20 Seward. — On the genus Myeloxylon (Brong.). 
Fig. 1 6. Longitudinal section of a vascular bundle from the same specimen as 
Figs. 14 and 15. G = ground- tissue. jP=phloem. S = spiral tracheid (protoxylem). 
(Objective D, Zeiss.) 
Fig. 17. Another bundle from the same specimen. Letters as in Fig. 16. 
(Objective D, Zeiss.) 
Fig. 18. Oblique section of xylem-elements in a specimen in the Botanical 
Department of the British Museum, p ? protoxylem. a — reticulate tracheid. 
(Objective D, Zeiss.) 
Fig. 19. Outline of a bundle of Cycas Thouarsii , to compare with Fig. 15. 
Af=xylem. P— phloem. 
Figs. 1 and 18 are from specimens in the British Museum. 
Figs. 2-12 are from Millstone Grit specimens in the Wood wardian Museum, 
Cambridge, and in my own collection. 
Figs. 13-17 are from the Binney specimen in the Woodwardian Museum, 
from the Oldham Coal-measures. 
