98-i HISTORICAL GEOLOGY. 



Falls in Fitzroy, 350' ; at Dulham Mills, 289' ; in the counties of Tienfrew, Lanark, Carl- 

 ton, and Leeds, 425' ; east of Montreal, near Upton Station, 257' ; farther east, on the 

 river Gouffre, near Murray Bay, 130' and 360' ; on Prince Edward Island, Tellina Grczn- 

 landica, at a height of 50'. At the Straits of Belle Isle, Labrador, the deposits, on either- 

 side, are about 400' above the sea ; at Chateau Bay, 500', probably 800' in some parts- 

 (Packard) ; and at Nachvak, 1500' (R. Bell), where there are shell-beds. In Lake Cham- 

 plain, the shell-beds extend to its southern extremity. 



The Leda clays of Dawson afford species living now at depths less than 100' ; the lower 

 Leda clays containing Tellina Grcenlandica and Leda arctica; and the upper, species 

 that are now living in St. Lawrence Bay. Of the higher sand-beds, Saxicava rugosa 

 is the common species. 



The more common shells of the Montreal beds are the following (Dawson) : Saxicava 

 arctica., Mya truncata, 31. arenaria, Macoma fragilis, 31. sabulosa, Astarte Laurentiana, 

 3Iytilus edulis, Natica clausa, Yoldia glacialis, Trophon clathratum, Buccinum Grcen- 

 landicum. 



Among the species at Beauport, there are the following: Lunatia Gra,nlandica, 

 L. heros, Turritella erosa, Scalaria Grcenlandica, Litorina palliata, Serripes Grcen- 

 la7idicus, Cardium Islandicum, Pecten Islandicus, Bhynchonella psittacea, and many 

 others. All are cold-water species, so that the fauna is more Arctic in character than that- 

 of Montreal, corresponding with the fact that Montreal is 150 miles northwest of Beauport 

 (Dawson). 



The Capelin {Mallotus villosus Cuv., a common fish on the Labrador coast) has been 

 found fossil on the Chaudiere Lake in Canada, 183' above Lake St. Peter ; on the Mada- 

 waska, 206' ; at Fort Colonge Lake, 365'. 



On the Bay of Fundy the shell-beds have a height of 200-225', and on the Bay of 

 Chaleurs, 200'. The beds descend below the sea level. The Leda clays of the latter 

 region contain Leda minuta, L. pernula, Mya arenaria, 31. truncata, 3fytihis edulis, 

 Nucula temiis, Saxicava rugosa (most common), 3Iacoma calcarea, Yoldia arctica (Leda 

 truncata), Buccinum undatum, 3Iargarita striata, Natica clausa, Serripes Grcenlandicus 

 (abundant), and other species (Chalmers, 1885). The Saxicava sand in the Bay of 

 Fundy contains 3Iya arenaria and 3Iacoma fusca ; but shells are rare. 



On the coast of Labrador, the elevated Champlain beds contain mostly the same 

 species, both those of the Leda clays, and the overlying beds. Among the species less- 

 abundant farther south, or not at all, are Gyclocardia borealis Con., Astarte Banksii, 

 3Iargarita varicosa, Turritella retictilata, T . erosa, Aporrhais occidentalis, Admete viri- 

 dula, Bela exarata, B. liarpularia Adams, B. robusta Pack., B. turricxUa, Fusus tornatus, 

 F. Labradorensis Pack., Buccinum undatum. (Packard.) 



On Grinnell Land, in the Arctic seas, shell-beds resting on Miocene have an elevation 

 of 1000', and contain the usual cold-water species, 3Iya truncata, Saxicava rugosa, Cardium 

 Islandicum, Astarte borealis, Pecten Groenlandicus, etc. (Feilden, 1877.) 



The paper on the Lake Champlain region, with a map by S. P. Baldwin, is contained, 

 in the Amer. Geol., xiii., 1894. Baron de Geer (Proc. B. N. H. Soc, xxv., 1892, Amer. 

 Geol., xi., 1893) gives 658' for the marine limit at St. Albans; but Baldwin concludes 

 that the terrace at this level was that of a glacial lake. 



3. Amount of subsidence over the Western Continental border. — In the re- 

 gion of Mount St. Elias, according to Russell, deposits of moraine material 400O 

 to 5000 feet thick occur in the Chaix Hills ; and the cliffs of Pinnacle Pass, 

 at the same height, contain shells of the Champlain species Mya arenaria, 

 Mytilus edidis, Leda minuta, Cardium Islandicum, Yoldia limatula, Thracia 

 curta, and others. B. Willis has reported that marine beds are found at a 



