Proostracum
Pro`os´tra`cum
n. | 1. | (Zool.) The anterior prolongation of the guard of the phragmocone of belemnites and allied fossil cephalopods, whether horny or calcareous. See Illust. of Phragmocone. |
英语词典包含2567994条英英释义在线翻译词条,基本涵盖了全部常用单词的英英翻译及用法,是英语学习的有利工具。