222 Proceedings of the Royal Physical Society. 



Fig. 2. 



Portion of hydroclade 

 of Selaginopsis ha/rtlaubi, 

 showing positions of three 

 (out of four) rows of 

 hydrothecas. x 25. 



Fig. I. 



Colony of Sihii/inn/isis h.arllauld, 

 slightly under nat. size. 



