308 BOTANY AND PALAEONTOLOGY 



tribution of the subconglomerate coal in Arkansas, one has the right to 

 assert that by and by coal will be found if not in very thick strata, at least 

 abundantly enough to supply the wants of the future manufacturing esta- 

 blishments of the country. 



To direct future researches it will be well to remember that the coal 

 strata of Arkansas generally underlie, at a distance of fifty to one hundred 

 feet, a bed of red ferruginous clay or red earth which is easily distinguished 

 wherever it appears in the counties mentioned as included in the area of 

 the coal-fields of Arkansas. It is also well to bear in mind that, although 

 two beds of coal may have been formed in Arkansas, it is the lowest only 

 which, up to the present time, has been found of workable thickness. The 

 Subcarboniferous measures generally underlie it at a short distance, and no 

 coal can be expected to be found within them. 



DESCRIPTION OF NEW SPECIES OF FOSSIL PLANTS COLLECTED IN THE SHALES 

 OVERLYING THE SUBCONGLOMERATE COAL OF ARKANSAS. 



Two considerations favor a careful description of the fossil-flora of the 

 coal of Arkansas : 



1st. The practical utility of palaeontology in its application to the identi- 

 fication of coal or any other geological strata. 



2d. The peculiar position of the coal of Arkansas, so well developed at 

 a geological horizon where until now the formation of a good workable 

 bed of coal has been considered as problematical. It is evident that the 

 ascertaining of the true place of this coal may direct researches for com- 

 bustible mineral at a lower level than where they have been pursued till 

 now in other States. Moreover, the scientific world at large is at present 

 very much interested in trying to solve the question of the distribution of 

 vegetation in the different geological strata of our globe, and to find links 

 of union which may exist between species and genera successively appear- 

 ing in various strata. It is worth while, therefore, to carefully collect and 

 record all the data which may afford reliable indication to the limits of the 

 flora of the true coal period. 



The following short description of the new species of fossil plants 

 found in connection with the shales overlying the coal of Arkansas is 

 given without following the natural and botanical order, but only as an 

 explanation of the figures of the plates. This report is not the place for 

 long scientific discussions and for close and comparative descriptions. 

 They would be useless to the reader who is not acquainted with fossil 

 plants, and to the botanist they would reveal nothing new. For the same 

 reason I omit describing the species already known which are common 

 to the Subconglomerate coal and to the coal above the Millstone Grit. 



