LYCOPODIALES— LEPIDODENDREJE— LEPIDODENDRON. 195 



111 liis admirable memoir, on the flora of the Radstock series Mr. 

 Kidston figm-es^ and describes stem, twig, and cone fragments which he 

 regards as belonging to L. lanceoJatum. The aspect of the larger fragment 

 and its bolsters, shown in fig. 3, 2)1. xxviii, of his memoir, is very close to 

 that of our species, and perhaps really represents it, though from his figure 

 it would appear that th^e shields are rather less distinctly diamond shaped. 

 As, in the American specimens, the leaf scars are obscure. The larger 

 twigs, fig. 4, which he refers to the same species, have much shorter and 

 blunter subfalcate leaves, while the leaves of the cone-bearing branchlet, 

 represented in fig. 5 of pi. xsvii, are very small, crowded, and upward 

 curved. These twigs seem to sustain a much closer relation to a form 

 known in Professor Lesquereux's works as Lepidodendron Sternbergii. In 

 fact, to judge by the figm-es on Kidston's pi. xxviii, it seems to me probatte 

 that the Radstock plant would have been labeled by Lesquereux under the 

 latter name. The small twig on Kidston's pi. xxvii would also seem to 

 deserve comparison with the Lexndodendron Sternbergii of Lesquereux or the 

 L. lycopodioides of Em-ope. However, the recognized danger of identifying 

 species of this genus from figures and too brief descriptions becomes doublj^ 

 great when the characters of the leaf scar are so little known. 



Lepidodendron lanceolatum is not difficult of distinction from the other 

 species of the flora from the Henry County region. It is easily separated 

 from L. Brittsii Lx. by the smooth carinate shield below the leaf scars and 

 the more slender leaves. L. scutatum Lx. has well-developed leaf scars 

 placed lower in the shorter bolsters, which have fretted keels, while the leaves 

 of the latter species are shorter, closer, more rigid, and are curved outward 

 and upward. Lepidodendron Sternbergii (as interpreted by Lesquereux), 

 to some of whose forms L. lanceolatum is most closely related and from 

 which our plant is probably derived, has its bolsters less angular at the 

 sides, the leaves being shorter, tapering less, and distinctly more or less 

 subfalcate. 



Localities. — Pitcher's coal mine. No. 377 of Dr. Britts's private collec- 

 tion. The specimens Nos. 5580-5583 of the Lacoe collection come from 

 the same place or vicinity from which apparently come Nos. 5460-5465, 

 Lacoe collection, labeled L. marginatum Presl. 



' Trans. Roy. Soc. Edinb., vol. xxxiii, 1887, p. 394, pi. xxvii, fig. 5 ; pi. xxviii, figs. 3, 4. 



