162 Manganese Nodules in Loch Fyne 



Their position in the mud, with dead shells above, below, 

 and on all sides of them, will, when carefully studied, no doubt 

 throw much light on their age and method of formation. 

 I have observed two nodules firmly attached to the interior 

 of shells, one having evidently been directed in its growth by 

 the shape of the shell. 



In endeavouring to procure a further supply I dropped 

 anchor in about the same depth, but about a hundred yards 

 further down the loch, and I obtained about the same amount 

 of mud, but it contained very much more shell and no nodules. 

 Also in Kilbrennan Sound, between Arran and Cantyre, in a 

 depth of eighty-five fathoms, there was much shell and pebble, 

 but no nodules. So far, therefore, this occurrence appears to 

 be very local. 



