196 THE ICE AGE IN CANADA. 



the Pleistocene sea. The layer of sand at the surface of 

 the boulder-clay is evidently here the representative of 

 the Leda clay, and affords its characteristic fossils, while 

 the stones projecting above the boulder-clay are crusted 

 with Bryozoa and Acorn-shells. At St. Nicholas, there is 

 a sandy boulder-clay, not unlike that of Biviere-du-Loup. 

 which has afforded some very interesting . fossils. It is 

 stated in the Eeport of the Survey to be one hundred and 

 eighty feet above the sea. 



Montreal. In the neighbourhood of Montreal very 

 interesting exposures of the Pleistocene beds occur, and 

 with the terraces on the Mountain have been described in 

 rny papers of 1857 and 1859. I may here merely condense 

 the leading facts, adding those more recently obtained. 



An interesting section of the deposits is that obtained at 

 Logan's Farm, which may be thus stated in descending 

 order : ft in 



Soil and sand 1 9 



Tough reddish clay (H 



Gray sand, a few specimens of Saxicava rugosa, Mytilus edulis, 

 Teltina Grcenlandica, and Mya arenaria, the valves generally 

 united 8 



Tough reddish clay, a few shells of Astarte Laurentiana, and 



Leda glacialis 1 1 



Gray sand, containing detached valves of Saxicava rugosa, Mya 

 truncata, and Tellina Grcenlandica : also Trichotropis bore- 

 alis, and Balanus crenatus ; the shells, in three thin layers. . 8 



Sand and clay, with a few shells, principally Saxicava in detached 



valves ...... 1 3 



Band of sandy clay, full of Natica clausa, Trichotropis borealis, 

 Fusus tornatiis, Buccinum glaciate, Astarte Laurentiana, 

 Balanus crenatus, &c., &c., sponges and Foraminifera. 

 Nearly all the rare and deep-sea shells of this locality occur 

 in this band 3 



Sand and clay, a few shells of Astarte and Saxicava, and remains 



of sea-weeds with Lepralia attached ; also Foraminifera ... 2 



Stony clay (Boulder-clay). Depth unknown. 



