. The testimony of the rocks; . e Oolitic flora; and similar bondsof connection seem to have eidsted in the florasof the still earlier ages. {Helmsdale.) In the Oolite of Scotland I have, however, at lengthfound trace of a vegetable organism that seems to havelain, if I may so express myself, outside the pentagon, andwas not a member of any of the great families which itcomprised. (See Fig, 151.) I succeeded about four yearsago in disinterring from the limestone of Helmsdale \s hat 496 ON THE LESS KNOWN appears to be a true dicotyledonous leaf, with the frag-ment of another leaf, which I at fi
. The testimony of the rocks; . e Oolitic flora; and similar bondsof connection seem to have eidsted in the florasof the still earlier ages. {Helmsdale.) In the Oolite of Scotland I have, however, at lengthfound trace of a vegetable organism that seems to havelain, if I may so express myself, outside the pentagon, andwas not a member of any of the great families which itcomprised. (See Fig, 151.) I succeeded about four yearsago in disinterring from the limestone of Helmsdale \s hat 496 ON THE LESS KNOWN appears to be a true dicotyledonous leaf, with the frag-ment of another leaf, which I at first supposed might havebelonged to a plant of the same great class, but which Inow find might have been a portion of a fern. WhenPhlehopteris Phillipsii was first detected in the Oolite ofYorkshire, Lindley and Hutton, regarding it as dicotyledo-nous, originated their term Dictyophillum as a general onefor all such leaves. But it has since been assigned to agreatly lower order, — the ferns ; and Sir Charles Lyell has Fig. 151. kindly shown me that an exotic fern of the present dayexhibits exactly such a reticulated style of venation as myHelmsdale fragment. (See Fig. 152, p. 497.) The otherleaf, however, though also fragmentary, and but indiffer-ently preserved, seems to be decidedly marked by thedicotyledonous character; and so I continue to regard it,provisionally at least, as one of tlie first precursors in Scot-land of our great forest trees, and of so many of our llower-ing and fruit-bearing plants, and as apparently occupying FOSSIL FLORAS OF SCOTLAND. 497 the same relative place in advance of its contemporaries asthat occupied by the conifer of the Old Red Sandstone inadvance of the ferns and Lycopodaceae with which I foundit associated. In the arrangement of its larger veins thebetter preserved Oolitic leaf somewhat resembles that of thebuckthorn; but its state of keeping is such that it has jfailed to leave its exterior outline in the stone. One or two general remark
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