OF LOWER GREENSAND PLANTS. 31,5 



spaces ; starchy contents frequent. Surrounding the pith and 

 following the outline of the inner bays of secondary wood, is a 

 broad perimedullary zone, with numerous anastomosing short 

 radial series and groups of small tracheids. Outside the bays 

 of the vertically running secondary xylem, successive zones, up 

 to 10 in number and probably more, alternate, so that zones cut 

 radially in the transverse section are cut transversely in the 

 true radial section. All the tracheids have scalariform pitting 

 on their radial walls, with wide borders and narrow slit-like 

 pores. Leaf- traces numerous, conspicuous, running nearly 

 straight out through the wood, and curving very slightly 

 upwards, arranged in close spirals, each leaf-trace about 1 cm. 

 distant from all its neighbour?. 



HORIZON. "Greensand" probably " Potton Sands," Lower 

 Greensand. 



LOCALITY. Unknown. Leighton Buzzard is not impossible. 



TYPE. V. 0312 and slides V. 0312 , b, c, d, e, /, g, 7*J, fr, I, 

 cut from it in 1915, and old slides V. 7796-V. 7801 from the 

 same block. Also V. 6127 (and all the slides cut from it in 

 1915) is probably part of the type-specimen itself, and if not is 

 a co-type. British Museum (Nat. Hist.). 



GENERAL DESCRIPTION. Some large and very thick uncovered 

 sections (V. 7790-7801), evidently cut long since, but transferred 

 from the Botanical Department in 1898 without any history, 

 showed, very imperfectly, an anatomical structure of great 

 interest. Owing to the thickness of the sections little more 

 could be seen than that there were four or five distinct zones of 

 secondary wood surrounding a very large cellular pith, thus 

 resembling superficially the specimens described above as Cycade- 

 oidea buzzardensis, sp. nov. (p. 309). These old sections are 

 unlabelled, but on one or two of them, cut in diamond into the 

 glass, is " Greensand, M. E. G.," and on another is " llaumeiia, 

 M. E. G." Two other sections (V. 10156 and V. 10168), 

 evidently cut from the same or a similar trunk, were found in 

 the collections ; these are equally thick, but have cover-glasses, 

 and on them " Haumeria (Goeppert) Greensaud, ? J. D. Hooker " 

 is cut into the glass. Mr. Edwards sought for further remains 

 of this interesting specimen, and found two pieces of a trunk, 

 registered under two different numbers, but evidently of the 

 surno species, if not actually parts of the same trunk. One of 



