1871.] DA^ysox — devonian tree ferns. 269 



4. On new Tree Ferns and other Fossils from the DEVONi.iJf. By 

 J. W. Dawson, LL.D., F.E.S., F.G.S., Principal of M'GiU College, 

 Montreal. 



[Plate XII.] 



Of the numerous ferns now known in the Middle and Upper Devo- 

 nian of North America, a great number are small and delicate 

 species, which w'ere probably herbaceous ; but there are other species 

 which may have been tree ferns. Little definite information, how- 

 ever, has, untn recently, been obtained with regard to their habit of 

 growth. 



The only species known to me in the Devonian of Europe is the 

 CauJopteris Peachii of Salter, figured in the Quarterly Journal of the 

 Geological Society for 1858. The original sj)ecimen of this I had an 

 opportunity of seeing in London, through the kindness of Mr. Ethe- 

 ridge, and have no doubt that it is the stem of a small arborescent 

 fern, allied to the genus Cauhptens of the Coal-formation. 



In my paper on the Devonian of Eastern America (Quart. Journ. 

 Geol. Society, 1862) I mentioned a plant found by Mr. Eichard- 

 son at Perry, as possibly a species of MegapTiyton, using that term 

 to denote those stems of tree ferns which have the leaf-scars in two 

 vertical series ; but the specimen was obscure, and I have not yet 

 obtained any other. 



More recentlj', in 1869, Prof. Hall placed in my hands an inter- 

 esting collection from Gilboa, New York, and Madison County, New 

 York, including two trunks surrounded by aerial roots, which I 

 have described as Psaronius te^vtilis and P. erianus in my ' Revision 

 of the Devonian Flora,' now in the hands of the Royal Society*. 

 In the same collection were two very large petioles, RhacMopteris 

 gigantea and R. jpalmata, which I have suggested may have belonged 

 to tree fei-ns. 



My determination of the species of Psaronius, above mentioned, 

 has recently been completely confirmed by the discovery on the part 

 of Mr. Lockwood, of Gilboa, of the upper part of one of these stems, 

 with its leaf-scars preserved and petioles attached, and also bj'' some 

 remarkable specimens obtained by Prof. Newberry, of New York, 

 from the Corniferous Limestone of Ohio, which indicate the exist- 

 ence there of three species of tree ferns, one of them with aerial roots 

 similar to those of the Gilboa specimens. The whole of these speci- 

 mens Dr. Newberry has kindly allowed me to examine, and has per- 

 mitted me to describe the Gilboa specimen, as connected with those 

 which I formerly studied in Prof. Hall's collections. The specimens 

 from Ohio he has himself named, but allows me to notice them here 

 by way of comparison with the others. I shall add some notes on 

 specimens found with the Gilboa ferns, and on a remarkable plant 

 from the Devonian of Caithness, kindly placed in my hands by Dr. 

 Wyville Thomson. 



It may be further observed that the Gilboa specimens are from 

 a bed containing erect stumps of tree ferns, in the Chemung group 



* Abstract in Proceedings of Royal Society, May 1870. 

 VOL. XXVII. PART I. TJ 



