American Scientific Association, 299 



called on Sir William Logan of Montreal for his views on the 

 subject. 



The latter said that on the Canada side of the boundary line 

 this limestone had been traced from Memphremagog lake near 

 Derby, to the Gulf of St. Lawrence in Gaspe, a distance of 500 

 miles. It was well stored with fossils at several places, and 

 appeared to be partly Upper Silurian and partly Devonian. One 

 of the localities of fossils was Memphremagog lake, when the 

 fossils appeared to be allied to Devonian forms. In this neigh- 

 bourhood there are masses of granite. Bebee's plain bordering on 

 the lake presents an area of thirty-six square miles of granite 

 from which emanate dykes cutting and dislocating the calcareous 

 strata. From this it is evident the granite is newer than the 

 limestone, and therefore may well be found occasionally to 

 overlie it. The granite he considered to be of the same age as 

 that so widely extended in New Hampshire and Maine ; it had 

 been traced to New Brunswick, and at Bathurst was found to 

 underlie the coal formation. Its age would thus be Devonian 

 On the west side of the Green Mountain range there was a 

 calcareous area related to the limestones of Rutland, which, from a 

 section he had lately made eastward from Lake Champlain in 

 the neighbourhood of Burlino-ton, he considered to be of the same 

 age as that at Memphremngog. 



Mr. J. P. Lesley of Philadelphia, said that since Sir William 

 Logan had informed them, that he had lately been making some 

 investigations in Vermont, he would probably be able to state 

 some opinion in regard to the Taconic rock?. 



Sir William Logan replied that having been referred to the 

 black slate outside of Sharp-Shins near Burlington, as an instance 

 of Taconic slates, these he had found lying conformably beneath the 

 magnesian limestones of the same point, and at Apple- tree Point 

 on the outside of this he had found, among similar slates, Triarthrus 

 Bcckii, a fossil known to belong to the shales of the Lower Silurian 

 series. The magnesian limestone and the black shales beneath, he 

 had traced in the same relation almost without a break, to the 

 Canada boundary. From Quebec he had traced black shales and 

 magnesian limestone, in the same relation to the same point on 

 the boundary line. At Quebec both the shales and the limestone 

 were characterized by rock-marked fossils. The fossils of the 

 shales were those of the Utica slate and Hudson River Group, and 

 he had no doubt that the slates of Sharp-Shins were of the same 



age. 



