578 WARREN S. SMITH 



This form is referred to this species because it is remarkable 

 for its larger size. Judging from a fragment, the complete leaf 

 was about 4X6 inches, as is that of Lesquereux in Fig. 8. There 

 are three pairs of secondaries, the lowest very faint, the innermost 

 very strong and straight. The margin is not preserved. Les- 

 quereux notes this form from Upper Miocene, but one of Heer's 

 examples is Miocene of Spitzbergen (equal to Eocene). 



Populus artica (Heer) 



Heer: Flora Foss. Arct., IV, Taf. XXXII. 



The Cascade form is very questionably referred to this species. 

 There is a single smooth, faintly veined leaf from beds F 831+50 

 whose base is almost cordate but otherwise agrees with P. artica, 

 and even similar bases are to be found in Heer's figures. 



Genus Protoficus (Saporta) 



Protoficus is represented by many beautifully preserved speci- 

 mens from shales of F 831 + 50. They are apparently all of one new 

 species. 



Protificus fossi N.Sp. (Figs. 9 and 10) 



The leaf is lanceolate, broadest just at the middle; the apex 

 is a short, sharp point; the margin is irregularly, sharply dentate 

 to one-third of the way to the base, then wavy to crenulate. The 

 base is blunt to slightly tapering and not absolutely symmetrical, 

 as seen in Fig. 10. The midrib is straight and moderately strong, 

 with seven pairs of secondaries. The members of each pair are 

 not strictly opposite, except above, where they are strongly bowed 

 outward. The nervation has a palmate aspect, since the two lowest 

 pairs of secondaries come off at the top of the petiole, and the rest 

 only above the lower half of the leaf, or even higher. Six 

 pairs of tertiaries arise from the second pair of secondaries and 

 form loops near the margin. Small nerves extend from these loops 

 into the teeth. All the other tertiaries are at right angles to the 

 midrib in parallel " horizontal'' rows. One small specimen measured 

 11 cm. in length by 4.5 in breadth (Fig. 10); the type (Fig. 9) 

 is 9 cm. in width by 15 cm. in length. 



