FLOliA OF 11 IK SHASTA KOliM A TIOX. 225 



plant is tho scantiness and imperfoction of the inaloiial. It may lio 

 descTil)ed as follows: Frond unknown, stoi'ilc form not certainly known. 

 Only portions of the nltimate fei'lile pimuc or pimiulcs h.ave been fouiuF 

 Pinnules or lobes in the fruit intr foi'ins. almost oi' (juitc I'ethiced to sliort 

 thickened nerves, wliicli \h\iv at thcii- (mhIs larfje globose or subrcnil'oi-m 

 .sori. The leaf sul)stance is very thick and (hii-able. .so that tlic plant 

 leaves a thick him of carbonaceous matt(M' on t he rock. 



(leiuis TIIYRSOPTERIS Kuiit/.r. 



TiivKsoi'i'EKis i!Ai:i\KK\is Fontaine? 



PI. LXV. Fi^rs. 2 4. 



18S9. 71iijrsf)jif( ris- rarinerris Font.: Potomac Flora (.MonojiT. F. vS. (lool. .Sur\'.. \'ol. 



XV). ]). ll'.'j, pi. .\.\vi, lii:;.s. 6. 7: |)1. xliii, figs. 4, 4a, 11, (ia: pi. \liv. fig.s. 1, 



la. 2, 5, ")a; pi. xlix, ligs. 2, 2a. 21); pi. clxix, fig.s. 6. 7. 

 lSi)4. Thyrti<)j>ff)-is ranvcfriii Font.? in Diller & Stanton: Bull. (icol. Soc. Am.. A'ol. 



V, 1). 4.-)(). (PI. LXV, Figs. .3, 4). 

 1S9.5 [1896]. 'rhyrfiopteris raiinerris Font.? in Stanton: Pall. 1'. .S. (ieol. Surv., No. 



VAA. p. 1.x (PI. LXV. Fig.s. ;^, 4). 



Several specimens of what seems to Ije the widely diffused fern 

 Thyrsoptens rarwenris were fountl. They w-ere obtained at localities Nos. 

 9 and 18. They consist of small portions of penultimate pinna^, carrying 

 pinnules not distinguislial)le from those of T. mrinervis Font., which was 

 first found in the Lower Potomac of Virginia, in which it is one of the most 

 common ferns. It has since been found in most of the regions of the 

 United States that yield plants of Lower Cretaceous age. The amount of 

 material is not sufficient to justify a positive determination of this plant as 

 Thyrsopteris rarinervis, and for this reason it is marked as doubtful. 



Family POLYPODIAC'EiE. 



Genus CLADOPHLEBIS Brongniart. 



Cladophlebis parva Fontaine. 



PI. LXV, Figs. 5-8. 



1SS9. CladnpJdehis parva Font.: Potomac Flora (Monogr. IT. S. Geol. Surv., Vol. 



XV), p. 73, pi. iv, figs. 7, 7a: pi. vi, figs. 1. la, 2, 2a, 3, 3a. 

 1894. Cladophlebis inclinata Font.? in Diller & Stanton: Bull. Geol. Sue. Am., 



Vol. V, p. 4.-.O. (PI. LXV, Fig. 8.) 



MOX .XLVIII — ().') 15 



