THNIOPTERIS. 123 
are certain distinctive features in the venation of the two genera 
which enable us to distinguish them in most instances. Heer’s! 
figures of Vilssonia ortentalis, Hr., probably represent a Teniopleris ; 
the apex of the leaf is like that of 7. Beyrichiit, Schenk, and 
the venation corresponds to 7. Dawsoni, sp. nov. 
The genus Oleandridium was founded by Schimper to include 
ferns with ‘‘Frondes simplices, lanceolato-elongatz vel lingulatz, 
coriacee. Fructificatio Aspidiacearum?’’? In Zittel’s ‘‘ Paleo- 
phytologie”’* this genus is described as differing from Zeniopteris 
by its more distinctly horizontal and stronger lateral veins which 
end in a marginal vein, and by the longer and more elliptical form 
of the leaf. Another writer‘ speaks of Oleandridium as comprising 
those leaves of the nervation type Zeniopteridis which have simple 
laminze not pinnately divided. 
It is unnecessary to suggest that there is a considerable amount 
of confusion and uncertainty about the two genera, Zeniopteris, 
Brong., and Oleandridium, Schimp. The latter name leads one 
to suppose some well-established affinity with the genus Oleandra. 
If specimens with fructification agreeing with that of the recent 
genus are found they might with advantage be so named, but to 
designate such a form of leaf, common among fossil ferns and 
common in recent genera, by names which imply affinities founded 
on external form and venation is utterly misleading. In adopting 
Schimper’s genus for a Chinese plant, Schenk® expressly states 
that he does not mean to convey the idea of a relationship with 
the recent genus Oleandra, but he makes use of the term Olean- 
dridium for the purpose of indicating a probable difference between 
the Tzeniopteroid ferns from Mesozoic and Paleozoic rocks. 
It has been shown in a suggestive paper by White,® that we 
have a number of Teeniopteroid leaves, from rocks of different 
ages, which may be safely placed in such genera as Daneaites 
and others suggestive of botanic affinity; but in the absence of 
good evidence, either from fructification on the specimens them- 
FI. foss. Arct. vol. v. pl. iv. figs. 4-9. 
Trait. pal. vég. vol. i. p. 607. 
Vol. i. p. 133. 
Solms-Laubach, Fossil Botany, p. 136. 
Paleontographica, vol. xxxi. 1885, p. 169. 
§ Bull. Geol. Soc. America, vol. iv. 1893, p. 123. 
ao fF 6 YP 
