FEliNS— MEGALOPTERIDE.E— NEUEOPTERIS. 137 



NbUROPTERIS DILA.TATA (L. and H.) Lx. 

 PI. XLI, Pig-.G; PI. XLII, Fig. 1; PI. XLIII; PI XLIY, Fig. 2. 



1833. Cycdopteris dilatata Lindley and Hiitton [non (L. & H.) Stb.], Foss. Fl.,vol. ii, 



pi. xci B. 

 1849. Fephropteris dilatata (L. and H.) Bronguiart, Tableau d. gen., p. l(i (65). 

 1809. Wephropteris dilatata (L. aud H.) Brougu., Schimper, Traite, vol. i, p. 430. 



1879. Dolerophyllum dilatatmn (L. aud H.) Schimper, iu Zittel: Haudb. PaliL^out., vol. 



ii, pp. 142, 252. 



1880. Neuropteris dilatata (L. aud H.) Lesquereux, Goal Flora, vol. i, p. 78. 



1893. Neuropteris dilatata (L. aud H.) Lx., D. White, Bull. U. S. Geol. Surv., Xo. 98, 

 p. 96. 



The specitic correlation of these large Cyclopterid pinnules is still 

 uncertain. The nomenclatural confusion arising from determinations influ- 

 enced by such characters as size, or distance of nerves along a broken edge, 

 or obscurity of nervation near the margin, is slightly increased by the 

 reference by some paleobotauists of these Cyclopterids to BoleropliyUum, 

 or Doleropteris, on the basis of a relation to a higher gymnospermic type. 



Through the courtesy of Dr. J. H. Britts, of Clinton, Missouri, I have 

 represented in PI. XLIII the specimen described by Professor Lesquereux 

 in the Coal Flora, page 78, and again by myself vpith others from the zinc 

 region of the same State ^ A good series of specimens was also gathered 

 by Mr. Van Ingen from the same locality. These American specimens I 

 have carefully com23ared with material in the Lacoe collection from Lindley 

 and Hutton's type locality. Felling Colliery, Newcastle, England, and 

 this comparison seems to confirm Professor Lesquereiix's identification. 



The leaf substance, which is not particularly thick, shows the same 

 intermediate fibers or ducts between the main nerves in the examples from 

 both England and Missouri. These fibers, as we luay for convenience term 

 them, in the plant from the " outliers" in the zinc region, are present in all 

 the well-preserved specimens In fact, the better the preservation of the 

 leaf the more clearly the filaments may in general be seen, although the)^ 

 are sometimes immersed in the parenchyma. The details given in Fig. la, 

 PI. XLII, fail to do justice to the continuity or distinction of these filaments 

 or ducts, though they sometimes seem to lack continuity, owing, apparently, 

 to a vertical undulation in the parenchyma of the limb. Fig. 6a, PI. XLI, 



I Bull. U. S. Geol. Surv., No. 98, 1893, p. 96. 



