429 



preserved and are now to be seen in their natural situation. But 

 if, instead of having been thus closely enveloped by argillaceous 

 matter, it had been surrounded by a loose arenaceous mass, and 

 under circumstances less favourable to bituminization, the harder 

 part only of the squamae, and the central receptaculurn, would have 

 obtained a prolonged duration of their original form ; whilst the 

 connecting membranous substances would have wasted away, and, 

 as they disappeared, the space they possessed would have become 

 filled up by earthy particles. Thus at a future distant period 

 there would be produced a stony substance with an imbricated sur- 

 face, containing within it another substance with a surface imbri- 

 cated in almost a similar manner. In- a word, a fossil would be 

 formed, which, in its general characters, would resemble the fossil 

 which has so particularly engaged our attention. It must, indeed, 

 be admitted, that the fossil vegetable figured at PI. IX. Fig. 1, the 

 extended outline to which marks the shape of the complete Strobilus, 

 as shown by the aid of another specimen, does not accord, in its 

 size, with the fossil with which it has been attempted to demonstrate 

 that it bears some analogy. The difference in size, however, affords 

 no material difficulty ; and the difference in the markings on the 

 surface, points out only perhaps a specific difference between these 

 supposed strobuli ; but two other circumstances demand still 

 further examination. One of these is, that the markings, as is fre- 

 quently the case, and as is the case with the fossil at PI. III. Fig 1, 

 is formed of detached spots or impressions, without any line pointing 

 out the figures of the squama ; but this appears to depend on cir- 

 cumstances being favourable, or otherwise, to the forming of the 

 impression ; since, in a fossil of this kind, nearly half a yard in 

 length, and about two inches and a half in its largest diameter, the 

 lines formed by the edges of the squama3 are distinctly observable; 

 so that nothing remains to contradict its origin having been that 

 which is here supposed, except its extraordinary length and 



