322 PROF. A. C. SEWARD AND MR. J. WALTON ON [vol. Ixxix, 



the midrib where it is continued below the torn lamina : the vena- 

 tion is of the Glossopteris-indica type. The venation is clearly 

 seen in fig. 18 (PL XXI) on a piece of lamina 3 cm. broad : the 

 meshes near the midrib are considerably larger than those farther 

 from the middle of the leaf, and are less rectangular in form. 

 This marked difference in the meshes is not a constant character, 

 but is well illustrated by leaves of the same species from South 

 Africa and India. 



The leaf shown in fig. 7 (PI. XIX) is probably a young leaf of 

 G. indica. The collection includes several narrow Glossopteris- 

 leaves identical in form with G. angustifolia Brongniart, as 

 figured by Halle from the Falkland Islands. 1 and by other authors 

 from different localities ; but, in view of the occurrence of spe- 

 cimens illustrating a complete transition between spatulate and 

 more linear examples, we have not adopted Brongniart's specific 

 name. Moreover, in none of the narrower leaves that we have 

 examined are there any distinctive venation characters other than 

 such as one would expect in a restricted lamina. None of our 

 leaves shows a type of venation identical with that figured by 

 Dr. Halle as characteristic of G. angustifolia. A few specimens 

 collected by Dr. Baker approach G. damudica in the course of 

 the lateral veins, but we have not seen any that could be clearly 

 distinguished in this respect as specifically different from G. 

 indica. 



Glossopteris indica Schimper, cf. var. TVilsoni Seward. 



The enlarged piece of lamina reproduced in fig. 13 (PI. XXI) 

 differs from most of the specimens in the very small number of 

 lateral anastomoses between the lateral veins, a feature shared 

 by some of the leaves of G. indica from Antarctica named 

 G. indica var. Wilsoni 3 and by specimens described by Zeiller 3 

 from the Lower Gondwana rocks of India. This variation from 

 the normal has probably no significance in relation to geological 

 age, and, in any case, the horizon of the plant-beds discovered by 

 Dr. Wilson 300 miles from the South Pole has not been definitely 

 fixed. 



Glossopteris indica Schimper, cf. G. decipiens Feistmantel. 

 (Fig. 15, PL XXI.) 



The leaf reproduced in fig. 15 (PL XXI) differs from the great 

 majority of specimens included in G. indica in having a less 

 clearly marked midrib, except in the lower part of the lamina. 

 In the distal portion of the leaf the highly inclined, arched veins 

 converge towards the middle of the lamina, where they follow a 

 vertical course ; lower in the lamina the midrib becomes more 

 distinct, and is studded with tubercles, a feature frequently seen 



1 Halle (11) pi. viii, fig. 2. 



2 Seward (14) pi. iii, figs. 11-14. 

 a Zeiller (02) pi. iii, figs. 3 & 3a. 



