216 DESCRIPTIVE CATALOGUE 



The elements comprising the medullary rays appear to be all 

 of one kind as regards their walls and pitting. Some of the 

 bands of elements seem to contain a much larger quantity of 

 resin than the others (text-figs. 61 & 62, mr.). In radial 

 extension a single ray-cell corresponds to from two to six 

 tracheids ; the end-walls are slightly sloping or curved. L 

 have been unable to detect any specialised thickening or 

 " abietinean pitting" on the walls. In the lateral walls 

 adjacent to the tracheids are single, rather large, roundish or 

 slightly oval pits (text-rig. 01, nip.). In a few cases there arc 

 two such pits in a tracheid-h'eld. In a few of the pits there i> 

 a faint suggestion of a border round the pit-pore, in other 

 cases they appear to be simple pit 



AFFINITIES. The number of fossil woods described as l\><lo- 

 carposeylon is small, and of these there are perhaps only UNO, 

 P. apat'cucliitiiHttosum, Gothan (1908 A), and /'. XcJm; n<l<r, Kubart 

 (1911), with which direct comparison need be attempted. Of 

 these, Gothan's Antarctic species is, as is indicated in its specific 

 name, devoid of wood-parenchyma, and therefore differs notice- 

 ably, though not fundamentally, from our fossil, in which the 

 resin-containing xylem-parenchyma is a marked feature: in 

 the Antarctic fossil also the radial section is not well enough 

 preserved to show the pitting very sharply. Though the two 

 fossils are generically allied, there does not serin any close 

 affinity between the species. On the other hand, between the 

 new English fossil and P. ^c/nr, n Jn , which is well preserved 

 and illustrated, there is a very close similarity. In the trncheid- 

 pitting the two fossils agree completely ; and in the pitting of 

 the radial walls of the rays, partly with simple pits and partly 

 with bordered pits, there is a close similarity. In our fossil, 

 however, there seems always to be only one pit or two placed 

 laterally per tracheid-field, while in the Austrian fossil there 

 may be two or three pits vertically above each other. The 

 Austrian fossil resembles ours also in having a considerable 

 quantity of xylem-parenchyma. 



I think there is little doubt that, of described fossils, P. wo- 

 bitrnet)se comes nearer to P. Schwemlce than to any other. The 

 Austrian fossil is, however, of uncertain geological age, being- 

 most probably either Tertiary or 1'lysch ; its extreme limit of 

 possible age is probably the Uppermost Cretaceous. 



