DEVONIAN. 325 



The Helderbergian fauna is apparently related with that of New York, and belongs to the 

 facies occurring on the western side of the Appalachian folds. The writer has collected this 

 fauna at Dalhousie, New Brunswick, and from the Gaspe region, Quebec, and both are of 

 another facies and belong to another basin. 



The presence of Rhipidomella recalling R. musculosa; Spirifer concinnus; an early variety 

 of S. murcMsoni; Spirifer n. sp., connecting phylogenetically S. concinnus and S. arenosus; 

 Camarotcechia pleiopleura; Gypidula pseudogaleata; and Rensselaeria acquiradiata shows that 

 the St. Helens Island Helderbergian is not as old as the New Scotland zone. Spirifer concinnus 

 and especially G. pseudogaleata and R. acquiradiata are characteristic Becraft zonal species. 

 However, the Oriskanian reminders, like R. near musculosa, S. murcTiison, S. near arenosus, 

 prove that the St. Helens Island Helderbergian is pretty well up toward the top of the New 

 York section, and may represent both the Becraft and Kingston zones. 



Spirifer macra and S. granulosus estabhsh the fact that, in the region of Montreal, there 

 was once a formation of marine origin later than the Helderbergian and as recent as the Onon- 

 daga (Comiferous) ; further, that the agglomerate of St. Helens Island and other places about 

 Montreal is not older than late Middle Devonic time. Its age is probably naore recent, and 

 there may be further paleontologic evidence in the agglomerate. 



L 18-19. QUEBEC, SOTJTHEASTEEN TOWNSHIPS. 



Ells ^" states that " areas of Devonian rocks occur at several widely separated 

 points in the area east of the Sutton Mountain anticline and its extension north- 

 ward." Small outliers are known on the Chaudiere. "While detached areas of 

 Silurian (Lower Helderberg) occur at a number of places between the Chaudiere 

 and the United States boundary, to the southwest, the only outcrops of strata 

 holding typical Devonian fossils are found on the western shore of Memphremagog 

 Lake." These rocks had been previously described by Logan and Billings and 

 had been assigned to the "Corniferous" horizon by Dana and by Ells. They are 

 plumbaginous limestones, underlain by somewhat dolomitic flaggy slates and shales, 

 which Ells describes as resting upon fossiliferous "Silurian" strata [Devonian 

 Helderberg limestone]. They are penetrated by intrusive dikes. ' With reference 

 to the relations of these Devonian rocks to the Silurian and to the Devonian of the 

 Gaspe Peninsula, Ells '^^* states : 



No well-defined break between the upper Silurian (Lower Helderberg) and the overlying 

 Devonian has been found, the conditions of deposition presumably being similar to those in the 

 Beauce [Chaudiere] district or in the similar beds of the Gaspe Peninsula, described under the 

 head of the Gaspe Limestone series in the "Geology of Canada," as weU as in subsequent 

 reports." In aU these locahties there appears to be a mingling of forms of upper Silurian and 

 lower Devonian horizons, in so much that it has been found very difficult, and in some cases 

 impossible, to define the exact fine of separation between the two systems. 



L 19. SOTJTHEBN NEW BB.TJNSWICK AND EASTERN MAINE. 



In southern New Brunswick Devonian rocks occur in two areas — one in Charlotte 

 County south of the Carboniferous basin, the other in St. John County, consisting of 

 the Mispec and Lepreau basins. The rocks of the latter area extend across the 

 international boundary and occupy the Perry Basin in eastern Maine. 



The belt which is mapped as Devonian in Charlotte and Queens counties south 

 of the Carboniferous basin was thus described in 1880: *^ 



The largest area of rocks of this age is that occurring in the northern part of Charlotte 

 County and extending eastward into Queens County. These rocks have been described in the 



o Geology of Canada, 1863, pp. 406-428; Rept. Progress, Geol. Survey Canada, 1880-82, pp. 3-16dd. 



