GENERAL LIFE-SYSTEM OF THE SILURIAN AGE. 



303 



Fig. 295. Fig. 296. 



Figs. 291-296.— Silurian Plants (after Hall): 291. Sphenothallns angustifolius. 292. Buthotrephis 

 snccnlens. 293 and 294. Buthotrephis gracilis. 295. Arthrophycus Harlani. 296. Cruziana 

 bilobata. 



