( 67 ) 



Nos. 1981, 1997, 2054. ? ? , Goyaz, April 1906.— Wing 65— 66J ; tail 55— 5f! ; 

 hill 16 mm. 



No. 1647. ? ad., Faz. Esperaiii;a, December 1905. — Wing 65 ; tail 57 ; liill 

 16 mm. 



Nos. 2294, 2295. ? ?, Rio Araguaya, July 1906.— Wing 68|, 69; tail 59, 

 00; bill loj, 16 mm. 



No. 2209. c? jnv., Rio Araguaya, June.— Wing 67 ; tail 57i ; bill 16i mm. 



Besides this series I liave examined in the present connection : 3 cJc?, 3 ? ? 

 from Chapada, received in e.-ccbange from the American Mnsenm, New York ; 

 1 c? ad., Jaboticabal, 1 ? ad., Itapnra, S. Panio, obtained from Prof, von Ihering ; 

 1 cJ ad., 1 c? imm., 1 ? ad., Engenho do Cap. Gama, types of T. sticturus Pelz., 1 t? 

 ad., Corumba, 2 ? ? , Urncum, 1 S ad., Goyaz, all belonging to the Vienna Mnseum ; 

 and 1 c? imm. from Goyaz, Castelnan & Deville coll., kindly lent by Dr. Mdn^ganx, 

 of the Paris Museum. 



Of the typical T. a. ambigum, I had before me twenty specimens of both sexes 

 from Bahia and the environs of Ilio de Janeiro, in the Tring and Vienna Mnseums. 



On carefully comparing this material, I find two forms easily separaVile. 

 The males from Goyaz, Blattogrosso, and Northern S. Paulo differ from those of 

 trne T. ambigiius by their lighter grey back, much paler lower parts with a large 

 amount of white in the middle of the abdomen, smaller bill, and by the white 

 marginal spot on the inner web of the outermost rectrix being absent or but faintly 

 indicated. In many cases the white sjiot on the inner web of the other rectrices is 

 likewise wanting ; this character, however, is subject to much individual variation 

 (see below). The females can also be easily recognised by their much brighter 

 ochraceous-buif foreneck, chest, and sides, and by the distinct white area in the 

 middle of the abdomen. In T. a. ambigiius ? all the lower surface (except 

 the whitish throat) is uniform dull buii-brown or fulvescent brown, hardly shading 

 into pale buff along the middle line of the belly. 



Variation in the markings of the rectrices in the males : 



in the type of T. sticturus (c? ex Engenho do Gama) and in the S from 

 Cornmbii the outer web of the rectrices only shows a white marginal spot. Two 

 <Jc? from Chapada and that from Jaboticabal have on both webs a white stripe 

 or spot, just as in T. a. ambiguus, but the markings on the inner web of the 

 two outer tail-feathers are decidedly narrower. In another <S from Cha])ada and 

 in two from Goyaz the two outer rectrices have the white stripe on the outer 

 web only, while the remaining fonr are spotted on both webs. Six other c?(? 

 from Goyaz have all rectrices spotted on both sides. 



The following summary of the geographical distribution of the two forms may 

 be not unwelcome to ornithologists interested in the neotropical avifauna : 



a. T. a. ambiguus (Sws.). 



Forest region of South-eastern Brazil from Rio de Janeiro to Bahia. 



State of Rio de Janeiro : Rio de Janeiro, Sapitiba, Registre do Sai (Natterer), 

 Corcovado (Zelebor), Cantagallo (Enler). Minas Geraes (Such). Bahia : (!atinga 

 woods of the interior of Bahia (Swainson). 



b. T. a. sticturus Pelz. 

 Interior of Brazil from Goyaz to Western Mattogrosso and south to the northern 

 districts of S. Paulo. 



