462 PALEOBOTANY. 



called Sternhergicc, as lias been already pointed out, are "pith- 

 cylinders," or, in other words, casts of the pith, of Dadoxylon. 

 They appear, however, to belong also to Sigillaria and Leiyi- 

 doiMoios. 



(J. Cycadacem. — The peculiar group of Gymnospermous 

 Exogens represented at the present day by the Cycads is 

 not known with certainty to be represented in the Carbon- 

 iferous rocks. Nceggerathia has been referred here, and the 

 Cycadaceous genus Pterophyllum has also been alleged to 

 occur. Brongniart has also conjectured that the Sigillarioids 

 are in reality most nearly allied to the Cycadacecc ; and this 

 opinion is supported by other high authorities. 



h. Angiospermous Exogens. — The occurrence of true Angio- 

 sperms in the Carboniferous period is very doubtful. No 

 Exogenous wood which is not Coniferous has been as yet 

 detected. The fossil known as Antliolithcs, which was at one 

 time conjectured to be possil^ly the inflorescence of an An- 

 giosperm, has now been shown to be really a raceme bearing 

 the fruit termed Cardioeaiyon ; and it remains uncertain to 

 what plant this really belongs. 



i. Moiiocotijledons. — The occurrence of Endogens in the 

 Coal-formation is also attended with some uncertainty. The 

 genus Nceggerathia has sometimes been referred to the Palms, 

 and the same group has been asserted to be represented by 

 species of Palmacites. The curious twisted bodies referred to 

 the genus Spirangium are supposed to be the fruits of Mono- 

 cotyledons, but their true nature is uncertain. The only ap- 

 parently unequivocal proof of the occurrence of Carboniferous 

 Endogens is, however, afforded by the so-called Pothocitcs, 

 which appears to have been the spadix of an Aroideous plant ; 

 but even this determination is not free from doubt. 



PERMiAiSr Plants. — The Permian Flora is, upon the whole, 

 very nearly allied to that of the Coal-measures, though the 

 Permian species are mostly distinct, and there are some new 

 genera. Thus, we find species of Lcpidodendron, Calamites, 

 Equisetites, Astcrophyllites, Anmdaria, &c. — all genera which 

 are highly characteristic of the Carboniferous period. On the 

 other hand, the Sigillarioids of the Coal appear to have finally 

 passed away with the close of the Carboniferous period. 



