381 



from the Eocene, forming a lower subdivision, the Paleocene, for the 

 ijlants representing- the most ancient types of the Tertiary. The flora 

 of Point of Eocks seems, in parr, referable to this Paleocene division 

 of the floras of Mount Bolca, of the calGaires grossiers of Paris, of the 

 gypses of Du Puy, of the London clay, of the gres of Sarthe, of the 

 lignites of Skoi)an, of the argiles vertes of Montmartre, and of the 

 gypses of Aux, are to be considered as a group representing the true 

 Eocene formations, we have to admit that till now at least, our lower 

 Liguitic flora has little in its species to relate it to that formation. But 

 then, it has mixed in it a number of Paleocene types and a preponder- 

 ance of Submiocene or Oligocene species, and this proves a persistent 

 general character of the whole flora from the base of the Lignitic at 

 Point of Eocks to its upper part at Golden and Black Butte, where the 

 predominance of more recent types becomes more marked as far as the 

 old ones disappear. There is therefore no reason as yet to snppose that 

 we have still, as they have iu Europe, intermediate floras of a distinct 

 and different character breaking the homogeneity of that of the Lignitic. 

 Constituted as it is, in its comparison to the distribution of European 

 flora, partly of Paleocene, or Lower Eocene types, partly of Oligocene, or 

 Upper Eocene ones, this flora must, of a necessity, represent the North 

 American Eocene. 



Another lot of specimens, sent also by Mr. Cleburn, is from a locality as 

 yet unknown to me, the Alkali stage-station, on the Sweetwater road, 

 about thirty miles north of Green Eiver station of the Union Pacific 

 Eailroad. The proprietor of the specimens has not himself visited the 

 locality, and does not give any details on the position of the beds where 

 the specimens were obtained. They represent only three species, all 

 new ones, as follows : — 



1. AL]^^ITES UNEQUILATERALIS, sp. nOV. 



Leaves thin, variable in size, broadly oval or ovate pointed, rounded 

 to a short petiole ; borders crenato-serrate ; nervation pinnate ; lateral 

 veins irregular in number and distance, curving in passing to the bor- 

 ders, at an angle of divergenee of fifty to sixty degrees and entering the 

 teeth by their ends or by small branchlets, when they pass under the 

 teeth and follow the borders. 



These leaves vary in size from four to eight centimeters long and 

 from three to six centimeters broad, one of the sides measuring generally 

 one-fourth in width more than the other. The irregularity iu the num- 

 ber of the veins is correspondingly great; one of the leaves, the smallest 

 for example, has, on one side, five lateral veins, the lower much branched 

 outside, and on the other, ten, all simple. The largest of the leaves 

 of this species, which is represented by a number of specimens, is 

 related by form and nervation to Fopulus Lehnmii, Wat., which Saporta 

 considers as referable to his Alnus cardiopliylla. It is represented in the 

 Sezaue Flora, (PI. XV, fig. 8). The general facies of the American leaves 

 is, however, difl'erent, the teeth being broader and more obtuse, the 

 nervation more distinctly pinnate, and the disposition of the veins to 

 enter the teeth by their extremity more marked ; and compared to Alnus 

 cardiophylla, it is especially difterent by the constant inequality of the 

 leaves. This last character and the irregularity of nervation are not of 

 frequent occurrence in the leaves of Almis. Alnus viridis and -A. serrulata 

 are, however, sometimes irregularly veined, and the inequality of the 

 sides is seen in a number of fossil species, Alnus cycladum, Ung., especi- 

 ally A. sporadAun, Sap. 



JETabitat. — Alkali station, William Cleburn. 



