xxxiv] PITYS 289 



described by Williamson^ as Lyginodend/ron (?) anomal/um from 

 the Lower Carboniferous volcanic ash of the Isle of Arran wotdd 

 appear to be closely related to, if not specifically identical with, 

 P. primaeva and, as Scott says, it should at least be included in 

 the same genus. 



Pitys Withami (Lindley and Hutton). The CraigUeth Tree. 



1831. Pinites Withami Lindley and Hutton, Poss. Flora, Vol. i. PI. n. 

 1831. Pinites medullaris. Ibid. PL rn. 



1902. Pitys Withami Scott, Trans. R. Soc. Edinb. Vol. xl. p. 354, PI. n. 

 fig. 10: PI. VI. fig. 21. 



This species was founded on some sections cut from an incom- 

 plete stem 36 feet long obtained in 1826 from the Calciferous 

 sandstone of the Craigleith quarry near Edinburgh. The specimen 

 named by Lindley and Hutton Pinites medullaris is no doubt 

 specifically identical with the larger stem. In the same year 

 (1831) Witham^ published an account of a still larger stem from 

 the same locality, 47 ft long and 5 ft in diameter in the lower part, 

 and in his book the name Pinites Withami is adopted. A large 

 specimen of this tree is erected in the grounds of the Natural 

 History Museum, London, and other specimens are preserved in 

 the Edinburgh Botanic Garden. Goeppert in 1850 referred the 

 species to Dadoxylon and later to Pitys^, while Brongniart* assigned 

 it to his genus Palaeoxylon. Scott* who examined Witham's 

 sections placed it in Pitys. The pitting of the secondary tracheids 

 is often multiseriate, but the medullary rays are narrower than in 

 Pitys antiqua and P. primaeva, rarely exceeding 4 cells in breadth, 

 though still of the manoxyUc type. Primary-xylem strands occur 

 in the peripheral region of the pith agreeing closely with those 

 of P. antiqua. There are no regular and continuous annual rings 

 though as Witham stated there are concentric markings on the 

 wood which superficially resemble true rings. The leaf-traces are 

 single and in their passage through the cyhnder of wood an arc of 

 secondary tracheids is added to the primary elements. 



1 WiUiamson (78) A. p. 352, PI. xxv. figs. 90—92; Williamson and Soott (95) 

 p. 770; Seward (97^) p. 80. 



2 Witham (31) A. ' Goeppert (50) p. 251; (81). 

 « Brongniart (49) A. 77. ^ goott (02) p. 364. 



s. nr 19 



