REPORT OF THE DIRECTOR I (J I 4 IICJ 



lands of Laurentia from the bays of southern England, Belgium 

 and the Rhine brought into the embay ments of the eastern Ap- 

 palachian rias, in Maine, in Nova Scotia and New Brunswick, 

 percentages of Coblentzian species quite foreign to the sandstone 

 or Oriskany fauna as it was normally developed in our interior sea. 

 The presence of these Coblentzian species in Atlantic lands is itself 

 another confirmatory evidence of the upstanding and overridden 

 land bridge across the north Atlantic continuing onward from early 

 Cambric time into the final and continental phases of Devonic sedi- 

 mentation. 



In Appalachia, the spread of the sands was not alone shoreward 

 over the low-lying rocks of the Siluric, but the disastrophy must 

 have been the slight movement of a low, inclined plane whose nega- 

 tive motion in the old land was counterbalanced by a positive move- 

 ment in the region of deeper water, for the earliest Oriskany sands 

 are notably calcareous in the fields which had been occupied by the 

 Helderberg sea, but as notably lime-free over regions of the shore- 

 ward transgression. These facts are evident in the Helderberg 

 regions of Maryland, Pennsylvania and eastern New York, close 

 upon the Appalachian heart, and confirmed by the sands of the 

 extra-Appalachian regions of western-central New York, Ontario 

 and Illinois. 



We may have been disposed to believe that the typical fauna of 

 these early sands in America, which in this place we may char- 

 acterize as Oriskany, an assemblage made distinctive by its heavy 

 shelled brachiopods, Rensselaeria (ovoides group), Hipparionyx, 

 Leptaenaventricosa, Spirifer (arenosus type) and species of the 

 Spirifer murchisoni group, large Leptostrophias, Plethorhynchus, 

 Leptocoelia Uabellites, etc., gastropods of large size (Diaphorostoma 

 ventricosa and many capulids) ; these and their less conspicuous 

 associates were normal to these shallow waters ; but there is good 

 evidence that the fauna of the sands and their shallow waters were 

 actually adjusted by slow adaption from the deeper waters of the 

 lime bottoms. This proposition would always be reasonable under 

 general conditions — the creeping of a deeper water fauna shore- 

 wards ; it is specifically indicated by the conditions in the north- 

 eastern Appalachians of Gaspe. One must bear in mind that in 

 respect to tectonic age these northeastern Devonic mountains are 

 the earliest of the entire chain ; the Appalachian folding was begun 

 here and proceeded thence southward. In direct semblance to the 

 relative age of these Gaspe folds are the heavy limestone beds 

 of the Grande Greve formation in whose profuse fauna are the 



