DESCRIPTION OF SPECIES— BETULACE^. 139 



Bet II I SI Stevensoni, Lesqz. 



Plate XVIII, Figs. 1-5. 



Betula Stevenaoni, Lesqx., Annual Report, 1871, p. 21)3 ; 1872, pp. 386, 401. 



Leaves of medium size, ovate, tapering or rounded to an obtuse point, snbcoidate at the slightly- 

 unequal base, short-petioled, serrulate; nervation craspedodrome. 



The leaves, varying in size from four to seven centimeters long and three 

 to four centimeters broad, are ovate, round-pointed, serrate, with equal short 

 teeth (fig. 3, enlarged); a half-round or subcordate base, and a short petiole; 

 the secondary veins, six to eight pairs on each side, opposite, at or near the 

 base, pass up to the borders nearly straight, scarcely branching under an angle 

 of divergence of 40°, joined nearly at right angle by strong curved nervilles, 

 interrupted by the veins. I found at Evanston, in connection with these 

 leaves, a few bracts of cones of Betula, one of them similar to that figured 

 by Heer (Fl. Arct., pi. xxv, fig. 25), which the author refers to B. prisca. 

 Another, with three short-pointed divisions, appeared of the same character as 

 that of fig. 30 {loc. cit.), named Betula Forshammeri. One of them or perhaps 

 both forms may belong to our species, whose leaves are abundant at the same 

 locality. 



Habitat. — Evanston, Utah ; Carbon, Wyoming. 



ALNUS, Tournef. 



As seen in the supplement to the Cretaceous Flora of Nebraska, in 

 Dr. Hayden's Annual Report for 1874, p. 35.''), the two forms of leaves pre- 

 viously referred in the Cretaceous Flora, p. 62, to Alnus and Alnites are 

 considered by Saporta as rather referable to Hamamelis than to Alnus, and 

 have been accordingly described in that supplement under the generic name 

 of Hamamelites. At the same time, another leaf of H. {Alnus) Kansaseanus, 

 found in a better state of preservation, has been represented in pi. vii, fig. 4, 

 of that same supplement. The reference indicated by the name of Hama- 

 melites is, however, quite as uncertain as that to Alnus, the more so that it is 

 not confirmed by paleontological records ; for, in the lowest Eocene of Point 

 of Rocks, a species of Alnus or Alnites has been discovered, while as yet 

 no' species of Hamamelis has been found in the North American Tertiary 

 flora, and none also in that of Greenland. The same can be said of tlie 

 Tertiary flora of Europe, where one species only, doubtfully referable to 



