26 T. G. HALLE, MESOZOIC DEPOSITS AND FLORAS OF PATAGONIA AND TIERRA DEL FUEGO. 
may be regarded — Morris” illustrations not being very clear — as presenting the 
typical characters of Cladophlebis australis. If M'CoY's specimen is accepted as a 
typical representative of C. australis, it is evident that the Patagonian specimens 
should be referred to that species, too. 
Another question is whether Cladophlebis australis ought to be kept as a separate 
species or included in C. denticulata Bron. "The former course has been adopted here 
because the fronds referred to C. australis seem to form a fairly distinct type, easily 
distinguished from most of the forms included in C. denticulata. The latter species 
has gradually been brought to inelude an ever increasing stock of fairly different 
forms, and it would appear to be of advantage to separate from it as many small 
species as can with some accuracy be recognized. SEwARD has preferred to use (1. c.), 
in this and similar cases, a designation as varieties; but, as the classification is not 
intended to be any expression of actual relationship, it does not seem necessary to 
use more than one name. From the typical C. denticulata the present species differs 
in regard to the shape of the pinnules, which have more parallel margins, taper more 
abruptly at the apex, which is more obtuse, and are only slightly, or not at all, 
faleate. In regard to the venation, it is characterized by a very slender midrib, 
which is somewhat flexuous in the upper part. The simple bifurcation of most of 
the secondary veins and the parallel course of their branches, which are other charac- 
ters of the Patagonian specimens, represent features common to a large part at least 
of the forms referred to C. denticulata. 
RENAULT (1. c.) has described fertile specimens of Cladophlebis australis under 
the name Todea australis, stating that the sporangia have the arrangement and struc- 
ture characteristic of the Osmundaceae. It is noteworthy, therefore, that the speci- 
mens from the English Oolite which are usually regarded as fertile fronds of Clado- 
phlebis denticulata, and which have been described by the present writer (1911) as 
Cladotheca undans (BRGN.), show a rather different structure of the sporangia, not 
in accord with an actual inclusion in the Osmundaceae. 
Cladophlebis australis is known at present only from the Southern Hemisphere. 
In addition to Australia and Patagonia, it occurs possibly in the northern island of 
New Zealand. At least it is undeniable that Polypodium Hochstetterr UNGER (1865, 
p. 5; pl. 2) from that island bears a very great resemblance to Cladophlebis australis 
and, in spite of some small differences, may be identical with it, as was remarked 
already by JACK & ETHERIDGE (1892, p. 317). The specimen figured by SEWARD 
(1903, pl. 6, figs. 16, 17) from South Africa under the name Cladophlebis denticulata 
BRGN. forma Atherstonet may, perhaps, be included in the present species; it has, 
however, the pinnules longer and still more linear, as well as more crowded. Although 
Cladophlebis australis has hitherto been recorded only from the Southern Hemisphere, 
it is possible that some of the European forms ineluded in Cladophlebis denticulata 
should be referred to it. The range of the species would thereby be extended to 
the Northern Hemisphere, just as the typical C. denticulata occurs in the Southern 
Hemisphere. There is, at any rate, no reason to believe that any one of these spe- 
cies is confined to one hemisphere only. 
