FLORA OF THE KOOTANIE FORMATION. 291 



Family POLYPODIACE.E. 



Genus CLADOPHLEBIS Brongniart. 



Cladophlebis falcata montanensis Fontaine n. comb. 



PL LXXI, Figs. 14-20. 



1S98. Thinnfeldia montanensis Font, in Weed & Pirsson: Eighteenth Ann. Rep. 

 U. S. Geol. Surv., 1896-97, Pt. Ill, p. 481. 



Plant probably arborescent; so far as seen, tripinnatifid. Only 

 fragments of pinnaj have been found. These contain a varied number 

 of portions of pinnae, showing pinnules on different parts of the pinnse, 

 and as the specimens are numerous a pretty good idea of different parts 

 of the plant can be formed. The rachises of the pinna? are strong and 

 rigid. The pinnules vary in character with their position on the pinnse 

 and fronds. Low down on the pinnae and frond they are long, linear, 

 and narrow, narrowing very gradually from their bases to their tips. 

 Fragments have been 45 mm. long and 5 mm. wide, indicating an entire 

 pinnule considerably longer. These have not been found attached, 

 although several occur together on some of the specimens, as if coming 

 from the same rachis. ' These pinnules have their margins more or less 

 incised, as represented in PI. LXXI, Fig. 15, the incisions varying in 

 depth from crenulations to rounded lobes cut halfway down to the 

 midnerve. These forms indicate that lower down on the frond the 

 lobes will pass into pinnules of the normal kind. Higher up on the 

 pinnae and frond the crenulate pinnules become entire, giving what we 

 may call normal pinnules. Toward the ends of the pinnae and through- 

 out those of higher parts of the frond the pinnules become smaller and 

 more and more united. The normal pinnules from the middle of the 

 pinnae are about 3 cm. long, as shown in PI. LXXI, Fig. 17. They 

 are widest at base and separate, but are very closely placed. They are 

 strongly falcate, alternately placed, and narrow gradually to a sub- 

 acute tip. The pinnules had apparently a coriaceous texture, so that 

 the fossils have a rigid aspect. They are united to the rachis by their 

 entire base, which is expanded and has the midnerve eccentrically 

 placed, so that the width of the lamina of the pinnule in front of or 

 above it is greater than that of the portion below. 



