Devonian Plants from O/tio. 5 1 



each other both laterally and vertically. Probably if their com- 

 plete outlines could be traced, it would be found that each one was 

 obovate in form, with the lower extremity truncated. 



The structure of this interesting fern-stem is not visible, as the 

 specimen found is only a cast, covered with a carbonaceous coat- 

 ing, which retains the general aspects of the external surface. 



The figure now given represents fairly well the general appear- 

 ance of about half the specimen. By referring to this, the most 

 superficial observer will be satisfied that this is a tree-fern, and the 

 botanist will discover that it has essentially the structure of many 

 tree-ferns of the present day. It differs from any known species of 

 Caulopteris^ but evidently belongs to the same group with C Lock- 

 7Voodi, from the Chemung at Gilboa, N. Y., and C. Peachii, from 

 the Upper Devonian of Scotland ; the latter described by Salter in 

 the Journal of the Geological Society of London, for 1858; the 

 former by Professor Dawson, in the same Journal of August, 1871. 

 From both these, however, it is easily distinguishable; in C. Lock- 

 ivoodi the trunk is much smaller, the leaf scars larger, broader and 

 more crowded: in C. Peachii they are more remote, much smaller 

 and more transverse. The specimen before us is much the best 

 example of a tree-fern yet found in the Devonian rocks. It was 

 obtained from the quarries in the Corniferous limestone at San- 

 dinky. Special interest attaches to it, not only on account of its 

 botanical character, but from the fact that it must have floated out 

 to sea from some not very distant land, and with Caulopteris pere- 

 grina, N., Sphenophyllum vetustum, N., and Lepidodendron Gaspia- 

 nu/n, Dwn, represents a beautiful and highly organized flora, 

 which grew on the land bordering the Corniferous sea, and hence 

 dating from the middle of the Devonian age. 



In looking over the indications which geology gives us of the 

 topography of our continent in Devonian times, we see that the 

 interior basin was occupied by an open sea, which was bounded 

 on the east by the Blue Ridge, on the northeast and north by the 

 Adirondacks, the Canadian Highlands and the Archaean area 

 south of Lake Superior. No part of this shore was less than three 

 hundred miles distant from the locality where these plants were 

 found, and it is therefore extremely improbable that several species 

 of land plants should be carried so far, and sunk in that little por- 

 tion of the sea bottom now opened by the Sandusky and Delaware 

 quarries. It seems indispensible that we should find some 



