DESCRIPTION OF SPECIES— MYKICAOEiE. 127 



Except for tliis last group, therefore, there is no rclalion whatever in the 

 distribution of species of Mijrka in both the Tertiary floras of Europe and of 

 America; and if we are able to trace on this continent some analogy of 

 distribution in the section of the Comptonice o{ the Upper Tertiary and of the 

 present flora, there is evidently none of this kind in Europe. 



Though the leaves of Myrica seem distinctly characterized, some of them, 

 nevertheless, have in their form and nervation a degree of relation to those 

 o( Froteacece, of the genera Dryandra and Lomatia especially. Some pale- 

 ontologists, d'Ettingshausen above all, have described a number of these leaves 

 under the generic name of Dryandroidcs and Lomatites. Since then the 

 seeds of some of those supposed Froteacecs have been found, and their refer- 

 ence to Myrica is positive; and now the opinion is prevalent that, if not all, 

 at least the largest number of these species belong to Myi'ica. Saporta, in 

 considering this question in a geological point of view, hypothetically demands 

 whether, as the Myricce and the FroteaeccB have originated in the Cretaceous, 

 and as there is now a kind of parallelism in some of their characters, seem- 

 ingly recording a common birth, they could not have been at the outset iden- 

 tical in their generic characters, and have branched through the geological 

 times into those two divisions, now so widely separated by some of their 

 more important botanical characters, as by their geographical distribution. 

 The celebrated author remarks on this subject that in the Cretaceous flora 

 of Belgium, Debey and d'Ettingshausen find the Myricce. with the Froteacece, 

 the first, however, in a very subordinate number, and that, from his own 

 observations, the relative position of both these groups is remarked to be the 

 same as high as the Gypses of Aix, when the Froteacecu began to decline and 

 the Myrica to take the ascendency. On this subject, the little we know of 

 the recent geological floras of this continent does not give any evidence for the 

 solution of hypotheses of this kind. The Froteacece of the Dakota group 

 (Cretaceous), Froteoides of Heer, are too indistinct in their characters to 

 afford a reliable point of comparison. These leaves, known especially by 

 their coriaceous consistence and their form, for the nervation is scarcely dis- 

 cernible, may represent a single species of plants of a group far different from 

 that to which they are hypothetically ascribed. At any rate, in passing up 

 to the Tertiary, we do not find any leaf comparal^le to any Froteacece except 

 in the Lower Yiocene, Myrica Torrey?', which resembles a Lomatia liy its 

 nervation, but with which seeds of Myrica have been found ; and, in tlie 



