Right here in McPherson County there was either a river or a lake at the time of the catastrophe. This is plainly indicated in several ways. In one place the dust rests on sand and clay, with imbedded shells of fresh-water clams. It is assorted in coarse and fine layers like a water sediment. Lowermost is a seam of very coarse grains. These must have settled promptly through the water, while the finer material was delayed. In another place it lies on higher ground, and here marks of sedges and other vegetation are seen extending up about a foot into the base of the deposit, from an underlying mucky clay. Bog manganese impregnates a thin layer just above the clay, indicating a marshy condition. Here also the material is somewhat sorted, but in a different way. It is ripple-bedded. The water was evidently shallow, if there was any water at all. A burrow like that of a crawfish extended down into the old clay bottom. On a slab of the volcanic ash itself some tracks appeared (Fig. 4). These were probably made by an individual of the same race in an effort to escape from the awful fate of being buried alive like the inhabitants of Herculaneum and Pompeii. [Illustration: FIG. 4.--TRACKS IN THE VOLCANIC DUST, PROBABLY MADE BY A CRAWFISH. Reduced to 2/8 diameter.] The shower must have lasted for a time of two or three days. I infer this from the nature of the wind changes, which are indicated by the ripples in the dust. These still lie in perfect preservation (Fig. 5), and may be studied by removing, inch by inch, the successive layers from above downward, for it is evident that as the direction of the wind changed, the ripples were also turned. The deciphering of this record must be made backward. The bottom layers were deposited first, and the excavation must begin on top. Otherwise the record is as perfect as if it had been taken down by an instrument when the shower occurred. It may be only local in its significance, for it shows the direction of the wind at this particular place alone. The wind may have been somewhat deflected from the general direction by local topographic peculiarities, though these appear to have been of small importance. In any case, the old legend is quite interesting to read, being, I believe, the only geological record ever found of the passing of a cyclone over the United States. [Illustration: FIG. 5.--RIPPLE MARKS IN THE VOLCANIC DUST. Reduced to 1/4 diameter.] [Illustration: FIG. 6.--PECULIAR ELEVATIONS CAUSED BY A CURRENT FROM THE SOUTHWEST TO THE NORTHEAST. Reduced to 1/2 diameter.]