中文摘要：

本文主要描述了南海南沙群岛永暑礁南永3井微型腹足类盘足目,新腹足目,异旋目,豆楯目和囊舌目共70个种.这些种类个体非常微小,大多数小于2mm.绝大多数种类为典型的热带海区分子,它们具有广泛的地理分布.本文按Okutani（2000）分类系统进行了分类.绝大多数种类系南沙群岛海区首次记录.

英文摘要：

This paper describes 70 microgastropod species under Orders Discopoda, Neogastropoda, Heterostropha,Cephalaspidea and Sacoglossa from the core Nanyong-3 of the Yongshu Reef lagoon of the South China Sea. These species are small in size, generally less than 2 mm. Most of the species are typical of tropic representatives, having wide geographic distribution. This paper adopts systematical classification of Okutani （2000）. The majority of the species are the first records in this area.