A specialised sensory organ located in the subepidermal connective tissue at the rostral end of late larval and adult amphioxus. They consist of between 1 and 4 nerve cells with axons, each with 2 cilia, surrounded by up to 7 sheath cells. The cilia extend into a protrusion of the basal lamina which surrounds each corpuscle. The axonal process contributes to the rostral nerve. [ http://www.ncbi.nlm.nih.gov/pubmed/11523831 ]