218 FLORA OF LOWER COAL MEASURES OF MISSOURL 



characteristic of the Triletes of Reinsch and Kidston, are sharp and promi- 

 nent, extending across one side of the flattened spore. 



The scales which I have described nnder the above name represent a 

 larger type, I believe, than any heretofore illustrated. Among the Old 

 World species it is comparable to Leindopliylliim majiis Brongn.^ It appears, 

 however, to differ specifically from the latter by tlie bx'oader apex of the 

 sporangiophore, the prominently dilated or auriculate base of the blade, 

 the proportionately very much greater expansion of the upper half of the 

 bract, and the contracted, acuminate apex. Lepidopliyllum atiricidatum Lx., 

 which is not well known, has a blade that tapers gradually from the middle 

 upward. The same difference exists in L. acuminatum, which has a propor- 

 tionately much larger sporangiophore. Finally, L. Mansfieldi, to which both 

 the blades and the sporocysts of our species bear the closest resemblance, 

 and which is undoubtedly its nearest relation, has the auricles much less 

 developed at the base of the blade, while the latter is broader in proportion 

 above the base, and is almost invariably transversely wrinkled in the lower 

 half, as though thicker and very much arched. 



Localities. — Most abundant at Gilkerson's Ford, U. S. Nat. Mus., 6060, 

 6062, 6065, 6066, 6072, 6081; Pitcher's coal mine, U. S. Nat. Mus., 6058; 

 Owen's coal mine, U. S. Nat. Mus., 6059!. The large cone fragment, loaned 

 to the United States National Museum by Dr. J. H. Britts, is from Pitcher's 

 coal mine. 



OMPHALOPHLOIOS D. White, 1898. 



Bull. Geol. Soc. Amer., vol ix, p. 336. 



OMPHALOPHLOIOS CYCLOSTICiMA (Lx.) D. W. 



PI. LXV; PI. LXVI, Figs. 1-5; PI. LXVII, Figs. 1, 2; PI. LXVIII, Figs. 1, 2, 



1870. Au Lepidodendron niammiUatum Lesquereux, Rept. Geol. Surv. Illiuois, vol. iv, 



p. 432, pl. XXV, fig. 1? 

 1879. Lepidodendron cyclostigma hes(\iiereax, Goal Flora, Atlas, p. 11, pl. Ixii, fig. o; 



text, vol. ii (1880), p. 39J:. 

 1898. Omphalophloios cijclostigma (Lx.) D. White, Bull. Geol. Soc. Amer., vol. ix, pp. 



329-342, pis. xx-xxiii. 



Stems or trunks of considerable size, the larger ones covered by more 

 or less clearly defined Lepidodendi-oid bolsters ; bolsters contiguous, some- 

 times partially obscure, especially in the young or badly compressed branches, 



' Prodrome, 1828, p. 87. Geinitz, Verst. Steink. Sachsen, 1855, p. 37, pl. ii, fig. 5. 



