腹足纲，新腹足目，笔螺科。笔螺在中国分布于福建、广东、台湾、海南和西沙、南沙群岛。笔螺无口盖，壳口细长，壳口内唇上常有三条齿状襞，这样可以逃避敌害。其多以裂叶石莼及其它海藻为主食，分布于礁岩裂缝彧潮池附近。
学名：mitre shell
英文名：Pen conch
This species belongs to the family of Mitridae,order of Neogastropoda.Distribution in Fujian, Guangdong, Taiwan, Hainan and Xisha, Nansha Islands in China. There are three dentate folds in mouth lip, so they can escape the enemy.Mainly lives on the leaves of Ulva and other seaweed, and inhabits in the reef fissure near the tide pool.