MACKIE — ON THE BOTTOM-ROCKS. 



189 



of Wicklow. It was there, however, nine years before Mr. Salter's 

 discoveries in Shropshire, that the first rehcs of a primordial organized 

 life were found by Dr. Kinahau. 



Of those fossils doubtfully an animal or a plant, we are as yet only 

 acquainted with one genus ; one species, the Oldhamia radiata,* I 



Lign. 4. — DiKELOCEFHALUs MiNNESOTENsis. (Two-thirds nat. size.) From the Lowest Sand- 

 stones, at Stillwater, Minnesota. (Reduced from the figure in Dr. Dale Owen's " Geological 

 Report of Wisconsin, Iowa, and Minnesota.") 



have already figured in Vol. I. {see Frontispiece) in connexion with 

 these papers. The other, and common form — for in these old Irish 

 schists they exist in myriads, the scaling surfaces of the rocks bein 

 completely bespattered with their elegant forms — I now present to 

 my readers in Plate VIII. 



* Lately another peculiar and obscure form has been found, HaugUonia. 



