322 



THE GEOLOGIST. 



company, I observed that many of the slabs Were most decidedly 

 ripple-marked. This is, I believe, the first time that such appear- 

 ances have been observed in the island ; indeed, with the ex- 

 ception of some doubtful fueoids, no fossils have been met with in 

 these beds. The ripple-marks, however, in this instance, were so dis- 

 tinct, that no doubt remained in my mind as to their shallow-water 

 deposition. The same feature also led me more carefully to look 

 out for other signs of littoral deposits, in the shape of worm-tracks, 

 sun-cracks, or rain-prints. Judge then my surprise — and, need 

 I say, delight ? — upon observing the impression of what I believe 

 to be footprints upon a layer of rock immediately below the ripple- 

 marked bed. There were three such imprints visible, each being about 

 six or eight inches out of the straight line, and alternately on each 

 side . The impressions are about tM' o feet six inches apart, and seemed 

 all to have been formed by the same agency. The most distinct of 

 them was broken just at the end, and a transverse section of the 

 imprint shows it to be lenticular, or, in other words, that the pre- 

 sent surface-appearance is not the original one, but is caused by the 

 filling up of the indentation. The outline of each print is remark- 

 ably distinct, and even where the surface-matter has fallen ofi" the 

 line is well preserved. The tout ensemble is very much like the 

 dotted outline of the Froticlinites figured in Owen's Palaeontology, and 

 which have been found in the Potsdam Sandstone of Canada, and 

 more recently in Lower Silurian rocks in Scotland. What seems to 

 bear out the fact that these are footprints, is that the quarrymen re- 

 marked they had frequently met with them. I have briefly mentioned 

 this fact, intending at some future period to take up the subject 

 again when my data are more numerous. 



The position of the beds containing the supposed footprints is 

 towards the top of the Manx Cambrians ; and near the place where I 

 obtained the slab which contains them, a fault occurs, which is beauti- 

 fully seen from the sea. This has thrown the layers up into an almost 

 perpendicular position on the right-hand side, whilst the others on 

 the left abut against them, something after the manner in which the 

 books on a shelf recline against the end ones when intervening ones 

 have been taken away. 



It is in the perpendicular beds, a few yards away from the fault, 

 that the impressions are met with, along with the ripple-marks. 



The slabs are quarried in great lengths, and are very equal in 

 thickness. Close to the bed containing the impressions there are 



