IO 
T. G. HALLE, 
(Schwed. Südpolar-Exp. 
The specimen consists only of a marginal portion of a pinna. The midrib and 
the median portion are not preserved, so the breadth of the pinna is not known. 
Fragments of three lobes are seen; these mea- 
sure about 6 — lo mm. from the base to the 
apex, are triangular and somewhat falcate with 
the proximal margin convex, the distal straight 
or concave. As the median portion of the 
pinna is not preserved, it is impossible to say 
how deeply the latter was dissected; the con- 
tinuous part of the pinna is about 5 mm. 
broad in the specimen. The apex of the 
lobes is somewhat obtusel}^ pointed. 
Dictyophyllum sp. ; a — portion of a pinna, ’/i; 
b — portion of the middle lobe in a, The venation stands out veiy clearly in 
relief. The secondary veins, the basal portions 
of which are not seen, are distinct, but not very strong. The tertiary veins are only 
a little finer; they branch up rapidly and anastomose with each other. The larger 
areoles thus formed surround finer ones arising from the anastomosing of the finest, 
quaternar}^ branches. The latter are remarkably strong, however; and, on the whole, 
the venation is characterized by the slight difference in thickness of the veins of 
different orders. 
As far as the characters of the pinna can be made out, the specimen is fairly 
closely comparable with D. exile (Brauns). The lobes are perhaps a little more 
falcate, and, what seems more important, the veins of different orders are more 
alike and the finest ones stouter than in the Rhætic species. Another species to 
which there is a yet greater resemblance, is D. japonicitm Yokoyama (1891, p. 243; 
pi. 33). The similarity is indeed so great that it is difficult to see any difference 
except in the venation. Especially the shape of the lobes appears to be the same. 
The venation agrees best with that in Yokoyama’S fig. 8 a; but even as compared 
with that, the veins are more equal in strength. 
The scantiness of the material does not permit of a specific identification; but 
it is strange to note that the specimen seems to be most closely comparable with 
Rhætic species. (The age of the Nagato Beds in which D. japonicmn has chiefly 
been found is considered by Yokoyama as probably Rhætic.) With the forms ot 
Dictyophyllum found in younger beds it does not seem possible to establish any 
close comparison. D. Roemeri (SCHENK, 1871, p. 224; pi. 31, fig. 3), the only spe- 
cies recorded from the Wealden, is too imperfectly known to permit of any com- 
parison with the present fragment: the venation appears to show some resemblance, 
however. The only known representatives of the genus in the Southern Hemisphere 
are Dictyophyllum Bremerense Shirley (1898, p. 25; pi. 13, fig. 2) from the Ju- 
