_Bokken_ are used almost exclusively for dredging and for taking out sand from the downs in the West of the country and in the region of the Rhine. Their shape is almost identical with that of the “Westlanders” but there is no planking above the planksheer. In the province of Utrecht, the _Slijkpramen_ are used for the same purpose. They correspond to the “Kromme Rijnaak”, the general type of the Utrecht boat. In the province of Groningen, mud is carried by the “Groninger Slijkpraam”, or “Vlotpraam”, a narrow boat with a rounded bottom which has nothing in common with the “Overijselsche praam” and which does not resemble it in any way. The forerunner of our dredges is the old _Moddermolen_ (literally, mud mill) or _Moddermolenschip_ used at Amsterdam since 1575. The _Zolderschuiten_ and the _Schouwen_, now called “Bakken”, may be mentioned as very old boats. Vessels of this sort were supplied, in 1829, with trap doors in the bottom, whence come _Klepschouwen_ or _Onderlossers_ (literally: boats discharging through the bottom). Finally, it is proper to mention also, in the class of vessels under consideration, the pleasure boats, or sailing Yachts, for which the _Boeierjacht_ (in South Holland) and the _Tjotter_ (in Friesland) are used as Dutch types. It is important to note here that pleasure boats are most generally called “Yachts”, even though these vessels have frequently no resemblance to the Yacht properly so called. Hence the name does not always mark the type. V. VESSELS FREQUENTING THE UPPER PARTS OF RIVERS (BOVENLANDERS). All vessels which frequent the upper rivers are called generally “Bovenlanders” be their shape what it may. These vessels, in spite of the interest which they offer, have rarely aroused attention; ~Witsen~ devotes only a few words to them and calls them simply “Aaken” or “Samoreuzen” (p. 170, col. 2), and ~Van Yk~ also gives them this latter name (p. 318). ~A~) _Boats of the Lower Rhine._ The Rhenish boats are of no uniform type. Those which frequent the lower part of the river (below Bonn) differ from those which circulate on the Upper Rhine and its tributaries, save for a small craft found on the Neckar which corresponds with the type below. The fundamental type of the downstream section is represented by the _Dorstensche Aak_, and this latter has produced the _Stevenschip_. These types, originating in the part of Western Germany of which Dorst is the centre, were imported into our country and have existed there for a very long time. This is why the “Geldersche Samoreuzen” are already mentioned in the XVIIth century. Although badly shown, they are to be seen also on old engravings. They are seen circulating on the Lower Rhine and the Waal where they are called _Hollandsche Aaken_ and _Stevenschepen_; even now, they are still built in North Brabant where they have been in existence for a very long time.