152 Sensitive Fern 



Newberry * is said to diflfer from it only in possessing a more 

 robust habit. Specimens of the fossil fern are said to practically 

 duplicate both the mature sterile and fertile leaves of our fern, 

 and the transitional leaves as well. According to Dr. Knowlton, 

 the fossil fern has been found only in the Fort Union Beds at 

 the mouth of the Yellowstone, and in the Canadian Upper 

 Laramie. 



* O. sensibilis fossilis Newberry, Ann. N. Y. Lye. Nat. His. 9 : 39. 1898. See 

 Lesquereaux, 111. Cret. and Tert. Plants, PI. VIII., Figs. 1-9, Figs. 1-5. 1878. New- 

 berry, Later Extinct Floras, 8: PI. XXIII., Fig. 3; PI. XXIV., Figs. 1-5. 1898. Knowl- 

 ton, Bull. Lon. Bot. Club. 705-706, PI. XXVI., Figs. 1-4. 1903. 



