NEW SPECIES OF PERMIAN OSMUNDACEA, 347 
On New Species of Permian Osmundaceæ. By M. D. ZALESSKY. 
(Communicated by Prof. A. C. Sewarp, F.R.S., F.L.S., Pres.G.S.) 
(PLATES 32-34.) 
[Read 29th November, 1923. 
Berore describing the new species of Osmundacee found in the Permian 
rocks of the Ural Mountains, I shall begin with an account of the stele of 
Bathypteris rhomboidalis which I discovered in a specimen belonging to the 
University of Kazan sent to me for study by the late Prof. Krotov. 
The stele of this fern was not previously known because a specimen which 
was described by Dr. Kidston and the late Prof. Gwynne-Vaughan, and was 
formerly in the hands of Kutorga and Eichwald, shows only the outer part 
of the stem which is covered by crowded petioles. In spite of the bad 
preservation of the stele in the Kazan specimen, the tissue of which is for the 
most part in a much worse state of preservation than in the Petrograd speci- 
men, I have been able to make out the salient structural features. Although 
the diameter of the Kazan specimen reaches 95 mm. its stele is only 6°5 mm. 
in diameter. ‘The stele consists of two kinds of xylem elements, narrower 
tracheids at the periphery, and wider elements in the centre ; both kinds of 
xylem elements have transversely elongated pits like those in the tracheids 
of Zalesskya and T'hamnopteris. It is unfortunate that the. stele is rather 
crushed and broken by radial cracks into a series of cuneiform portions which 
become narrower towards the centre; the clements are much compressed 
tangentially (Pl. 33. fig. 6). Between these deformed cuneiform pieces of 
xylem one sees the tracheids of the inner xylem which occupy the remainder 
of the stele. The phloem is preserved in some places as a brown tissue 
abutting on the xylem. Its structure is difficult to determine. The xylem 
bundles of the leaf-trace, as seen in this region, are oval in outline (Pl. 33. 
fig. 7). The protoxylem elements are found on the adaxial side of the 
bundle. Occasionally at the periphery of the vascular cylinder one sees the 
vascular bundles of roots passing out at a wide angle. The inner cortex, 
preserved in some places, consists of parenchymatous cells, sometimes 
elongated and with more or less sinuous cell-walls. The inner cortex, in 
which cavities occur marking the position of leaf-traces, is crossed in all 
directions by roots, oblique and longitudinal sections of which are met with 
in the middle of this tissue. 
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LINN. JOURN.— BOTANY, VOL, XLVI. 
