138 



Scientific Proceedings, Royal Dublin Society, 



In Ehacopteris the frond is simply pinnate ; and in R. aspleniies^ (Gutb.) 

 Soliimp., the pinna possesses a midrib, and, but for its more laciniate lamina, 

 shows great likeness to the pinna of Archceopteris Tschermaki. "Were it not for 

 the sporangia in our specimen, I should liave felt compelled to regard the latter 



Fig- 1. 



Fig. 2. 



Fig. 1. — Drawing of the portion of the frond preserved of ArclMopteris Tschermaki, showing the 

 dichotomous venation of the pinnae, the bifurcated raohis at a and b, and the fertile 

 segments at s. 



Fig. 2. — Illustration of a frond of Archaopteiis Tschermaki, Stur (after Stur).. Eeproduced fur 

 comparison with Fig. 1. 



as a Ehacopteris. It is possible that fertile specimens of Ehacopteris may 

 yet be found in the Carboniferous, with fructifications of the Archseopteris 

 type, suggestive of Ophioglossum. 



iH. Potonie: Abbild. u. Beschr. foss. Pflanz., Lief. 1. 1903, fig. 1. 



