the Ophioglossaceae . 17 
4 . Bower, F. O.: Studies in the morphology of spore-producing members. II: Ophioglossaceae. 
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6. -: The origin of a land flora. London, 1908. 
7 . Braun, A. : Flora, 1839, P* 3 QI * 
8. Campbell, D. H.: On the affinities of the Filicineae. Bot. Gaz., xv, 1890, pp. 1-7. 
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11 . Farmer, J. B., and Freeman, W. G.: On the structure and affinities of Helminthostachys 
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15 . Jeffrey, E. C. : Are there foliar gaps in the Lycopsida ? Bot. Gaz., xlvi, 1908, pp. 241-58. 
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16 . Lang, W. H.: On the prothalli of Ophioglossum pendulum and Hehninthoslachys zeylanica. 
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PP- 433 - 570 * 
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EXPLANATION OF PLATES I AND II. 
Illustrating Dr. Chrysler’s paper on the Ophioglossaceae. 
PLATE I. 
Fig. 17. Todea barbara. Transverse section through midrib of leaf at level of origin of a pair 
of pinnae. The vascular supply of one pinna is visible on the right side. The adaxial side is placed 
upward in this and all the other figures, x 10. 
Fig. 18. Osmunda Claytoniana. Transverse section through midrib of leaf at level of origin of 
a pair of pinnae. The gaps left by the exit of the branches supplying the pinnae have closed, x 20. 
Fig. 19. Botrychium virginianum. Transverse section through petiole, showing the origin of 
the strands which supply the fertile spike. These strands appear at the upper side of the figure. 
X 20. 
Fig. 20. Botrychhim ternatum. Transverse section through axis of the fertile spike, showing 
the mode of origin of two branch strands, x 25. 
C 
