Introduction 679 



the rocks between the Hudson River and Clinton groups is considered, it be- 

 comes evident tbat a vast period of time must have passed away during their 

 deposition ; and yet as the Oneida conglomerate is unfossiliferous and the 

 Medina sandstone has yielded but a few inconspicuous species, we have been 

 almost wholly without the means of ascertaining the natural history of the 

 American seas of that epoch. The fossils of the middle portion of the rocks 

 of Anticosti fill this blank exactly, and furnish us with the materials for con- 

 necting the Hudson River group with the Clinton, by beds of passage contain- 

 ing some of the characteristic fossils of both formations, associated with many 

 new species which do not occur in either." 



On the basis of Eichardson's work and the fossils gathered by him, 

 Billings divided the 2,300 feet of Anticosti strata into six divisions, to 

 which he applied the first six letters of the alphabet. The lower 960 feet 

 are of Divisions A and B, and to him it appeared ^S^ery probable that 

 these divisions are a portion of the Hudson Elver group." They termi- 

 nate his lower Silurian. To these must be added his Division C, as it 

 has the fanna of the other two divisions. 



In 1857 the "Hudson Eiver gronp" of 'New York was terminated by 

 the Lorraine, and nothing that is now embraced under the term Eich- 

 mondian was then known to occnr above the Pulaski and Lorraine forma- 

 tions. In reality the "Hudson Eiver group" of the Hudson Eiver Valley 

 is based on the very thick and greatly deformed mass of black shales 

 holding an Atlantic province fauna mainly of graptolites that are older 

 than the Htica and younger than the Cambric. In fact, the term is 

 practically synonymous with the "Quebec group." The "Hudson Eiver 

 group," however, was already extended at that time to include the Ordo- 

 vicic strata of the Ohio Valley, now known as the Cincinnatian series, or 

 Cincinnatic system^ w^hich not only has the equivalents of the Lorraine, 

 but is the t}^ical area for the Eichmondian series. The use Billings 

 here makes of the term "Hudson Eiver group" is in the sense of the Lor- 

 raine equivalents; but the Anticosti Divisions A and B are not of this 

 time, but of the higher Eichmondian series. As yet, no strata of Lor- 

 raine time have been shown to occur on Anticosti or in the Saint Law- 

 rence Valley; but even though such may occur in both regions, Billings 

 had in mind the correlation of Divisions A and B of the Anticosti strata 

 with the Lorraine of New York and its equivalents about Cincinnati. 

 Therefore we must modernize Billings's "Hudson Eiver" strata of Anti- 

 costi as the equivalents of the Cincinnatian series. 



The remaining strata of Anticosti he divided into Di^dsions C, D, E, 

 and F, that together "constitute a series of deposits to which it is pro- 

 posed ... to give the name of the Anticosti group." "The fossils 

 of the middle portion of the rocks of Anticosti [that is, C and D, he 



