240 



CONIFEEALES 



[CH. 



this connexion it is noteworthy that Fliche states that the pits in 

 his wood are occasionally circular. 



Xenoxylon lati'porosum (Cramer). 



Gothan's examination of the specimens on which Cramer 

 founded this species^ enabled him to confirm the main points of 

 the original description: he regards Cramer's species Piniies 

 fauciforosus as identical with the type-species with which he also 

 identifies Araucarioxylon horeanum Felix^. Xenoxylon lati'porosum 

 is characterised by the large size of the pits on the radial walls of 



Fig. 730. 



A, Xenoxylon phylhcladoides. B, C, Xenoxylon latiporosum. 

 (A, after Gothan ; B, C, after Cramer. ) 



the tracheids, 20 — 40ju, broad and 15 — 20/a high, their vertically 

 flattened form (fig. 730, B) and their occurrence in one or two con- 

 tiguous rows, the pits of double rows being generally opposite. The 

 medullary rays are uniseriate, reaching 17 cells in depth, character- 

 ised by the narrow form of the cells, the absence of pits on the 

 horizontal and vertical walls and by the presence of large simple 

 pores on the lateral walls, usually one pore in the field (fig. 730, C) 

 which it almost fills, or occasionally two; there is no xylem- 



1 Gothan (10) p. 23, Pis. rv., v. 



- Felix (87) PI. xxv. fig. 1. 



