T. G. HALLE, 
58 
(Schvved. Südpolar- Exp. 
not reach each other with their bases but leave a narrow median zone of the rachis 
exposed between them; this is a very characteristic feature that is found in all the 
Greenland species mentioned. The corresponding Antarctic forms are different in 
this respect: the bases of the opposite pinnæ meet at the median line of the rachis, 
and when they are oblique they ma}^ even partly overlap. This character must be 
regarded as an important one, and excludes the possibility of a specific identity.^ 
Yet the obvious correspondence between the Arctic and the Antarctic series of forms 
is a matter of some interest. 
ZamiteS Anderssonii shows a great habitual resemblance to Z. borealis Hr., but 
there is a certain difference in the venation. In the latter species the veins appear, 
as stated by Heer. to be simple, whereas in Z. Anderssonii they are distinctly, 
though not very frequently, bifurcating. This character is perhaps not ver}' im- 
portant, since a great variation is found in this respect in some species of Zamites^ 
but it is perhaps sufficient for a specific distinction, quite apart from the general 
difference between the Arctic and the Antarctic fronfls. 
Zamites antarcticus n. sp. 
PI. 7, figs. 19?, 20r, 23, 24, 28?; text-fig. 13. 
Frond large, rapidly tapering at the aj^ex. Pinnae attached to the upper surface 
of the rachis, at a wide angle. Bases of pinnae parallel to the axis of the rachis, 
slightly contracted; those of opposite pinnæ meeting at the median line of the rachis. 
Pinnæ linear, long and narrow, sub-acute. Veins strong, dense, about 8 or more in 
number, occasionally bifurcating. 
This species is represented only by small portions, which do not give an}' clear 
idea of the shape of the fronds. The frond is seen to have been rather broad, the 
largest fragments measuring up to 5 cm. across. The specimens figured in pi. 7, figs. 
23 and 24, show that the frond was fairly abruptly tapered at the apex. It is difficult 
to ascertain the exact mode of insertion of the pinnæ, because they are not spread 
out flat in the plane of the rachis, but their upper surfaces are strongly convex 
near the rachis, so that the insertion comes to be at the bottom of the deep furrow 
thus formed. The pinna is seen to be slightly contracted at the base, which is 
parallel to the rachis, and the opposite pinnæ meet at the median line of the rachis. 
It cannot be decided whether there is an}^ callosity at the base of the pinnæ or not. 
The pinnæ are quite straight or very faintly curved forward. The venation is re- 
markably dense (up to five veins per mm.) and distinct; bifurcating occurs typically, 
' Heer’s type-specimens are in the l’alæoliotanical Department of the State Museum of Natural History 
at Stockholm. I have been able to convince myself that his figures are correctly drawn in this respect, 
and that there is a considerable difference between the Greenland fronds and those of the Antarctic specie^. 
