152 OSMUNDACEAE [CH. xxi 



adopted in Hooker's Synopsis Filiaiui, it appears best to recognise Lepto- 

 pteris as a sub-genus of Todea, leaving only two substantive living genera in 

 the Family. Neither of these appears decisively the more primitive as 

 regards form or anatomical structure: but the marginal placentation of 

 Osiminda is certainly primitive, while the superficial placentation of Todea 

 and the filmy texture of Leptopteris are both held to be derivative features. 

 The genera may then be placed thus : 



OSMUNDACEAE 



I. Sporangia typically marginal. 



(i) Osmunda (Linnaeus, 1753) ... ... 9 species. 



II. Sporangia typically superficial. 

 (2) Todea (Willdenow, 1802) 



\\. Eu-Todea,^2\^&c, 1868 ... ... i species. 



§ ii. Z^/>/^//'^rz>, Baker, 1868 ... ... 7 species. 



BIBLIOGRAPHY FOR CHAPTER XXI 



406. ElCHWALD. Lethaea Rossica. Vol. i. Stuttgart, i860. 



407. Russow. Vergleichende Untersuchungen. p. 87. 1872. 



408. Bower. Phil. Trans. Pt. ii, p. 565. 1884. 



409. Bower. Quart. Journ. Micr. Sci. Vol. xxv, p. 75. 1885. 



410. Gardiner & Ito. Ann. of Bot. Vol. i, p. 41. 1887. 



411. Raciborski. Engler's Jahrb. Vol. xiii, p. i. 



412. Campbell. Bot. Gaz. Vol. xv, p. i. 1890. 



413. Bower. Ann. of Bot. v. p. 109. 1891. 



414. Zenettl Bot. Zeit. p. 72. 1895. 



415. Zeiller. Bull. Soc. bot. de France, xliv, p. 195. 1897. 



416. Faull. Bot. Gaz. p. 381. 1901. 



417. Engler & Prantl. Natiirl. Pflanzenfam. i. 4. p. 372. 1902. Here the systematic 

 literature is fully quoted. 



418. Jeffrey. Phil. Trans, cxcv, p. 119. 1902. 



419. Seward & Ford. Linn. Trans, vi. p. 250. 1903. 



420. Bower. Origin of a Land Flora, p. 530. 1908, where the literature to date was fully 

 quoted. 



421. Faull. Trans. Can. Inst, viii, p. 515. 1909. 



422. Seward. Fossil Plants, ii, p. 324. 1910. 



423. SiNNOTT. Foliar Gaps in the Osmundaceae. Ann. of Bot. xxiv, p. 107. 1910. 



424. KiDSTON & Gwynne-Vaughan. Fossil Osmundaceae. Trans. Roy. Soc. Edin. No. 

 i, 1907. No. ii, 1908. No. iii, 1909. No. iv, 1910. No. v, 1914. 



425. Gwynne-Vaughan. Ann. of Bot. xxv, p. 525. 191 1. 



426. P. Bertrand. Progressus Rei Bot. iv, p. 189. 1912. 



427. M™^ M. lOSSA. L'appareil conducteur des Osmundace'es et Gleicheniacees. Geneve. 

 1914. 



428. Campbell. Mosses and Ferns. 3rd. Edn. p. 346. 191 8. Here the literature is fully 

 quoted. 



429. ScOTT. Studies in Fossil Botany. 3rd. Edn. Part i, p. 264. 1920. 



430. Bower. Address on Size. Proc. Roy. Soc. Edin. p. i. 1920. 



431. Stopes. Osniundites Kidstoni. Ann. of Bot. xxxv, p. 55. 1921. 



432. POSTHUMUS. Osiini7iditcs Kidstoni. Ann. of Bot. xxxvifi, p. 215. 1924 



