Decorticated branches of the above species may no doubt be mistaken for _Psilophyton_, but are nevertheless quite distinct from it, and the slender branching dichotomous stems, with terminations which, as Miller graphically states, are "like the tendrils of a pea," are too characteristic to be easily mistaken, even when neither fruit nor leaves appear. With reference to fructification, the form of _L. Milleri_ renders it certain that it must have borne strobiles at the ends of its branchlets, or some substitute for these, and not naked spore-cases like those of _Psilophyton_. The remarkable fragment communicated by Sir Philip Egerton to Mr. Carruthers,[BT] belongs to a third group, and has, I think, been quite misunderstood. I am enabled to make this statement with some confidence, from the fact that the reverse or counterpart of Sir Philip's specimen was in the collection of Sir Wyville Thomson, and was placed by him in my hands in 1870. It was noticed in my paper on "New Devonian Plants," in the "Journal of the Geological Society of London," and referred to my genus _Ptilophyton_, as stated above under Section II., page 86 _et seq._ [BT] "Journal of Botany," 1873. Mr. Salter described, in 1857,[BU] fragments of fossil wood from the Scottish Devonian, having the structure of Dadoxylon, though very imperfectly preserved; and Prof. McNab has proposed[BV] the generic name _Palæopitys_ for another specimen of coniferous wood collected by Hugh Miller, and referred to by him in the "Testimony of the Rocks." From Prof. McNab's description, I should infer that this wood may, after all, be generically identical with the woods usually referred to Dadoxylon of Unger (_Araucarioxylon_ of Kraus). The description, however, does not mention the number and disposition of the rows of pores, nor the structure of the medullary rays, and I have not been able to obtain access to the specimens themselves. I have described five species of Dadoxylon from the Middle and Upper Erian of America, all quite distinct from the Lower Carboniferous species. There is also one species of an allied genus, Ormoxylon. All these have been carefully figured, and it is much to be desired that the Scottish specimens should be re-examined and compared with them. [BU] "Journal of the London Geological Society." [BV] "Transactions of the Edinburgh Botanical Society," 1870. Messrs. Jack and Etheridge have given an excellent summary of our present knowledge of the Devonian flora of Scotland, in the Journal of the London Geological Society (1877). From this it would appear that species referable to the genera _Calamities_, _Lepidodendron_, _Lycopodites_, _Psilophyton_, _Arthrostigma_, _Archæopteris_, _Caulopteris_, _Palæopitys_, _Araucarioxylon_, and _Stigmaria_ have been recognised.