Apparently from Greek "tropaias", which is feminine.
Melvill, J. C. (1910). A revision of the species of the family Pyramidellidae occurring in the Persian Gulf, Gulf of Oman and North Arabian Sea, as exemplified mostly in the collections made by Mr. F.W. Townsend (1893-1900), with descriptions of new species. iProceedings of the Malacological Society of London. 9: 171-207, pls 4-6. available online athttp://www.biodiversitylibrary.org/page/30825003