Arber . — On the Past History of the Ferns. 223 
which closely resemble the sporangia of recent Eusporangiate Ferns, this 
conclusion can no longer be held with the same confidence. How far it 
will be necessary to modify it, it is impossible to say at present. 
We may again approach the problem by attempting to recognize in 
either the Palaeozoic or Mesozoic floras the broad phase of the life-figure of 
this race. We may first ask, Is there any evidence that the Eusporangiatae 
were a dominant group in the Rhaetic, Jurassic, or Wealden vegetations? 
So far as our present knowledge is concerned, this question can be answered 
by an emphatic negative. There is no member of these floras which can be 
regarded, with the least degree of probability, as allied to the family Ophio- 
glossaceae. Further, it is difficult to recall more than a very few species 
which are or may be assigned to a position in or near to the Marattiaceae. 
Of these the best examples are to be found in certain fronds of Taeniopteris , 
occurring more especially in the Rhaetic and Liassic rocks. 
The genus Taeniopteris is a frond-genus, including simple, entire, 
ribbon-like leaves, often of fairly large size, usually lanceolate or elliptical 
in form, with a well-marked midrib, and simple or occasionally dichoto- 
mizing lateral veins, which pursue a course almost at right angles to the mid- 
rib. This type of frond first appears in the Carboniferous and Permian 
floras of both the Northern and Southern Hemispheres, but it is more 
especially characteristic of the Rhaetic and other of the earlier Mesozoic 
floras. It can, of course, be closely matched among living Ferns, a con- 
sideration which is, however, of absolutely no value. 
In the case of the widely distributed and characteristic Rhaetic species, 
Taeniopteris Miinsteri, Goeppert 1 , fertile fronds have been discovered. The 
synangia borne on these fronds have, it must be confessed, so far as one can 
judge from impressions, a most striking resemblance to those of the modern 
Fern, Marattia . The discovery of such fertile examples of T. Miinsteri 
in the Rhaetic rocks of Tonkin, led Professor Zeiller 2 to go so far as to 
almost place this species within the recent genus. In the case of Swedish 
examples, which by the kindness of my friend Professor Nathorst I have 
recently had an opportunity of studying in Stockholm, the resemblance is 
equally striking. 
Another, but in my opinion less satisfactory instance, is to be found in 
the genus Danaeopsis , Heer, and the species D. marantacea, Presl 3 , from 
the Triassic of Germany and elsewhere in Europe. The frond of Danaeopsis 
may be roughly described as a pinnate frond, whose pinnae resemble the 
simple fronds of Taeniopteris. Here the synangia are said to recall more 
closely those of the recent genus Danaea , but I am not quite satisfied that 
this is the case. 
1 Nathorst (’78 2 ), p. 48, pi. I, fig. 6 (Hoganas yngre). 
2 Zeiller (’03), p. 63, pi. IX, figs. 6-8, as Taeniopteris ( Marattia ) Miinsteri , Goeppert. 
3 Schimper (’69), vol. i, p. 614, pi. 37. 
