﻿Vol. 64.] FOSSIL PLANTS FKOM SOUTH AFRICA. 103 



CYCADOPHYTA. 



Genus Pterophyllum. 



Pterophtllum sp., cf. Pt. TiETZii, Schenk. (PI. II, fig. 5.) 



The very incomplete specimen, from the Burghersdorp Beds at 

 Kraai-River Bridge, represented in PI. II, fig. 5 is similar to 

 several species of the genus from Rhsetic rocks in different regions, 

 and it may be compared with some of the Jurassic species as well as 

 with species of Triassic age. The axis, 9 centimetres in length, 

 forms a fairly-prominent ridge, from which are given off at right 

 angles linear segments of unequal breadth : the divisions of the 

 lamina are characterized by numerous parallel veins, apparently not 

 less than nineteen in a breadth of 5 millimetres of lamina. The 

 longest segment reaches a length of 2*2 centimetres ; the greatest 

 breadth at the base is 1*2 centimetres, and the narrowest segment is 

 6 millimetres broad. Owing to the absence of a perfect lamina, it is 

 impossible to describe the form of the distal end. The great number 

 of Pterojjhyllum-froiids in Triassic and Jurassic rocks differing but 

 little one from the other in the relative abundance of the veins 

 and in the form of the segments renders impossible the accurate 

 determination of imperfect specimens. It is, however, interesting 

 to find evidence of the existence in South Africa of this widely- 

 spread genus. In view of the close resemblance of the Burghersdorp 

 specimens to Pteropliyllum Tietzii, first described by Schenk ^ from 

 the Rha?tic of Persia and afterwards recognized by Prof. Zeiller ^ in 

 the Tongking flora, we may speak of them as Pteropliyllum sp. cf . Pt. 

 Tietzii. The similarity of the frond-fragment shown in PI. II, fig. 5 

 to several other species of the genus detracts from the value of this 

 member of the Burghersdorp flora as an index of geological age. 



As examples of other forms of Pterophyllmn resembling the 

 African plant and in some cases probably identical with it, I may 

 mention Pt. longifolium and Pt. Jcegeri ^ of Brongniart, figured by 

 Heer and Leuthardt from the Keuper of Switzerland ; the Tongking 

 species Pt. ineonstans and Pt. Portdli "^ ; Pt. multilineatum from 

 the Ipswich Beds of Queensland and Pt. yerongense from the same 

 locality'^; Pt. (Equate, a species recorded by Prof. JSTathorst from the 

 Rhaetic of Scania, as also by Schenk and Fontaine from the Jurassic 

 of China and Oregon respectively ^ ; specimens from the Rhaetic of 

 Honduras figured by Newberry'^; and a Greenland plant compared by 

 Dr. Hartz with Pt. ineonstans.^ Similar, but not identical, specimens 

 are figured from the Rajmahal Hills of India.^ 



1 Schenk (87) p. 6 & pi. vi, figs. 27-29. ^ Zeiller (02) p. 189 & pi. xlvii. 



^ Heei' (76*) pis. xxx-xxxvi ; Leuthardt (03) vol. xxx, pis. v-vi & x. 

 -^ Zeiller (02) pp. 177, 186 & pis. xliii, xliv, xlvi. 

 ^ Shirley (96) pis. vii & vii rt ; (98) pi. xxii. 



« Nathorst(78) p. 67 & pi. xv, figs. 6-10; Schenk (83) pi. xlviii, fig. 7; 

 Ward (05) pi. xx. 



"^ Newberry (88) pi. viii. 



« Hartz (96) pp. 235-36 & pi. xv, figs. 6, 8, 9. ^ Oldham & Morris (63). 



