Halystina simplex (Barnard, 1963) *
Seguenzia simplex Barnard, 1963a: 265, fig. 16a. Kensley, 1973: 42, fig. 96. Type loc.: Cape Point N 89° E, distant 36 miles, 700 fathoms [1280 m]; syntypes in SAMC (A7421).
Halystina simplex — B.A. Marshall, 1991: 88.
Distribution. Known only from the type locality.
Seguenzia Jeffreys, 1876 . Type species (m.): Seguenzia formosa Jeffreys, 1876 .