32 FLORA OF LOWEE COAL MEASUEES OF MISSOUEl. 



upward, broader, more deeply dissected iu the lower part of the pinnules 

 and higher in the larger pinnules, varying much according to the develop- 

 ment of the pinnule, becoming narrower, closer, and more spinous toward 

 the tip, where they often resemble short claws, the terminal one being 

 usually tinally developed as a spinous process; limb not very thick, rather 

 coriaceous, arched upward between the nerves, and very finely striate in 

 the direction of the nervation, probably by rows of minute hair-like scales; 

 ner^-ation coarse, rather distant, slightly depressed above, clear and in relief 

 beneath, originating at a single point on the rachis, curving rapidly outward, 

 and forking, often three or four times, rather openly, before reaching the bor- 

 ders, where they are slightly turned upward in entering the lobes or teeth. 



In the coui'se of my examinations of the Paleozoic plant types in the 

 Illinois State Museum of Natural History and of the Missouri specimens 

 from the Lesquereux collection, now part of the Lacoe collection, I had 

 opportunities to examine the type specimens from both the Missouri and 

 the Illinois localities and to verif}' their specific identity, together with a 

 fine series of examples from the Missouri locality. Tliis comparison has 

 convinced me that the apparently anomalous nervation of the pinnules in 

 figs. 3 and 4 of Odontopteris spJienopteroides on pi. xxi of the Coal Flora, 

 which are otherwise Sphenopteroid, is due entirely to imperfect drawing, the 

 actual nervation being more truthfully represented iu the detail, fig. 3«, of 

 the same plate, which is obviously not Odontopteroid. Additional material, 

 labeled perhaps at the time of description or soon after the publication of the 

 species, shows still more clearly the Mariopterid outlines and teeth, often 

 developed into claws or blunt subspines, the terminal, especially in the larger 

 pinnules and pinnte, passing into nearly naked prolongations of the main 

 nerve or rachis. Thus, in pinnation, flexuosity, outlines, marg'inal wing, 

 lamina, and nervation, the species is plainly Sphenopteroid, of the group 

 included by Professor Lesquereux in Psendopecopteris or by Zeiller in Mari- 

 opteris. In the younger pinnules the apex is somewhat obtuse-truncate and 

 cut into narrow and less blunt teeth. 



In the mode of development of its pinnules, nervation, and limb, 

 Mariopteris siihenopteroides suggests a dentate modification of Mano])teris 

 nervosa (Brongn.) Zeill., or M. latifoUa (Brongn.) Zeill/^ My own studies 



'See Mariopto-is murkata (ScUoth.) Zeill., Fl. foss. houill. Valenciennes, pi. xs, figs. 2, 3, 4; 

 -If. acuta (Brongn.) Zeill., loc. cit., pi. xviii, fig. 2. Also see Stiir, Fame d. Carbou-Fl., Diplothmema 

 pilositm Stur, pi. xsxiv, fig. 2. 



