90 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 
[Ramphocenus] semitorquatus Scuarer and Satvin, Nom. Av. Neotr., 1873, 73. 
Rhamphocenus semitorquatus ScuaterR, Ibis, 1883, 96 (Veragua, Panama; Antio- 
quia, Colombia; crit.); Cat. Birds Brit. Mus., xv, 1890, 262 (Veragua; 
Antioquia).—Satvin and Gopman, Biol. Centr.-Am., Aves, ii, 1892, 219 
(La Balsa, Rio Sucio, and San Carlos, Costa Rica; Santiago de Veragua, 
Calovevora, and Lion Hill, Panama; Colombia).—Banes, Proc. New Engl. 
Zool. Club, iii, 1902, 42 (Volcan de Chiriqu{, Panama, 1,000-2,000 ft.).— 
CarrRIkerR, Ann. Carnegie Mus., vi, 1910, 612 (Caribbean lowlands to 1,500 
ft., Costa Rica; habits). 
[Rhamphocenus] semitorquatus SHarPs, Hand-list, iii, 1901, 28. 
(?)Rhamphocenus cinereiveniris (not of Sclater?) ScuarER and Sanvin, Proc. 
Zool. Soc. Lond., 1879, 525 (Antioquia, Colombia; crit.). 
Genus CERCOMACRA Sclater. 
Cercomacra SctatER, Proc. Zool. Soc. Lond., 1858, 244. (Type, Myrmothera 
cxrulescens Vieillot.) 
Medium-sized Formicariide (length about 120-135 mm.) with 10 
rectrices, distinct rictal bristles, and color plain gray or blackish 
with concealed white dorsal patch and narrow white tips to wing- 
coverts (sometimes with broad white tips to lateral rectrices), the 
adult female of some species brown above, tawny or ochraceous 
below. 
Bill shorter than head, moderately stout, rather broad and de- 
pressed basally, its width at frontal antie much greater than its 
depth at same point and equal to at least half the distance from 
nostril to tip of maxilla; culmen distinctly ridged, straight basally, 
gently decurved for about terminal half, the tip of maxilla distinctly 
but not conspicuously uncinate; maxillary tomium nearly straight, 
minutely notched subterminally; mandibular tomium nearly straight, 
minutely (very indistinctly) notched subterminally; gonys faintly 
convex (more decidedly so basally), moderately ascending terminally. 
Nostril exposed, posteriorly in contact with feathering of latero- 
frontal antie, small, broadly oval, margined above and posteriorly 
by very narrow membrane, with an internal tubercle showing within 
posterior portion. Rictal bristles distinct; feathers of chin and 
malar apex with distinct terminal sete. Wing moderate, with 
longest primaries distinctly longer than secondaries; sixth, fifth and 
fourth, or fourth and fifth primaries longest, the tenth (outermost) 
one-half to nearly three-fifths as long as the longest, the eighth 
about as long as secondaries. Tail as long as wing or a little shorter, 
graduated (graduation about equal to length of tarsus), the rectrices 
(10) broad, rounded terminally. Tarsus much longer than whole 
culmen (a little more than one-third as long as wing), slender, the 
acrotarsium rather distinctly scutellate, the planta tarsi completely 
fused; middle toe, with claw, much shorter than tarsus (about as 
long as exposed culmen); outer toe, without claw, reaching to 
beyond middle of subterminal phalanx of middle toe, the inner toe 
