CARBONIFEROUS LYCOPODS AND SPHEN'OPHYLLS. 



91 



only part of the width of the ribs, distant or approximate, fre- 

 quently having a transverse lunate depression above the scar. 

 Cone-scars situated in the furrows. Type, Sigillaria (Rhytido- 

 lepis) ocellata, Sternb. Typical form, Sigillaria scutellata, Brongt. 



Section II. — Favularia, Sternberg, 1826. 



Stem ribbed, ribs flexuous, divided into sub-hexagonal compart- 

 ments by transverse depressions; leaf -scars alternate, approxi- 

 mate, or only separated by a very 

 short distance, usually occupying 

 the width of the rib. The lateral 

 angles of the leaf -scars project 

 slightly, and alternate with those 

 of the neighbouring ribs, impart- 

 ing to the longitudinal furrows a 

 more or less zigzag course. 



Its chief distinguishing char- 

 acter is the approximate leaf -scars 

 and zigzag furrows. Type, Sigil- 

 laria (Favularia) alveolaris, 

 Sternb. Typical form, Sigillaria 

 elegans, Sternb. sp. 



Fig. 17. — Sigillaria Brardii, 

 Brongt. Cope's Marl Pit, 

 Longton, Staffordshire. Shale 

 above Peacock coal, Middle 

 Coal Measures. A, Leaf 

 cushion (a). Leaf-scar {b) ; c, 

 cicatricule of vascular bundle ; 

 d cL parichnos ; enlarged. 

 (No, 817.) 



Section III — Clathraria, 

 Brongt., 1822. 



Cancellata, Weiss. Foss. Flora 

 der jilngst. Steinkohlf. u. d. 

 Rothliegenden, p. 161. 1869. 



Stems without ribs, leaf-scars 

 placed on contiguous rhomboidal 



slightly elevated cushions, which are separated by deep oblique 

 furrows. Cone-scars placed in the furrows between the leaf- 

 cushions. Type, Sigillaria Brardii, Brongt. 



Section IV. — Leiodermaria, Goldenberg, 1857. 



Leiodermaria, Goldenberg. Flora sar&p.foss., Heft. 2, p. 7. 1857. 



Stem without ribs, leaf-scars distant and leaf-cushions absent. 

 Surface of bark between the leaf -scars variously ornamented with 



