JURASSIC FLORA OF DOUGLAS COUNTY, OREG. 73 



slender and the pinnules are more acute. It is more like the plant that 

 Heer calls Dicksonia acutiloba,"' and no doubt it is the same species. It 

 is not clear why Heer regarded this plant as a Dicksonia. He does not 

 say that he found fructification on it. In the absence of that, and in 

 view of its obvious Cladophlebis features, it should be placed in this genus. 

 PL XI, Fig. 11, gives one of the specimens, and Fig. 12 an enlarge- 

 ment of one of the pinnules. 



Cladophlebis pecopteroides Fontaine n. sp. 



P]. XI, Figs. 1.3-15. 



An elegant fern, with finely-cut foliage, was found in two specimens 

 at locality No. 1. One of the specimens is quite small and shows only a 

 terminal portion of the penultimate pinna that comes apparently from 

 high up on the compound pinna. The other one, given in Fig. 29, shows 

 considerable portions of the penultimate pinnae that seem to come from 

 low down on the compound pinna. They are so placed as to show that 

 they were once attached to the rachis of a pinna of superior order. By 

 the small diminution of the pinnules they indicate that the ultimate 

 pinnae, of which they formed parts, had a very considerable length. The 

 rachises of these pinnae are strong, with their margins raised cord-like, 

 and they have a cord-like rib running down their centers. These pinnae 

 carry a number of pinnules that for a considerable distance maintain a 

 very uniform size. The pinnules are closely approximate, sometimes 

 overlapping, and are falcate and 4-5 mm. wide. The pinnules are linear- 

 oblong in form. They are about 1 cm. long, with obtuse or subacute tips. 

 Their character gives the plant a marked elegance. They are set on the 

 rachis at an angle of about 45°, and are more or less deeph^ incised into 

 oblong or ovate, very obtuse lobes. The deepest incision goes about 

 two-thirds of the way to the midnerve. These lobes or pinnules are 

 strikingly like those of some of the Carboniferous pecopterids and the 

 species is named from this resemblance. The nervation, however, is that 

 of Cladophlebis. The leaf substance is quite thick and obscures the 

 nerves. Apparently the lobes, in lower parts of the compound pinna, 

 pass into distinct pinnules, which may have crenate margins. In ter- 

 minal parts, on the other hand, the lobed pinnules diminish to those with 



aFl. Foss. Arct., Vol. IV, Pt. II, (Beitr. z. Jura-Flora Ostsibiriens), p. 93, pi. xviii, fig. 4. 



