270 Gwynne- Vaughan.— On the Anatomy of 
figure of Angiopteris (Studies, III, PI. II, Fig. 77) and the description 
(p. 55), there are the same large, turgid, thin-walled brown cells on the 
peripheral side ; laterally the same bands of deep prismatic lignified cells ; 
while the central face, which is thin- walled, bears in a median position 
the fissure of dehiscence. A transverse section from the distal end of 
the sporangium shows the narrow bridge of indurated tissue extending 
from the lateral bands just described across the apex (compare 1. c., Fig. 76) ; 
and thus the arch of indurated tissue or “ annulus ” is complete over the 
apex, as it is in Angiopteris, and the mechanism of dehiscence will be 
the same. Longitudinal sections, i. e. vertically through the sorus, show 
a structure similar to that seen (1. c., Fig. 72) for Angiopteris, with a 
slight difference of outline, Archangiopteris being more pointed at the 
apex. 
4 There can be no doubt of the near affinity to Angiopteris . There 
may, however, be some difference of opinion as to the phyletic relations 
of these two Ferns. So far as a conclusion can be drawn from the outline 
of the sorus, I should be disposed to look upon the long sorus of Archangi- 
opteris as a derivative and secondary condition ; while the compact, almost 
circular sorus of Angiopteris , corresponding as it does with most of the 
modern Marattiaceae, and with the very large majority of Palaeozoic Ferns, 
would seem to be the more primitive type. It may be that the extension 
of the sorus to the dimensions now seen in Archangiopteris was T an incident 
of relatively late occurrence.’ 
EXPLANATION OF FIGURES IN PLATE X. 
Illustrating Mr. G wynne- Vaughan’s paper on '■Archangiopteris and other Marattiaceae.’ 
Figs. 1 and 2. Views of the specimen of Archangiopteris Henry i seen [from opposite sides 
(Natural size.) 
Fig. 3. Adaxial aspect of the youngest leaf seen in Fig. 2, showing the stipular appendages. 
w wings of stipule ; com., transverse commissure ; the mark x indicates the points at which the 
arrested apices may be found. 
Fig. 4. Adaxial aspect of the base of the upper leaf seen in Figs. 1 and 2. Lettering as in 
Fig * 3 * 
Fig. 5. Diagrammatic representation of the end of a rhizome of Kaulfussia , showing stipular 
appendages. Lettering as in Fig. 3. 
Fig. 6. Archangiopteris. Transverse section of stem ; the departing traces of two leaves are 
shown, s. s., meristeles of stem ; int. s., internal strand ; 1. 1., leaf-trace ; r., root stele. The dotted 
line indicates the limit of the root cortex. 
Fig. 7. Archangiopteris. Transverse section of the stem in a region where no internal strand is 
present. Lettering as in Fig. 6. 
