FOSSIL PLANTS. 417 



angle, each having a regular curve from its point of origin to the margin, 

 while in this species they diverge at an angle much less acute, and are 

 generally somewhat bent at the fork, or at a short distance above it, thus 

 breaking the continuity of the curve. This feature is not quite perfectly 

 shown in fig. la, which represents the nervation enlarged. Fig. 2 repre- 

 sents the largest specimen yet found. Fig. 3 shows the apex of a very 

 small one. 



Location same as previous species. 



Megalopteris ovata (sp. nov.). 



Plate 47, figs. 1,2, and 2a. 



The pinnae of this species are ovate or ovate-lanceolate, the terminal 

 ones obovate. The nervation is similar to that of M. minima. This 

 plant resembles considerably M. Harttii, but its pinnae are very much 

 shorter and more ovate, and the nervation is coarser, like that of M. 

 minima. In the decurrent portions of the pinnas the nerves are so curved 

 as to reach the margin nearly at right angles, while in M. Harttii they 

 reach the margin at an angle of 45°, or less. It is a smaller and shorter 

 plant than M. Harttii. Fig. 1 represents a terminal portion of the plant. 

 Fig. 2 shows a lower portion, with the short, broad leaves which charac- 

 terize this species. Fig. 2a shows the nervation near the base of the de- 

 current portion of the leaf. 



Locality same as that of previous species. 



Megalopteeis lata (sp. HOY.). 



Plate 47, figs. 3 and 3a. 



This species is established on very large detached pinnae. Margin 

 entire. Nervation as in M. Harttii, but differing in this, that after the 

 last forking the nervules are parallel and proceed straight to the margin, 

 and not in a continuous curve. The pinna3 are sometimes bifurcated, as 

 shown in fig. 3. No apex of pinna has been Immd, and the form of 

 termination is unknown. The size of the pinnae (of which some of the 

 fragments are over twenty centimeters long and five centimeters wide) 

 and their nervation indicate a distinct species. The plant resembles M. 

 Dawsoni, Hartt, but the pinnae are not rugose, and the nervules do not 

 fork near the margin, and are not continuously curved, but proceed 

 straight and parallel to the margin, the straight or tangential portion 

 occupying from half to two-thirds the distance from margin to midrib. 

 27 



