FIFTH REPORT OF THE DIRECTOR I908 



29 



the northerly passages ended, in the open sea or that that part of 

 the geosyncline in which they flourished failed entirely of con- 

 tinuity with the eastern continent while more southerly parts left 

 freer connection with the east at contemporaneous periods. These 

 affiliations with European faunas have been specifically indicated 

 in the text and imply a well defined westward invasion along these 

 •eastern channels in this early period of the Devonic. 



9 There was still another quite well defined channel of this time 

 which has not here been specially considered, namely that repre- 

 sented by the beds of Perry, Me. — St John, New Brunswick — 

 Annapolis, Nova Scotia. This southernmost Devonic channel is 

 little known at present. Its fossils have been studied by Dawson 

 and Matthew for the New Brunswick and Nova Scotia occurrences 

 and by Williams for the manifestations in Washington county, Me. 

 We have had extensive collections from the last but the preserva- 

 tion is not favorable and yet good enough to demonstrate that 

 exact information in regard thereto is still to be desired. 



10 All these various channels of the early Devonic in the north- 

 east converged southwestward. It is probable however that they 

 passed on southward, after the union of some of them, by dif- 

 ferent thoroughfares. We here come face to face with certain 

 hypotheses with substantial evidence behind them but they may 

 be stated in terms which will permit of their modification after 

 more detailed knowledge is acquired. 



11 The possible trunk troughs entering the southern portions of 

 the geosyncline may be indicated thus : 



(/ Connecticut valley trough. The valley of the Connecticut is 

 ancient, probably not differing in origin from the parallel valleys 

 of Lake Champlain and the Hudson as a graben valley or at least 

 outlined by a zone of master faulting. Between the crystalline 

 boundaries of this trough at Lake Memphremagog and southward 

 arc evidences showing that it was open earlier that the Devonic, 

 as witness the limestones at Littleton, N. Y. with species of Dal- 

 manites (D . lunatus Lambert) apparently of very late Siluric 

 age. 



At Lake Memphremagog are grits carrying Taonurus which 

 have been identified by Dr Ami with the Esopus grit but the ar- 

 gillites both above and below these grits contain fossils ; a Dal- 

 manitcs similar to the D. coxitis of the Grande Greve lime- 

 stone, an Orthoceras of distinctive character, with traces of other 

 fossils. While the Taonurus alone can not be taken as a safe 

 guide for identification with the Esopus horizon of New York yet 



