72 MESOZOIC FLORAS OF UNITED STATES. 



oblong and narrow toward their tips, so as to have obtuse lancet-shaped 

 ends. They are quite wide in proportion to their lengths. The nerves 

 are slender. The midnerve splits up, about two-thirds of the distance 

 from base to tip, into numerous branches. The lateral nerves go off 

 obliquel}^ and are twice forked in the lower ones, the forking lessening 

 in ascending. 



Phillips gives a figure of Pecopteris haiburnensis" in which the pin- 

 nules are smaller than those in Lindley and Button's figure, but are still 

 somewhat larger than those of the Oregon plant. The difference in size 

 is probably due to a different position on the compound pinna. A more 

 important difference between the English and Oregon plants is in the 

 decurrence of the pinnules given in the figures of Phillips and of Lindley 

 and Hutton. It is probable that both of these figures are of the same 

 specimen. In the more complete figure of Lindley and Hutton there 

 seems to be some distortion, which may account for the decurrence. 



PI. XI, Fig. 8, shows the specimen natural size, and Figs. 9 and 10 

 enlarged pinnules with detailed nervation. 



Cladophlebis aoutiloba (Heer) Fontaine n. comb. 



PI. XI, Figs. 11, 12. 



1876. Dicksonia acutiloba Heer : Fl. Foss. Arct., Vol. IV, Pt. II (Jura-Fl. Ostsibi- 

 riens), p. 92, pi. xviii, figs. 4, 4c. 



A small Cladophlebis was found in five specimens, two each at local- 

 ities Nos. 7 and 18, and one at No. 17. The specimens are small and 

 show only fragments of penultimate pinnae, which contain portions of 

 ultimate pinnae that carry a number of pinnules. The latter are very 

 small. The rachis is narrowl}' winged. The pinnules nearer the rachises 

 of the pinnae are ovate-elliptical, widest below their middle, and constricted 

 at base. Those higher up are more or less triangular and more united. 

 All have acute tips. The larger pinnules are 3-4 mm. long. The nerves 

 are distinct. The midnerve splits up into branches. The lateral nerves, 

 few in number, are given off obliquely, and are mostly unforked. No 

 fructification occurs. This plant resembles Saporta's Cladophlebis brevi- 

 loba from the Middle Oolite of France,'' but the rachis is much more 



a Geology of Yorkshire, 3d ed., p. 211, lign. 25. 



''Pal. Francaise, Plantes Jurassiques, Vol. I, pp. 303, 305, pi. xxxiv, fig. I. 



