142 FLOKA OF LOWEE COAL MBASUHES OF MISSOUEI. 



the obliquely cordate base. Besides its more delicate habit, it further dif- 

 fers b}' the obliquity of the narrowed bases of the distinct pinnules, the 

 more slender upper, confluent pinnules, and the closer nervation. There is 

 perhaps no generic difference between the two plants. Alethopteris maxima 

 Andr.,^ as seen in a specimen from Rushville, Ohio, determined by Professor 

 Lesquereux, is an Alethopterid, though the difference between it and Pro- 

 tohlechnum may not be of generic rank. At probably nearly the same stage 

 a form perhaps somewhat similar existed in the Alethopteris ingens Daws.,^ 

 the pinnules of which, more than 1 inch in width and 3 inches or more in 

 leno'th, have the Danceites nervation. The A. discrepans Daws.,^ also from 

 the beds of supposed Middle Devonian age, but undoubtedly, as shown by 

 the peculiar composition and distribution of the flora, belonging to the 

 Carboniferous, at St. John, New Brunswick, the long, ribbon-like, open 

 pinniiles of which are imited, however, by a narrow decurrent wing, should 

 also be taken into comparison. So far as the form and development of the 

 jDinnules, and to some extent the nervation, are concerned, a closer resem- 

 blance obtains in the cases of Psetidodanceopsis reticulata Font.,* from the 

 Upper Trias at Clover Hill, Virginia, or the forms of Tceniopteris Mimsteri 

 Goepp. (Angiopteris, fide Schenk), from the Lias of Bornholm ^ The upper 

 pinnules of the Virghiia species are united, as figured by Fontaine, while 

 the lower ones are long, ribbonlike, and distinctly and nearly equally 

 rounded at the base, as in our plant from Missouri. Perhaps its nearest 

 affinity is, however, with the TcBiiiopteris jejunata of Grand 'Eury,'' from 

 the Upper Carboniferous and Permian of Ffance. In this species, of which 

 the upper parts of the pinnae are, I believe, unknown, the pinnules are 

 sometimes short- pediceled, the lamina thin, and the nerves generally more 

 oblique near the midrib and more regular, as figured, in passing to the 

 margin than in our species.' In form the Missouri species is also close to 



■ Geol. Suiv. Ohio, Pal., II, p. 421, pi. 1, figs. 3, Za-h. 



-Foss. PI. Dev. Sil. Form. Can., pi. xviil, fig. 206, p. 54. 



= 0p. cit., p. 54, figs. 203-205. 



^Older Mes. FL, U. S. Geol. Surv. Monogr., vol. vi, p. 59, pi. xsx, figs. 1-4. 



■■■ Bartholin : Botaiiisk Tidsskr., vol. xviii, hft. i, KjObenhavu, 1892, p. 23, pi. ix, fig. 9; 

 '^Fl. carb. Loire, p. 121. Zeiller, Fl. foss. Commentry, pt. 1, p. 280, Atl., pi. xxii, figs. 7-9. 

 Zeiller, Fl. foss. Autun, Epinac, p. 162, pi. xii, fig. 6. Potoni^, Fl. Rothl. Thiiringen, p. 145. pi. xvil, 

 fig. 3. 



'The nervation seen iu the figures of T. missourieitsia is dravrn with fidelity in detail from the 

 originals. 



