EXPLANATION OF PLATES. 193 



^ PLATE V. 



DlCTTOPHYTON REDFIELDI, 



This figure represents that part which was the upper side of the specimen as im- 

 bedded in tlic stone. The upper spreading portion of the frond has been split open 

 ( probablyfroni pressure) , and the margins of this separation can be distinctly traced, 

 while the upper and lateral portions of the frond are folded into the cavity. 



\ 



'X 



W/ 



V-^ Vfl! To^i. Hi. 



[Senate, No. 115.] 25 



