88 The Testimony of the Rocks. 



ested in fossil botany will find in this part of the work a collection of 

 valuable facts which have hitherto been singularly neglected by 

 Scottish geologists. The following extract gives a summary of 

 the oldest fossil land plants of Scotland, which there as in Ireland 

 and in America, occur unequivocally for the first time in the Devo- 

 nian series. 



"The remains of a terrestrial vegetation in this deposit are 

 greatly scantier than those of its marine plants ; but they must be 

 regarded as possessing a peculiar interest, as, with the exception 

 of the spore cases of the Ludlow rocks, the oldest of their class, 

 In at least the British islands, whose true place in the scale can 

 be satisfactorily established. In the flagstones of Orkney there 

 occurs, though very rarely, a minute vegetable organism, which I 

 have elsewhere described as having much the appearance of one of 

 our smaller ferns, such as the maidenhair-spleenwort, or dwarf 

 moonwort. It consists of a minute stem, partially covered by 

 what seems to be a small sheath or hollow bract, and bifurcates 

 into two fronds or pinnae, fringed by from ten to twelve leaflets, 

 that nearly impinge on each other, and somewhat resemble in 

 their mode of arrangement the leaflets of one of our commonest 

 Aspleniums, — Asplenium trichomanes. One of our highest au- 

 thorities, however, in such matters (Professor Balfour of Edin- 

 burgh) questions whether this organism be in reality a fern, and 

 describes it from the specimen on the table, in the Palseontologi- 

 cal chapter of his admirable Class-Book, simply as " a remarkable 

 pinnate frond." (Fig. 13, p. 56.) We find it associated with the 

 remains of a terrestrial plant allied to lepidodrendon, and which 

 in size and general appearance not a little resembles one of our 

 commonest club mosses, — Lycopodium clavatum* It sends out 

 its branches in exactly the same style, — some short and simple, 

 others branched like the parent stem, in an arrangement approx- 



* I figured this species from an imperfect Cromarty specimen fifteen 

 years ago. (See " Old Red Sandstone," first edition, 1841, Plate 

 VII. Fig. 4.) Of the greatly better specimens now figured I owe the 

 larger one (Fig. 120) to Mrs. Mill, Thurso, who detected it in the richly 

 fossiliferous flagstones of the locality in which she resides, and kindly 

 made it over to me ; and the specimen of which I have given a magnifi- 

 cent representation (Fig. 12, p, 55) to my friend Mr. Robert Dick. I 

 have, besides, seen several specimens of the same organism, in a better 

 or worse state of keeping, in the interesting collection of the Rev. 

 Charles Clouston, Sandwick, near Stromness. 



