Prionovolva is recharacterized as having a wide aperture, outer labral teeth visible in lateral view, and a strongly projecting, smoothly curving terminal ridge. A new species, Prionovolva melonis, is described from Somalia, Zanzibar, and the Saya de Malha Bank, Indian Ocean, and compared to P. breris (Sowerby 1,1828) and P. castanea Cate, 1978, with which it has been confused. Prionovolva castanea is newly synonymized with P. breris, as is P. nivea Cate, 1974. Synonymy of P. wilsoniana Cate, 1973 with P. brevis and placement of Galera choshiensis Cate, 1973 in Prionovolva are confirmed. Prionovolva freemani Liltved & Millard, 1994 is reinstated to Prionovolva, having previously been placed in Habuprionovolva and Testudovolva, and its range is extended from South Africa to Mozambique. Prionovolva ericae Cossignani & Calò, 2002, is transferred to Testudovolva, yielding the new combination T. ericae. A lectotype is designated for Prionovolva aureomarginata Shikama, 1973, which is synonymized with Margovula tinctilis Cate, 1973. A lectotype is designated for Globovula cavanaghi Iredale, 1931, with the same specimen designated as neotype of Amphiperas bullatus Gould, 1861, making them objective synonyms, but G. cavanaghi is given precedence under ICZN Article 23.9.