acorn worm

acorn-worm的词性：
n.（名词）

1. Any of a class (Enteropneusta) of hemichordate, wormlike animals that inhabit shallow burrows in mud or sand flats of intertidal zones and are equipped with an acornlike proboscis used for digging and collecting food.
玉钩虫：一种（肠鳃类）半索动物，形似小虫，栖居泥沟或潮间带的沙子里，有橡实形的喙，用以挖土和收集食物