APPENDIX. XVUl 



Cyclopteris Yirginiana, M. 



PI. I, fig. 3, a, b, c. 



Frond apparently attaining a large size, and probably tri pin- 

 nate. Primary pinnsg with a rather stout, rigid, smooth, or 

 slightly striated rachis. Secondary pinnae long lanceolate, 

 regularly alternating, nearly straight, rather closely arranged, 

 and standing nearly or quite at right angles to the rachis. 

 Pinnules more oblique, rather approximate and regularly alter- 

 nating ; lower or inner ones shorter and broader than the others, 

 abruptly narrowed, or apparently sometimes subcordate at the 

 base, and attached to the rachjs by an extremely short petiole, 

 more or less distinctly trilobate, the lobes being obtuse, and 

 broad-ovate in form; succeeding pinnules gradually becoming 

 five-lobed, more elongated, or obtusely sublanceolate, more ob- 

 lique, and less abruptly tapering at the base ; beyond these, the 

 others are less and less strongly lobed, or merely undulated on 

 the margins, while a few near the extremities of the pinnae are 

 quite simple, still more oblique, and very gradually tapering 

 to, and more or less decurrent upon, the rachis. Nervation dis- 

 tinct, nerves slender, palmately spreading, and bifurcating seve- 

 ral times. 



If specimens of this species, like the one figured, are imperfect 

 primary pinnse, and not fronds, it must have been a very large 

 beautiful fern. It seems to have been much more rare than the 

 last, as only the two specimens figured occur in a collection, con- 

 taining fifteen or sixteen more or less imperfect examples of the 

 last. 



Although very distinct specifically from the foregoing, this 

 seems, like that form, to stand as it were intermediate between 

 several of the established genera. In some respects it is related 

 to both Sphenopteris and Cyclopteris, while Prof Schimper has 

 included some similar forms in his genus Triphyllcpteris. Still 

 other high authorities have placed apparently congeneric forms 

 under the names Adiantites and Asplenites. It is therefore pos- 

 sible that when the affinities of the ancient types of ferns can be 

 better understood, and the confusion that now exists in their 

 nomenclature is corrected, the name of this species may have 

 to be changed to Sphenopteris or Triphyllopteris Virginiana. 

 I am not sure, however, that it should not be called Archaeopteris 

 (Palseopteris) Virginiana. 



Cyclopteris (Arch^opteris) Alleghanensis, M. 



PI. I, fig. 2, a, b. 



Frond tri- or bipinnate. Primary pinnse (or possibly the 

 frond) narrow, or apparently lanceolate, with a comparatively 

 strong, transversely wrinkled, rigid rachis, that is provided 



(43) 



