The author, after noticing the fishes in which an electrical apparatus had been discovered, stated that, with the exception of Geoffroy St Hilaire, no writer had endeavoured to shew that Skates possessed electrical organs. The organ to which that writer alluded, the author regarded as nothing else than muciparous ducts, identical with the very same organs in the Torpedo, and quite distinct from the electrical organs. The circumstance was then mentioned which directed the author's attention to the tail of the skate, and led him to suppose that an electrical organ might exist in it.