THE HAMILTON ASSOCIATION. l6l 



ants of the more ancient hydroza perhaps. The late Professor E. 

 BiUings, either in a letter of a paper I received from him, expressed 

 the opinion that possibly some of the graptolites fixed to the sea 

 bottom were accidentally detached (broken off) and yet lived on, 

 in the same way as the free species. In one instance a deudrograptus 

 stalk he remarked was rounded at the base (it looked as if the 

 fracture had been repaired) and the slight stem trailed behind it. It 

 is not uncommon here to find merely the impression of the base of 

 a callograptus or dictyonema ; so we may infer Billings' specimen 

 was not the only species liable to such an accident. 



When Dr. Spencer published his papers on the Niagara 

 graptolites we entertained no suspicion that the glaciated chert 

 beds contained more than three or four species, callyptograptus 

 radiatus, acanthograptus pulcher (Spencer), I noticed as occurring 

 in a more or less fragmentary condition in a polished and grooved 

 layer which had been shattered a little way back from the present 

 road. I concluded it proceeded from a single stalk, as one or two 

 others unquestionably did a little lower down the chert. But later 

 a shot was fired and the blast revealed that remarkably well pre- 

 served acanthograptus, described and figured as a pulcher. Since 

 that time many other graptolites have been found differing from 

 all below glaciated grooved layers with a few exceptions. 



The upper blue building bed (Niagara limestone) contains quite 

 a number of specimens probably new to this continent. They occur 

 confined to certain parts as it were of the beds. A single shot a few 

 years ago exposed a dozen at least. Since then I got only three by 

 splitting the upper flag, the pentamerus bed or base of the Niagara 

 series or the old Clinton limestone from which I obtained about 

 seven new species (three figured by Spencer), formerly presented. I 

 have had no chance of late years of obtaining any from the ravine 

 below the Mountain View hotel. Since the Incline Railway was 

 started no loose blocks have detached from the bed above. 



Resting on the Barton Niagara in the till above the Albion Mills 

 I occasionally find fragments of white chert, more flinty in texture 

 than any noticed in the immediate vicinity of the city. I feel dis- 

 posed to believe that a second and higher layer of chert existed 

 before the great Ice Age. Our Vice-President may recollect I men- 

 tioned that the sloping sides of a high cliff near Dundas (hardly ac- 



