374 Palaeontoloffie. 



fe' 



the Osmimdaceae to be "directly descended frora an ancestral stock 

 from which at least two other types of structure also arose — that 

 of Botryopteris and that of Zygopteris.'''' M. C. Stopes. 



Kidston, R. and D. T. Gwynne-Vaughan. On the Fossil Osmim- 

 daceae. Part III. (Trans. Roy. Soc. Edinburgh. XL VI. 3. 23. p. 



651—665. pl. 1—8. 1909.) 



This paper contains a redescription, and illustrationsof the genera 

 Tham^iopteris , Bathyoptevis and Anoniorrhoea, from the internal 

 anatomy of the stems and petioles. 



Thamtiopteris Schlechte) idalii, Eichwald, sp. with its leaf bases, 

 was more than 12 cm. in diameter, with a central stele 13 mm. wide. 

 The authors consider that when living the xylem of the stele was 

 quite solid. Among the tracheids there is no soft tissue. The leaf 

 traces depart like those of Zalesskya gracüis. The xylem Strands of 

 the roots are inserted on the leaf traces. 



Bathyoptevis rhomhoidea Kutorga sp. The fossil consists of lear 

 bases and some of the cortex of the axis. The petiole bases are 

 unique among the Osmiindaceae in being entirely devoid of any 

 stipular expansions. The petioles are loosely arranged, and the peri- 

 pher}'' beset by emergences. Diarch, and also triarch roots run in 

 the Spaces between the petioles. 



Anomorrhoea Fisheri Eichwald. The specimen consists of petiole 

 bases, with small fragments of the outer cortex. The sclerotic ring 

 of the petiole is well developed, and there are small stipular wings. 

 The roots are all diarch. In the general conclusions, the authors 

 place Thamnopteris in a position of special importance. It confirms 

 the suggestions made after a study of Zalesskya, and proves that 

 the central Clements of the xylem are really tracheal in nature. The 

 authors consider the possible line along which the Osmimdaceae 

 and the Zygopterideae may have evolved in a parallel manner from 

 a solid-steled ancestor and they are prepared for the discovery of 

 a solid-steled Zygopteris, as a link in the series. The mesarch struc- 

 ture of the petiole near the stem, which is frequent in Zalesskya, 

 and constant in Thamnopteris, is taken to be a clue to the phylogeny 

 of leaf trace Strands. M. C. Stopes. 



Scott, D. H. Studies in fossil Botany. IL Spermophyta. (p. 

 355—676. with Figs. 129—213 and Frontispiece. A. and C. Black. 



1909.) 



This second volume of the second edition deals with seed-bearing 

 plants and contains 84 figures of which 36 are not found in the 

 first edition. Chapter X, the first of this volume, is concerned with 

 the Lyginodendreae. An account is given of Lagenostoma Lomaxi. 

 A brief notice of Physostoma is added. A concise account, founded 

 on Miss B e n s o n ' s and K i d s t o n ' s work , is given of the microsporangia 

 of the genus. The treating of the afifinities of the Lyginodendreae 

 has been largely rewritten. It is thought that Williamson's Cono- 

 stoma may have belonged to Heterangiiim, and that Renaul t's 

 Permo-Carboniferous Gnetopsis elüptica is more probably allied to 

 the Lyginodendreae than, as thought by Renault, to the Gnetaceae. 

 In the foUowing chapter the most important additions include the 

 interesting Observation that in the Medullosae the departing traces 

 leave no gap in the steles; the probabilitj^ that the frond of Cc>//)ox>7o« 



