138 An Ancient Lake-deposit in Queen's Park. [Sess. 



disclosed the soft, loose nature of a considerable portion of the 

 strata beneath the marl, in alternating bands of mud and clay 

 and gravel, so that piles had to be driven to the depth, in some 

 cases, of nearly twenty-five feet for the drain to rest on. No. 

 3 bore gave a section in all of fully 40 feet before the under- 

 lying rock was struck, and here the peat was 3 feet thick and 

 the white marl 9 feet. At No. 5 bore 9 inches of tree-roots 

 were found embedded in the peat. At No. 6 bore the marl 

 disappeared, showing that the margin of the lake had been 

 reached, and here the peat extended to the thickness of 14 feet 

 6 inches. 



The peat and its underlying shell-marl would alone un- 

 mistakably indicate the lacustrine nature of this deposit, and 

 its character in past ages, when the whole trough or cavity 

 was filled by a sheet of water. The peat, when examined 

 under the microscope, revealed an aquatic vegetation in the 

 shape of reeds and rushes and plants of similar nature. The 

 striated and knotted stems of some of these plants were very 

 characteristic, and wonderfully fresh after their long entomb- 

 ment. The marl was studded with countless myriads of shells, 

 testifying to the abundant molluscan life which inhabited 

 these waters. The genera observed were few — viz., one 

 bivalve and three univales — but of some there were several 

 species. The most plentiful was the whorled limna^a or pond- 

 snail {Limncca 'pcregcr) ; the next, the bivalve cyclas {Cyclas 

 ohtusale), like a miniature cockle ; then the trochus-like 

 valvata ( Valvata ioisci7udis and V. cristata) ; and, lastly, the 

 beautiful discoid planorbis (Planorhis nitidus and P. glctbcr), 

 like a tiny ammonite, which seemed to be relatively least plenti- 

 fuL On comparing these shells with those taken from the 

 Borough Loch in 1842, and included in the "Hugh Miller 

 Collection " at the Museum of Science and Art, they will be 

 found to be nearly identical. Nor need this surprise us when 

 we remember that the same mollusca are still alive in the 

 neighbouring lochs and ditches. The shells were very light, 

 and extremely brittle. Hugh Miller, in the work already 

 quoted, speaking of the shells taken from the Borough Loch 

 deposit, remarks that " twenty of them, of the average size, 

 scarce weigh a grain." In order to test this, a hundred of by 

 no means the smelliest specimens from the Queen's Park deposit 



