What is "polynoidae"

A family of scaled Polychaete worms known as the "scale worms". Short and flat, specimens reach as much as 20 cm in length and 10 cm width (Eulagisca gigantea). An almost-constant number of small segments is the norm. They are covered by scales, technically termed elytra. They are active hunters, but generally dwell in protected environments such as under stones.