234 FLORA OF LOWER COAL MEASURES OF MISSOURI. 



of the leaf, surmounted by (1) the leaf scar, the lateral angles of which 

 project sharply beyond the borders of the cushion; (2) a thin apron or 

 surplice-like area or shield which extends downward from the leaf scar, 

 and is more or less round or sometimes even nearly semicircular in its lower 

 outline. In some instances the boundary of this appears to correspond Avith 

 the impression of the bolster, as illustrated in fig. 3 of the second volume 

 of the Illinois reports. This area, which is dimly indicated in the partially 

 decorticated fragment, Fig. 4, PI. LXX, and further in Fig. 3, is well 

 delineated by Weiss. In addition to this field the bolster supports another 

 narrow transverse field contiguous to the upper border of the leaf scar. 

 This vertically narrow field, which in its widest portion near the median line 

 is nearly one-half the altitude of the leaf scar, rounds on either side of the 

 middle to tapering acute lateral angles lying against the angles of the leaf 

 scar, which is but little wider horizontally. This superior field, the lower 

 border of which is the upper outline of the leaf scar, seems in a few cases to 

 have been misinterpreted and misfigured as a part of the foliar cicatrix, an 

 error easy to understand after a comparison of the photographs, Fig. 3 or 

 Fig. 1, PI. LXX. In Fig. 3, however, which represents a specimen on which 

 a portion of the epidermis is preserved, it is clearly seen. Here it is found 

 in most cases to be interrupted at the median line by a V-shaped depression, 

 which penetrates from the upper border nearly across the field to the leaf 

 scar. In the angle or depression thus formed is situated the suprafoliar, 

 punctiform cicatrix or "ligular scar." In many of the specimens this depres- 

 sion resembles a V-shaped incision, but in reality the details of this field 

 ao-ree with interesting precision with material illustrated by Weiss and 

 Sterzel.^ 



In most of the stems and impressions, especially those from which the 

 epidermis or a portion of the subjacent tissues have been removed, the 

 lateral cicatricules of the leaf scar present what appears to be a slightly 

 ovate or subannulate structure encircling and often obscuring the vascular 

 trace. In the figure above referred to, which represents most of the cuticle, 

 these cicatricides are linear-crescentic, and, while in one scar they appear to 

 unite above, they are distinctly separate at the base. The close scrutiny of 

 others convinces me, however, that they are a little distant at the top also. 

 These details agree substantially with those illustrated in fig 23A on the 



• Op. cit., pi. iv, figs. 22a, 25a. 



