1899] 269 



NOTES, REVIEWS AND COMMENTS. 



Giant Ripple Marks. — At the New York meeting of the Geol. 

 Society of America la.st December, Prof. G. K. Gilbert of the United 

 States Geol. Survey drew the special attention of the fellows to a very 

 interesting phenomenon which he had observed in the Medina Sand- 

 stone. There were giant undulations in the strata which marked extra- 

 ordinary ripple marks varying in width from 10 to nearly 30 feet. 

 Having discussed the mechanical forces at work in the production of 

 ordinary ripple marks, their orientation, the accompanying phenomenon 

 of cross-bedding, he calculated the height of the waves required to 

 form such giant ripple marks. These he described as waves which must 

 have measured at least sixty feet in height. 



The occurrence of these in sandstone strata had been noticed, but 

 not previously accounted for. This structure interferes very materially 

 with the workability of many a sandstone quarry in the United States. 



During the summer of 1897 Dr. Ami noted the occurrence of 

 similar structures in the upper Carboniferous or Permo-Carboniferous of 

 Pictou Connty, Nova Scotia as exemplified in McKean's Quarry, east 

 of Pictou town, in Macpherson's Quarry on the West River, and in the 

 sandstones of the same age near Little fiarbour. They can be readily 

 compared with the giant ripple marks as described from the Medina 

 of Lockport by Prof. Gilbert. 



Fine Microscopical Material. — At the close of the Fourth 

 Soiree of the Club, on behalf of Mr. George Bryce Scott, a most 

 enthusiastic microscopist of Moncton, New Brunswick, Dr. Ami distri- 

 buted a large quantity of fine microscopical material in the shape of 

 foraminiferal mud or marl most promising indeed. The material was 

 collected at the northern extremity of the Bay of Fundy in a heap of refuse 

 material — probably used as ballast by some of the vessels which visit 

 that portion of Canada in search of 'plaster' or gypsum so abundant 

 around Hillsboro and vicinity. Any member of the Club or person 

 interested in Foraminifera can obtain more of this material from the 

 undersigned until the supply runs out. More than sixty distinct species 

 of Foraminifera have been detected already. The exact locality whence 

 this ballast came has not yet been ascertained, but the marine shells 



