xv] 



LEPIDOSTROBUS 



183 



and those of the recent genus Lycopodium is the greater radial 

 elongation of the sporangia in the former. Some species of 

 Lepidostrobus may have been homosporous ; some are known to 



Fio. 188. Lepidostrobus. Middle Coal-Meaaures, Bardsley, Lancashire. From 

 a Bpecimen in the Manchester Museum. (J nat. size.) 



be heterosporous. In the latter the megasporangia borne on 

 the lower sporophylls usually contain several megaspores as in 



