Locality
From Hollick (1930) (p. 68)
"Yukon River: north bank, about 8 miles below Kaltag (original No. 35); collected by W. W, Atwood and H. M. Eakin in 1907 (lot 4640)."
Description
From Hollick (1930) (p. 68)
"Leaf 4.5 centimeters in length by 3.4 centimeters in width across the middle, rhomboid-elliptical, tapering to base and apex, sharply dentate from the middle upward, entire below; nervation simply pinnate, craspedodrome; midrib straight; seeondary nerves six on each side, arranged in opposite or subopposite pairs, leaving the midrib at acute angles of divergence, the lower ones with one or more branches from the under sides toward the extremities."
From Hollick (1930) (p. 68)
"This leaf differs so little from Betula beatricina Lesquereux (1868; 1874) (p. 95; p. 61, pl. 5, fig. 5; pl. 30, fig. 4) from the Dakota sandstone of Nebraska, that it might be regarded as specifically identical. It appears, however, to be broader, relative to its length, with dentition that is sharper and more serrate than in the specific type. It resembles Lesquereux's Figure 4 on Plate 30 more nearly than it does his Figure 5 on Plate 5 and more nearly than his two figures resemble each other.
Comparison is also suggested with Betula atavina Heer (1883) (p. 22, pl. 55, figs. 8, 21b) from the Patoot beds of Greenland, and with one of the forms of Betulites snowii Lesquereux (1892) (p. 64, pl. 5, fig. 2) from the Dakota sandstone of Kansas."