The difficulties in the way of dredging at Madeira are many and considerable. This has probably prevented any of this work having been done since the publication of Mr Macandrew's list of Mollusca, presented to the British Association in 1854. The author having dredged for several years at Madeira, confirms Macandrew's generalisation of the Mediterranean character of the Mollusca— excludes 12 of Macandrew's named list as having crept in by mistake, and to the 115 remaining species identified by Macandrew as Madeiran has added 200 to 250 more, making nearly 400 in all, of which 80 or perhaps 100 are probably new. These he hopes soon to publish.