STRATIGRAPHY OF THE SKYKOMISH BASIN 577 



anastomosing of the secondaries of the veining are correct. The 

 tertiaries, arising at right angles to the secondaries and dovetailing 

 with the tertiaries from adjacent secondaries, are also similar to 

 Heer's figures. The form is noted from the Canadian Miocene — • 

 really Eocene. 



Genus Populus 



Populus is represented by numerous more or less fragmentary 

 remains, in which, however, many of the characters are fortunately 

 plainly discernible. Three of Ward's species are believed to be 

 present, besides one of Heer's. The three forms are noted from 

 beds called Laramie, now considered of Fort Union age. 



Populus amblyrhynca (Ward) 

 Ward: U.S.G.S. Bull. No. 37 (1887), 20; PI. VI, Figs. 1-8. 



Reference of the forms to this species is made with great cer- 

 tainty. In the Cascade form the base is somewhat natter than in 

 Ward's figure, the identification resting chiefly upon the character 

 of the thick tertiaries sent out from the inner side of the second 

 pair of secondaries. The resemblance is closest to Ward's Figs. 2 

 and 3 of PI. VI. 



Populus cuneata (Newb.) 



Newberry: Later Ext. Floras, pp. 31, 64. 



Illus. Cret. and Tert. Plants, PI. XIV, Figs, 1-4. 

 Lesquereux: Cret. and Tert. Floras, p. 225; PI. XL VI, Fig. 5. 

 Dawson: "Cret. and Tert. Floras of Brit. Col. and N.W. Terr.," Trans. Roy. 



Soc. Can., Sec. IV (1882), p. 32. 

 Ward: U.S.G.S. Bull. No. 37 (1887), p. 19; PI. IV, Figs. 5-8; PL V, Figs. 1-3. 



One specimen was so called because the first pair of secondaries 

 here, as in the figures of P. cuneata, leave the midrib about 5 mm. 

 up from the attachment of the petiole. 



Populus zaddachi (Heer) 



Heer: Flora Foss. Arct., I, 98; Taf. VI, Figs. 1-4; II, 468; Taf. XLIII,Fig. 

 15a; Taf. XLIV, Fig. 6. 

 Flora Foss. Alaska, p. 26; Taf. II, Fig. 5a. 

 Lesquereux: Mem. Mus. Comp. Zobl., VI (1878), Xo. 12; PI. VIII, Figs. 1-8. 



