LYCOPODIALES— SUBSIGILLAKl.^5— ASOLANUS. 233 



The peculiar type of SigiUaria described in 18(;o Ijy Dr. Wood as 

 Asolanus camptotcenia and by Professor Lesquereux in 1866 as SigiUaria 

 monostigina is now one of the more familiar and most easily recog-nized 

 species in the Coal Measures of the United States. Therefore little need 

 be added by way either of description or of illustration to the material pub- 

 lished by the latter author in the Reports of the Geological Sui-vey of 

 Illinois and the Coal Flora.^ 



However, some additional details ascertained during- the course of a 

 critical examination of the leaf scars in the materials lately received, as well 

 as in the older collections in the United States National Museum, are worthy 

 of a brief consideration. 



As generally seen, the fragments of SigiUaria camptotcBnia show well 

 enough the characters of the interfoliar cortical surface, but the leaf scars 

 are presented in the published figures in a variety of aspects, some of which 

 have been erroneously described as superficial, owing to the relative delicacy 

 and consequent general absence of the tissue surmounting the narrow bolster 

 or cushion. Thiis the lateral angles of the foliar scars which seem to be 

 most fragile are often first to be lost, leaving an apparently rounded, narrow 

 leaf scar against which the cortical striations abut, the latter appearing, in 

 fact, continuous over the surface originallj- covered by the leaf-scar angles. 

 Suggestions of this phase are seen in the photographs, PI. LXIX and PI. 

 LXX, Fig. 4. It is also well shown in Weiss's fig. 25, pi. iv, vol. ii, of the 

 "Sigilliarien," though the striations in the cortex of the fragments illustrated 

 are hardly typical of the species. When still further decorticated or abraded 

 the leaf cushions often have the appearance shown in fig. 4 of pi. Ixxiii of 

 the Coal Flora. But in the best-preserved fragments we find the round, 

 narrowly obovate-triangular or obovate-fusiform bolster, which does not 

 even protrude so far as to become semicylindrical as it rises to the support 



' The general aspect of the decorticated and Kiiorria stages is seen in Rept. Geol. Suit. Illinois, 

 vol. iv, 1870, pi. xxvi, fig. 5; op. cit., vol, ii, 1860, pi. xlii, fig. 4; Goal Flora, pi. Ixxiii, figs. 5, 6. Par- 

 tially decorticated fragments are illnstrated, Rept. Geol. Surv. Illinois, vol. iv, pi. Ixsiii, figs. 2, 5; Coal 

 Flora, pi. Ixxiii, figs. 3, 4, 5, 6. The same conditions as well as the supracortical aspects are figured 

 by Weiss, Sigillarien, vol. ii, 1893, pi. iv; and Grand 'Eury, Geol. et pal. bassin houill. Gard, pi. 

 ix, figs. 4, 6, 7, and 8. 



The facies of the outer cortex is well represented by Wood, Proc. Acad. Sci. Phila., vol. xii, 

 1860, pi. iv, fig. 1; Trans. Amer. Phil. Soc, vol. xiii, 1866, pi. ix, fig. 3. The form of the leaf scars is 

 seen in Lesquerenx's figures, Rept. Geol. Surv. Illinois, vol ii, 1866, pi. xlii, figs. 1, 3, and 5; Coal Flora, 

 pi. Ixxiii. fig. 3, and in the figures cited under Zeiller in the above synonymy. The details of the 

 foliate scars il]ustv:iti-il by Weiss, op. cit.. pi. iv, are the most complete and satisfactory yet published. 



