The Present Position of Palaeozoic Botany. 181 



sporangium. The form of the fertile frond is well sliOAvn in a spe- 

 cimen of Zijijopteris pinnata from Commentry; the leaflets of the 

 vegetative form are here undeveloped, and their place is taken by 

 tufts of sporangia (Fig. 13). The indications of heterospory. which 

 E e n a u 1 1 believed he had detected both in Botryopteris and Zygopteris, 

 have not proved to hold good. 



The genus Corynepicris of B a i 1 y appears, on present evidence, to 

 be referable to the Botryopterideae ; the specimens at present known 

 are preserved as impressions, and thus exhibit the external form, 

 which is otherwise only known in the case of Zygopteris pinnata. 

 Several species have been described from the Coal-Measures, some 

 with a Pecopteroid, others with a Sphenopteroid habit. The fructi- 

 fications, which are borne on the ordinary fronds, consists of spor- 

 angia grouped in circular sori, recalling the synangia of certain 

 Marattiaceae, but each sporangium has a multiseriate annulus closely 

 resembling that of Zygopteris. In this connection it may be pointed 

 out that the genus BiplolaUs of Kenault, from the Lower and Upper 

 Carboniferous of France, which in the structure of the petiole has 

 something in common with Zygopteris, appears to have had a synangic 

 form of fructification, though in this case the sporangia are without 

 an evident annulus (Renault, 1896, p. 11). 



Other genera which may be referred to the Botryopterideae are : 

 Anachoropteris (Carboniferous and Permian) with a stem -structure 

 almost identical with that of Zygopteris but differing in the structure 

 of the petiolar bundle, which forms a strongly incurved arc, concave 

 towards the stem; Aster ocJitaena (ranging from Upper Devonian to 

 Permian) with a deeply lobed stele, exaggerating the stellate form 

 found in Anachoropteris and Zygopteris, and lanceolate petiolar bundles, 

 which may be concave or convex towards the stem, according to the 

 species; Tubicaulis, with a simple solid stele ^), comparable to that 

 of Botryopteris, and arc-shaped petiolar bundles, convex towards the 

 stem. A new species of this genus, T. SutcUfßi, S top es, from the 

 Lower Coal-Measures of Lancashire, has just been described by 

 Miss Stop es-); the only species previously known was of Permian age. 



The new genus, Botrycliioxylon, not yet fully described^), may be 

 mentioned, on account of its interesting anatomical structure. The 

 specimens in this case also are from the Lower Coal-Measures of 



^) I once thought that the Rachiopteris corrugata of Williamson, wich I now 

 have good grounds for referring to Zyyopteris, might he a Tubicaulis (Scott, 1900, 

 p. 296). The solid wood of the latter genus, a character not clearly recognized at 

 the time, is alone sufficient to exclude the species in question. 



^) A new Fern from the Coal-Measures: Tubicaulis SutcUffii, spec. nov. Mem. 

 and Proc. Manchester Lit. & Phil. Soc, Vol. 50, Pt. Ill, June 29, 1906. 



') Shortly referred to in Journal of R. Microscopical Society, August 1906. 



