LAPLYSIA, a genus of marine insects, belonging to the order of vermes mollusca. The body is covered with membranes reflected. It hath a shield-like membrane on the back, a lateral pore on the right side; the vent on the extremity of the back, with four feelers resembling ears. The figure shews the common size. Those of Italy grow to the length of eight inches. Pliny calls it ossa informis; and, placing it among the venomous marine animals, says that even the touch is infectious. The smell is extremely nauseous.