334 STUDIES IN FOSSIL BOTANY 



the plant last described, for the crowded petioles here 

 form a dense envelope round the stem. The stele 

 has a solid cylinder of xylem, as in Botryopteris ; the 

 spiral elements are stated to be at the periphery, but 

 this requires further investigation. The leaf-traces and 

 petiolar bundles have the form of a straight tangential 

 band, described as having the spiral elements at the 

 two ends. The genus is imperfectly known. Small 

 sporangia of the Zygopteris type were found by Renault 

 in association with the plant, but there is no proof of 

 connection. 



The genus Tubicaulis, as now limited, has a re- 

 markable history. Only two specimens referable to it 

 have ever been discovered ; one was found in the 

 Permian of Saxony in 1815, and described by Cotta 

 in 1 8 3 2 ; 1 the other was found by Mr. Lomax a 

 couple of years ago in a roof-nodule in the Lower 

 Coal-measures of Shore, Lancashire, and described by 

 Miss Stopes in 1906. 2 The two specimens are, of 

 course, specifically distinct. The Permian species is 

 T. Solenites, Cotta ; that from the Coal-measures is 

 named T. Sutcliffii, Stopes. Both were large plants ; 

 the specimen of T. Solenites was, when found, a yard 

 long, and from 5 to 8 inches in diameter, most of this 

 thickness being made up of the crowded leaf-bases and 

 petioles, while the fragment representing T. Sutcliffii 

 had a diameter of 2 x 4^ inches. The structure of the 

 stem is excessively simple, the stele having a solid 

 cylindrical strand of xylem, which Miss Stopes believes 



1 Die Dendrolithen in Beziehung auf ihren inneren Bau, p. 21, Taf. ii. 



2 "A New Fern from the Coal-measures: Tubicaulis Sutcliffii, spec, 

 nov.," Mem. and Proc. Manchester Lit. and Phil. Soc. vol. 1. 



