130 



THE GEOLOGIST. 



From Caen I took the steamer back to Havre, and thence trudged 

 along the shore by Fecamp and Dieppe to Boulogne. A sketch from 

 my notebook at Etretat may well close this gossiping article. The 

 needles and arches of our Isle of Wight are household words in the 

 British geologist's mouth. So are the arches and needles of Etretat 

 in every Frenchman's. Etretat was a fishing village. It was fast 

 rising, when I was there, into a watering-place ; it may boast by this 

 time of handsome rows of marine residences, but it will not be more 

 worthy of visiting than when it was as my pencil presents it to my 

 readers in Plate IX. 



. ON THE OCCTJKJiENCE OF ACANTHODES IN 

 PALAEOZOIC KOCKS. 



By Eev. Hugh Mitchell, M.A. 



"Whatever theory we may conceive or adopt respecting the origin 

 of species, it is undeniable but that Acanthodes — a genus of fossil 

 fishes — has maintained a noble struggle for life. Known to occur 

 first of all in the Lower Devonian or Old Eed Sandstone, it has been 

 found also in the Middle Division of that great system, and again in 

 the coal-measures, and finally disappears in the Lower Permian — the 

 Eoth-todt-liegende or Lower Dyas of German authors. 



In the accompanying table we have endeavoured to put into acces- 

 sible and readable shape the particulars of its occurrence, so far as 

 known to us, among the rocks. 



The Rocks. 





The Species. 



The Authorities. 



Permian . | 



Upper 

 Lower 



* 



Acanthodes gracilis, 

 Beyr 



.1 



Murchison, Journal of Geol. Soc. I 

 vol. xix. p. 303. 



Carboniferous , 



/ Upper 

 . Lower 





A. Brouni, Ag. 

 A. sulcatus, Ag. . 



Egerton,Geol. Surv. Dec. 10, p. 57. 

 Agassiz, P. ¥., p. 125. 



Devonian . 



' Upper 



Middle 

 „ Lower 



* 



A. pnsillus, Ag. 

 A. Peachi, Eg. 

 A. coriaceus, Eg. . 

 A. Mitchelli, Eg. . 



Agassiz, P. F., p. 301. 

 Egerton, Geol. Surv. dec. 10, p. 57. 

 Egerton, Geol. Surv. dec. 10, p. 59. 

 Egerton, Geol. Surv. dec. 10, p. 61. 



"We first detected the occurrence of Acanthodes in the Lower De- 

 vonian or Old Eed Sandstone at Farnell, in the county of Porfar, 



