LYCOPODIALES— SUBSIGILLARI.E— ASOLANUS. 237 



directly nor meet the four neighboring scars as in 5'. camptotcenia, is hardly- 

 less apparent in Weiss's or Nathorst's figures of portions of the type specimen. 

 The difference is still more marked in the small sketch given by Schenk.'- 

 For my own part I can say only that among several scores of specimens 

 from the Coal Measures of Missouri, Illinois, Ohio, and Pennsylvania, I 

 have not seen any with striae arranged in this manner. This form, together 

 possibly with the phases illustrated by Weiss, op. cit., figs. 24 and 28, 

 appears to represent a variation tending toward the other Leiodermance. 

 At least they are not typical of the American form, though their departure 

 therefrom may be less than varietal in importance. I regard fig. 2 of Gold- 

 enberg's plate as quite different from the species in hand, as may also 

 be figs. 3 and 4 of the same plate. The Lepidodemh-on harhatum of 

 Roemer^ seems to be near these, though it may be merely a fragment of 

 Sigillaria camptotmiia in which the leaf scars are abraded or partially 

 decorticated. 



The reference of Grand 'Eury's Sigillaria camptotmiia gracilenta to Dr. 

 Wood's species, made by SterzeV and more recently by Potonie,Mn his 

 very interesting studies on the zone variations in Sigillaria, may be fully 

 substantiated by an examination of the American material, while phases, 

 such as that named Pseudosigillaria dimorpha on Grand 'Eury's plate,' are 

 well illustrated in the fine series from Cannelton, now a part of the Lacoe 

 collection in the United States National Museum. 



The discovery almost simultaneously by Weiss" and Zeiller' on the 

 trunks of Sigillaria Brardii Brongn. of both the typical form and arrange- 

 ment of the scars of that species and other distantly disposed scars referable 

 to S. spinulosa Germ, has since been supplemented by abundant evidence, 

 thus proving the impracticability of longer attempting to maintain the dis- 

 tinction of Clatliraria or Gancellata and Leiodermaria. Accordingly, most 



'Die fossileu Pflanzenreste, 1888, p. 82, fig. 41. 



- Beitr. z. geol. Kenntn. n.-w. Harzgebirges, p. 40, pi. viii, fig. 12. 



'J. T. Sterzel, in Weiss : Sigillarien d. Preuss. Steinkohl. u. Rothl., pt. ii, p. 67, footnote. 



■" Die Wechsel-Zonen-Bilduug der Sigillariaceen : Jahrb. d. k. Pr. geol. Lande.sanst. ii. Bem-akad 

 1893 (1894), p. 36. ° '' 



■■"'Geol. et pal. bassin houill. Gard, pi. ix, figs. 7, 8. Fig. 7 is also cited in the text as Sig. campt. 

 moiiostigma. 



" Beobachtungen an Sigillarien von Wettin und Umgegend : Zeitschr. d. deutsch. geol. Gesell., vol. 

 xli, 1889, p. 376. 



' Sur les variations de formes du SiijiUaria Brardii Brongniart: Bull. soc. g^ol. Fr., (3) vol. svii, 

 p. 603, pi. xiv. 



