52 THE HAMILTON ASSOCIATION. 



the Fucoid (Arthrophycus) in the CHnton beds at Grimsby and 

 Hamilton, he states : " You have discovered for the plant a new 

 "horizon. Now I want you, if possible, to get a photograph or 

 " photographs of the Grimsby rocks referred to in your letter for me, 

 " it would be more satisfactory." I furnished Dr. Hall with a few 

 very fine slabs, one presenting on the surface the small Arthro- 

 phycus, which, if not a new species, as the writer thinks, may be 

 looked upon as a variety at least. They occur in distinct beds. 

 This seems important. 



THE HAMILTON NIAGARAS. 



The local limestones lately presented quite unexpectedly some 

 organic remains whose occurrence may well be recorded in our Pro- 

 ceedings, and which were revealed accidentally under the following 

 circumstances : It was found necessary to break up these beds 

 (used chiefly for building purposes) into small blocks for the city 

 stone crusher. Although usually broken across, they are at times 

 split along the line of bedding. It so happened the Pentamerus 

 layer was so treated lately, and the quarryman remarked a very well 

 preserved Dictyonona made its appearance on one part which 

 was opened out by the sledge. He was not aware that the 

 other portion had a like impression. I am inclined to think that 

 none of the seven graptolites noted by the writer as occurring in 

 the base of the Niagaras (the old Clinton limestones of Hall) 

 belonged to the Dictyonemas., and this was the only one ever noticed 

 in this layer. 



In a few days after, on looking over a heap of broken flags 

 prepared for the crusher, I noticed the slab from the same bed with 

 the coral on an inner surface, and the one containing quite a num- 

 ber of rather obscure impressions, to which I called attention 

 formerly. Hinge lines and muscular impressions seem wanting, if 

 they should prove to be valves of a Mollusc. 



The Stricklandinia bed is the second one below the thick lime- 

 stone. The " Nigger Head," the intermediate layers between this 

 and the base bed, are known to us as '' the barren Niagaras " here. 

 True, they were considered unfossiliferous, but they held the 

 gigantic Cephalopod alluded to by Dr. Spencer, F. G. S. And 

 recently a very large valve of a Stricklandinia (a new species or 



