The food-gathering arm of a blastoid or a cystoid (phylum Echinodermata, subphylum Blastozoa). The arms are biserial and are simple versions of the arms that occur in crinoids (Crinoidea). They are rarely preserved.
科学参考收录了60776条科技类词条，基本涵盖了常见科技类参考文献及英语词汇的翻译，是科学学习和研究的有利工具。