The endemic fauna of achatinoid terrestrial molluscs for the Socotran Archipelago (Yemen) is revised. The main group falls into two genera, viz. Riebeckia E. v. Martens, 1883 with five species and Balfouria Crosse, 1884 with seven species, two of which are here described as new to science, i.e. Balfouria nitida n. sp., and Balfouria minima n. sp. Another globally distributed species could be found, and the endemic Zootecus species of the outer island of Abd el-Kuri is illustrated. The highly specialised shell structure of Balfouria is discussed, which is used to camouflage the animals with a mixture of clay and mucus protecting the shell during the individual lifetime of a specimen.

中文翻译：

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阿拉伯及邻近地区的大陆疟疾动物区系。Socotran群岛（Gastropoda，Pulmonata）的Achatinidae科（Coeliaxinae，Subulininae）

修订了索科特拉群岛（也门）的achatinoid陆地软体动物的特有动物区系。主要人群分为两个属，即。Riebeckia E. v。Martens，1883年，有5种；Balfouria Crosse，1884年，有7种，其中有两种被描述为科学新手，即Balfouria nitida n。sp。和Balfouria minima n。sp。可以发现另一种全球分布的物种，并举例说明了阿卜杜勒-库里岛外岛的地方性兽疫物种。讨论了Balfouria的高度专业化的壳结构，该结构用于在标本的单个生命周期中用黏土和黏液的混合物来伪装动物，以保护壳。