]Imnuu!MK?'i«in Ro!/al Microscopical Society. HI 



present j^aper togetlier in one group^ considering that tliey probably 

 differ only in the state of their preservation. He then enters into 

 an investigation of the merits of Lindley's and Buckland's inter- 

 pretation of the nature of the scar, and shows that the impressions 

 on the under-half cannot be the scales of the stem, as they are 

 arranged in a series peculiar to themselves, and different from that 

 of the stem ; and those on the upper part cannot be scars of cone 

 scales, for they do not have the convex outer surface characteristic of 

 all such scales. Unfortunately for the students of fossil botany, 

 the 'Histoire' stopped at page 72, in the middle of a sentence, 

 sufficient of which is printed to enable us to ascertain his critical 

 o])jections to Buckland's views, but leaving untold his own inter- 

 pretation of the nature of the scars. This loss is imperfectly 

 remedied by the short note on the genus in his ' Tableaux des 

 Germes Fossiles' (1849). Here he describes the scars as conical 

 or hemispherical tubercles covered with fohar cicatrices, and pro- 

 longed in the centre into the beginning of a branch or adventitious 

 root. His exposition is based on the beautiful specimen figured by 

 Allan in the 'Edinburgh Transactions,' but he has overlooked the im- 

 portant fact that this specimen is a cast in sandstone of the outer 

 surface of the stem, so that the elevated tubercles of the cast repre- 

 sented depressions in the original stem. He recognizes Megajpliytum 

 as a distinct genus allied to Ulodendron, and both forming a group 

 near to Lejndodendron. 



Goppert, in his 'Gattungen der Fossilen Pflanzen ' (1841), 

 figures a single scar, and considers it to belong to Knorria, and to 

 represent in the central portion the point of attachment of a small 

 branch, while the small scars are the bases of leaves arranged in re- 

 lation to the branch — the interpretation afterwards given, as we have 

 seen, by Brongniart. 



Macalister, in a paper read to the Geological Society of Ireland 

 (May, 1864), considered the fossil to be a cycadaceous plant, whose 

 leaf scars were large and circular, and whose scales were as nume- 

 rous and small as those of a Lycopod. 



Dawson, in his 'Acadian Geology' (1868), refers Ulodendron 

 and Bothrodendroji to Lomatophloios, and says the scars " usually 

 mark the insertion of the strobiles, though in barren stems they 

 may also have produced branches ; still the fact of my finding the 

 strobiles in sihi in one instance, the accurate resemblance which 

 the scars bear to those left by the cones of the Ked Pine when 

 borne on thick branches, and the actual impressions of the radiating 

 scales in some specimens, leave no doubt in my mind that they are 

 usually the marks of cones ; and the great size of the cones in 

 LepidoiMoios accords with the conclusion" (p. 456). 



The genus Megaj^hyton he considers a tree fern, as the scars 

 are not round and marked with radiating scales, but reniform or 



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