. Second contribution to the studies on the Cambrian faunas of North America [microform]. Paleontology; Arthropoda, Fossil; Arthropoda, Fossil; Paléontologie; Arthropodes fossiles; Arthropodes fossiles. Im:' f J' I I t * ti 20 CAMBRIAN FAUNAS OP NOBTH AMERICA. (BULL 30 nIuiIch, but, on each Hide of the great ^Mentile," deposition contuctg were seen and no evidenee of the presence of faults was observe*!. If is actually the case, we have nearly ten thousand feet of stmta that we know to be of Cambrian age by its contained fauna. Of this, I refer 4,500 feet to the Middle Cambrian or G
. Second contribution to the studies on the Cambrian faunas of North America [microform]. Paleontology; Arthropoda, Fossil; Arthropoda, Fossil; Paléontologie; Arthropodes fossiles; Arthropodes fossiles. Im:' f J' I I t * ti 20 CAMBRIAN FAUNAS OP NOBTH AMERICA. (BULL 30 nIuiIch, but, on each Hide of the great ^Mentile," deposition contuctg were seen and no evidenee of the presence of faults was observe*!. If is actually the case, we have nearly ten thousand feet of stmta that we know to be of Cambrian age by its contained fauna. Of this, I refer 4,500 feet to the Middle Cambrian or Georgia Formation, or 1 to 7, inclusive, of the Georgia section. § 22. The typical Georgia fauna, Kutorgina cingulata, K. Labrador- ica, OlenelluH, MeHonads, Bathynotus, Ptychoparia Adamai, and ProUjpm »enectuH^\B found in the upper portion of the great limestone seiies,in the sandy and argillaceous shales resting on it, and in the masses of interbedded calciferous sandrock which Prof. Marcou referred to the Potsdam. (See § 15.) How far this fauna extends up into the shales we do not know. One species, Ptychoparia Adamsiy Is represented in the great "lentile" of the Georgia section; but I have drawn the pro- visional upper line of the Georgia Formation at the base of the "lentile," as it is here that we meet with a decided change in the fauna, and the deposit is unlike that found below. It will probably be found that the limestone conglomerate, east of Swanton, occurs at about the same rel ative horizon as the "lentile" of the Georgia section. § 23. In the group of sections, taken across New Hampshire and Ver niont, by Prof. C. H. Hitchcock (Bull. Amer. Mus. Nat. Hist., vol. I, pis. 16 and 17, 1884) we find the Georgia series called Potsdam and Cambrian; and, in section XI, pi. 17, the Georgia shales (Cambrianof section) are represented as resting conformably on the magnesian lime- stones (Potsdam of section), in the town of Milton. This is the
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