QUATERNARY AGE. — CHAMPLAIN PERIOD. 553 



water inferred for these deep-sea beds by Dawson, from the species of shells, is 100 to 

 300 feet. Dawson makes the marine formation in Canada to consist (1) of unstratified 

 bowlder-clay; (2) deep-water clays just mentioned, called Leda clays, from one of the 

 fossils; (3) the overlying shallow-water sands and gravels, called also the Saxicava 

 tands. 



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

 Arctica Desh., Mya truncata Linn., M. armaria Linn., Macoma fragilis Adams, M. 

 sabulosa Mi'.reh. Astarte Laurentiana Daws., Mytilus edulis Linn., Natica clausa Brod., 

 Yoldia GhcialU Gray, Trojjhon clathratum Morch, Buccinum Grxnlandicum Hancock. 



Among the Beauport species, there are the following: Lunatia G ramland lea Adams, 

 L. heros Adams, TwrriteUa erost Couth., Scalaria Grcenlandica Perry, Litorina palliata 

 Verr., Serripes Groenlamlicus Beck, Cardium Jslandicum Chemn., Pecten Islundicus 

 Chemn., Rhynchonella jjsittacea Gm., 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 Beaupoi't (Dawson). 



The coast of Maine has afforded (Packard): Pholas crispata Linn., Saxicava Arctica, 

 Mya truncata, M. arenaria, Thracia Conradi Couth., Macoma fragilis, M. sabulosa, 

 Mactra oralis Gould, Astarte Bunksii Leach, A. elliptica Brown, A. Arctica Moller, 

 Cardium Islindicum, Serripes Graznlandicus, Leda pernula Mull., L. minuta Fabr., Yol- 

 dia glacialis, Pecten Gramlnndicus Sow., P. Islandicus, Natica clausa, Lunatia heros, L. 

 Gramlandica, etc. 



The species thus far discovered, with perhaps one or two exceptions, are identical with 

 those now inhabiting the Labrador seas. They number over two hundred. 



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

 found fossil on the Chaudiere Lake in Canada, 183 feet above Lake St. Peter; on the 

 Madawaska, 206 feet; at Fort Colonge Lake, 365 feet. 



On the Bay of Fundy, at Goose Creek, there are several levels of beaches, up to a 

 height of 490 feet. (Hind.) 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 Cyclocardia borealis 

 Con., Astarte Banlcsii, Margarita varicosa Mighels, Turritella reticulata Mighels, T. 

 erosa, Aporrhais occidentals Beck, Admete viridula Stp., Bela exarata Mull., B. harpu- 

 laria Adams., B. robusta Pack., B. turricula Montf., Fusus tornatus Gld., F.Labrador- 

 ensis Pack., Buccinum undatum Linn. (Packard.) 



South of Cape Cod, at Sancati Head on Nantucket, and at Gardner's Island, the 

 species were the warm-water kinds, now inhabiting this region, and not the subarctic 

 that existed north of the Cape. 



On the Pacific side, there are shell-bearing sea-border beds, at San Louis Obispo and 

 San Pedro, 80 or 90 feet above the sea, and at higher levels (Newberry); on north bank 

 of Lobos Creek, and west of Black Point, near San Francisco, 80 to 100 feet. Terraces 

 occur also about Sonora, Mexico. 



HI. General Observations. 



1. Geographical Conditions in North America due to the subsidence. 

 — The elevated sea-border formations that have been described prove 

 that, in the Champlain period, the land, where such formations occur, 

 was at the water's level. They show, for example, that southern New 

 England was 10 to 25 feet below its present level ; Sancati Head, on 

 Nantucket, 85 feet ; the coast region of Maine, in some parts, 217 

 feet ; the borders of Lake Champlain, between 350 and 400 feet ; the 

 region of the St. Lawrence, along by Montreal, nearly 500 feet ; about 

 the Bay of Fundy, 350 to 400 feet; the Labrador coast, 400 to 500 

 feet ; parts of the Arctic regions, over 1,000 feet. 



