Palaeontologie. 421 



Cycadeorachis, pseudo-genus nov. Cycadeomyelon, Saporta (pseudo- 



genus). . , n ^- „f 



Coniferales. A füll discussion of the various classifications ot 

 Conifer woods is given and the following scheme is adopted: 



I. Resin canals universally absent. Bordered j 

 pitsintwoormorerows.alternatingandhexagonally / 

 compressed, or in one row, flattened or rounded. V Araucarioxylon. 

 Medullary ray cells all alike, with several small, i 



bordered pits per tracheid-field in their radial walls. ) 



II. Resin canals present or absent. Bordered 

 pits generallv in a Single row if in two, the pits 

 side by side' and not alternating or compressed. 

 Medullary ray cells sometimes highly speciahzed 

 and differentiated. Ray-tracheids often present. 



A. Secondary tracheids with strongly mar- \ Taxoxylon. 

 ked accessory spirals. S 



B. Secondary tracheids without spirals or 

 with very fine and delicate markings. "Abietinean 

 pitting" in ray-cell end-walls noticeable. 



1. Resin canals both vertical and horizontal j pnyoxylon. 

 present in wood and in multiseriate medullary rays. S 



2. Resin-canals only vertical in the wood. \ pyotopiceoxylon. 

 Medullary rays all uniseriate normally. ) 



3. Resin-canals normally absent. Resin-con- ) 



taining xylem-parenchyma generally absent or / Cedroxylon. 

 present in exceedingly small quantities. } 



C. Typical "Abietinean pitting" generally 

 absent. Resin-canals absent, but resin parenchyma 

 plentiful. 



a. Medullary ray pits smal, roundish, 1 — 8 ^ Cupressinoxylon. 

 per tracheid-field, commonly 1 — 6. ^ 



b. Medullary ray-pits large, chiefly 1, ) 



sometimes 2 per tracheid-field, tending to be \ Podocarpoxylon. 

 laterally extended. ) 



Araucarineae. There is no evidence of the presence ot this group 

 in the Lower greensand of ßritain. 



Taxodineae. Sequoia giganteoides, sp. nov.-type a twig. 



Abietineae. Protopiceoxylon Edwardsi, sp. nov. a petnhed brauen. 

 Pityoxylon Sewavdi, sp. nov. a portion of the secondary wood. 

 Pityoxvlon Benstedi, sp. nov. a small petrified stem. Pityoxylon sp. 

 Pitxoxylon Woodwardi, sp. nov. a portion of secondary wood. 

 Piüostrobus sussexiensis, comb. nov. Pinostrobiis Benstedi, comb. nov. 

 Pinostrobus oblongus, comb. nov. Pinostrobus patens, comb. nov. 

 Pinostrobus c\lindroides, comb. nov. Pinostrobus pottoniensis, comb, 

 nov. Pinostrobus sp. Cedrostrobus Leckenbyi, comb. nov. Cedrostrobus 

 Manlellii, comb. nov. Cedroxylon maidstonense, sp. nov. secondary 

 wood. Cedroxylon pottoniense, sp. nov. twig. Abietites cf. bobnst 

 (Seward) several twigs. Abietites sp. Abietinean or Taxodmean iree 

 of uncerlain affinity — ''Benstedtia Condition" of Coniferous Trunk — 

 "The Dragon Tree". ^ . , 



Cupressineae. Cupressinoxylon ectense , Barber. Cupressinoxylon 

 luccombense, sp. nov. woody branch. Cupressinoxylon cryptomerioides, 

 sp. nov. small branches. Cupressinoxylon Hortii, sp. nov large woody 

 trunk. Cupressinoxylon sp. indet. 



