30 FLOEA OF LOWEE COAL MEASUEES OF MiaSOUEI. 



delicate tlian those fig-ured by Artis, Andi-a/ or Stur^ and seem to differ from 

 botliby their broad pedicels and percm-rent rachises. 



Locality.— Owens's coal bank, U. S. Nat. Mus., 5618, 5667. 



MAEIOPTEEIS Zeiller, 1878. 



1877. Biplothmema Stui', Culm-Flora, vol. ii, p. 226 (pars). 



1878. Mariopteris Zeiller, Bull. Soc. geol. Fr., (3) vol. viii, p. 93. 



1879. Pseudopecopteris Lesqoereux, Coal Flora, Atlas, p. 6; text, vol. i (1880), i). 190 



(pars). 



MAEIOPTEEIS cf. NEEVOSA (Brongn.) Zeill. 



1832 or 1833. Pecopteris nervosa Broagniart, Hist. v6g. foss., p. 297, pi. xciv, pi. xcv; 



figs. 1, 2. 

 1836. Alethopteris nervosa (Brougn.) Goeppert, Systema, p. 312. 



1877. Diplothmema nervosum (Brongn.) Stur, Culm-Flora, vol. ii, p. 23<1. 



1878. Mariopteris nervosa (Brongn.) Zeiller, Veg. foss. terr. houill. Fr., pi. clxvii, figs. 



1-4; text (1879), p. 69. 



1879. Pseudopecopteris nervosa (Brongn.) Lesquereux, Coal Flora, Atlas, p. 6, pi. 



xxxiv, figs. 1, 2 (uon 3?); text, vol. i (1880), p. 197. 



The rather comprehensive species, Mariopteris nervosa (Brongn.) Zeill., 

 seems to be represented by a single fragment from the \acinity of Clinton. 

 This fragment has a close resemblance to specimens of M. nervosa figured by 

 Sauvenr,^ Zeiller,^ and Stm-,'' or the figures given by the last-named author^ 

 as Diplothmema muricatum (Schloth.) Stur. The specimen from Missouri 

 difi"ers from the common American form, which has very broad, triangular 

 leaves, by the somewhat ovate shape of the latter, which are constricted at 

 the base and turned slightly upward at the point. 



On account of the many transitional and polymorphous phases 

 observed in and between M. nervosa and M. nmricata, Professor Zeiller 

 and several others of the most distinguished paleobotanists agree to include 

 all these forms under the latter name. Our American material, however, 

 appears to show a much greater diversity of forms than the European, the 

 extremes being much farther apart, while the stratigraphic series covered by 

 the group is well marked by the difi'erence between the older and the younger 



^ Spheiiopteris namvmlaria, Vorweltl. Pfl., p. 35, pi. xi. 



■Diplothmema trifolioJatiim (Art.) Stur, Fame d. Carbon-Fl., p. 349, pi. xlx, figs. 1-4. 



^ V<5g. foss. terr. hoiiill. Belg., pi. xliv, fig. 1. 



■i Veg. foss. terr. houil). Fr., pi. clxvii, fig. 2. 



" Fame d. Carbou-Fl., pi. xxiv, fig. 2. 



" Stur, op. cit., p. 393, pi. xxii, figs. 3-5. 



