14 Annals of the South African Museum. 



Plate II., tig. 6 (361c). 



A portion of a pinna, slightly enlarged, from a lower part of a 

 frond than the pinnule outlined in fig. ^h. 



Other Specimens : 339c, 340c, 349c, 350c, 351c, 358c, 359c, 363c, 

 366c, 369c, 373c. 



Cladophlebis denticulata (Brongn.), forma athekstonei. 



Plate VI., figs. 16, 17. 



1867. Pecoptcris Athcrstonei Tate, Quart. Journ. Geol. Soc, vol. xxiii.,, 



p. 145, pi. v., figs. 2a, 26. 

 1867. P. liiihidgei, ibid., p. 146, pi. v., figs, la, lb. 

 1867. P. africana, ibid., p. 146, pi. vi., figs, la, lb. 



Frond bipinnate, rachis broad, giving off pinnae at a wide angle ; 

 the branches or pinnse bear crowded linear pinnules attached by the 

 whole of the broad base to the comparatively broad axis ; the linear 

 pinnules reach a length of slightly over 3 cm., apices bluntly 

 pointed ; midrib strong, giving off secondary veins at a wide angle, 

 which branch dichotomously as they pass obliquely upwards to the 

 edge of the lamina. Fertile pinnules unknown in the South African 

 form. 



The most abundant plant in the material collected two miles east 

 of Herbertsdale is a fern characterised by linear pinnules of the 

 Cladophlebis type, which, owing in part to the friable nature of the 

 rock, is seldom preserved except in small broken pieces of pinnae. 

 Fragments of Tceniopteris fronds (pi. ii., fig. 5) are constantly found 

 in association with this form of Cladophlebis. The piece represented 

 in fig. 16, pi. vi., shows the venation very clearly preserved, and 

 with fig. 17 illustrates the form of the pinnules. There can be no 

 doubt that this fern is the one named by Tate Pecopteris athcrstonei ; 

 an examination of Tate's type-specimens leads me to regard the 

 smaller form named by this author Pecopteris rubidgei as a frag- 

 ment of the same species. In all probability we may safely include 

 Tate's name P. africana as another synonym under P. athcrstonei. 

 No trace of sori or fertile pinnae has been found, and we must thex-e- 

 fore be content to leave the plant as a member of the Filices of 

 uncertain family position. As regards the question of nomenclature : 

 there is no more common type of fern frond among recent genera 

 than that of the bipinnate leaf with hncar pinnules, attached by the 



