270 PALAEONTOLOGY: FOSSIL OKGANIC TIEMAINS. 



parts of the surface of the earth which were then exist- 

 ing, as in New Holland, Canada, Greenland, and Melville 

 Island. ( 32 ^) 



The vegetation of the ancient world presents forms 

 which, by their affinities with several families of living 

 plants, shew that in their extinction we have lost many 

 intermediate links in the organic series. Thus, for example, 

 the lepidodendra find their pace, according to Lindley, be- 

 tween the coniferse and the lycopodiacese ; ( 324 ) whilst the 

 araucarise and the pines present differences in the junction of 

 their vascular fascicles. Even limiting our consideration to 

 the present vegetable world, we perceive the great impor- 

 tance of the discovery of cycadese and coniferse, in the 

 flora of the coal measures, by the side of sagenarise and 

 lepidodendra. Coniferse are allied not only to cupuliferae 

 and betulinse, with which they are associated in the lig- 

 nites, but also to the lycopodiacese. The family of the 

 eycadese in their external aspect approach palms, while 

 in the structure of their flowers and seeds they present 

 material points of accordance with coniferse. ( 325 ) Where 

 many beds of coal are placed one above another, the genera 

 and species are not always intermingled, but are more often 

 eo disposed that only lycopodiacese and certain ferns are 

 found in one bed, and stigmatise and sigillarise in another. 

 To give an idea of the luxuriance of vegetation in the pri- 

 mitive world, and of the immense vegetable masses accumu- 

 lated in particular places by streams or currents, and 

 transformed ( 326 ) into coal, I will notice the coal measures 

 of Saarbruck, where a hundred and twenty beds are found 

 one above another, exclusive of a great number which 

 are not more than a foot thick* and there are beds 



