Bradypterus is a genus of small insectivorous songbirds ("warblers") in the newly recognized grass warbler family (Locustellidae). 

1/ Gray Emutail, or Madagascan grassbird or feather-tailed warbler (Chích cỏ Madagasca, Bradypterus seebohmi)
The bird is found only in Madagascar. 

Locustellidae, Locustella is from Latin and is a diminutive of locusta, "grasshopper".
Bradypterus: Greek bradus slow, sluggish; -pteros -winged (pteron wing).