On Polypodium vulgare. Dundee, March 30, 1839. Plethodon somewhat emergent from beneath the cuticle, reticular, with a minute orifice, discharging white sporidia, sporules minute. although the sporidia a being discharged adhere in a series, yet no connecting gelatine is apparent, hence this species seems excluded from Normandia. from Athenea it differs by the absence of [illegible]. It appears on close examination a minute pale translucent point at the back of the Fern. Aifice narrow, from which a pressure the sporidia's are ejected, but they may be directed without any mechanical force in one location springing in a spirilliform manner and carrying the orifice with a white series. Sporidia have with a celluloid single coat, water accumulates, narrower at one end. Sporules as reinforcement points accumulate at one end. Plethodon partially emergent, when the cuticle of the Fern is removed they appear suspended in a thick, more opaque cup (a. the gland in the cup of the Fern) rising about half way towards the ruminant, and leading out numerous white cadicles, down into the farinaceous substance of the Fern leaf.