Sowerby, G. B. III. (1915). Descriptions of five new species of Mollusca of the genera
Drillia, Marginella, Apicalia, Plesiotrochus, and
Ringicula, all from Ceylon; also notes on the genus
Plesiotrochus.
Proceedings of the Malacological Society of London. 11 (4): 213–216. (29 March).