OECHILTJS.— COLOPTEKUS. 17 



1. Orchilus atricapillus. 



Todirostrum ecaudatum, Lawr. Ann. Lye. N. Y. ix. p. 110'. 



Orchilus atricapillus, Lawr. Ibis, 1875, p. 385 '' ; Scl. Cat. Birds Brit. Mus. xiv. p. 89 \ 



" The entire crown is black ; the lores are also black, except a white mark extending from the bill to the eye 

 on each side, separating them from the black crown ; eyelids white ; under the eye blackish-ash ; the 

 colour on the sides of the head behijid the eye, extending to the hind neck and on the upper part of the 

 back, is of a clear bluish-cinereous; breast also cinereous, but lighter in colour; throat greyish- white; 

 abdomen pale yellow ; flanks and thighs blackish-ash ; under wing-coverts pale yeUow ; back, rump, and 

 upper tail-coverts yeUowish-green ; wings black, the primaries narrowly edged with olive-green, the 

 secondaries aud wing-coverts conspicuously margined with yellow of a greenish tinge ; tail black, the 

 feathers with margins of the colour of the back ; bill black ; tarsi and toes very pale flesh-colour. First 

 primary shorter than the fifth, third and fourth equal and longest. Length 2| inches, wing l^g, tail §, 

 biU Jg-, tarsus |." — Lawrence, loc. cit. 



ffab. Costa Rica, Angostura {CarmioU), Volcan de Irazu {Zeledon^). 



We have copied Mr. Lawrence's description of this species, as we have no specimen 

 of it ourselves. 0. atricapillus resembles 0. ecaudatus, but has a black head instead of 

 a grey one. The first specimen was obtained by Carmiol at Angostura, but being in poor 

 condition was referred by Mr. Lawrence to 0. ecaudatus. A second and better one was 

 secured during the late Prof. Gabb's expedition to the Talamanca country, this, with a 

 suggestion of Salvin's to the effect that the bird was really distinct and undescribed, 

 led to a fresh examination of the specimens and to their description under the name 

 of Orchilus atricapillus'^. The allied species has a wide range from Venezuela to 

 Bolivia, but is everywhere rare. 



COLOPTERUS. 



Colopterus, Cabanis, Monatsber. Ak. Berlin, 1845, p. 216 (type Motacilla galeata, BoM.) ; Scl, 

 Cat. Birds Brit. Mus. xiv. p. 90. 



This singular genus contains two species which differ from one another in that 

 C. galeatus, the type, has elongated occipital feathers like Lophotriccus, while C. pileatus 

 is not so adorned. The range of the genus extends from the State of Panama to 

 Colombia, Venezuela, Guiana, and the lower part of the Amazons valley. 



In the form of the bill, tail, and tarsi this genus is like Lophotriccus, but the peculiar 

 modification of the wings makes it easy to recognize both from Lophotriccus and the rest 

 of this group of genera. In the male of C. pileatus the outermost four primaries are 

 attenuated and shortened to little more than half the longest of the remaining normal 

 feathers. Of these four shortened feathers the outermost is the longest, and the rest 

 are gradually shorter, the fourth being the shortest of the series. In the female this 

 feature is not carried to nearly the same extent, moreover the outermost or first 

 primary is the shortest, and the fourth nearly attains its normal place in the wing. 

 In C. galeatus the male has three attenuated primaries instead of four. 



BIOL. CENTK.-AMBB., Aves, Vol. IL, December 1888. 3 



