Septa triangularis G. Perry, 1811

    Authorities are not unanimous on the identity of Septa triangularis G. Perry, 1811, but the shape, coloration, and pattern suggest a sub-adult Cymatium perryi Emerson and Old, 1963.  The latter authors considered the Perry taxon a species inquirenda, which means a species of doubtful identity requiring further investigation.
    Below is George Perry's description and illustration from:   Conchology or the natural history of shells: containing a new arrangement of the genera and species, illustrated by coloured engravings, executed from natural specimens, and including the latest discoveries. William Miller, London pp 1-4 + 61 plates with facing captions (unpaginated) + index (1 p.) [Plate XIV, fig. 6].

Septa triangularis G. Perry, 1811