DESCRIPTION OF THE SPECIES. 269 



Carpolithus latus, sp. nov. 



Plate CXXXV, Fig. 3. 



Seed of medium size, broadly pear-shaped, with a ver}- short acute 

 projection or mucro on the summit as wide as long, narrowed below into 

 a comparatively very stout pedicel, showing on the upper surface two 

 strong flat ribs, which are placed on each side of the medial line and run 

 nearly parallel with the margins. 



Locality : Fishing hut above Dutch Gap Canal. 



Only one specimen of this plant was found, and hence its character is 

 imperfectly shown. It is clearly different from all the other Potomac forms 

 of Carpolithus. It shows a peculiar flaring out in width in the middle. 

 It is probably a seed of some Baieropsis. 



Carpolithus cuevatus, sp. nov. 



Plate CXXXV. Fig. 17. 



Seed large, elongate, broader at one end than at the other, curved on 

 one margin and nearly straight on the other, convex, covered with a thick, 

 smooth, and shining epidermis. 



Locality : Fredericksburg ; found in only one specimen. 



This curious foi'm casually inspected looks something like the imprint 

 of a shell. It is in shape and size unlike all the forms of Carpolithus 

 found in the Potomac beds. It may be a Cycadeospermwn. 



Carpolithus sessilis, sp. nov. 



Plate CXXXVI, Fig. 9. 



Seed small, subrhombic to elliptical in form, acute, nuich narrowed at 

 each end, upper surface marked with three lines denoting ridges, sessile; 

 principal stem comparatively stout. 



Locality : Fishing hut above Dutch Gap Canal. 



This and the form next to be described are very rare. They are both 

 much like the nut-like seed of Ccphalotaxus, and probably belong to some 

 species of Ccphalotaxopsis. 



