192 FLORA OF LOWER COAL MEASURES OF MISSOURI. 



Leindodendron BrittsU is easily distinguished from all other species of 

 this genus, except L. Wortlieni and L. Volkmanniammi, by its generally 

 elongated, fusiform bolsters, which are rounded and transversely corru- 

 gated, and by its thin crescentic leaf scars. The narrow form of its leaf 

 scars and its more acute bolsters separate it from the older species. The 

 chief distinctions between it and L. Wortheni, as figured by Lesquereux,^ 

 seem to lie in the much broader, more oval leaf scars of the latter, and the 

 continuation of the distinct corrugation up to the base of the leaf. Unfortu- 

 nately I have seen no really good representative of the Illinois species for 

 comparison. Professor Zeiller has, however, figiu-ed two specimens from the 

 Valenciennes Basin," in which the details as well as the general appearance 

 are striking'ly similar to L. BrittsU. In fact, whatever ma}' be its relation 

 to L. Wortheni, the branch on the right in fig. 1, pi. Ixxi, of the Valenciennes 

 Flora is perhaps nearer in its characters to that of L. BrittsU, shown in our 

 PI. LIII, Fig. 1, than many of the fragments referred by various authors to 

 the same species. While there can be no doubt of the very close relation 

 of the two plants, the more truncate bolsters in the latter species, the higher 

 place of the leaf scar in the bolster, the less conspicuous nerve scar, and the 

 apparently longer leaves, seem to furnish characters ample for a differentia- 

 tion of varietal if not specific rank. From L. Cliftonense Dn. ^ our species 

 may at once be distinguished by the distinctly diamond-shaped leaf scars 

 of the former, whose twigs are larger, the leaves being several times as long. 



Localities. — Pitcher's mine, U. S. Nat. Mus., 5640, 6042; Deepwater 

 mine, U. S. Nat. Mus., 6040; Hobbs's mine, U. S. Nat. Mus., 6039. 



Lepidodendron lanceolatum Lx. 

 PI. LIII, Fig. -2. 



1879. Lepklodetidron lanceolatum Lesquereux, Coal Flora, Atla.s, p. 11, pi. Ixiii, figs. 



3-5, 5a; text, vol. ii (1880), p. 369. 

 1887. Lepidodendron lanceolatum Lesquereux, Kidstou, Foss. Fl. Radstock Ser., p. 39-4, 



pi. xxvii, fig. 5; pi. xxviii, figs. 3, 4. 

 1884. Lepidodendron (Beryeria) marginatum Presl, Lesquereux, Coal Flora, vol. iii, 



p. 784 (pars) ; pi. evil, fig. 3. 



' Geol. Surv. Illinois, vol. ii, 1866, pi. xlix, figs. 4, .5, p. 452. Copied in Atlas to Coal Flora, 1879, 

 pi. Isiv, figs. 8, 9, p. 388. 



^Fl. foss. liassin houill. Valencienues, Atlas, 1886, pi. Ixxi, figs. 1, 2, p. 467. 

 ' Bull. Geol. See. Am., vol. ii, 1890, p. 533, pi. sxii, figs. 5-8 ; pi. xxi, fig. 4. 



