824 W. T. GORDON ON RHETINANGIUM ARBERI, A NEW GENUS OF 
BIBLIOGRAPHY. 
ARBER, E. A. NEWELL, “On the Roots of Medullosa anglica,” Ann. Bot., vol. xvii., 1903. 
‘Corba, Beitrdge zur Flora der Vorwelt, 1845. 
GOPPERT u. STENZEL, “ Die Medullosex,” Palxontographica, vol. xxviii., 1881. 
Kinston, R., and Gwynne-Vaueuan, D. T., “On the Fossil Osmundacee,” Trans. Roy. Soc. Edinburgh, 
1908-1910. 
Kinston, R., and Gwynnse-Vaueuan, D. T., “On the Carboniferous Flora of Berwickshire: Stenomyelon 
Tuedianum,” Trans. Roy. Soc. Edinburgh, vol. xlviii., 1912. 
Renavtt, B., Végétaux silicifiés recueillis aux environs d’Autun et de St Etienne, 1878. 
RENAULT, B., Cours de botanique fossile, vol. iii., 1883. 
Renavtt, B., ‘‘ Flore fossile d’Autun et d’Epinac,” Gites minéraua de la France, 1896. 
Scorr, D. H., “On Medullosa anglica, a new representative of the Cycadofilices,” Phil. Trans. Roy. Soc. 
London, B, vol. 191, 1899. 
Scort, D. H., “On Suteliffia insignis, a new type of Medullosex from the Lower Coal Measures,” Trans. 
Lin. Soc, London, 2nd series, Botany, vol. vii., 1906. 
Scort, D, H., Fossil Botany, 2nd edit., London, 1909. 
Sewarp, A. C., ‘‘Notes on the Binney Collection of Coal Measure Plants: Part ii., Megaloxylon,” Proc. 
Cambridge Phil. Soc., vol. x., 1899. 
Wittiamson, W. C., “On the Structure of the Dictyoxylons of the Coal Measures,” Sectional Report, 
Brit. Ass., Edinburgh (1871), No. 41, p. 111, 1872. 
Wixuamson, W. C., “Organisation of the Fossil Plants of the Coal Measures,” Part iv., Phil. Trans. 
Roy. Soc. London, 1873. 
Wiuttamson, W. C., and Scort, D. H., “Further Observations on the Organisation of the Fossil Plants 
of the Coal Measures,” Part iii., Phil. Trans. Roy. Soc. London, B, vol. 186, 1895. 
EXPLANATION OF PLATES. 
(Figures all taken from untouched negatives by the author. Unless otherwise stated, the figured 
specimens are in the author’s collection.) 
Puate I, 
Rhetinangium arbert. 
Fig. 1. Transverse section of stem. «!=primary wood; x?=secondary wood; %.c.=inner cortex ; 
sc.0.c. = sclerotic hypoderma. Slide 1045. x 3:7 diameters. 
Fig. 2. Transverse section of central vascular axis. «#!=primary wood; «?=secondary wood; 7.c.= 
inner cortex ; 0.c. = outer cortex; A, B, C,=points of emission of petiole-traces. Slide 1000. x 8-5. 
Fig. 3. Longitudinal section of stem. «!=primary wood; x?=secondary wood; m.r.=medullary ray ; 
ph. = phloem ; 7.c.=inner cortex ; 0.c. = outer cortex ; sc.o.c.=hypoderma. Slide 984, x 9. 
Fig. 4, Transverse section of stem and petiole base. a!=primary wood ; «?=secondary wood ; sc.o.c.= 
sclerotic hypoderma ; pet. b.= petiole base; A=point of emission of petiole-trace from the cortex. Slide 
1003. x 2°3. 
Fig. 5. Longitudinal section to show tracheides. «!= primary wood ; ¢.p.=conjunctive parenchyma of 
primary cylinder; x?=secondary wood; m.7.=medullary ray; phk.=phloem; 7.c.=inner cortex. Slide 
984. x 23. 
Fig. 6. Longitudinal section of primary cylinder to show protoxylem. #«=primary xylem; pra. =proto- 
xylem (exarch). Slide 986. x 170. 
Fig. 7, Transverse section of primary wood to show secretory sacs. «!=primary wood; #?=secondary 
wood ; s.s,=secretory sacs. Slide 1007. x19. 
