320 Geological Society. 



are, for the greater part, variously contorted ; but near Arthurstown 

 they dip 70° to the north, and are overlaid by beds of old red sand- 

 stone, which also dip to the north, but at an angle of only 30°. At 

 Duncannon Fort an impure limestone occurs, containing Trilobites, 

 corals and testacea, and considered by Mr. Austin to be analogous 

 to species found in the Silurian system. 



On the opposite or Waterford side of the Haven the old red sand- 

 stone occurs at Creden Hill and Knockavelish Head, eminences cor- 

 responding to Broom Hill ; a small patch of it is displayed a little 

 to the northwards, inserted unconformably in the slate series ; and 

 it forms the rock of Passage, a prolongation of the old redsandstone 

 near Arthurstown. Between Knockavelish Head and Passage the 

 slate series prevails, except near Newtown Head, where trap-rocks 

 are exposed. A little to the north of that headland are some highly 

 inclined fossiliferous strata, corresponding in position to the beds 

 near Duncannon Fort on the opposite side of the Haven ; they are 

 visible only at ebb-tide. 



The trap-rocks constitute the point on which stands Duncannon 

 Fort ; Newtown Head is also formed of trap ; and Mr. Austin is of 

 opinion that the same mass strikes westwards to Tramore and thence 

 to Great Newtown Head, where it is lost in the St. George's Chan- 

 nel. Along this line, wherever the trap comes to the surface, the 

 slates are tilted. 



"With respect to the numerous contortions exhibited in the schist- 

 ose rocks, Mr. Austin ascribes their existence to lateral pressure, 

 which he says must have been excessive ; and he is of opinion that 

 a considerable portion of the upper part of these contorted beds has 

 been removed by denudation. 



A paper by C. Lyell, Esq., F.G.S., was afterwards read, " On the 

 Freshwater Fossil Fishes of Mundesley, as determined by M. 

 Agassiz." 



In a memoir on the boulder formation and associated freshwater 

 deposits of Eastern Norfolk*, Mr. Lyell stated, on the authority of 

 Mr. Yarrell and the Rev. L. Jenyns, that the scales and teeth of fishes 

 which had been then procured in the fluviatile beds of Mundesley 

 belonged to the Esox lucius, to a trout or an undeterminable species 

 of Salmo, to a carp, probably the Cyprinus carpio, and to a distinct 

 species of Perca. 



This collection, with some additions recently sent to the author 

 by Mr. Wigham, was examined by M. Agassiz during his late visit 

 to England. The decision of Mr. Jenyns with respect to the distinct- 

 ness of the perch, M. Agassiz fully confirmed ; but he was of opinion 

 that the pike differs from the Esox lucius, and that the supposed carp 

 is a species of Leuciscus ; and that the trout is not truly a trout, al- 

 though one of the same great family. 



From this examination, therefore, Mr. Lyell says it is apparent that 

 these remains belong to species not identical with any European 



* See Proceedings, ante, p. 171. [The paper here referred to appeared 

 in Phil. Mag., Third Series, vol. xvi. p. 345.] 



