Vol. 62.] STRTJCTTTKE OF THE SGIIRR OF EIGG. 55 



The earliest notice is by Macculloch (1814). He states that the 

 pitchstone lies in a bed of ' marie ' 3 or 4 feet thick, which rests 

 upon a bed of hard reddish sandstone, and that 



' Large masses of wood, bituminized and penetrated with carbonat of lime, are 

 found in the marie stratum, not at all flattened. Portions also of trunks of 

 trees, retaining their original shape, are seen in the same bed, silicified, and 

 their rifts filled with chalcedony, approaching in aspect to semi-opal.' x 



Later 2 he made a correction, stating that what he had termed 

 ' marie ' was a ' mixture of limestone, clay, and sand.' He found 

 reason to believe that it was not a continuous bed, but either a 

 lenticle entangled between the pitchstone and the subjacent mass 

 or a part of the latter. This underlying mass he described as 



'a conglomerate consisting of small and large fragments of red sandstone, 

 trap, and silicified wood, imbedded in a basis of trap ' (Joe. cit.). 



Macculloch's ' marie ' is the pale brecciated and decayed base of 

 the pitchstone, and the 'conglomerate' below is the rock which 

 will here be described as a volcanic agglomerate. The large pieces 

 of wood are correctly described as occurring in the former, and 

 Macculloch is equally accurate in recording fragments of wood in 

 the latter also. 



Yon QEynhausen and von Dechen 3 apparently failed to find 

 wood, but they unwittingly contributed to the confusion of the 

 subject. Their paper mentions, as occurring immediately beneath 

 the pitchstone on the south side, a conglomerate with pieces of 

 pitchstone, horn stone, chalcedony, and calcspar ; and this they 

 identify with Macculloch's conglomerate containing red sandstone 

 etc., though it must certainly be the brecciated and decomposed 

 base of the pitchstone. 



Fossil wood from beneath the Sgurr of Eigg was described and 

 figured by Witham 4 (1831), and shortly afterward by Lindley & 

 Hutton. 5 From both accounts it might be inferred that this wood, 

 named Pinites eiggensis, occurred in place in Jurassic strata at the 

 base of the Sgurr. This misapprehension was corrected by William 

 Nicol, 6 who had supplied the material described, and who states 

 that it was found ' among the debris of the prismatic columns of 

 porphyritic pitchstone.' The specimens described and figured, then, 

 were not obtained in situ, but from loose fragments. It is fairly 

 certain, however, that their source was the former of the two 

 occurrences recorded by Macculloch, namely, the decaying base of 

 the pitchstone. 



1 Trans. Geol. Soc. ser. 1, vol. ii (1814) p. 408. 



2 'Description of the Western Is. of Scotland' vol. i (1819) p. 522. 



3 Karsten's Archiv fur Min. vol. i (1829) p. 107. 



4 ' Observations on Fossil Vegetables' 1831, p. 37 & pi. v, figs. 13-14. Also 

 ' The Internal Structure of Fossil Vegetables ' 1833, pp. 63-65, pi. xiv, figs. 13- 

 14, & pi. xv, figs. 6-9. 



5 'The Fossil Flora of Great Britain' vol. i (1831-33) pp. 91-92 & pi. xxx. 



6 Edin. New Phil. Journ. vol. xvi (1833) p. 154. See also Rep. Brit, Assoc. 

 for 1834 (Edinburgh) Trans. Sections, p. 660. 



