20 Stopes, a New Fern from the Coal Measures. 



while to Count Solms-Laubach I am indebted for the 

 gratification of seeing a microscopic section shewing 

 several of its petioles. From the examination of these 

 specimens, as well as from the facts stated in Stenzel's 

 description, I gather that though they are so alike, there 

 is enough difference between them to indicate that the 

 plants are specifically distinct. 



As has been already stated, the preservation of 

 Tubicaulis Sutcliffii is not propitious, and that of T. Sole- 

 nites is also rather unsatisfactory, but in a totally different 

 way, so that minute comparison of the two plants is very 

 difficult. The tissues agree in a general way, and in the 

 shape of the meristele and axis, and the size of the 

 tracheides, the agreement is exact. T. Soletiites evidently 

 had pitted tracheides like those of T. Sutcliffii, though 

 I did not see them in the sections. Stenzel describes- 

 them (p. 7) as having about four rows of short cross-pits, 

 though he had no very satisfactory longitudinal sections 

 to deal with. The differences between the two plants,, 

 which taken together appear to warrant specific separation, 

 are the following : — The relative differences in the sizes 

 of petioles and axes, T. Solenites with a main stele 6 mm. 

 in diameter, has smaller petioles than T. Sutcliffii with a 

 main stele 2 mm. in diameter. The petioles of T. Solenites 

 seem to have branched much earlier than those of 

 T. Siitcliff'ii (see Stenzel, //. i, figs. 2 — 8), giving off 

 many pinnules very close to the main axis ; this was 

 pointed out by Stenzel as a peculiarity of this fossil plant, 

 and unlike recent ferns. The phyllotaxy in T. Solenites 

 is stated to be '^ and \\, while that of T. Sutcliffii is |. 

 Further there is a considerable difference of horizon and 

 locality, which presupposes a difference of species, as but 

 few organisms run absolutely unchanged from the Lower 

 Coal Measures to the Middle Permian. 



