Flame cells present in flatworms are specialised in

Flame cells function like a kidney, removing waste materials. 

Flame cells are ciliated cells that form part of the excretory and osmoregulatory system of flatworms, rotifers, and nematode worms. 

This system, known as a protonephridium, consists of branching tubules that open to the exterior through excretory pores; flame cells occur at the ends of the tubules, into which their cilia project.