54 TRANSACTIONS. NATURAL HISTORY SOCIETY OP GLASGOW. 



Middle and Lower Coal Measures ; while Lejndophloios laricinus, 

 Sternberg, is very rare. These are the only species of whose 

 occurrence in Britain we have certain knowledge.^ 



Lepidophloios has given rise to the creation of many genera, 

 formed on the various conditions under which it appears, as 

 evidenced by the generic synonymy given above, but on this 

 point I shall not enter further, as I have already dealt with this 

 question in a paper published in the Trans. Boy. Soc. Edin. " 



Lepidophloios is easily distinguished from Lepidodendron by 

 the form and structure of the leaf -cushion and the position of the 



leaf -scar. The leaf-scar is always 

 placed at the top, or very near 

 the top, of the cushion. When 

 the cushion becomes deflexed it 

 appears as if placed at the base. 

 The leaf-scar is shown at c, fig. 7, 

 and immediately beneath it and 

 on the line of the keel is a small 

 tubercle. This small tubercle is 

 not always present, and on Lepi- 

 dophloios Scoticus it has never 

 been observed, though I have 

 examined very many beautifully- 

 preserved specimens. " 



The form of the cushion varies 

 <; Lepidophloios acerosus, L. and according to the species and age 



krid'(x\o Is """^ ^''^^"'''""' '"' °^ ^^'^ P^'"''*- ^"^ °^*^ '*^"''' ^'■''°' 

 ° " ' the lateral strain caused by in- 



crease in girth, it is often transversely elongated. 



In the fragments of bark as usually found it is impossible to 

 determine the direction of growth, but occasionally one meets 



1 Mr. Hemingway has brought under my notice a Yorkshire specimen of 

 a Lepidophloios, which may be the Lepidophloios aurictdatus, Lesqx. Geol. 

 Rep. lllin.. Vol. IV., p. 439, PI. XXX., fig. 1, 1870; also Coal Flora, p. 

 421, Pl.LXVIIL, fig. 3. 



- " On Lepidophloios, and on the British Species of the Genus," Vol. 

 XXXVII., Part iii., pp. 529-563, Pis. I. -II. 



3 It clearly occurs beneath the leaf-scar, but has the same appearance as 

 the " ligule-scar " in Lepidodendron. Its true function and significance do 

 not appear to me to be satisfactorily determined, 



Fig. 7. — a, Jjcpidophloios Scoticus, 

 Kidston, natural size ; b, cushion 

 and leaf-scar, enlarged (No. 529) ; 



