Lately the Leyden Museum received from Prof. K. Martin some specimens of Siphonaria sipho Sow., collected by himself at Batoe Kapal on the eastcoast of Hoeamoeal, a peninsula of the island of Ceram, one of the Molucca’s. Now it is not to be wondered at, that this species, widely distributed in the Molucca’s, was also found in the quoted locality; but an observation about its mode of attaching, made by Prof. Martin, who communicated it to me, and kindly allowed me to publish it, seems to be very remarkable. On a piece of „Glimmerschiefer” (n° 389 of Prof. Martin’s collection) he observed some small specimens of Siphonaria sipho, attached with their apices to the stone, so as to form little cups. Prof. Martin himself loosened the shells and took the soft parts out of them. The apices of the shells show no characters different from those of other shells of this species in our collection.