Page:The Geologist, volume 5.djvu/153

Rh for; but, recollecting Mr. A. Hancock's remarks on the so-called Annelide tracks, published in the 'Annals of Natural History,' 3rd series vol. ii. p. 443, plates 14–19, I looked carefully on the wetter parts of the clay, along the edges of the puddles, and soon saw little beetle- like insects boring into the clay, and apparently traversing such galleries, just beneath the surface, as the little narrow convex sinuous markings may be due to. One of these insects I enclosed alive in its clay habitat, but I could not afterwards find it, when I had the specimen of surface-marked clay at home. The cut edges of the pieces of clay show the openings of the numerous little galleries (fig. 1 b). Some of them are close to the surface; some are an eighth of an inch or more below: in the latter case, probably the roof of the gallery received coatings of mud after it was raised up, retaining its convexity. At some spots the roofs of the galleries were the only markings of the surfaces; at other places the concave trails were most abundant. The origin of these was obscure; for the pools were too temporary to be the home of molluscs or crustaceans; insects or worms, therefore, may have caused them. The Rev. Mr. Hislop showed me, not long since, a specimen of hard reddish shale (possibly of Triassic age) from Korhadi, Central India, on which one of the many superficial long, narrow, hollow trails slopped short with what certainly appeared to be an insect, coated with muddy matter, and entangled, as it were, in the clay whilst ploughing its little furrow.

In fig. 2, we have some faint rain-prints at one corner (a),—numerous small bubble-rings over a large portion of the surface,—several deep, long, concave trails all over the specimen,—three or four faint convex gallery-marks, and some footprints of birds. The latest bird-track shows three footprints, deeply marked on the bubbly surface, probably a slightly depressed area remaining moist after the other