338 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 
Threnetes ruckeri RetcHenBAcH, Aufz. der Colibr., 1854, 15; Troch. Enum., 1855, 
12—Bonararte, Rev. et Mag. de Zool., 1854, 249; Ibis, 1873, 428 (Guate- 
mala).—Satvin and Exuior, Ibis, 1873, 278, part (Costa Rica; Panamé; 
synon.; crit.).—Munsanr and Verreaux, Hist. Nat. Ois.-Mouch., i, livr.1, 
1873, 47.—Musant, Ann. Soc. Linn. Lyon, xxii, 1875, 200—Satvin, Cat. 
Birds Brit. Mus., xvi, 1892, 265 (Guatemala; Angostura, Costa Rica; Mina 
de Chorcha, Paraiso, and Lion Hill, Panamé).—Satvin and Gopman, Biol. 
Centr.-Am., Aves, ii, 1892, 316.—Boucarp, The Hum. Bird, ii, 1892, 84 
(Veragua); Gen. Hum. Birds, 1895, 371, part (Verégua).—Ricumonp, Proc. 
U. 8. Nat. Mus., xvi, 1893, 516 (Rio Escondido, Nicaragua).—Banes, Auk, 
xxiv, 1907, 295 (Pozo del Rio Grande, Costa Rica).—Carriker, Ann. Car- 
negie Mus., vi, 1910, 518 (Caribbean lowlands of Costa Rica; habits; descr. 
nest and eggs). 
[Threnetes] ruckeri ScLatER and Satvin, Nom. Av. Neotr., 1873, 79.—SHARPE, 
Hand-list, ii, 1900, 98 (Panam4; Costa Rica; Guatemala). 
T\hrenetes] ruckeri Harrert, Das Tierreich, Troch., 1900, 14 (monogr.). 
(?) Threnetes ruckeri Boucarp, The Hum. Bird, v, 1895, 7 (Rio Dagua, n. w. 
Colombia). 
Genus AITHURUS Cabanis and Heine. 
Polythmus (not Polytmus Brisson) Lesson, Tabl. Esp. Ois.-Mouch., 1829, p. 
xviii. (Type, Trochilus polytmus Linnzus.) 
Polytmus (not of Brisson) Rercnensacu, Av. Syst. Nat., 1849, pl. 39. (Type, 
Trochilus polytmus Linnzus.) 
Aithurus 4 CaBanis and Herne, Mus. Hein., iii, March, 1860, 50. (Type, Trochi- 
lus polytmus Linnzeus.) 
Aethurus (emendation) Simon, Cat. Troch., 1897, 24. 
Medium-sized Trochilide (length, not including elongated rectrices, 
about 100 mm.) with outermost (tenth) primary shorter than the 
next,’ nasal operculi nude, and tail about two-thirds as long as wing, 
double-rounded in female but in male forked and with the next to 
outermost pair of rectrices excessively elongated; adult male with 
a crest on each side of occiput, top and sides of head (including 
crests) together with tail black, back, etc., and under parts metallic 
green; the female dull white below, and lateral rectrices broadly 
tipped with whitish. 
Bill a little longer than head, broad and depressed basally, faintly 
decurved; culmen rounded anteriorly, posteriorly contracted into a 
ridge, especially on mesorhinal portion (ridged only at extreme base 
in females); tomia smooth throughout; mandible with a broad longi- 
tudinal groove above middle portion. Nasal operculum rather nar- 
row, moderately tumid, nude except for upper-posterior portion, the 
frontal feathering extending to about its middle portion with a nar- 
rowly convex or nearly truncate anterior outline. Tarsus very 
stout, feathered on upper-anterior portion; lateral toe about equal 
@ “Von defSoupoc (stets kampflustig).’” (Cabanis and Heine.) 
b Aithurus is the only genus in the entire family in which the tenth primary is 
shorter than the ninth, except Goldmania (adult male, see p. 452.) 
