On Variations of Sigillarice. 45 



his Traite de Paleontogie Vegetale, M. Schimper gives two 

 figures (Plate 67, Fig. 8-9) showing the confluence of the de- 

 corticated geminate scars of 8. reniformis. 



The species 8. laevigata-, Brgt. is subject to a Similar union 

 of the geminate sub-cortical scars. The figures on Plate IV 

 are from specimens in the collection of Prof. J. S. Newberry ; 

 locality, the Wyoming coal basin, probably the Lackawanna 

 portion. Fig. 6 shows the variations upon a single slab : the 

 scar a is the natural form. Fig. 7 shows scars from different 

 parts of a large specimen. The greater number of scars have 

 a distinct rectilinear form, like the one marked b. The rows 

 are about two inches apart, but much broken and shifted. 

 Upon one side of the slab, two broken rows are brought end 

 to end, which belong to adjacent rows. The scars are very 

 close longitudinally, and are much raised ; furrows obsolete. 



Fig. 8 represents the variation in two outside rows and 

 the middle row of scars, upon a slab having five rows three 

 inches apart. The furrows are obsolete. In the figure, the 

 scars have their true relative positions, viz. : from the ends 

 and middle of the rows. The left-hand row of scars is 

 changed to an irregular row of very small scars; some- 

 times several to one leaf-base, and without regularity or order 

 in any respect. 



Another singular form is shown in Fig. 9. The scars are 

 represented in this figure in their natural position ; and they 

 are a portion of a single row. The slab shows two rows of 

 these double scars, with an intervening space of three inches ; 

 furrows obsolete. The geminate scars appear sub-geminate. 

 Apparently we have in this figure only two leaf-scars ; c and d 

 constituting a single one. Whether such is the fact, or if the 

 leaves were in double rows, I can not positively determine. 

 It is very peculiar in either case. 



Several of these forms are so different that, if studied 

 separately, they might have furnished several species of 

 Sigillaria. This is a good illustration of the difficulty in clas- 

 sifying isolated fragments of fossil plants, and of the conse- 

 quent multiplication of species. 



