The Laivrencian Formation. 339 



locate themselves. « Mr. Sowerby remarks that they are fre- 

 quently found on the outside of oysters, protected by their irre- 

 gularities, and in the clefts of rocks or corals, roots of sea-weeds 

 and perforating oysters, chalk, limestone and hardened clay." 

 It IS hvmg, according to Professor E. Forbes, " in all the seas of 

 Northern and Arctic Europe, Northern America and Greenland. 

 It ranges as far south as the Canary Isles. Its vertical range is 

 very great. In the British Seas, it is found abundantly in the 

 lammarian and coralline regions. In the Mediteranean, it has been 

 observedalive at all depths between twenty and eighty fathoms."* 



Fig. 1. 



Fig. 2. 



Fiff. 3. 



Fig. 1. — Saxicava rugosa. 



Fig. 4. 



Fig. 2.- 



Fig. 3. — Tellina calcarea. 



■Tellina Groenlandica. 



Fig. 4. — My a truncata. 

 In Canada it is found fossil in very numerous localities over all 

 the valley of the St. Lawrence and the flat country south of the 

 Ottawa. On the mountain of Montreal it occurs at a level of more 

 than 400 feet above the St. Lawrence. Along the base of the 

 mountain we have seen it at the brick-yard near the toll-gate, St. 

 Lawrence Street, near McGill College, at several places on s'her- 

 brooke Street, and at Cote St. Antoine. The most astonishing lo- 

 cality, however, is at Beauport, three miles from Quebec. There is 



* Forbes, in Memoirs of Geological Surrey of Great Britain, vol 1 

 'page 410. * » 



