35 



Mountain, and another and more abundant series along the hills on one of which 

 we now stand, the latter evidently occupying a zone lower tlian the former. The 

 former are the irregular conglomerate-looking calcareous strata which often 

 contain remains of our Old Red fish ; the latter indicate that great bed of 

 limestone which you have seen to-day, and in which I have as yet failed to find 

 any trace of organic remains. This is no mere local deposit, but a bed which, 

 where it has escaped denudation, may be traced for mUes in the hills on either 

 side of the Golden VaUey. Whether it may ever have been continuous with 

 the similar beds found elsewhere, as for instance that which we saw last year 

 around Dinmore Hill and near Leominster, is a point which I could at present 

 only venture to suggest. Now, if further observation shows that this is not a 

 mere "irregular course of mottled red and green earthy limestone called Com- 

 atone," as described by Murchison, but a definite geological formation extending 

 over a wide area, it would prove a most valuable landmark or zone. 



From repeated observations which I have made with the aneroid barometer, 

 I have calculated that the point where we now stand is about 270 feet above the 

 Pontrilas railway station, or in round numbers about 500 feet above the sea level. 

 The point, however, to which I wish especially to direct your attention is, that 

 we are 135 feet above the bed of Comstone, which we passed just now on our way 

 up the hill, yet here we find Pterygotus, the fossil known as Parka decipiens, so 

 commonly associated with it, and believed to be the egg packet of that crustacean, 

 and the round bodies called Pachijtheca spherica, and believed to be the seeds of 

 Lycopodiaceous plants. Now all these, where they come up into the Old Red 

 Sandstones at all, are only known to exist in its lowest portions, and they thus 

 afford proof of the very low position of this bed of Cornstone. The other organic 

 remains found here are portions of fish spines and a plant bed, but in the present 

 state of our knowledge these do not afford much assistance in determining our 

 position. The most important of the other quarries which we shall visit to-day 

 is that at Rowlestone, where that unique fossil, the Stylonurus Symondsii, 

 figured in the last volume of our transactions, was found. I have not yet satisfied 

 myself as to the exact position of that quarry, but I believe it to be higher than 

 this at which we now stand, but as I have found there Cephalaspis and Parka 

 decipiens, it is probably not very much higher, and I have no doubt whatever that 

 it is much lower than the upper series of Cornstone, which, as I have pointed out 

 to you on the map, is seen along the sides of the Black Mountains. 



Above the upper series of Cornstone the Old Red Sandstone is remarkably 

 barren in organic remains, the only thing I have found being some plant markings, 

 until we come to the very top of the system, which occasionally yields fish remains. 

 In all the quarries which we shall visit to-day you will observe that the sandstones 

 are much less red than in the middle portions of the formation, most of them 

 being gray, greenish, or yellowish. 



Those who consult the geological map will observe that the Comstone is not 

 laid down on this hill, or at any of the numerous points where it is worked near 



