flame bulb

…the hollow cell, called a flame bulb (or flame cell) if it possesses cilia, or a solenocyte if it has a flagellum. In either form, the cilia or the flagellum wave filtered urine down the tube to the outside.

…type known as solenocytes, or flame cells. The possession of solenocytes by some annelids is one of the characteristics that allies them with other nonsegmented phyla that have no true body cavity. They also have a system of tubules opening at the surface and ending internally in flame cells embedded…