174 FLORA OF LOWER COAL MEASURES OF MISSOURI. 



verticil, each sporangium being supported at the upper end by a pedicel 

 arising from the ventral surface of the bract and curving outward, upward, 

 and finally inward to the point of union to the sporangium. Each pedicel 

 is traversed by a vascular bundle, which is regarded by M. Zeiller as a ven- 

 , tral lobe of the bract, presenting an arrangement analogous to the fertile 

 fronds of the MarsileacecB or the Ophioglossacece. A similar arrangement is 

 described by the same author in Splienopliyllum ohlongifolium and S. gracilis. 



Taking into account, then, the structiire of the cones. Professor Zeiller 

 would make the Splienophyllem constitute a distinct class among the vascular 

 cryptogams, comparable to the MarsileacecB and Opliioglossacece. 



It would seem as though the fertile specimens of Splienophyllmn trichoma- 

 tosum Stur described and illustrated by Mr. Kidston^ might differ in structui'e 

 from S. cuneifolium only by the single circle of sporangia, attached, perhaps, 

 though not necessarily, by the base to a short j^edicel, the position on the 

 inner surface of the bracts being the same. 



In an earlier reference to the nature of the genus Sp)lienophyllum, I 

 have expressed an inclination to regard it as belonging to the Calamarian 

 family.^ This view now seems untenable. 



With reference to the systematic position of the genus, I may add that 

 Dr. Potoni^, after discussing the details collated by Zeiller, reaches the con- 

 clusion^ that the Sphenopliyllum should be ranked in the group Pteridales of 

 Prantl, near the Salvinece. In the genei-a Splienopliyllum, Trizygia; Salvinia, 

 and Alalia, Dr. Potoni^ would detect a genetic as well as a geologic sequence. 



Sphbnophyllum cuneifolium (Stb.) Zeill. 



1823. Rotularia asplenioides Steruberg, Versucb, vol. i, fasc. 2, p. 30, pi. xxvi, figs. 4a-&. 

 1823. Rotularia cuneifolia Sternberg, Versucb, vol. i, fasc. 2, jj. 33, pi. xxvi, tigs. 4rt-6. 

 1826. Rotularia pusilla Steruberg, Versucb, vol. i, fasc. 4, tent., p. xxxii. 

 1826. Rotularia jioli/phylla Steruberg, Versucb, vol. i, fasc. 4, p. 42; tent., p. xxxii, 



pi. 1, fig. 4." 

 1828. Rotularia dichotoma Germar and Kaulfuss, I^ova Acta Acad., 0. L. C. nat. cur., 



vol. XV, pt. 2, p. 226, pi. Ixvi, fig. 4. 

 1828. SphenophyUum fimhriatum Brongniart, Prodi'ome, p. 68. 

 1828. Sphenophyllum dentatum Brouguiart, Prodrome, p. 68. 

 1850. Splienophyllmn dentatum Brongn., Unger, Gen. et Species, p. 70. 



>0n the Fructification of Sphenopliijllum trichomatosiim Stur, from the Yorkshire Coal Field: 

 Proc. Eoy. l^hys. Soc. Edinb., vol. si, 1892, pp. 56-62, pi. i. 



-Bull. U. S. Geol. Surv., No. 98, 1893, p. 36. 



'Ueber die Stellung der Sphenophyllaceen iiii System: Ber. d. Deutsch. bot. Gesell., vol. xii, 

 1894, Hft. 4, pp. 97-100. 



