LPENHALLOW] A REPORT ON FOSSIL PLANTS 317 
while B. perantiqua, Dn., occurs in the Upper Cretaceous of Baynes 
Sound (9), and yet another not specifically defined is met with in the 
Upper Cretaceous of Vancouver Island (8). Knowlton enumerates 
(37) not less than nineteen, while Ward (56) gives seven Ter- 
tiary species out of a total of fifteen. As, furthermore, eighteen out 
of these twenty-six species are distinctly Eocene, it may be concluded 
that in the absence of definite evidence to the contrary, any large repre- 
sentation of the genus would give to the flora facies of a distinctly 
Eocene character. 
Cyperacites haydenii, Lesq., which occurs in the Kettle River flora, 
and which was originally described from the Green River Group (42: 
p. 140), serves to definitely indicate the probable age of the flora now 
under discussion. This conclusion is emphasized by the fact that the 
somewhat large number of species originally described by Heer (26: 
46, 52), from Greenland and Spitzbergen, are all of Eocene age. Of 
these latter, Cyperacites paucinervis, Heer., is also found in the 
Eocene of Vancouver Island (13: iv. 144). In the enumeration of the 
fossil flora of the Yellowstone National Park, Knowlton (35: p. 779) 
shows that of the four species known there, three are definitely refer- 
table to the Fort Union Group, while only one is referred to the Mio- 
cene. Finally, Ward (56: p. 464) indicates similar relations when, 
in his Synopsis of the Laramie Group, he enumerates four species, all 
of which he shows to be exclusively of Eocene age. From this sum- 
mary it becomes obvious that Cyperacites is essentially and typically an 
Eocene genus, the chief aspect of which is Lower Eocene. The only 
exception to this which has come under my notice, is the case of an 
undescribed species recorded by Sir William Dawson in his description 
of specimens from the Kootanie Group at Anthracite, B.C. (5: p. 91), 
but this reference is a doubtful one, as the species does not correspond 
with the usually accepted characters of the genus, or with those of the 
existing genus Cyperus, and I therefore exclude it from further con- 
sideration in this connection. 4 
The reference to Potamogeton in the present instance is based 
altogether upon the fruit, but there seems little reason to question 
the correctness of this conclusion. Knowlton records seven species of 
Potamogeton (37), five of which are from the later Tertiary, but two 
are from the Eocene. Ward (56) shows that there are fifteen species 
of Potamogeton in the Eocene Flora, two of which are also common to 
the Senonian; while Heer defines no less than nine species from the 
Tertiary of Europe (31: I, p. 102; II, p. 88; III, p. 170), and five 
from the Eocene of Greenland (29: I, and 23, VII), Spitzbergen (27: 
