Triphora exigua (C.B. Adams, 1850) is a nomen dubium (not a nomen nudum) according to WoRMS. Cerithium exiguum C.B. Adams, 1850 is unidentifiable ánd a primary junior homonym. The name was - unjustly - used for several brown-coloured Triphora specimens and should therefore not be used any more (Marien Faber in litt.).