106 LYCOPODIALES [CH. 



characters as those for which Sternberg had chosen the name 

 Lepidophloios. The leaf-cushions of Lepidophloios differ from 

 those of the true Lepidodendron in their relatively greater lateral 

 extension (cf. fig. 146, A and C), in their imbricate arrangement 

 and in bearing the leaf, or leaf-scar, at the summit. In some 

 species referred to Lepidophloios the cushions are however 

 vertically elongated and in this respect similar to those of 

 Lepidodendron: an example of this type is afforded by Lepido- 

 phloios Dessorti a French species described by ZeillerV In 

 younger branches the cushions may be directed upwards having 

 the leaf-scar at the top; but in the majority of specimens 

 the cushions are deflexed as in figs. 146, D; 160, A. The shoot 

 of Lycopodium dichotomum shown in fig. 121, B, with the leaves 

 in the reversed position bears a close resemblance to a branch 

 of Jjepidophloios. 



The photograph of Lepidophloios scoticvs Kidst.* reproduced 

 in fig. 160, A, illustrates the dichotomous branching of the 

 stem and the form of the cushions with the leaf-scars pointing 

 downwards. In the fertile branch of the same species shown in 

 fig. 160, B, the leaf-scars face upwards. 



In most species the cushions are simply convex without a 

 median keel, but in some cases a median ridge divides the 

 cushion into two cheeks as in the genus Lepidodendron. The 

 leaf-scar bears three small scars, the larger median scar marking 

 the position of the leaf-trace, while the lateral scars are formed 

 by the two arms of the parichnos: in some examples of deflexed 

 cushions, though not in all, a ligular pit occurs on the cushion a 

 short distance above the leaf-scar. 



The drawing reproduced in fig. 146, A, showing the leaf-scar 

 on the upper edge of the cushion should have been reversed 

 with the leaf-scars pointing downwards. This figure represents 

 part of the surface of a specimen consisting of the outer cortex 

 of a stem with leaf-cushions 3 cm. broad. The thickness of 

 this specimen is 4 cm. : a section through the line ab is repre- 

 sented in fig. 146, D (reproduced in the correct position, with 

 the leaf-scars, sc, pointing downwards): internal to the cushions 

 is a band of secondary cortex (the shaded strip on the outer 

 1 Zeiller (92) A. ^ Kidston (93) p. 561, Pis. i. and ii. 



