198 



CONIFERALES 



[OH. 





Many of the species included by authors are not described in 

 sufficient detail to satisfy modern requirements with regard to the 

 structure of the medullary rays and other characters. From the 

 point of view of geographical distribution reference may be made 

 to Cupressinoxylon antarcticum described by Beust 1 from Kerguelen 

 Land. 



pood 



[Glyptostroboxylon Conwentz.] 



This generic name was first employed by Conwentz 2 for w 

 from sub-Oligocene beds in Argentina which he described as 

 Glyptostroboxylon Goepperti : no figures accompany the description 

 and it is hardly possible to determine with accuracy the precise 

 affinity of the specimen. The annual rings are said to be distinct, 

 the pits on the tracheids uniseriate and contiguous ; resin-paren- 

 chyma occurs, and the medullary-ray cells have large circular pits 

 on the radial walls. It is suggested by Gothan 3 that this species 

 should be transferred to Podocarpoxylon, though in the medullary- 

 ray pitting it differs from typical representatives of the Podocar- 

 pineae. Kraus 4 described the pits in the radial 

 walls of the ray cells of Glyptostrobus as large 

 and circular and in a Tertiary specimen from 

 Niederwollstadt, named Glyptostrobus tener Kr., 

 he figures the pits in the field as simple (fig. 

 719) ; these are said to be 1 8 in number and 

 they are arranged in horizontal series, a feature 

 characteristic of Taxodium. 



Sections of wood of Glyptostrobus hetero- 

 phyllus which I have examined show 2 8 pits 

 in the field but there is a distinct border and the 

 pore is narrow and oblique or in the spring- wood 

 the pore may be broader and almost horizontal. 

 Xylem-parenchyma is scattered through the wood and the thick 

 transverse walls are pitted. Gothan believes that the medullary-ray 

 pitting of Glyptostrobus is distinguishable from the Cupressoid type 

 by the increase in the breadth of the pore as the ray cells are 

 followed from the summer- to the spring-wood and by the fact 



FIG. 719. Cupressin- 

 oxylon tener (Kraus). 

 (.After Kraus.) 



1 Beust (85) PI. iv. 

 3 Gothan (08) p. 9. 



2 Conwentz (85) p. 13. 



4 Kraus (64) p. 195, PI. v. fig. 12. 



