The cells are connected to each other in chains through their bristles. Each valve, or the top and bottom of the cell, is surrounded by 12-32 bristles. The bristles are about twice as long as the diameter of the valve and their split ends lie flat against the chain. The bristles at the end of the chain are different from the others. They curve inwards towards the middle of the chain, forming an umbrella shape. These end bristles have a spiral, wavy appearance and are not split into two parts.