Bd. Ill: 14) 
THE MESOZOIC FLORA. 
15 
and placed alternately. There is some uncertainty as regards the venation of C. Ocr- 
stedi. Heer states the secondary veins to be simple (1882, p. 30; 1883, p. 2); but 
on the accompanying figures they are practically always represented as branching. 
In C. antarctica the veins are divided into two branches, but this is only seen on 
a very close examination. The proximal branch easily escapes notice on account 
of its different course, forming a comparative!}' open angle with the distal branch 
which continues in the same direction as the basal part of the vein. 
Cladophlebis (Coniopteris.^) arguta (Lindl. & HuTT.). 
ri. 2; figs. I~3, 5. 
Nenropteris arguta, Lindley & IIuïTON 1834, pi. 105. 
Pecopteris Liitdhyana, v. Sternbekg 1838, p. 153. 
Pecopieris LindL’yana, Phillips 1875, p. 209, fig. 22. 
Coniopteris arguta, Seward 1900, p. 115; pi. 16, fig. 3 (?): pi- 17, figs- 4, 5 ; text-fig. 16. 
The specimens shown in pi. 2, figs, i — 3 and 5, agree so closely with Lindlev 
& Hutton’s type-specimen and with other specimens figured of Cladophlebis arguta 
that they are best referred to that species. William.SON’S drawing, published 
by Ihndley & Hutton, shows two separate fronds differing considerably from 
each other. In other specimens, however, both types are stated to occur in connec- 
tion with each other. Seward (1900, p. 115) includes in the same species also 
Pecopteris acutifolia and Spheuopteris serrata of Lindlev & HUTTON (1835, pis. 157 
and 148 resp.) evidently on account of a certain resemblance shown by these forms 
to the upper specimen in pi. 105 of the same authors. The Antarctic specimens 
resemble the lower specimen represented in the same plate and show no transition 
either to the upper specimen or to Pecopteris acutifolia or Spheuopteris serrata. 
The Antarctic specimens represent portions of bipinnate fronds. The rachis is 
comparatively stout, as in typical specimens of C. arguta. The pinnæ are linear, 
attached at a fairly open angle. In fig. 5, they are seen to be directed more for- 
wards, perhaps an indication that the specimen represents the upper part of a frond. 
The pinnules are attached at a very open angle, often nearly a right angle, and are 
mostly distant, more seldom closely set. The pinnules are inserted only by a por- 
tion of the base. (In the drawing, fig. i a, however, the retreciation at the base has 
been considerably exaggerated.) The pinnules are slightly falcate, only exceptionally 
as much as in fig. l a, or almost straight. The margin is entire or slightly undu- 
lating. The venation is of the usual Cladophlebis-ty^e, the lateral veins dividing 
once or twice. — A characteristic feature of all the Antarctic specimens is that the 
laminae appear corrugated, bulging out, on the impressions of the lower side, be- 
tween the veins. 
