292 



PITYBAB 



[CH. 



with Pitys^. The above account is based in part on Zalessky's 



description and partly on specimens in Dr Kidston's possession. 



Miss Blkins and W. Wieknd^ have recently described some 



Upper Devonian wood from Indiana characterised by a grouping 



Fig. 489. Gallixylon Trifilievi. A, C, the inner margin of the secondary 

 xylem showing strands of primary xylem, a, b, and C. B, traoheids of the 

 secondary xylem. (A, C, from photographs supplied by Prof. Zalessky; 

 B, Cambridge Botany School.) 



of the circular or elhptical bordered pits in the radial walls of the 



tracheids similar to those in Gallixylon Trifilievi which they include 



1 Scott (12) p. 1024. 2 Elkins and Wieland (14). 



