ARYSSEE.--The existence of the _débris_ of a remarkable lake-dwelling in the Aryssee became known in 1863, in consequence of the discontinuance of a mill which had its motive power supplied by the surplus water from this lake, and the subsequent deepening of its outlet, which had the effect of lowering its level about seven feet. Its remains have been investigated and described by various persons, notably Professor Heydeck, of Königsberg, who has made plans and models of its peculiar structure. These, as well as a large collection of relics, are now deposited in the Prussia Museum at Königsberg. It appears to have been a kind of _Packwerk_. There were, first of all, two or three layers of round timbers lying transversely to each other on the bottom of the lake in the form of rectangles, after which their sides only were continued upwards by single beams, laid successively on each side, thus leaving empty spaces above. These horizontal beams were kept in position by numerous uprights, which here and there flanked them on both sides, as well as by deep cuts towards their extremities where they overlapped each other, precisely similar to the plan adopted at Persanzig and elsewhere. This understructure had a thickness of three to four feet, and over it was laid a wooden platform, above which the huts of its inhabitants were constructed. Clay floorings were found over these platforms, with evidences here and there of fire-places. The relics were found both on the platform and in the originally empty spaces, which, of course, were now filled up with _débris_. Upon its first appearance there was a layer of from 1½ to 2 feet of mud over the woodwork, but after its exposure for some time the mud dried and became greatly contracted. The central area of this structure measured 72 by 36 feet, and was surrounded by three rows of piles. A bridge or gangway, also constructed on a triple row of piles, extended to the shore, a distance of about fifty yards. At first, and for several years after its discovery, no metal objects were found, and hence it was supposed to belong exclusively to the Stone Age; but this is no longer the case, as latterly it has furnished both iron and bronze objects.