140 NEW YORK STATE MUSEUM 



garded by him as of the age of the Lower Helderberg of New York, 

 at a time when the Helderberg fauna was not estimated with pre- 

 cision. Almost all the divisions were found to be fossiliferous, but 

 the uppermost, 7 and 8, specially so. 



It became evident from the identification of the fossils of the 

 upper beds by Billings that divisions 7 and 8 correspond more 

 nearly in fauna to the Oriskany of New York than to the Helder- 

 berg, and these have been generally conceded to have this 

 equivalence, but of the fauna of the lower beds, its composition and 

 variations, we know only enough to see therein clues to the origin 

 of the later fauna and invaluable lights on the derivation of all early 

 Devonic faunas of the Atlantic and Mississippian provinces. Con- 

 trasted with the other beds in profusion of fossils and diversity of 

 species, divisions 7 and 8 have been distinctively designated, Dr 

 Ami having proposed to call these beds the Grande Greve lime- 

 stones. To them Logan ascribed a thickness of about 800 feet, and 

 in them is a fauna which differs from that of the Oriskany of 

 eastern New York in as many respects as it agrees therewith and yet 

 is bound to it by such striking paleontologic features as the co- 

 existence of Rensselaeria, Megalanteris, Hipparionyx, Chonostro- 

 phia, Spirifer murchisoni, S. arenosus and many 

 other organisms. 



Over the Grande Greve limestones lie the Gaspe sandstones of 

 Logan, shown in apparently conformable contact with the rocks 

 below at Little Gaspe, and attaining an immense thickness. Sir 

 William estimated them at over 7000 feet and subdivided them 

 largely on lithologic characters, as they vary from drab ferruginous, 

 fine grained quartz and feldspar sandstone to coarse conglomerates 

 and red sandstones, the latter being mostly toward the top. From 

 the lower beds Dawson described many interesting plant remains 

 all presenting the aspect of such sedimentation as characterizes both 

 in New York and Europe the deposits of the Devonic or Old Red 

 lakes or lagoons. The lower beds about Gaspe basin contain a 

 fairly rich marine fauna which has been partly described by Billings 

 and to which we have been able to add evidences of both early and 

 middle Devonic age. 



