Trigonocarpum and Gardiocarpum (which latter was 

 thought by Brongniart to belong to a Lepidodendrous 

 plant) ; but our distinguished fellow-member, Mr. 

 Carruthers, considers it to be a gymnosperm of an 

 extinct type, confined, as far as is yet known, to the 

 palaeozoic rocks, and, possibly, to have been the fruit 

 of the Taxinian, Dadoxylon. The devonian flora in 

 many respects resembles that of the mesozoic period, 

 and of modern tropical countries more than the 

 carboniferous, which might, possibly, arise from the 

 absence of the wide undulated plains of that period, 

 and, perhaps, from a higher temperature. From the 

 great diversity of the devonian rocks, it seems that 

 during their deposition, Europe was an archipelago, 

 the sea, of course, predominated, and, as far as is 

 known, there were no fresh-water deposits. Gmynos- 

 perms and acrogens form the two prominent groups ; 

 the former are the lowest of the flowering plants, the 

 latter the highest of the flowerless. 



In the succeeding carboniferous age, Cordiates 

 appears for the first time ; it is a gymnosperrnous tree of 

 considerable height, resembling the recent Podocarpus 

 in its growth, bearing coriaceous leaves several feet 

 long, and fruit analogous to the Taxinece. No less than 

 three hundred and twenty land plants are found in 

 the carboniferous beds ; the conditions favourable for 

 their pieservation was forest growth, in swampy ground 

 about the mouth of a river with rapid oscillations of 

 level, the coal produced during subsidence being 

 covered over by the sediment brought down by the 



