082 THl^ GENUS FORMICAKIUS RIDCiWAY. 



Adult fcnude (No. ()SL*45, same locality and colle(;tor). — Similar to the 

 adult male, as described above, but upi)er parts less reddish browu 

 (nearer "bister" than " munnny,"tlie upper tail coverts bri!.;:ht mummy 

 brown instead of chestnut nniber); chest and sides brownish slate- 

 gray, the latter Mashed witli olive-brown; middle line of breast and 

 belly, also the anal region, dirty Avhitish. Total length (skin), 0.30; 

 wing, ').40: tail, -.10: exposed cnlmen, 0.72; tarsus, l.L*.']; middle toe, 

 0.70. 



Yonn<i female (No. 8108, Museo Nacional de Costa Eica, Jimenez, 

 Costa ]\ica, July 11, 1892, A. H. Verrill). — Similar in general colora- 

 tion to the adult female, but whole i)ileum uniform brownish black 

 with tips of feathers more browu, chin and throat butt" spotted with 

 dull black, chest sooty blackish, feathers of belly tipped with brownish 

 gray (producing an indistinct spotted or clouded appearance), and 

 longer under tail coverts uniform black. Basal two-thirds of lower 

 mandible light colored (dull j-ellowish in dried skin). 



The nineteen adult specimens of this form show the same amount of 

 individual variations as other forms. This variation affects chiefly 

 the exact hue of the brown color of the upper parts (which ranges from 

 rich mummy brown to clear bistre on the back and rich burnt-amber, 

 almost chestnut, to mummy brown on the ujtper tail coverts, the aver- 

 age hue beiug intermediate) and the relative amount of browu and 

 gray on the under parts. The adult male described above has the 

 under parts more brown than any others in the entire series. Tlie 

 opx)Osite extreme is represented by No. 912G4, U. S. National Museum, 

 from Los Sabalos, Nicarag.ua (adult male. May 17, 1883, C. C. Nut- 

 ting), and No. 7170, Costa Eica National Museum, Eeventazon, Costa 

 Eica (adult male, February 21, 1892, N. Carrauza), in which the uiuler 

 parts are a nearly uniform deep smoky slate color, (linker on the chest, 

 paler on the belly, only the sides and flanks being distinctly tinged 

 with olive. In a few specimens (as No. 128349, adnlt nnile, Escondido 

 Eiver, Nicaragua, Septembei- C, 1892, C. W. Eichmoml) the belly 

 is (juite extensively light colored — pale bufly grayish, sometimes in- 

 clining to soiled white towaid the anal region. In the coloration of 

 the under tail coverts there is practically no variation, the longer or 

 more posterior feathers being always blackish, merely margined with 

 rusty brown, only the shorter or more anterior feathers being uniform 

 rusty, aisd this not nearly so light and tawny a hue as on the same feath- 

 ers of F. lioffmanni. In none of the nineteen specimens does the rusty 

 color of the sides of the neck show a tendency to extend across the 

 fore neck, forming an incipient or occasionally distinct though narrow 

 collar, as frequently occurs in i^. hoffmanni; and, while the black of the 

 throat always has a definite posterior outline, the color of the chest 

 is sometimes so dark that the contrast is by no means conspicuous. 



From F. nionilifjer thia form maybe readily distinguished by the 

 entire absence of the rusty baud across the fore neck and the more 

 rusty shorter under tail coverts. 



