1 72 THE POTOMAC OE YOUNGER MESOZOIG FLOEA. 



acute ; nei'ves very numerous and closely placed, fine but distinct, forked 

 at base or simple, occasionally forked a little higher, parallel after forking. 



Locahties: Fredericksburg; Kankey's; banks of Dutch Gap Canal; 

 fishing-hut above the canal ; near Telegraph Station. 



This fine plant is the most common cycad at Fredericksburg, where 

 it is not very rare. PI. LXX, Fig. 1, is the most complete specimen seen, 

 but in this the nerves unfortunately were obscure. It is almost always 

 found in the form of detached fragments of the basal portions of leaves, 

 showing that they were very deciduous and disai-ticulated, so as to leave 

 the detached base more or less heart-shaped. They were apparently 

 attached by a callosity. In PI. LXXVI, Fig. 7, a small bit of the rachis 

 may still be seen attached to the base of the leaf. When the leaves have 

 been detached from the callosity by which they were attached, their bases 

 have a cordate sinus. The plant does not seem to be nearly allied to any 

 described fossil. 



Zamites ceassinervis, sp. nov. 



Plate LXIX, Fig. 4 ; Plate LXXXIII, Fig. 3. 



Leaves broadly elliptical, short, acute, abruptly narrowed at base and 

 attached by a callosity ; nerves simple or forking at the very base, very 

 strong, distant, parallel to near the apex, where they are more crowded. 



Locality : Fredericksburg ; rare. 



This is a well-marked form of a type a good deal like some of the 

 species of Naf/eiopsis, to be described later, but the leaves seem to have 

 been very deciduous, unlike Nageiopsis, and are at base, when detached, 

 somewhat heart-shaped. 



Zamites distantinervis, sp. nov. 



Plate LXXXIII, Fig. 4. 



Leaves long, slender, slightly narrowed towards the base, which was 

 not seen, and gradually so towards the tip, which is lancet-shaped and sub- 

 acute, almost acunainate, slightly curved and subfalcate ; nerves strong, 

 proportionally ver}^ remote, parallel, not forking in the parts seen. 



Locality: Fredericksburg; very rare. 



