er- 

 The 



478 PAL^OBOTANY. 



vesicular structure; but this I believe to have been produced by the weath 

 ing out of minute globular concretions, probably of calcareous matter. T 

 appearances are rather those of roots or slender herbaceous stems than of 

 Algse. If found in the Coal-measures it would probably be regarded as an 

 obscure Pinnularia. 



2. Buthotrephis radiatm. This shows radiating branchlets or leaves, 

 with the same vesicular structure as the preceding, and having some re- 

 semblance to the whorls of Annularia, though without any midrib. 



It is auite possible that both of the above may belong to the same species. 

 If a land-plant, allied to Annularia, the first may represent the roots or sub- 

 aquatic stems, and the second its whorls of leaves. If an Alga, the first 

 may represent branching fronds, and the latter the fructification. Under the 

 former supposition, they may be compared with Annularia laxa of the 

 Devonian, and the radiating root-like bodies associated with it. (Dawson, 

 ' Report on Devonian Flora.') Under the supposition that the plants are 

 Algre, they may be compared with Spharococcites Schurtzanus of Goeppert, 

 from the Lower Silurian (Etage D.) of Bohemia, though they do not come 

 under the technical definition of Steinberg's genus Sphcerococcitts. 



Fig. 378. Fragment of Eopkytott Linneanum. Lower Cambrian. 



SILURIAN PLANTS. The remains of plants in the Silurian 

 series are few in number and require little consideration. In 



