Any of several velvety, usually brightly colored worms of the phylum Nemertina(or Nemertea) that have a flat, unsegmented body with an extensible proboscis and live in the sea or in the mud of the intertidal zone.

• 纽形动物扁形动物门的一个纲，具有柔软身体、常常是鲜艳颜色的蠕虫，无体腔、不分节、可收缩，生活在海中或潮湿地带的泥中