FOSSIL PLANTS. 461 



GENUS RHABDOCARPOS, Gopp. and Bergr. 



Fruits oval or cylindrical oblong, marked lengthwise on their surface by nar- 

 row equal striae. 



RHABDOCARPOS CLAVATUS?, Sternb. 



PI. xxxi, fig. 11. 



Our specimen much resembles the figure given of this species by Geinitz, in 

 Versteinerungen, pi. xxii, fig. 13, though it is much larger than the fruit fig- 

 ured by Sternberg. The endocarp is about round, elongated upwards in a col- 

 lum resembling the neck of a bottle ; its surface, which is somewhat convex, 

 is a mass of coaly matter, cut across by deep wrinkles, caused by disruption ; 

 the exocarp surrounding it is about one line thick, of the same shape as the 

 endocarp, but slightly enlarged at the point and funnel shaped. It looks of a 

 harder texture than the internal fruit. 



In a concretion from Mazon creek. 



RHABDOCARPOS MAMMILLATUS, Sp. nov. 



PI. xxxi, fig. 12 to 15. 



A FINE small nutlet, quite entire and separated from the 

 stone. It is apparently of a hard texture, oval, marked on its 

 surface by regular, distinct deep striae, running down from the 

 borders of a smooth mammillate top to the base, as seen fig. 

 14 and 15. 



The surface of the nut is a thin shell which, as seen from a small part which 

 is detached, covers a hard, smooth fruit. 



From Mazon creek, in concretions. 



