238 Canadian Record of Science. 



never seen concretions exposed from this wall of apparently 

 pure clay excepting close to the water's edge, where there 

 is no possible way of getting them but to stand in the river 

 and dig, a trowel or stout carving-knife being the best im- 

 plement for the work. 



In collecting claystones it is better to row up the stream 

 than down, for in the latter case the dislodged clay renders 

 the water so turbid it is impossible to see the claystones 

 which have been washed into it, and which often have a 

 story to tell. The concretions of each clay bed should be 

 kept separate, and when this is done the fact is proved that 

 each led has a form of concretion peculiar to itself. You would 

 never find, for instance, a circular disk and a cylindrical 

 claystone imbedded together, or a botyoidal mass and an 

 animal form ; these are four typical concretions of as many 

 separate beds. 



While each bed has its characteristic form, this is not at- 

 tained with an unvarying degree of perfection. There 

 seems to be an ideal and a struggle to attain it ; the result- 

 ing concretion being more or less perfect as the conditions 

 are favorable or adverse. When the conditions are favorable 

 and constant, the typical form is repeated many times. One 

 of the most striking examples of this fact we found in a bed 

 nearly opposite Whitemore's ferry. Out of twenty-six 

 concretions, twenty-four had the same peculiar markings- 

 One of the two exceptions, I have little doubt, was the 

 incipient form of the others, and would have developed like 

 them had we let it remain. The other was not found 

 imbedded, and therefore, I presume to say, came from some 

 bed up the river. I have seen in a private collection, forty- 

 eight specimens from one bed so similar one could not tell 

 them apart. 



Occasionally the typical form is doubled or trebled in the 

 same specimen, as shown in those from Saw Mill River. 



Yery long concretions are seldom found, although we 

 have one in our collection measuring twenty-two and a half 

 inches. Imitative forms are abundant, We have spectacles, 



