﻿88 piioF. A. c. SEWAED ON [Feb. 1908, 



of China ^ have recently been described as identical with the 

 Scanian species. Another instance of the occurrence of a similar 

 form of cast is afforded by a specimen from the island of Kotelny, 

 figured by Prof. Xathorst - as ScMzoneura sp., which he compares 

 with a fossil figured by Mr. Newton & Dr. Teall from Pranz- Josef 

 Land as PhylJotheca.^ 



The sandstone-east represented in PI. Ill, fig. 1, bears a striking 

 resemblance to Equisetaceous stems figured by several authors from 

 the Punter Peds of the Yosges * and by Heer from Switzerland ' as 

 Calamites or Equisetum Mougeotii. In the European species the 

 regularity of the ribs is probably the result of the presence of 

 strands of strengthening tissue in the stem ; but in the Purghers- 

 dorp specimens (PI. Ill, fig. 1) the ridges arc confined to a part of 

 the surface. Although there appear to be no essential differences 

 between the European Triassic species and the African type, we are 

 hardly justified in assuming specific identity. There is no reason 

 to suppose that several species of the genus may not appear to be 

 identical, if represented only by their pith-casts and impressions 

 of a leafiess cortex. 



In the case of mere pith-casts, attempts at accurate determination 

 must be even more tutile. As examples of some of the many 

 specimens bearing a resemblance to those from Purghersdorp, men- 

 tion may be made of Calamites Guembeli ^ figured by Schenk from 

 the Phsetic of Franconia (a species regarded by Prof. jS"athorst " as 

 identical with ScMzoneura hoerensis), and o£ Equisetites arenaceus 

 as figured hy Schcenlein * from the Keuper of Germany. 



The larger cast with broader ribs represented in text-fig. 1 

 (p. 87) may be compared with some of the specimens figured as 

 E. Mougeotii,^ and with a New Mexican fossil which Mr.Fontaine has 

 named E. Knowltoni}'^ A more striking similarity is, however, 

 presented by a tapered pith-cast figured by Mr. Etheridge, Jun.^^ 

 from the Hawkesbury Sandstone of Port Jackson. 



As regards the bearing of these comparisons on the question of 

 geological correlation, Schizoneura Carrerei is a Phaetic species ; but 

 the other specimens to which I have not given a specific designa- 

 tion are of comparatively-little value as indices of age — they favour 

 a reference of the rocks to a Phaetic or to a somewhat lower 

 horizon. 



The fossils from Pasutoland, presented to the South African 

 Museum by Dr. Long, were obtained from a locality beyond Mafeking 



1 Yokoyama (06) pp. 29-30 & pi. vii, fig. 10. 



- Kathorst (07) p. 3 & pi. i, fig. 1. 



3 Newton & Teall (97) p. 504 & pi. xli, figs. 1-3. 



^ Schimper (74) pi. xii ; Schimper & Mougeot (44) pi. xxix. 



^ Heer (76*) pi. xxvii. fig. 10. 



^ Schenk (67) pi. i, figs. 8-10. 



7 Nathorst (78) pp. 24, 25. 



8 Schcenlein & Schenk (65) pi. ii ; Jreger (27) pi. iii. 

 ^ Schimper (74) pi. xii, fig. 4. 



^^ Fontaine & Knowlton (90) p. 283 &, pis. xxiii-xxiv. 

 11 Etheridge (90j pi. xvii. 



I 



