GGO ME. J. STARKIE GARDNER ON EOCENE FERNS FR01I 



Hemitelites, and finally to Osmunda Torellii, Heer. It seems 

 probable that these may belong to a variety of the same fern, 

 such as the one found in the Fort Union G-roup of Dakota, and 

 still found living in the United States. The Tort Union Group 

 is a freshwater series considered by American geologists to belong 

 to the Eocene Formation, containing numerous plants, among 

 them being 0. sensibilis in considerable abundance. The type of 

 this fern met with in it is more robust than any living, or 

 than the fossils met with in the older localities ; and it is perhaps 

 worth mentioning, without entering into the merits of the ques- 

 tion here, that I am inclined, if not to doubt the Eocene age of 

 the deposit, to regard it as a very late member of the formation. 

 These specimens were collected by Dr. Hay den and are finer than 

 any obtained elsewhere. In speaking of them Prof. Newberry 

 remarked, " there is little room for doubt, therefore, that during 

 the Miocene age a species of Onoclea (Euonoclea) flourished in 

 the interior of our continent, of stronger habit than either of the 

 living varieties, and holding a middle position between them. 

 He seems to regard its horizon in the United States as Miocene, 

 and living it is quite common at the present day. 



Like so many other species and genera of Eerns and Conifer®, 

 whose characters are so sharply defined that they appear to 

 have no affinities with other existing species, Onoclea sensibilis 

 is a survival from a flora belonging to a past so remote that 

 nearly all its companion species have become extinct or modified 

 beyond specific recognition. We are far from able to trace its 

 pedigree ; but we at least know that in Mull it once occupied 

 a station separated by thousands of miles from its nearest exist- 

 ing habitat. It either once ranged synchronously from America 

 through Europe to its present habitats on the temperate coasts 

 of Asia, having since died out in the intermediate areas, or it 

 emigrated from some original home to the Amur and Japan, 

 and, via Europe and Greenland, to America. Its limited pal#- 

 ontological range lends little support to the former theory, 

 but is not opposed to the latter. Prof. Newberry thinks that 

 it had an American origin; but it is clearly found in older 

 rocks in Scotland and Greenland than in the United States. 

 With such slender data speculations are scarcely warranted; 

 but a satisfactory interpretation of the known facts would be, that 

 we had a well- developed ancestral form of Onoclea sensibilis, 

 relatively small and fragile, established in Mull during the cooler 



