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Oba. The specimens from Salto do Girao (Rio Madeira) and Rio Jurud,, 

 W. Brazil, mentioned by me as belonging to this form (Nor. Zool. xiii. p. 368), 

 are probably referable to T. c. persimilis. When I examined them (both are 

 adult <?iJ) I did not know that there was in the interior of Brazil a nearly 

 allied form without a white dorsal patch. 



$ ad. Uniform drill, blackish slate-grey, the bases of the interscapular feathers 

 scarcely paler cinereous than the apical portions. Edge of the wing dark slate-grey. 

 Axillaries and under wing-coverts pale grey. 



i ad. Upper parts light olive-brown, with a large concealed white inter- 

 scapular blotch. Throat and breast pale buft'y brown, abdomen and under tail- 

 coverts tawny ochraceous (Ridgw. Nomencl. v. fig. 4). 



Material: 8 c?c? ad., 3 ?? from Bahia, in the British, Tring, and Vienna 

 Museums. 



b. T. caesius hoffmannsi Hellm. 

 Cfr. Nov. Zuol. xiii. p. 367. 



llnh. District of Para. 



S ad. Above plumbeous (rather darker than Ridgw. ii. 15), below cinereous. 

 Throat variegated with white, ear-coverts with narrow white shaft-lines. Edge 

 of the wing, axillaries, and under wing-coverts white. 



? ad. Exactly like the ? of T. c. caesius. 



Material : 3 <?<? ad., 1 6 jr., 3 ? ?, Para. 



c. T. caesius per&imilis Hellm. 



Hah. Envirous of Teffe, on the south bank of the Rio Solitudes, Brazil. 



c? ad. Above rather deeper plumbeous than T. c. hoffmannsi, nuderparts deep 

 bluish plumbeons, nearly as dark as the back. Ear-coverts aud edge of the wing 

 uniform slate-grey. Throat dark plumbeous, only the chiu sometimes with a 

 few indistinct whitish shaft-lines. 



? ad. Differs at a glance from the ? ? of T. c. caesius and '/". c. hoffmannsi 

 by having the breast and abdomen of a much deeper ochraceous or ferruginous 

 colour, the throat and foreueck alone being pale brownish, mixed with buff. 



Material : 2 SS ad., 1 6 vix ad., 3 ? ? from Teffe. 



This bird appears to have a peculiarly restricted range, as in North-east Peru 

 and Northern Bolivia the next form, '/'. c. glaucus, is met with. 



d. T. caesius glaucus Cab. 

 Thamnomanet glaucus Cabanis, Arch.f. \ T «turtj. 13. i.p. '230 (1847.— Cayenne). 



Huh. Cayenne, Surinam, British Guiana, thence through the Orinoco region 

 (Manduapo, Bichaco, and Canra River) to the Rio Negro (Marabitanas, Rio Icanna, 

 Barcellos, Manaos), to Eastern Ecuador, North-east Peru (Yurimaguas, ( 'hamicuros, 

 Pebas, etc.), aud Northern Bolivia (Yuracares). Also found in Bogota collections. 



$ ad. Differs at once from all the preceding forms by the presence of a large, 

 concealed white interscapular patch. Edge of the wing dark slate-grey. General 

 colour as in T. c. persimilis. 



? ad. Exactly like that of T. c. persimilis. 



1 am unable to detect any differences between specimens from Cayenne, 

 Guiana, etc., aud others from the Rio Negro, Peru, aud Yuracares, Bolivia.. All 



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