The name of Wentletrap, by which this shell is now so well known, is derived from the Dutch Language, and signifies according to the technical phraseology of the Dutch architects in building, a winding stair case, or flight of stairs turning spirally round a central column, into which one end of every step is mortised as they ascend from the base upwards. The term Wentletrap, Wenteltrap, or as the Dutch sometimes call it, Wendeltrap,[19] is the name given by Rumpfius the Hollander to this shell, as a synonymous name with his latin term _Scalare_. It is an allusion, somewhat fanciful we must allow, to the disposition of the costal ridges upon this shell, and which when viewed laterally as they traverse or pass over the upper convexity of the whorls on each side, have the appearance of a flight of steps turning spirally round the body of the shell, just as a winding staircase would be carried spirally round a cone or sub-cylindrical body. The singularity of this species (for it is not a peculiarity or character even of the new genus Scalaria as established by Lamarck and Cuvier) consists in having the whole whorl of the shell, from the mouth to the summit, entirely unconnected, while in spiral shells the suture of the whorls is united throughout. The tube is perfectly detached from the mouth to the apex, and the whorls linked together only by means of the longitudinal ribs which traverse the tube at regular intervals, so that the only connexion of the whorls is at the junction of those ribs, which touching each other unite at that part which in regular spiral shells that have the whorls united, would be denominated the suture of the whorls.