BY K. ETHERIDGE, JUN. 241 



Gangainopteris obliqica on the other, but Feistinantel has figured 

 some forms of Glossopteris, such as G. tceniopteroides,* G. inter- 

 mittens,^ in which the mid-rib seems to be dissolved into a series of 

 parallel veins ; whilst in his Gangamopteris ClarkeiX there is an 

 entire absence of the cross reticulating veinlets of the typical mid- 

 rib of that genus. Neither will the non-auriculate base of the 

 fronds in Gangamopterisi wholly stand good as a differential 

 character, for Feistmantel says that in Gangamopteris cyclopteroides, 

 var. sabauriculala,'^ the base is partially auriculate. The same 

 observer also figures another transitional form in his Glossopteris 

 decipiens,\\ from the Lower Gondwana formation, wherein the 

 secondary veins occupying the top portion of the frond closely 

 resemble those in a similar position on the leaves of Gangamo2)teris. 



It is, therefore, questionable how far the two genera, except in 

 extreme species, can be separated. At the same time, it cannot be 

 denied that on a casual glance the two genera have a very 

 different appearance, and it will perhaps be better to regard the 

 points of difterentiatiou as those of a broad general, rather than of 

 a minutely morphological nature. This view does not, of course, 

 take into consideration the habit of growth, which may ultimately 

 prove to be of a widely different character. 



6. Relation of Glossopteris to Sagenopteris. 



According to Schenk,^ in Sagenopteris, Presl., the frond consists 

 of four hardly petiolate leaflets, carried on a cylindrical stem, 

 whilst later the same Author** says these are arranged in two pairs. 



* Mem. Geol. Survey N.S. Wales, Pal. Series, No. 3, 1890, p. 128, t. 18, f. 1. 



+ Pal. Indica (Gondwana Flora), 1881, Hi. Pt. 3, p. 99, t. 33a, f. 2-4. 



J Mem. Geol. Survey N.S. Wales, Pal. Series, No. 3, 1890, p. 123, t. 20, f. 3. 



§ Pal. Indica (Gondwana Flora), 1879, Hi. Pt. 1, p. 13, t. 15, f. 1 and 3. 



II Pal. Indica (Gondwana Flora), 1879, in. Pt. 1, p. 17, t. 18, f. 3, 4, 5. 



H Fo^. Flora Grenzsch. Keupers-Lias Frankens, 1867, p. 59. 

 **ZittersPaleontologie(Fr. trans.), Pt. ii.— Paleophytologie, Pt. 1, 1891, 

 p. 150. 



