DESCRIPTION OF SPECIES. 107 
Paururus ovauis Dn. 
Pl SONU Sigs: 8.9: 
Paliurus ovalis Dawson, Mesozoic Floras of Rocky Mountain Region. Trans. Roy. 
Soe. Canada, Vol. III, sec. 4, 1885, p. 14, Pl. IV, figs. 4, 8. 
The leaves now figured are rather smaller than, but otherwise indistin- 
guishable from, those figured by Sir William Dawson, which he collected 
at Mill Creek, Canada, from about the middle of the Cretaceous series 
Lesquereux describes a somewhat similar leaf, P. membranaceus, from 
the Dakota group (Cret. FL, p. 108, Pl. XX. fig. 6), but it differs mani- 
festly in this, that the lateral nerves are relatively finer and do not reach 
to or near to the summit, as they do in the leaves figured by Dawson 
and myself. There is littke doubt in my mind that our leaves should be 
set off in a new genus, as they are almost equally three-nerved, and the 
lateral nerves are drawn in to join the midrib at the summit, as in Smilax. 
Sir William Dawson suggests that there are scarcely any good characters 
by which these leaves can be distinguished from those of Ceanothus, but 
while this is true of the Cretaceous and Tertiary species, such as P. mem- 
branaceus Lesq., from the Dakota group, P. ovoideus Heer, from the Tertiary 
of Giningen, and of a part of the leaves deseribed by Heer under the name 
of P. Colombi, the leaves now under consideration—those described by Sir 
William Dawson (loe. cit.) and that figured by Heer (FI. Foss. Aret., Vol. 
VU, Pl. LXIX, fig. 9), with entire margins, ovate elliptical outlines, and 
three nerves which come together at the summit—present characters so- 
unlike those of the serrated or crenulated leaves called Paliurus that they 
should be placed in a distinct genus. 
Order VITACEAE. 
CissIres FoRMosus Heer. 
Pl. XLVII, figs. 1-8. 
Cissites formosus Heer, Fl. Foss. Arct., Vol. VI, Abth. II, p. 85, Pl. XXI, figs. 5-8. 
Quite a number of leaves are here represented which I have referred 
to the above species. Unfortunately, most of the specimens are in a bad 
state of preservation, owing to the fact that at the locality where they were 
