difficulty--a difficulty which, as we shall afterwards see, is equally applicable to the Scottish and Irish crannogs. But, whatever doubts may be cast on their antiquity and early origin, there can be none as to the comparatively late occupancy of many of them. A bone skate and a comb made of square bits bound together by cross pieces, and showing that the teeth were cut by a saw after the pieces were put together, precisely as may be seen in the combs from the Scottish crannogs and the terp-mounds of Holland, were found by Virchow in the Dabersee Pfahlbau. Iron hatchets (Dabersee, Persanzigsee, and Alt Friesack), horseshoes, and other iron implements (Soldinersee), pottery of Slavish type (Bonin, Kloppsee, Persanzig, etc.), leather (Bonin), and even armour and bricks of the thirteenth century (Lübtowsee), leave no doubt as to their almost mediæval character. Reindeer horns were found at Butzow, Soldinersee, and Kownatkensee; but these objects do not necessarily indicate great antiquity, as this animal, though not referred to in the early annals of North Germany, is stated to have been an inhabitant of the country in the time of Cæsar. The undoubted contemporaneity of many of these lake-dwellings with the Burgwälle opens up a field of research of considerable importance to European archæology; but their exact chronological relationship still remains an obscure problem, owing chiefly to the mystery which surrounds the latter. _Burgwälle_ or _Rundwälle_ is the general name given to the remains of a remarkable class of prehistoric constructions found scattered over the larger portion of middle and north-western Europe, embracing the southern parts of Russia around the shores of the Black Sea, Roumania, Bulgaria, Transylvania, Hungary, Austria, Bohemia, Poland, North Germany, France, Great Britain, and the southern parts of Scandinavia. Their foundations now only remain and these show that the structures were generally circular or oval, but sometimes square and semicircular. They may be divided into three kinds, according to the materials of which their foundations are constructed, viz.:--earth, stones or stones in vitrified condition (_Erd-, Stein-und Schlackenwälle_). Their sizes vary from 20 to 100 paces in diameter, and their height from 10 to 30 feet, and they contained one, two, or sometimes three walls. Those made of earth were circular and generally situated in swampy land, or in countries where stones were not readily accessible. The Steinwälle were in hilly districts and varied in form according to the nature of the ground. Sometimes they assumed the irregular outline of a promontory or peninsula in a lake, at other times, especially when placed on an overhanging cliff, they were mere semicircles. Those of vitrified materials are of special interest to Scottish archæologists owing to the number of vitrified forts in Scotland. They are not very numerous on the Continent, Saxony and Bohemia containing the largest number.