320 



J?EOF. A. C. SEWARD AND ME. J. WALTON ON [vol. lxXlX, 



Fig. 3. — Parenchymatous 

 cells seen in outline on 

 the surface of the specimen 

 shown in fig. 12 (PI. XX). 

 X 45. Cfi Neocalamites 

 Carrerei (Zeiller). 



narrower and more crowded ribs, from those previously recorded. 

 A good example is shown in fig. 8 (PL XX). The node is marked 

 by a slight transverse depression, a, on which there are faint indi- 

 cations of leaf-trace scars : a short distance from the node there is 

 a much more irregular depression, b. The specimen reproduced in 

 fig. 12 has the same type of internodal ribbing ; but on one side 

 of the node, and at rather a higher level on the rock, the surface 

 is smooth, and under the microscope reveals the outlines of paren- 

 chymatous cells (text - fig. 3) 

 which doubtless represent the 

 epidermis. There are no traces 

 of stomata. The epidermal fea- 

 tures agree with those described 

 by Halle in a specimen of the 

 Triassic species Neocalamites hoer- 

 ensis (Schimper) from Sweden. 1 

 Cells of similar size and shape 

 are more clearly shown on a frag- 

 ment, which we regard as a piece 

 of the surface of the same type 

 of stem as that shown in fig. 12 

 (PI. XX); and their arrangement 

 in regular longitudinal rows is a 

 striking feature. A larger spe- 

 cimen of a stem identical in the 

 ribbing with that shown in fig. 8 (PI. XX) has an internode 9 cm. 

 long, and is 4 cm. in diameter. The juxtaposition of two surfaces, 

 an outer, smooth surface and a lower, ribbed cast, seen on the 

 small piece of stem shown in fig. 12 (PI. XX), suggested the 

 reference to our second type of Equisetaceous stem of certain 

 specimens with a smooth outer surface, a feature characteristic 

 of Neocalamites as described by other authors. The specimen 

 reproduced in fig. 10 (PL XX) shows only the outer, smooth 

 surface : the internode above the node, a part of which is seen in 

 the figure, is at least 8 cm. long and 3'5 cm. in diameter. 

 Small leaf -trace scars occur at a on the nodal line, and at b there 

 is a less regular transverse line corresponding to that seen at b 

 in fig. 8. There is a very close resemblance between the stems 

 shown in figs. 8, 10, & 12 and the Rhsetic species from Tongking 

 described by P. Zeiller as Schizoneura Carrerei? but subsequently 

 transferred by Dr. Halle to his new genus Neocalamites,?' on the 

 ground that the long linear leaves are borne separately and not 

 coalescent basally into a sheath. Specimens from the Molteno 

 Beds (Upper Karroo), 4 probably Upper Triassic in age, of South 

 Africa, have been referred to Neocalamites Carrerei, and Krasser 5 



1 Halle (08) pi. i, fig. 4. 



2 Zeiller (02-03) Atlas ; (02) pis. xxxvi-xxxviii. 



3 Halle (08). 



4 Seward (03) p. 48 & pi. ix, fig. 5; (08) p. 85. 



5 Krasser (00) pi. iii, figs. 1 & 2. 



