus, 27-29 in male, 
25 in female); breast plain, like abdomen. (British Guiana to Rio Negro 
and Rio Madeira.)...........-...-.-Deconychura longicauda (extralimital).¢ 
@ Hellmayr was the first to call attention to the fact that this genus possesses twelve 
rectrices, not ten, as stated by its describer. (See Bull. Brit. Orn. Club, xiv, 
1904, 52.) 
b According to Hellmayr (Novit. Zool., xiv, 1907, 368). I have, however, seen 
only D. typica, from which alone the above diagnosis and description are taken. 
¢ Adapted from Hellmayr, Novit. Zool., xiv, 1907, 368. 
4 Dendrocincla longicauda Pelzeln, Orn. Bras., i Abth., 1868, 42, 60 (Borba; Mara- 
bitanas; Barra do Rio Negro); Sclater, Cat. Birds Brit. Mus., xv, 1890, 165.—Deco- 
nychura longicauda Hellmayr, Novit. Zool., xiv, no. 2, Nov., 1907, 367 (crit.). 
