original description
(of Cyclostoma gratum Petit de la Saussaye, 1850) Petit de la Saussaye, [S.]. (1850). Notice sur le genre <i>Cyclostoma</i>, et catalogue espèces appartenant à ce genre. <em>Journal de Conchyliologie.</em> 1(1): 36-55, pls 3-4., available online at https://www.biodiversitylibrary.org/page/25135835
page(s): 53, pl. 3, fig. 10 [details]
additional source
Godwin-Austen, H. H. (1903). Morphological observations on species belonging to the families Cyclostomidae and Helicidae. In: Forbes, H. O. (ed.), The Natural History of Sokotra and Abd-el-Kuri. Liverpool (The Free Public Museums): 159-174, pl. 13A. , available online at https://www.biodiversitylibrary.org/page/24884398 [details]
From editor or global species database
Type locality "les montagnes d'Abd-el-Goury" [details]
From editor or global species database
From other sources