the Province of Buenos Ayres. 177 



? . Upper mandible dark horn-colour between the nos- 

 trils, and from there to the corner of the mouth dull primrose- 

 yellow. Under mandible, tip horn-colour, fading into prim- 

 rose-yellow towards the base. Inside of mouth very pale 

 horn- colour, with a tinge of yellow under the tongue. This 

 species is common at Baradero in April, but only black- 

 plumaged birds are seen. 



39. Machetornis rixosa (Vieill.) ; Scl. et Salv. P. Z. S. 

 1868, p. 143. 



Spring visitor, arriving in August ; but it does not seem to 

 be a common bird. 



40. Centrites NIGER (Bodd.) ; Scl. et Salv. P. Z. S. 1868, 

 p. 142. 



Autumn and winter visitor, and common on open camp- 

 land. Common at Baradero in April. 



41. Hapalocercus flaviventris (Lafr. et D'Orb.) ; Scl. et 

 Salv. P.Z.S. 1869, p. 160. 



Having only observed this bird from October to April, I 

 suppose it is a summer visitor. Between these months it is 

 common in the riverain wood and in low damp places where 

 the reeds aflPord any cover. Plentiful at Baradero in April. 



42. Serpophagasubcristata (Vieill.); Scl. et Salv. P. Z. S. 

 1868, p. 142. 



Resident and abundant everywhere. Common at Baradero 

 in April. 



43. Serpophaga nigricans (Vieill.) ; Scl. et Salv. P. Z. S. 

 1868, p. 142. 



Resident, but not so common as the last-named species. 

 I have always found this bird amongst the bushes and thick 

 growth of sauce- and ceiba trees near the river. 



44. Cyanotis AZAR^ (Licht.); Scl. et Salv. P.Z.S. 1869, 

 p. 159. 



Resident and common in reed-beds, generally found where 

 there is a foot or so of water. It has a low piping note, which 

 it constantly utters whilst busily hunting over the reeds for 

 insects. Common at Baradero in April. 



