22 StopeS, a Neiv Fern f rout the Coal Measures. 



A. krigisica the meristele is apparently unbent, while in 

 A. laxa and A. raviosa the concave side is toward the 

 main axis in the normal manner of ferns. In all cases 

 the main axis is surrounded by a mass of petioles which 

 come off in rapid succession, enlarging somewhat as they 

 get further from it, but they never, grow to so great a size 

 as to exceed the main axis, a character which seems to 

 belong to Tiibicaiilis alone. 



Another group which may also be near these plants 

 is the AnacJio7'opteris series, in which the meristele is a 

 single horseshoe shaped curve. Unfortunately the main 

 axis is only known in one species, A. Decaisnii ; this was 

 described by Renault ('69) as being very like Zygopieris, 

 that is, with a single five-rayed stele with the central 

 vascular elements of smaller size than the rest and mixed 

 with parenchyma. The meristele first comes off from this 

 in the form of an elipse of hollow wood (see Renault, 

 plate 10, fig. 4), which soon becomes an open curve. 

 A. rotunda ta and A. pulclira have similar meristeles, 

 which though detached are described by Corda ('67, 

 p. 86-7) as being disposed with the concave side away 

 from the main axis ; this he gathered from the shape of 

 the petiole cortex which seems to indicate the fact. It 

 this is correct, then AnacJioropteris is like Tubicaulis in 

 this unusual feature as well as in the form of its meristele, 

 though the latter is slightly more incurved and compli- 

 cated in Anachoropteris than in Tubicaulis where it is 

 absolutely simple. 



All these plants belong to the large family of 

 Botryopterideae, and within this group, somewhere near 

 the base of the series among its simpler members, it will 

 be safe to place Tubicaulis, near to Graniviatopteris and 

 AsterocJdaena. The sporangia associated with Tubicaulis 

 in no way militate against this view. To go into further 



