1 64 THE POTOMAC OR YOUNGER MBSOZOlC FLORA. 



corresponding to that depicted in PI LXV, Fig. 4. Plate LXIV, Fig. 3, 

 shows some irregularity in the ^^acing of the penultimate pinnae or pin- 

 nules, the central ones on the left-hand side showing an abnormal crowd- 

 ing. Plate LXVII, Fig. 7, appears to be an ultimate pinna or pinnule 

 from still lower on the frond than any of the others, and the lobing is 

 irregular, two of the lobes from the middle of the specimen on the right- 

 hand side being cut deeply into falcate, narrowly oblong, or ovate lobes. 

 While the general plan of the lobes and teeth is the same throughout, some 

 variation is shown in the number, arrangement, and shape of the teeth. 

 Thus we have in PI LXV, Fig. 5, the lobes or incipient pinnules sub- 

 quadrangular, curved forward, with a terminal ovate tip, and on the exte- 

 rior margin near the tij) a broadly triangular tooth directed outwards. 



Zamiopsis longipknnis, sp. nov. 



riato LXI, Fig. 8. 



Frond unknown ; ultimate pinnae or pinnules very long, ensiform, 

 slightly falcate, acuminate ; margins of the pinnules cut into shallow, nar- 

 rowly ovate single or double teeth, midnerve strong towards the base and 

 vanishing towards the ends of the pinnules, splitting up into branches, in 

 the upper portion not placed centrally in the pinnules ; lateral nerves dis- 

 tinct, going off very obliquely, curving outwards and forked once or twice, 

 with the ultimate branches long and slender. 



Locality : Fredericksburg : only one specimen found. 



This may possibly be the summit of a pinnule of Zamiopsis insignis, 

 but it has features not seen in that species, and the pinnule was evidently 

 much longer than any seen on it. The eccentric position of the midnerve 

 and the convex expansion of the lower margin near the summit of the pin- 

 nules are peculiar features. 



Zamiopsis laciniata, sp. nov. 



Plate LXYI, Fig. 1, .5-8. 



Frond verj^ large and wide-spreading, probably arborescent ; ultimate 

 pinnae alternate, the lower ones very long, rapidly diminishing in length 



