(ofEnnea percivali Preston, 1913)Preston, H. B. (1913). Diagnoses of new species and varieties of agnathous Mollusca from Equatorial Africa. <em>Proceedings of the Zoological Society of London.</em> 81 (2): 194-218, pl. 32-35. [30 May]., available online athttps://www.biodiversitylibrary.org/page/31994693 page(s): 216, pl. 35, figs 5, 5a. [details]
original description(ofEnnea percivali Preston, 1913)Preston, H. B. (1913). Diagnoses of new species and varieties of agnathous Mollusca from Equatorial Africa. <em>Proceedings of the Zoological Society of London.</em> 81 (2): 194-218, pl. 32-35. [30 May]., available online athttps://www.biodiversitylibrary.org/page/31994693 page(s): 216, pl. 35, figs 5, 5a. [details]