1872.J Dr. C. R. A. Wright on the Opium Alkaloids. 



203 



those of the medullary cylinder. The bark of the fossil plants is compared 

 with those of Lycopodium chamcecyparissus and Selayinella Martensii, 

 which two combined represent the former. 



These discoveries necessitate some changes in generic nomenclature, 

 since the several parts of the plant not only represent the three genera 

 above mentioned, but also several others. Meanwhile some other errors 

 require correction. Corda erroneously defined his genus Diploxylon as 

 having no medullary rays, and Brongniart relied upon this distinction in 

 separating Diploxylon from Siyillaria ; but no difference exists between the 

 ligneous structures of the two genera, so far as Siyillaria is illustrated by 

 Brongniart's S. eleyans. Corda, Brongniart, and King all agree in regard- 

 ing Diploxylon (which is identical with Witham's Anabathrd) as belonging 

 to the Gymnospermous Exogens. The necessity for abandoning this sepa- 

 ration of the plants in question from the Lycopodiacece, urged in the author's 

 previous memoir, is now made more obvious than before, the distinctions 

 upon which the great French botanist relied in his classification being 

 now shown to be such as mere differences of age can produce. The author 

 concludes from his own observations that the genera Diploxylon, Ana- 

 bathra, Lomatophloios, and Leptoxylon must be united. Brongniart had 

 already brought into one generic group Corda's genera Lomatophloios, 

 Leptoxylon, and Calamoxylon, Goppert's genus V achy phy Hum, and Stern- 

 berg's genus Lepidophloios, giving the latter name to the whole. Hence 

 no less than six obsolete generic names are disposed of. The author finally 

 follows Brongniart in adopting the term Lepidophloios, and temporarily 

 assigns to the plant described the trivial name of L. brevifolium. The 

 further relations of this genus to more ordinary forms of Lepidodendron 

 require further investigation. 



Much credit is due to G. Grieve, Esq., of Burntisland, for the energy 

 with which he has worked amongst the deposits at Burntisland ; and the 

 author acknowledges his great obligations to that gentleman for liberal 

 supplies of specimens for examination. 



March 14, 1872. 

 The EARL OF ROSSE, D.C.L., Vice-President, in the Chair. 

 The following communications were read : — 

 I. " Contributions to the History of the Opium Alkaloids. — Part 

 IV." By C. R. A. Wright, D.Sc, Lecturer on Chemistry in St. 

 Mary's Hospital Medical School. Received January 29, 1872. 



§ 1. On the Action of Hydriodic Acid on Morphia in presence 

 of Phosphorus. 



It has been shown in Part III. of these researches* that when hydriodic 

 acid acts on codeia in presence of phosphorus, a series of products are ulti- 



f Supra, p. 8. 



