1871.] 



DAWSON — DEVONIAN TREE FERNS. 



271 





pteris *, a genus characteristic of the same beds, but of very different 

 hftbit of growth. This accords with the fact that there is in Prof. 

 Hall's collection a mass of fronds of Oi/clopteris (Archceopteris) Jack- 

 soni, so arranged as to make it probable that the plant was an her- 

 baceous fern, producing tufts of fronds on short stems in the ordi- 

 nary way. The obscurity of the leaf-scars may render it doubtful 

 whether the plant above described shoidd be placed in the genus 

 Caulopteris or in Stemmatopteris ; but it appears most nearly allied 

 to the former. The genus is at present of course a provisional one ; 

 but I think it only justice to the diligent and successful labours of 

 Mr. Lockwood to name this curious and interesting fossil Caulopteris 

 Lockwoodi. 



I have elsewhere remarked on the fact that trunks, and petioles, 

 and pinnules of ferns are curiously dissociated in the Devonian 

 beds — an effect of water-sorting, characteristic of a period in which 

 the conditions of deposition were so varied. Another example of this 

 is, that in the sandstones of Gaspd Bay, which have not as yet afforded 

 any example of fronds of ferns, there are compressed trunks, which 

 Mr. Lockwood's specimens allow me at least to conjecture may have 

 belonged to tree ferns, although none of them are sufficiently perfect 

 for description. 



Mr. Lockwood's collection includes specimens of Psaroniits textilis ; 

 and in addition to these there are remains of erect stems somewhat 

 different in character, yet possibly belonging to the higher parts of 

 the same species of tree fern. One of these is a stem crushed in 

 such a manner that it does not exhibit its form with any distinct- 

 ness, but surrounded by smooth cylindrical roots, radiating from 

 it in bundles, proceeding at first horizontally, and then curving 

 downward, and sometimes terminating in rounded ends. They re- 

 semble in form and size the aerial roots of Psaronius erianus ; and I 

 believe them to be similar roots from a higher part of the stem, and 

 some of them young and not prolonged sufficiently far to reach the 

 ground. This specimen would thus represent the stem of P. erianus 

 at a higher level than those previously found. My idea of the 

 possible connexi n of these fragments is represented in fig. 3. 

 Mr. Lockwood's collections also contain a specimen of the large fern- 

 petiole which I have named Ehachiopteris punctata. My original 

 specimen was obtained by Prof. Hall from the same horizon in New 

 York. That of Mr. Lockwood is of larger size, but retains no re- 

 mains of the frond. It must have belonged to a species quite di- 

 stinct from Caulopteris Lochvoodi, but which may, like it, have been 

 a tree fern. 



2. Caulopteris antioua, Newberry. 



(Plate XIL fig. 4.) 



This is a flattened stem, on a slab of limestone, containing Bra- 

 chiopods, Trilobites, &c. of the Corniferous Limestone. It is about 



* The genus to which the well-known Ci/dopteris {Adiantifes) hibernicus of 

 the Devor ian of Ireland belongs. 



