CONCRETIONARY STRUCTURE IN ROCKS— WESTON. 139 



fill one should be in referring any forms of a concretionary 

 nature to organic structure. 



About the year 1868, forms with a decided concretionary 

 aspect were found in the Huronian rocks of St. John's, New- 

 foundland. (The label on the specimen now in the geological 

 museum, Ottawa, gives the exact locality, but not the date.) 

 They were at once pronounced to be fossils, and even referred to 

 the genus Oldhaviia, having a slight resemblance to 0. radiaia 

 of the Cambrian rocks of Ireland. A number of pieces of green 

 argillite with these markings were sent to Sir Wm. Logan for 

 examination. I was instructed to slice and examine them with 

 the microscope, but before doing so ventured to tell Sir 

 William that they were only concretions, and that, moreover, they 

 lay transverse to the bedding of the rock. He was much vexed 

 and showed a long paragraph about them which had appeared 

 in one of the Newfoundland papers. Much to the disappoint- 

 ment of the discoverer of these supposed wonderful fossils, they 

 were only concretions. 



Concretions in Huronian Rocks of Newfoundland, 



Similar forms can be seen in the Potsdam rocks on the coast 

 of Labrador, and in the red slates and argillites on some of the 

 small islands in the St Lawrence River. 



