138 PEOCEEDINGS OF THE GEOLOGICAL SOCIETY. [DoC. 20, 



species. L. dichotomum (=L. Sternbergii) also resembles it to some 

 extent. (Fig. 41, PL IX.) 



L. Pictoense, Dawson. — This species I described as follows, from 

 young stems, in my "Synopsis of the Coal-Plants of N'ova Scotia:" — 

 "Areoles contiguous, prominent, separated in young stems by a 

 narrow line, long-oval, acuminate ; breadth to length as 1 to 3 or 

 less ; lower half obliquely wrinkled, especially at one side. Middle 

 line indistinct. Leaf-scar at upper end of areole, small, triangular, 

 with traces of three vascular points, neai'ly confluent. Length of 

 areole about 0-5 inch." 



Additional specimens from Sydney show that in old trunks of this 

 species the areoles do not enlarge, but the bark becomes split into 

 strips. I have reason to think that a new species from Nova Scotia 

 which I have described in the A^i^endix, L. iJersoncUum, agrees with 

 it in this respect. (Pigs. 37, 38, and 39, PI. IX.) 



The Lejndodendra resemble each other too closely to admit of good 

 subgeneric distinction. The grounds on which the distinction of 

 Sagenaria and Aspidiaria is founded are quite worthless, the ap- 

 parent position of the vascular scars in the areoles depending on 

 accidents of preservation much more than on original differences. 

 The genus Knorria includes many peculiar conditions of decorticated 

 Le;pidodendra. 



In regard to the accumulation of coal, Lepidodendra, when pre- 

 sent, appear under the same conditions with Sigillarice, the outer 

 bark being converted into shining coal, and the scalariform axis 

 appearing as mineral charcoal of a more loose and powdery quality 

 than that derived from Sigillaria. On the planes of lamination of 

 the coal the furrowed bark of old trunks can scarcely be dis- 

 tinguished from that of old jSigillaricB. 



10. Lepidojjhioios. — Under this generic name, established by Stern- 

 berg, I propose to include those Lycopodiaceous trees of the Coal- 

 measures which have thick branches, transversely elongated leaf- 

 scars, each with three vascular points and placed on elevated or 

 scale-like protuberances, long one-nerved leaves, and large lateral 

 strobiles in vertical rows or spirally disposed. Their structure 

 resembles that of Lepidodendron, consisting of a Sternhergia pith, a 

 slender axis of large scalariform vessels, giving off from its surface 

 bundles of smaller vessels to the leaves, a very thick cellular bark, 

 and a thin dense outer bark, having some elongated cells or bast 

 tissue on its inner side. 



Eegarding L. laricinmn of Sternberg as the type of the genus, and 

 taking in connexion with this the species described by Goldenberg, 

 and my own observations on numerous specimens found in N^ova 

 Scotia, I have no doubt that LomatopJdoios crassiccndis of Corda, and 

 other species of that genus described by Goldenberg, Uhdendron 

 and Botlirodendron of Lindley, Lejyidodendron ornatmimmn of Brong- 

 niart, and Halonia punctata of Geinit^r all belong to this genus, and 

 differ from each other only in conditions of growth and preservation . 

 Several of the species of Lepidostrohus ,and LepidopJiyllum ' also 

 belong to Lepidophhios. 



