242 PROCEEDINGS OF THE AMERICAN ACADEMY 



and two Acrotreta ; all having a decidedly primordial aspect. Grapto- 

 lites are also found. 



On the whole, the parallelism of the lower part of division 3 

 (Etagc 3), and of the " Dyctonemaschiefer," with the Phillipsburgh 

 and Point Levis Group, can hardly admit of doubt. 



Above come the schists with compound Graptolites, called " Phyllo- 

 graptus schiefer," or 3 i, in which are found the Graptolites of Point 

 Levis. Then comes group 3 c, the two first subdivisions of which, 3 c a 

 and 3 c ^, form, with the 3 ^, a mass of sixty feet average thickness 

 of schists with Graptolites at the base, and then with limestone lentils 

 filled with fossils, four fifths of which belong to the second fauna, 

 the primordial fauna only being represented by one Af/7iosti(s, and 

 some Brachiopods (Orihis, Liitgula, Lingulella, Discina?), and one 

 Acrotreta. 



The schist with Graptolites, or 3 b, may be considei^ed as equivalent 

 to those of Point Levis, Quebec, and Swanton, of the " Swanton 

 Group." But farther up there is an important hiatus in the series of 

 Norwegian fossils ; those of the subdivisions 3 c a and 3 c /3 appear- 

 ing to belong to the fauna of the subdivision 3 c y. or " Orthoceren- 

 kalk," which in Norway certainly i-cpresents the Chazy and Black 

 River of the second fauna in America. 



A slight tie, however, unites the Norwegian fauna of 3 c a and 3 e /3 

 to the Supra-Primordial fauna; and considering the great distance of 

 Norway from the typical Taconic region of America, it seems proba- 

 ble that the two faunoe were contemporary, and we have there the last 

 term of the Taconic System. 



It is certain that the conditions in America for the development of 

 organic life in the Taconic seas were far more favorable than those 

 of Scandinavia, and it is not strange if we find important differ- 

 ences in the evolution of life in two regions so far distant from each 

 other. 



The small division of the " Potsdam sandstone" has no representa- 

 tive in Scandinavia, nor in Bohemia ; not that the sediments were 

 arrested in this part of Eui'ope during the time that this formation 

 was deposited, but because we have not yet the means of finding the 

 parallelism. It is possible that the '■'■ Porainhonites schicht" (schists 

 with Spirifer poramhonites), of only tliree feet thickness, which form 

 the base of the " Orthocerenkalk " at the section of Vestfoscn near 

 Lunde, Norway, may be the representative of the Potsdam ; and in 

 Dalecarlia (Sweden) the " Oboluskalk," containing Obolella, only six to 

 ten feet thick, which has been found between the " Ceratopyge lime- 



