364 DR R. KIDSTON ON A NEW SPECIES OF DINEURON AND BOTRYOPTERIS. 



The roots which rise direct from the xylem of the stem (fig. 6, r.) are very small, and 

 contain a typical diarch strand composed of scalariform tracheae. 



The foliage and fructification of Botryopteris antiqua are unknown. 



Botryofiteris antique is a- typical member of the genus, though perhaps its smallest 

 species, and is easily distinguished by its minute size and the protoxylem elements of 

 the leaf-trace being evenly distributed and not forming prominent teeth as in the other 

 known species. The tracheae of the stem are scalariform, not porose. 



The general character of growth of Botryopteris antiqua was that of a fern with a 

 branching stem of slender dimensions which bore petioles of large size when compared 

 with the stem from which they originated, and that must have supported itself by 

 scrambling amongst the surrounding vegetation. 



It is an interesting point to notice the progressive development of the protoxylem 

 in the form of prominent teeth. In Botryopteris antiqua, from the Calciferous Sand- 

 stone series (Culm), protoxylem teeth are absent ; in Botryopteris hirsuta, Will., sp., 

 from the Lamarkian series,* they are very distinct, and in some specimens even pro- 

 minent ; while in Botryopteris forensis, Renault, from the Upper Coal Measures of Grand- 

 Croix, they form long, narrow prolongations. There seems to be a tendency in the 

 petiole trace to become more simple in form as traced back in geological time. 



EXPLANATION OF PLATE. 



[s.= stele; prx. = protoxylem ; in.C = inner cortex; o.C. = outer cortex; end. — endodermis ; pet. 

 petiole ; r. = root ; h. = hairs ; pin. = pinna.] 



Figs. 1-3. Dineuron ellipticum, Kidston, n. sp. 



Fig. 1. Trans, section of petiole. x 30. Slide No. 57. 



Fig. 2. Trans, section of stele. x 70. 



Fig. 3. Trans, section of protoxylem group, x 160. 



Figs. 4-12. Botryopteris antiqua, Kidston, n. sp. 



Fig. 4. Trans, section of stem giving off two petioles. x 30. Slide No. 1084. 



Fig. 5. Trans, section of stele of last specimen. x 70. 



Fig. 6. Trans, section of stem showing division of stele, petiole, roots, and hairs. x 15. Slide No. 549c. 



Fig. 7. Trans, section of stem giving off a petiole x 15. Slide No. 782. 



Fig. 8. Trans, section of leaf-trace. x 80. Slide No. 508. 



Fig. 9. Trans, section of petiole giving off pinna. x 30. Slide No. 1347. 



Fig. 10. Trans, section of petiole giving off pinna. x 30. Slide No. 1086. 



Fig. 11. Trans, section of petiole showing early stage of dichotomy of leaf-trace, x 30. Slide No. 1348. 



Fig. 12. Trans, section of petiole showing leaf-trace dichotomously divided, x 30. Slide No. 1346. 

 All the figured specimens are in the Author's collection. 



* Kidston, Quart. Journ. Geol. Soc., vol. lxi., p. 320, 1905. 



