G74: THE GENUS FORMICARIUS RIDGWAY. 



ail iiulistiiict central spot of white; sides of neck li^ht bister, like 

 liiiul neck, dhest dull slate color, the remaining under parts (except 

 under tail coverts) lighter gray, tinged with olive on sides and flanks 

 and inclining to whitisli gray on lower part of belly. Under tail coverts 

 Avliolly clear deep tawny. Bill, blackish; legs and feet, horn color. 

 Total length (skin), G.iO; wing, 3.52; tail, 2.18; exposed culmen, 0.75; 

 tarsus, 1.20; middle toe, 0.72. 



An adult in the collection of the .Vmerican Museum of Natural His- 

 tory (Xo. 30700 bis.) from Yungas, Bolivia, altitude 0,000 feet, (H. H. 

 liusby) is brighter bister brown above, with the dark centers of the 

 feathers of the pileum far less distinct; the white loral si)ot much 

 larger; the sides of the neck and postocular region ajjpreciably dif- 

 ferent in hue from the hind neck and other upper ])arts (deep wood 

 brown instead of light bister) and the under parts are paler and less 

 pure gray, the entire chest, as well as sides and flanks, being strongly 

 tinged with light brownish. The under tail coverts, however, are col- 

 ored exactly as in the Ycpiitos specimen. Length (skin), 0.50; Aving, 

 3.40; tail, 2.00; exposed culmen, 0.70; tarsus, 1.22; middle toe, 0.72. 



What will doubtless prove a local form of this species, aproachiiig 

 F. mgricapUlus Cherrie in its characters, is re])iesented in the collec- 

 tiou of ]\[essrs. Salvin and Godman by an adult from Sarayacu, north- 

 eastern Peru (C. Buckley). This differs from tlie Bolivian specimens 

 in its much darker coloration throughout, the upi)er surface ranging 

 from dark sepia on the head to mummy brown on upper tail coverts, 

 the under part? ranging from dark sooty slate on the chest to deep- 

 olive-gray on sides and flanks. The under Aving coverts and axillars 

 have their basal portion bright tawny, and tlie under tail coverts, 

 instead of being deep clear tawny, are rich chestnut. The white loral 

 spot is about as well developed as in the Yquitos specimen. Total 

 length (skin), 5.70; wing, ,'>.57; tail, 2.05; ex])Osed culmen, 0.72; tar- 

 sus, 1.25; middle toe, 0.71. 



Of this very easily recognized form 1 have seen three specimens, all 

 mentioned above. These agree minutely, in essential features, with the 

 original «h,'scrii)(ion and colored tigure by Lafresnaye and D'Orbigny, 

 in which the cinnamomeous coloring on the sides of the neck in all the 

 related species (except F. nl^ricapiUus Cherrie) is conspicuously 

 absent, and no doubt represent the true F. analls. In the Lafresnaye 

 collection, for sometime the property of the Boston Society of Natural 

 History, are the alleged types of i*'. (oitdi.s: but they certainly are not the 

 tyi)es of that species, siiKH* they unquestionably belong to the forms 

 subsequently sc])aratcd as F. crissfdis by Cabanis and F. safiiratus by 

 the author of the i)rescnt i)aper, and are i)robably froDi Guiana or lower 

 Amazonia and some ])art of Colombia, respectively. (See remarks 

 under F. crissaJis and F. sat unit n.s. on pages 071 and 079) 



.'vccordiug to B'.Orbigny, the naked postocular space is Avhitish in 

 life, the eyes red, and the feet violet; but Ta'czauOwski (Oru. P(?r., ii. 



