2 
PBOFESSOB W. C. WILLIAMSON ON THE OBGANIZATION 
of Autun ; and whilst he thought that these specimens displayed a structure analogous 
to that of some Monocotyledons, especially of Dracaena , he adds, “ il y ait des differences 
fort essentielles et qui rendent tres-difficile d’etablir des rapports entre ces fossiles et 
les vegetaux vivants”*. M. Brongniart consequently proposed to make Cotta’s 
Medullosa elegans the type of a distinct genus under the name of Myeloxylon. At a 
later page of his work (p. 97) he further gives a list of fourteen Carboniferous Mono- 
cotyledons, in which he includes seven species of Trigonocarpum , his proposed genus 
Myeloxylon , and the Palmacites carbonigerus and leptoxylon of Corda, at the same 
time declaring that all these supposed Carboniferous Monocotyledons are “ tres-douteuses 
et imparfaitement connues.” At p. 89 of his work he retains Corda’s genus Palmacites , 
but remarks respecting the two species from the Carboniferous strata, viz. P. carbonigerus 
and leptoxylon, that they appear to be distinct from the Palms, and probably also from 
the group of Monocotyledons, thinking them analogous to the Medullosa elegans of 
Cotta, adding, in reference to the latter plant, “ qui n’est certainement pas un palmier.” 
In 1864 Goeppert referred to the Medullosa elegans under the name of Stenzelia 
elegans , separating it from Cotta’s other species f, and regarding it as a generalized 
type of vegetable organization combining characters which are to be found separated 
in Dracaena , in Ferns, and in some Gymnospermous stems. 
In January 1872 Mr. Binney made a very brief reference to Medullosa elegans in a 
communication to the Literary and Philosophical Society of Manchester, in which he 
says that “ from some specimens in his cabinet he is- led to believe that Cotta’s 
Medullosa elegans is merely the rachis of a Fern or a plant allied to one”$. The context 
shows that Mr. Binney had obtained specimens of the plant from the Carboniferous 
strata of Oldham. 
In September 1873 I made a communication to the Botanical Section of the 
British Association for the Advancement of Science at their Meeting at Bradford, where 
I directed special attention to the organization of this plant, and announced my con- 
viction that it was not only a Fern, but that it belonged to the aberrant group of the 
Marattiacese. 
On January 26, 1874, my indefatigable fellow-labourer in the field of palseophytology, 
Professor Renault, presented to the Academie des Sciences of Paris another of his very 
important series of memoirs, entitled “ Recherches sur les vegetaux silicifies d’ Autun 
this last of which he designates “ Etude du genre Myelopteris .” Under this generic 
name he comprehends the Medullosa elegans , with its various synonyms of Medullosa , 
Stenzelia , and Myeloxylon. He assigns his reason for adopting the new name in the 
abstract of his memoir (which alone has yet been published) in the ‘ Comptes Rendus ’ 
of the above date : — “ Pour conserver le nom, premier en date, donne par M. Brongniart 
a ces portions de plantes, et en meme temps pour rappeler leur nature, je les designerai 
sous le nom de Myelopteris .” The reason thus assigned may probably suffice to justify 
* Loc. tit. p. 60. f Die fossile Flora der permischen Formation. 
+ Proceedings of the Lit. and Phil. Soc. Manchester, vol. xi. no. 7, p. 69. 
