178 Mr. O. V. Aplin on the 



and suddenly to mount straight up into the air, and, as sud- 

 denly, turn and come straight down to its perch again, a 

 humming noise being produced. Often when flying along 

 this bird^s wings make a curious whirring rattle. 



41. Machetornis rixosa. Short- winged Tyrant. 

 Common and resident, a familiar bird about estancia 



houses. A pair bred in an old nest of Anumbius acuti- 

 caudatus, just in front of our living room, and they and 

 others were often to be seen running about on the quartz 

 sand of the inner and outer patios. The young were out of 

 the nest (which appeared to have had some wool added) on 

 the 28th October. The note is a shrill chattering, almost a 

 song. 



42. Centrites NIGER. Ucd-backcd Tyrant. 



An autumnal visitor. I only met with it on three occasions 

 (the first being on 20th April), frequenting the neighbour- 

 hood of small canadas. 



43. Habrura pectoralis. Thin-tailed Tyrant. 



I only met with two of these birds, one on the 7th and the 

 other on the 11th November, both males, and both in the 

 same place, a belt of young plantation with undergrowth of 

 grass, thistle, and other plants, joining the barley chacra. 



44. Serpophaga subcristata. Small-crested Tyrant. 

 Not uncommon in quinta and parts of monte, where it flits 



about the bushes like a Willow Wren. On 9th November 

 a pair were feeding brancher-young on the orange-trees in 

 the quinta. 



45. Serpophaga nigricans. Blackish Tyrant. 

 Common ; always seen along rivers or canadas, whether 



edged with monte or merely grown up with water-plants here 

 and there. When watching a pair one day in spring, I 

 observed the male raise his head and sing a burst of short 

 trilling notes. The usual sound one hears from it, however, 

 is a single plaintive note as it flits from one spot to another, 

 rather after the fashion of a PhyUoscojms, making its way 

 along a bush-sheltered water-ditch on a cold spring day. 



