Siphonosoma dayi (Stephen, 1942)
Body surface ridged or covered with low, quadrangular simple papillae. Trunk long. Introvert (anterior part of body that can be retracted into trunk) short, when everted, ring of short tentacles around mouth visible.
Live in rock-crevices or burrow into sandy mud. Detritus-feeders
Three species with restricted distributions recorded in South Africa. S. dayi a sought-after bait species colloquially known as sandworm.