The author, in this communication, referred, in the first instance, to the three species of Lamelliferous Polyparia, described in his “British Animals,” Edin., 1828, exhibiting specimens of the Caryophyllea cyathus, and Turbinolia borealis of that work, together with a characteristic drawing, by the late Mrs Hibbert, of the Pocillopora interstincta, there alluded to as a native of the Zetland seas. He then exhibited a specimen, six pounds in weight, of the Madrepora prolifera of Müller, which was found last summer by fishermen, their lines having become entangled with it, in the sea between the islands of Rum and Egg. This species was known to Pontoppidan, as a native of the Norwegian seas, and is now ascertained to be a native of the Hebrides.