FEUNS— MEGALOPTERIDE.E— T!ENIOi'TEKIS. 141 



ing from the lower part, with borders straight or shghtly undulate and 

 nearly parallel, to a rather acute tip, long, sometimes reaching a lengtli of 8 

 cm. or more, and measimng 6-13 mm. in width, the lower ones slightly 

 narrowed toward the cordate, nearly symmetrical base ^^'ith its narrowed 

 attachment which overlaps the marginal lamina of the rachis, the higher 

 ones becoming attached by the whole base, those near the top of the pinnse 

 becoming shorter, more distinctly decurrent and confluent, the margins 

 more rapidly converging; limb of the pinnules rather thick, dull, broadly 

 canaliculate along the midrib, somewhat convex near the borders, ovei'lap- 

 ping the marginal laminae of the rachis, constricted to a rather narrow 

 attachment in the lower and middle pinnules, spreading and uniting those 

 near the apex of the pinnte, where it forms a wing incised by acute and 

 decurring angles at the confluence of the pinnules; nervation Tteniopteroid ; 

 midrib strong, depressed, broad and striate beneath, broadly canaliculate 

 above, originating from the central portion of the rachis, passing along the 

 middle of the lamina and tapering to the apex of the pinnule ; lateral nerves 

 rather fine salient above, distinct beneath, originating at an oblique or some- 

 times nearly a right angle from a slender cordlike bundle often distinctly 

 in relief traversing the center of the canal, usually forking at or near the 

 midrib, rarely simple, curving quickly if oblique, and passing fairly straight 

 and generally parallel perpendicularly to the border, usually forking again 

 at a varying distance in the lamina, and counting 24 to 28 per centimeter 

 at the margin; basal nervils of the upper decurrent pinnules springing from 

 the rachis; those of the uppermost Alethopteroid pinnules rather more 

 oblique in passing to the margin. 



Among the known Paleozoic plants are several species described as 

 Banceites, Alethopteris, TcBniopteris, and Besmopteris which have many char- 

 acters in common with Tceniopteris "? missouriensis. Of the American forms, 

 Banmites (^Alethopteris) macrophylla Newb. sp , Alethopteris maxima Andr., the 

 types ranged under Orthogoniop)teris and Protoblecknmii, and an unpublished 

 species of CalUptericlmm described by Lesquereux deserve comparison. 

 Newberry's Alethopteris macrophylla,^ the fully developed pinnules of which 

 are somewhat similar to those of our specimens, is Alethopteroid in arrange- 

 ment, only the lowest, so far as I have observed, becoming contracted to 



' Geol. Surv. Ohio, Pal., I, p. 383, pi. xlviii, figs. 3, Za. 



