REPORT OF THE STATE PALEONTOLOGIST 1901 651 



from that of the formation introducing the movement, but in 

 this case the formation that might claim that distinction has 

 not been named nor has its fauna been described. 



The small Helderbergian outlier near Montreal 1 probably be- ^ f e MoSreIi an 

 longs with the Gaspe' series, since there is no clear evidence that gaspe and 



r Dalhousie 



the Albany county, N. Y., area ever connected with Montreal 

 by way of the Champlain valley, as was supposed by Logan and 

 Dana 2 to be the case. About Gaspe" there is a grand develop- 

 ment of Helderbergian and Oriskanian, whose faunas are closely 

 related to those of their equivalents in New York; and another 

 area occurs near Dalhousie N. B., with a fauna peculiar to it. 

 Concerning these two areas, the latter appears to belong to a 

 subprovince distinct from that of the Appalachian Mediter- 

 ranean. 



The Helderbergian invasion of the southern Mississippi valley 

 began after the Cayugan emergence, since its first deposit seems 

 to be of Coeymans age. Part of the underlying Meniscus or 

 Clifton limestone of Safford may also belong to this invasion. 

 It came in from the south and spread north along the western 

 side of the Cincinnati arch through Tennessee into southern 

 Illinois and Missouri. The invasion continued throughout Hel- 

 derbergian time and ceased with the Camden chert of early 

 Oriskany age. Another area lies in Indian Territory, and the 

 faunas of all the southern Helderbergian and Oriskanian depos- 

 its are of the Appalachian faeies. 



No Helderbergian deposits are reported from the Rocky moun- 

 tain region, but we have good reasons for stating that equiva- 

 lent deposits occur in the Devonic of the White Pine and Eureka 

 districts of Nevada as defined by Walcott and Hague, holding a 

 rather peculiar, though on the whole recognizably Helderbergian 

 fauna. 



The Oriskany formation in the Appalachian Mediterranean, oriskanian 



emergence of 



or Cumberland basin is in full force only in the region to the M^lterm?" 

 north and south of Cumberland Md. In southern Pennsylvania, nean 



'Schuchert. Am. geol. 1901. 27:245-53. 

 2 Manual of geol. Ed. 4. 1896. p. 558. 



