372 Seward . — The Anatomy of Lepidodendr on aculeatum, Sternb. 
Williamson wrote : — ‘ It appears to me that much uncertainty exists 
amongst Palaeobotanists respecting the structures that distinguish Lepido - 
dendron from Lepidophloios V The specimen described below adds point 
to this opinion. 
A few examples of lepidodendroid stems founded on anatomical 
characters serve to illustrate the grounds on which one or other of these 
two generic names has been used. 
The specimens described by Binney, in 1863, as Sigillaria vascularis 
and Lepidodendron vascidare 1 2 were afterwards recognized as one and the 
same type. Carruthers 3 identified the species, founded on anatomical 
characters, with Lepidodendron selaginoides Sternb., but the nature of the 
evidence on which the anatomical structure of Lepidodendron vascidare was 
referred to Sternberg’s species, founded on external characters, is not stated. 
On the strength of Mr. Carruthers’ identification we may regard Lepido- 
dendron vascidare , Binney, as a well-defined anatomical type associated 
in some cases, though not necessarily in all, with the external features 
of Lepidodendron selaginoides , Sternb., which is a synonym of L. Stern- 
bergii , Brongn. 4 . The common practice of speaking of Binney ’s type as 
L. selaginoides is, I think, unfortunate : though a comparatively small point, 
the name L. vascidare has the advantage of not committing us to the infer- 
ence that all stems with the type of structure associated with Binney s 
species necessarily agree in the form of the leaf-cushions with the plant 
named by Brongniart L. Sternbergii , and by Sternberg L. selaginoides. 
The species described by Witham 5 as Lepidodendron Harcourtii has 
been investigated by several botanists since 1832 6 . Some of the specimens 
originally included by Williamson in Witham’s species were subsequently 
recognized by him as distinct, and referred to a new species Lepidodendron 
fuliginosum 7 ; for this type Solms-Laubach proposed the name Z. William - 
soni 8 , but the former designation has been generally adopted. The true 
Lepidodendron Harcourtii is considered by Kidston to be a species of the 
genus Lepidophloios as ‘ it has all the peculiarities * 9 of that genus, but 
no satisfactory evidence has been adduced as to the external features of 
Witham’s anatomical species. 
In 1890 Messrs. Cash and Lomax 10 mentioned a petrified stem in their 
possession — { whose external surface is marked by tolerably well-preserved 
characters, which leave no doubt that it must be referred to the genus 
Lepidophloios as defined by Sternberg’ — exhibiting the type of structure 
1 Williamson (’94), pp. 423, 424, footnote. 2 Binney (’62). 
8 Carruthers (’69), p. 179. 4 Kidston (’86), p. 151. 
5 Witham, (’32). 
6 Bertrand (’91) has given a comprehensive historical sketch of our knowledge of L. Harcourtii 
in his Memoir on the anatomy of the species. 
7 Williamson (’87). 8 Solms-Laubach (’87). 
9 Kidston (’01), p. 59. 10 Cash and Lomax (’90). 
