244 P. L. Sclater on the 



that locality, the bill is stronger, the black head extends far- 

 ther down the nape, and the under plumage of a much darker 

 tinge. 



29. Thamnophilus CjERUlescens, Vieill. 

 Batara negro y aplomado, Azar. No. 213; ii. p. 199, unde. 



Bat. pardo dorado, Azar. ii. p. 202, No. 214 ($), unde. 

 Thamnophilus cwrulescens, Vieill. Nouv. Diet. iii. 311 (J). 



Th. auratus, Vieill. 1. c. p. 312 ($). Th. ncevius, Gray's 

 Gen., i. p. 297 (pars.), d'Orb. Voy., p. 170 \ 



Hab. Paraguay (Azara) ; Bolivia, Chiquitos (d'Orb.) 



The account given by Azara of this bird seems to agree best 

 with the true " nazvius." As, however, we have here several 

 closely allied species, to all of which a loose description is 

 equally applicable, I am unwilling at present to attach this to 

 any of them, and propose to leave it by itself until the exami- 

 nation of specimens from Paraguay and Bolivia shall afford 

 the means of clearing up the doubt. 



30. Thamnophilus ventralis, Sclater. 



T. cinereus ; fronte, pileo, nucha et dorso medio nigris, hujus 

 pennis interne niveis ; alis nigro-brunneis, primariis stricte 

 albo limbatis ; tectricibus alaribus nigris albo terminatis ; rec- 

 tricibus nigris, duabus mediis exceptis, albo terminatis ; unae 

 utrinque extimse pogonii externi dimidio apicali alba, macula 

 ovali subapicali nigra; subtus albo-cinereus, ventre medio 

 crissoque albis lateribus subcinerascentioribus ; mandibula su- 

 periore pedibusque nigris, inferiore plumbescente. 



Long, tota 6*2, alse 2*8, caudse 2*6. 



Hab. South Brazil. 



The greater amount of black upon the head, and whiteness 

 of the middle of the belly and crissum, as also the want of 

 white edgings to the secondaries, distinguish the bird above 

 described, of which I possess one specimen, from Th. naivius 

 and ambiguus ; but the chief peculiarity which I rely upon for 

 its being undoubtedly separable from those birds consists in the 

 colouring of the outer pair of tail-feathers. The white spot 

 on the outer web of these, instead of being confined to a small, 

 nearly square space, as in the two other species, here reaches 



