lower cornstones of this country ; the middle eeries or Caithness 

 flagstones, bituminous and calcareous ; and third, the uppermost, 

 consisting of yellow sandstones. These latter have been a vexata 

 qucestio ; for they have been described by Sir Eichard Griffiths, 

 in Iieland, as carboniferous, as also by Mr. Jukes. Their proper 

 place seems to be now definitely settled as the uppermost member 

 of the Old Eed, and the equivalents of the Dura-Den beds in 

 Fifeshire, which have proved so rich in fish remains. In this 

 country, the same beds are to be found, according to Mr. Symonds 

 and Dr. Melville, in the escarpment of the Daren, near Crick- 

 howeU, just underlying the mountain limestone and millstone grit 

 of Pen Carreg Calch. Sir E. Murchison once found here a scale 

 of Holoptychius nobilissimus, a very characteristic fish, which seems 

 to corroborate the assumption ; and I hope some day in the course 

 of the summer, to be able to examine it more thoroughly than I 

 have yet done. The same beds are, I think, to be found on the 

 opposite side of the valley of the Usk, under the limestone of the 

 Llangattock quarries. At Dura-Den they appear to be one mass of 

 fish remains in the most perfect preservation, and of the most 

 characteristic type. A still higher point of interest lies in the fact 

 that in these upper yellow sandstones, reptilian remains have been 

 found of an organization still higher than even the Telerpeton 

 Elginensis. The Stagonolepis, which was for long considered a fish, 

 has been declared by Professor Huxley to present a very close 

 resemblance in some points to the Crocodilian, and in others to the 

 Lacertian tribes. In fact it diverges materially from all known and 

 recent forms. This circumstance warns us not to pin our faith too 

 strongly on the limits of animal life, for of late many an example 

 has occurred which has forced us to become more liberal (to use a 

 political phrase) in our determining points, both as to horizons of 

 life, as well as individual features. Before I quit the subject of the 

 Old Eed, I must not omit to mention the discovery of the fish bed 

 on the Wall Hills at Ledbury, which has yielded to the praise- 

 worthy researches of two working men, Pteraspis and Cetiocaris, 



