nu 



JURASSIC FLORA OF DOUCiLAS COrXTY. ORFG. 71 



PI XI. Fi^. 1, sliows lh(> most complole specimen, whicli is a frag- 

 .it of •inullimate pinna having several pinmiles. These are .lisL.rted 

 and slickensid.Ml. The prcdnction of shckensides is not an unconnnon 

 featnre in the Oregon phuits whenever they have a firm resisting textnre. 

 The creep of th(. rock seems often to have taken pUice along tlie snrface 

 of the plant, polishing it and obliterating the nerves. Fig. 2 shows an 

 enlarged pinnule of this. Fig. 3 depicts a fragment <.f .an ultimate puma, 

 havino- one entire pinnule that shows indications of denticulation toward 

 ils tip'^ This pinnule is shown enlarged in Fig. 4. Fig. 5 gives a small 

 fragment of an ultimate pinna with several pinnules of the more slender 

 kind Fig. shows two fragments of ultimate pinn* with mutilated 

 pinnules that occair toward the termination of the phma^. Fig. 7 gives 

 a pinnule enlarged to show the nerves. 



The plant is most common, l)ut still rare, at locality No. 19, and is 

 found also at localities Nos. 1, 2, 7, <). 12, U. 17, and 18. 



Clauoi-hlebis iiAiBrRNENSLS (Liudlev .^ Ilutton) Bron-niart ? 



Fl. XI, Fio;s. s-l(). 

 ls:i(i. PecopWrls haihurnensis L. & II.: Fc.ss. Fl. Gt. Brit., V..1. Ill, p. 97, ,.1. 



clxxxviii. 

 1S49 Cladophhhls hmburnensis (L. & H.) Bron<,ni.: TahU-au, !>. 105. 

 1S6.5. Pterin haihurnensis (L. & H.) Ett.: Farnkniuter dor Jetztvvelt, p. 11-1. 

 ISOq iJethoptens haihurnensis (L. & H.) Schiinp.: Pal. V.'g., \<)1. I, p. 56,5. 

 isoo. ThluHJMla haihurnensis (L. & H.) Rac: Bull. Int. Aca.l. Sci. do (^acvie, 

 Janvier, 1S90. p. ■Vl. 

 A single specimen of a fern of marked Cladophlebis type was found 

 at locality'^No. 1. It seems different from any of the other Cladophlebis 

 of the Oregon Jurassic. The specimen shows only a fragment of an ulti- 

 mate pinna carrying several pinnules. These agree so well with the tern 

 called bv Lindlev and Hutton Pecopteris haihurnensis" that it is most 

 probably the same species. The English fern is clearly a Cladophlebis 

 and not" a Pecopteris. The amount of material, however, is not sufficient 

 to justify a positive identification. It may possibly be an abnormal form of 

 Cladophlebis vaccensis, but the entire aspect of the i)lant is different from 

 that fern. The rachis is slender. The pinnules are slightly falcate and 

 attached hx the entire, somewhat widened base. They are in form 



«Foss. Fl. Ot. Brit.. Vol. Ill, pp. (IT-itS, pi. clxxxviii. 



