CASH AND LOMAX : LEPIDOPIILOIOS AND LEPIDODENDRON. 479 
Inasmucli, however, as Corda's genus LomatopJiloios is Stern- 
berg's Lepidophloios, there is sufficient justification for his conchision 
that tlie structure of Lepidodendron Harcoiirtii may occur in 
Lepidophloios. 
Further, the same authority states that the plant described by 
WilUamson as Lepidophloios hrevifolium is intermediate in structure 
between Lepidodendron Harcoiirtii an;l Lepidodendron msculare, 
Binney {L. selaginoides, Carr and Will.) Its primary xylem has not 
the crenulated outline of the former species, though its structure is 
the same, but its leaf-trace bundles run downwards with only a slight 
projection, as in the latter. It further agrees, he adds, with the 
latter in the massive development of its secondary xylem. To these 
proofs of the near relation of the two genera under consideration, we 
are in a position to add yet another, drawn from a specimen which 
we discovered some short time ago. This consists of a fossil stem 
whose external surface is marked by tolerably well-preserved charac- 
ters, which leave no doubt that it must be referred to the genus 
Lepidophloios as defined by Sternberg. 
Transverse sections of it show, however, that in internal struc- 
ture it is identical with the plant described by Williamson in his 
Xlth memoir as Lepidodendron Harcoiirtii, but since named by him 
Lepidodendron fiiliginosiim . 
The primary xylem has an outer periphery slightly crenulated, 
is in the form of a thin, hollow cylinder, and encloses a tolerably 
large pith composed of thin-walled parenchyma. Surrounding the 
primary xylem is a zone of dark, indistinct tissue in which are 
radially disposed elements, and which Williamson regards as the 
exogenous zone (secondary xylem) in an immature condition. Outside 
this is the thick cortex, which, in its general appearance as well as in 
the structure and the arrangement of several layers, is in close 
agreement with that of Lepidodendron fuliginosumr 
* Communicated to the Meeting of the British Association, 1890. 
