中文摘要：

本文主要描述了南海南沙群岛永署礁南永3井微型腹足类盘足目,翼舌目和异旋目共49个种,包括2个新种,Serpulorbis spiralis sp.nov.和Cerithiopsis bellatulus sp.nov.。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 49 microgastropod species from the core Nanyong-3 of the Yongshu Reef lagoon of the South China Sea, including two new species： Serpulorbis spiralis sp. nov. and Cerithiopsis bellatulus sp. nov. , of the Orders Discopoda, Ptenoglossa and Heterostropha. These species are small in size, generally less than 2mm. Most of the species are typical tropic representatives, of wide geographic distribution. This paper adopts systematical classification of Okutani （2000）. The majority of the species are the first records in this area.