XLIV] CUPRESSINOXYLON 199 



that the pits in the region of the spring- wood may be simple. 

 The same author 1 points out that this type of medullary-ray 

 pitting occurs in Cunninghamia. The impression produced by 

 an examination of the recent Glyptostrobus is that this so-called 

 Glyptostroboid pitting is not a sufficiently well-defined type to 

 serve as a trustworthy diagnostic character. The medullary-ray 

 pitting in the region of the summer- wood is similar to that in some 

 species of Podocarpoxylon (= Mesembrioxylon), while in the spring- 

 wood the pits in the field are rather of the type associated with 

 Cupressinoxylon and the scattered xylem-parenchyma is another 

 characteristic of the latter genus. There would seem to be no 

 adequate grounds for regarding the two fossil species referred to 

 Glyptostroboxylon as more nearly related to Glyptostrobus than to 

 certain other recent genera. The retention of the name Glypto- 

 stroboxylon is inadvisable in that it implies an affinity which is not 

 supported by satisfactory evidence. 



CUPRESSINOXYLON, sub-genus TAXODIOXYLON Felix. 



The generic name Taxodioxylon was applied to a Tertiary 

 species from Hungary, originally referred by Felix 2 to Rhizotaxo- 

 dioxylon, on the ground of a resemblance in structure to the wood 

 of the recent genus Taxodium. Schenk 3 , who examined the type- 

 specimen, confirmed this comparison. Taxodioxylon has been 

 adopted for fossils agreeing with the wood of Taxodium and 

 Sequoia sempervirens : Sequoia gigantea, on the other hand, agrees 

 more closely with typical species of Cupressinoxylon. Taxodio- 

 xylon, while similar in most respects to Cupressinoxylon, is said to 

 differ in the medullary-ray pitting, the pits in the field being 

 almost simple and elliptical with their long axis horizontal in con- 

 trast to the more definitely bordered pits of the Cupressoid type. 

 This distinction is, however, not entirely satisfactory : in the wood 

 of Taxodium the pits in the field are rather large and, though often 

 simple, they occasionally present the appearance of pits with a 

 well-developed border and the pore may be almost vertical or 

 horizontal. In the recent species, as in some fossil examples, 

 the tendency of the pits to arrange themselves in one or two 



1 Gothan (05) p. 49. * Felix (84) p. 38. 



3 Schimper and Schenk (90) A. p. 872. 



