494 PAluEOBOTANY. 



are recognised by the great size and concentric rings of their 

 prostrate, rarely erect trunks, and by the fact that the micro- 

 scope exhibits punctated fibres in their wood. Their fruit is 

 unknown, unless, as is very probable, it is constituted by the 

 so-called Trigonocarpa. If this be the case, the Carboniferous 

 Conifers must have been " Taxoid," resembling the recent 

 Yews in producing berries instead of true cones. The so- 

 called Sternbergioe, as has 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 Lepido- 

 phloios. 



g. Cycadacece. The peculiar group of Gymnospermous 

 Exogens represented at the present day by the Cycads is not 

 known with certainty to be represented in the Carboniferous 

 Rocks. Nceggerathia has been referred here, and the Cyca- 

 daceous genus PteropJiyllum has also been alleged to occur. 

 Brongniart has also conjectured that the Sigillarioids are in 

 reality most nearly allied to the Cycadacece ; and this opinion 

 is supported by other high authorities. 



//. 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 Antholithes, which was at one 

 time conjectured to be possibly the infloresence of an An- 

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

 the fruit termed Cardiocarpon ; and it remains uncertain to 

 what plant this really belongs. 



i. Monocotyledons. The occurrence of Endogens in the 

 Coal-formation is also attended with some uncertainty. The 

 genus Ncegge rat hia has sometimes been referred to the Palms, 

 and the same group has been asserted to be represented by 

 species of Palmacites. The only apparently unequivocal proof 

 of the occurrence of Carboniferous Endogens is, however, 

 afforded by the so-called Pothocites, which appears to have 

 been the spadix of an Aroideous plant. 



PERMIAN 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, Asterophyllites, Annularia, 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. 



Ferns are abundant in the Permian Rocks, and belong for 

 the most part to the well-known Carboniferous genera Alethop- 



