JURASSIC FL()1{A OF OOlCiLAS COrXTY. OHECi. 73 



slender ami the pinnules ai'e more acut(\ It is more like the plant that 

 Heer calls Dicksonia acutHoha," and no (hmht it is the same species. It 

 is not clear why Ileer i'(><iar(l('(l tliis plant as a Dicksonia. He does not 

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

 view of its obvious Cladophlebis fcalures, it should b(> placed in this genus. 

 PI. XI, Fig. 11, gives one of th(» specimens, and l"ig. 12 an enlarge- 

 ment of one of the pinnules. 



("LADopin.Kius rEroPTf.T!on)Es Fontaine ii. sp. 



PI. XI, Fi<;.s. 13-15. 



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

 at locality Xo. 1 . One of the specimens is quitc^ small and shows only a 

 terminal portion of the peindtimate pinna that comes apparently from 

 high up on the compound })inna. The other one, given in Fig. 29, shows 

 considerable portions of the penultimate pinna> 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 

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

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

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

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

 very vmiform size. The pinnules are clo.sely ap[)roximate, sometimes 

 overla})ping, 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 deeply 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 Cladophlel)is. 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 



«F1. Foss. Arct., Vol. IV, Pt. II, (Beitr. z. Jura-Flora Ostsibiriens), p. 93, pi. xviii, fig. 4. 



