32 T. G. HALLE, MESOZOIC DEPOSITS AND FLORAS OF PATAGONIA AND TIERRA DEL FUEGO. 
tion is very indistinct; it appears to be flabellate. The degree of dissection varies 
considerably, being stronger towards the bases of frond and pinnae. In fig. 8, pl. 4, 
there is shown another specimen, which consists only of two detached pinnae. Itis 
undoubtedly identical with the one already described. 
In spite of the fragmentary state of the material, it appears very probable that 
these specimens are identical with YABE'S Sphenopteris naktongensis. There is a very 
close agreement in the general habit and in the shape of the pinnae and the pin- 
nules. The venation is indistinct both in YABE'sS illustrations and in the Patagonian 
specimens, but does not seem to be inconsistent with the specific identity of the 
two forms. 
Sphenopteris naktongensis is only known from Korea, where it was found in 
rocks which are probably of the age of the Wealden. 
The species was found together with Sphenopteris (Onychiopsis?) psilotoides in 
the uppermost part of the Rio Fösiles valley. 
Sphenopteris patagonica n. sp. 
P1. 2, figs. 1—3. 
Under the new name Sphenopteris patagonica is described here a fern which 
seems to occupy a fairly isolated position in the Mesozoic fiora. 
Frond with flattened rachises, several times deeply pinnately dissected into 
branching, narrowly linear segments. Ultimate segments short, rounded, of the same 
breadth as the rachises and not markedly set off against the same, uninerved. 
The specimens are too fragmentary to give any idea of the general shape of 
the frond. Yet, the species is very peculiar and well characterized by the unusual 
manner of dissection of the frond. The dissection is pinnate, but it is not possible 
to state how many times the pinnate division is repeated. A very characteristic 
feature is that the rachises are flat, of nearly the same breadth in the segments of 
different orders, and pass insensibly into the ultimate segments which represent merely 
the ultimate ramifications of the rachises. The pinnae and the pinnules are thus 
reduced to little more than the flattened rachises themselves. The ultimate segments 
are short, often a little widened at the rounded apex. They are mostly uninerved, 
with the vein usually ending abruptly a little short of the apex. 
The specimen shown in pl. 2, fig. 3, is a little different from the typical ones 
as described above, and probably represents the uppermost portion of the frond. 
The pinnules are more markedly set off, their lobes being more closely arranged 
though not confluent to form a common lamina. There are numerous examples of 
transition from this specimen to more typical ones, and there is no doubt that they 
belong to the same species. 
There are only very few specimens of Mesozoic ferns figured which are at all 
comparable with the present species. The greatest resemblance is shown by a spe- 
cimen which is figured by SAPORTA (1873, p. 387; pl. 50, fig. 4) as Stachypteris lilho- 
