160 MESOZOIC FLORAS OF rNITKI) STAl MS. 



so that tlie jilant niattei' of the piiiiiulos is usually well ])rescrvod and 

 leaves a sliiuiuir film on Ihe stone. The i-achis of the ultimate pinna is 

 winged 1)V the decui'i'ence of a pimuile, oi- lobe, placcMl in the angle l)etween 

 the lower side of the base of the ultimate rachis and the penultimate one. 

 The larger pinnules in PI. XXXIX, Fig. 9, the dentate ones, may he 

 regarded as normal for the frond. As stated above, they diminish in 

 ascending on the frond, and also toward the ends of the ultimate jjimue, 

 becoming entire and nioi-e united, until they pass into lobes and hnally 

 into teeth. The general character of the noi'mal pinnules is maintained 

 until they are reduced to lobes and teeth, when they become proportion- 

 ally broader at base, taking more or less of an ovate form. 



The normal pinnules are narrowly oblong and acute. They are 

 decurrent at base and united with the next lower ones, forming a narrow^ 

 wing on the idtimate rachis. On the upper side of the base they are 

 slightly constricted, the constriction being more pronounced the deeper 

 the toothing. The larger and lower pinnules have minute teeth that 

 are acute and inclined strongly toward the tips of the pinnules. They 

 often have a spiny look and can not be seen distinctly without the help 

 of a lens. The pinnules are generally straight, but may l)e slightly falcate. 

 They go off obliquely from the ultimate rachis and are inclined forward 

 toward its end. 



The midnerve of the pinnules is rather slender and continues to near 

 the end of the pinnules. The lateral nerves go off pinnately and very 

 obliquel}'. They are straight. In the toothed pinnules the lower ones 

 are once forked, the rest are single. In the entire pinnules and lobes 

 they are single. This plant has a good deal of resemblance to Aspidium 

 montanense Font." of the Kootanie strata of Great Falls, Mont. But 

 the Montana plant has the pinnules, lol)es, and teeth more obtuse and 

 not so strongly inclined forward. PI. XL, Fig. 7 probably repi-esents a 

 portion of a penultimate pinna from the upper part of the compound 

 pinna, where the ultimate pinnse carry pinnules reduced to lobes. It 

 shows the slender elongate form of these. Figs. 8 and 9 show enlarged 

 pinnules of this. 



The fossil Lesquereux determines as Pinufi! Staraischini does not 

 seem to be Pinus. It looks like the rachis of Ckidoplilebis alata. 



' Doscriptioii iif some fossil plants froiii tlie Groat Falls <-i>iil liclil of Mdiilarui : I'idc. U. S. Nat . Mils., \'ol. 

 XV, p. Am, pi. I.\,\.\ii; pi. l.wxiii, nj;s. 1, la, 2, 3. 3a. 



