166 Palaeontoiogie. 



The second part of the paper is devoted to a re-examination of 

 the 5 species (C. annularis, C. aniericana , C. Saturni, C. fasciciilaris 

 and C. Beinertianä). A Synopsis ot the characters of these species 

 is given on p. 221. 



The affinities of the species are then considered, with reference 

 to Dr. Zalessky's proposed Separation of C. fascicularis and C. 

 Beinertianä under the generic narae Enstophyton\ the conclusion is 

 reached that, while generic separates maj'^ ultimately be justified, 

 all the five species form a natural series, in which C. Satt{7-ni occn- 

 pies, in certain respects, an intermediate position, between C. an- 

 nularis and C. americana on the one hand, and C. fascicularis and 



C. Beinertianä on the other. 



Lastly, the affinities of the genus are discussed. While the 

 whole Calamopitys series should remain in CycadofiUces, the nearest 

 affinity being with the Lyginopterideae, through Heteravgium , the 

 species C. fascicularis and C. Beinertianä show some advance to- 

 wards the strticture of Cordaitales and especially of the family 

 Cordaiteae, Agnes Arber (Cambridge), 



Scott, D. H., The Structure of Mesoxvlon muUirame. (Ann. 

 Bot. XXXII. p. 437—457. 4 pl. and 2 text figs. 1918.) 



This memoir forms a continuation of a series of papers, with 

 which the author has already been associated, dealing with Meso- 

 xylon — a genus differing essentially from Cordaites in the pre- 

 sence of centripetal wood in the stem: Scott, D. H. and Mas- 

 len, A. J:. On Mesoxylon, a new Genus of Cordaitales. Preliminary 

 Note. Ann. Bot. XXIV, 1910, p. 236; Maslen, A. J., The Structure 

 of Mesoxylon Sutclifßi (Scott). Ann. Bot. XXV, 1911, p. 381; Scott, 



D. H.: The Structure of Mesoxylon Lomaxii and M. poroxyloides. 

 Ann. Bot. XXVI, 1912, p. 1011. 



An emended diagnosis of Mesoxylon multirame, Scott and Mas- 

 len, 1910, is presented in the foUowing form: Leafbases moderately 

 crowded, not quite covering tbe surface of the stem. Pith large, 

 discoid, with a persistent outer zone. Twin bundles of the trace 

 remaining distinct for several internodes after reaching the pith, 

 and never definitely fusing before they become merged in the 

 Woody zone. Trace dividing into eight bundles in the cortex. 

 Centripetal xylem persisting about as long as the two Strands re- 

 main distinct. Sheath variable, limited to the region where the 

 Strands first reach the pith. Tracheides of the whole in the inner 

 part of the wood spiral, reticulate, or scalariform, Bordered pits in 

 the rest of the wood usually in two rows. Tangential pits present 

 in places. MeduUary rays 1 — 12 cells in height, usually uniseriate. 

 Ray-cells pitted on radial walls. Xylem-parenchyma occasionalh' 

 present. Phloem consisting of resiniferous(?) tubes, parenchyma, 

 and sieve-tubes. Phloem-rays dilated. An axillar3^ shoot present in 

 many of the leafaxils. Shoot'leafless, with a flattened stele, branching 

 distichously, the branches bearing scale-leaves or bracts. 



Seam-nodules, Shore, Littleborough, Lower Cool Measures. 



From M. poroxyloides, M. multirame differs in the course of 

 the leaf traces in the wood and in the axillary steles. From M. 

 Lomaxii it shows obvious differences in the course of the bundles 

 and the structure of the inner part of the wood. In the latter cha- 

 racter and also in the nature of the axillar}'- shoots it differs from 

 M. Suicliffii. 



