LYCOPODIALES— LEPIDODENDKE.E— OMPHALOPHLOIOS. 221 



are in agreement with the original figured by Lesquereux.^ It will Ije 

 observed that the bolsters are low, rounded, and destitute of keel or caudal 

 ornamentation, either above or below the scar; that the central convex area 

 as compressed varies from round to more or less distinctl}- triangular, and 

 that the boundar}^ of the latter is often a sharp, clear furrow, from the lat- 

 eral angles of which short, (piickly vanishing lines pass outward toward the 

 curved bolster margin, which tliey fail to reach. Other compressed speci- 

 mens, mostly impressions, to which reference will be made, show the great 

 variability in the aspect of these central areas. The photograph of the 

 example under consideration fails to sljow a punctiform mammilla situated 

 near the center of the convex area or but a very little nearer the lower 

 border. This, which we ma}^ temporarih^ designate as the central trace, is 

 visible to the unaided eye, as are also, in a few instances, two rather indefi- 

 nite, rounded, low, vertical grooves, crossing the central area, one on either 

 side of the central trace. The figure of this specimen is so placed on the 

 plate that the central, obscurely subtriangular area comes generally at a 

 little above the middle. Thus the transverse side, which is seen in many 

 cases either to be crescentic or to contain a very obtuse angle, is made to 

 constitute the base. This arrangement, which seems to conform with that 

 of Fig. 1, PI. LXVII, is made largely for the sake of preserving the mor- 

 phologic similarity of the bolsters of this tree with those of the conventional 

 type of Lcjiidodendron, as represented, for example, in L. dypeatum.. I con- 

 fess, however, a lack of assurance as to the actual attitude of some of the 

 stems. I have attempted to make them conform in position to other better- 

 preserved fragments, the orientation of which will be discussed farther on. 

 Passing now to the originals, described by Lesquereux, we find that 

 the figure given in the Coal Flora represents a small portion of an irregular 

 fragment 27 cm. in length and 15 cm. in width. In this fragment, which, 

 like the one described above, is a mold or impression, the Lepidodendroid 

 form of the bolsters is clear. In a portion of the slab one end, presumablv 

 the lower, of the bolsters is shghtly truncated by pressure in fossilization. 

 The convex central areas or compressed central bosses are mostly ovate- 

 triangular or ovate, as is shown in the original figure, though many are 

 round and some are transversely oval. The lateral angles, as well as the 

 short, vanishing, lateral furrows, are distinctly indicated in most eases, 



> Coal Flora, Atlas, pi. Ixii, fig. 5. No. 5501 of the Lacoe collection, U. S. Nat. Mus. 



