456 THE CARBONIFEROUS SYSTEM. 



Regarding L. laricinutn 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 Nova 

 Scotia, I have no doubt that Lomatophloios crassicaulis of Corda, and 

 other species of that genus described by Goldenberg, Ulodendron and 

 Bothrodendron of Lindley, Lepidodendron ornatissimum of Brong- 

 niart, and Halonia punctata of Geinitz, all belong to this genus, and 

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

 Several of the species of Lepidostrobus and Lepidophyllum also 

 belong to Lepidopldoios. 



The species of Lepidopldoios are readily distinguished from Lepi- 

 dodendron by the form of the areoles, and by the round scars on the 

 stem, which usually mark the insertion of the strobiles, though in 

 barren stems they may also have produced branches ; still the fact of 

 my finding the strobiles in situ in one instance, the accurate resem- 

 blance which the scars bear to those left by the cones of the Red Pine 

 when borne on thick branches, and the actual impressions of the 

 radiating scales in some specimens, leave no doubt in my mind that 

 they are usually the marks of cones ; and the great size of the cones 

 of Lepidopldoios accords with this conclusion. 



The species of Lepidopldoios are numerous, and individuals are 

 quite abundant in the Coal formation, especially toward its upper 

 part. Their flattened bark is frequent in the coal-beds and their 

 roofs, affording a thin layer of pure coal, which sometimes shows the 

 peculiar laminated or scaly character of the bark when other charac- 

 ters are almost entirely obliterated. The leaves also are nearly as 

 abundant as those of Sigillaria in the coal-shales. They can readily 

 be distinguished by their strong angular midrib. 



I figure, in illustration of the genus, all the parts known to me of 

 L. Acadianus, and characteristic specimens of other species. One of 

 these, L. parvus, is characteristic of the Upper Coal formation. ( Vide 

 Figs. 170, 171.) 



3. Cordaites or Pychnophyllum. — This plant is represented in the 

 Coal formation chiefly by its broad striated leaves, which are 

 extremely abundant in the coal and its associated shales. Some thin 

 coals are indeed almost entirely composed of them. The most com- 

 mon species is C. borassifolia, a plant which Corda has shown to 

 have a simple stem with a slender axis of scalariform vessels resem- 

 bling that of Lepidopldoios ; for this reason, notwithstanding the 

 broad and parallel-veined leaves, I regard this genus as belonging 

 to Lycopodiacece, or some allied family. It must have been extremely 

 abundant in the Carboniferous swamps ; and, from the frequency of 



