THE HAMILTON ASSOCIATION I4I 



when I was stationed in camp there I succeeded in getting a good 

 specimen of a Trilobite (Homalonotus delphinocephalus). This 

 circumstance oerhaps induced the professor to pay the locality a 

 visit, and it was arranged to proceed there on the following morning. 

 We fortunately found Mr. Walker at home when we called on him, 

 and had an opportunity of examining his fine collection of Hexac- 

 timelid Sponges, aud beautifully prepared sections, together with the 

 large number he recently received from Professor H. Rauf, of 

 Germany. 



In the afternoon we visited the corporation quarry, the field 

 where the Chert-flint-flake fossils occur and the higher portion of the 

 same containing sponges, sections. We succeeded in securing several 

 Graptolites, Brachiopods, etc. Prof. Schuchert, on breaking up 

 one of the globular lumps of Chert, laid bare a good section of a 

 sponge, which under the magnifying glass displayed the internal 

 structure, Spicules. I called particular attention to the upper green 

 and Clinton iron bands so well displayed in rear of the upper reser- 

 voir, near Judge Robertson's, and pointed out some peculiarities in 

 the Graptolite bed of the lower green band, by which it may be 

 recognized elsewhere. 



The general impression among local geologists was apparently 

 that the Clinton series seemed to die out at Grimsby. The upper 

 green band there, rich beyond conception in Dr. Jas. Hall's much 

 debated Fucoid, Arthrophycus Harlani, rested on a red and mottled 

 sandstone. It was represented and figured as a characteristic fossil 

 of the Grey-band Medina Freestone. As the lower beds there are 

 concealed by vegetation in the ravine, their non-existence was erron- 

 eously inferred, and while slabs of the concealed measures certainly 

 put in an undoubted appearance in the bed of the brook itself, they 

 were looked upon by myself and others as mere drift material derived 

 from some adjacent locality in the Glacial Age, like the Hudson 

 River rock occasionally noticed there in the bed of the stream. 



While residing this past summer at Winona Park, about five 

 miles from Grimsby, I availed myself of the opportunity it aflbrded 

 me of making a closer investigation of the field geology of the district. 

 Indeed the chief inducement was to ascertain how far the Niagara 

 Chert beds extended, if at all, in that direction (easterly), likewise to 

 correct hurried examinations made there while in command of the 



