258 LOXSOMACEAE [CH. 



a radiate type: for this character it would be necessary to look back among 

 marginal types to the tasselled sorus of Zygopteris, or of Corynepteris or of 

 Osniunda. But these are without indusial protection. It is the absence of 

 any direct or distinctive indication of affinity downwards that points the 

 family out as generalised. But the nearest affinity upwards is clearly with 

 the Dicksonioid series, and in particular with Thyrsopteris. 



BIBLIOGRAPHY FOR CHAPTER XXVIII 



516. Hooker & Bauer. Genera Filicum. Tab. xv. 1842. 



517. Bower. Phil. Trans. Vol. 192, p. 47, 1899. Also Land Flora, p. 571, 1908. 



518. Gwynne-Vaughan. Ann. of Bot. Vol. xv, p. 71, 1901. 



519. DiELS. In Engler u. Prantl, Naturl. Pflanzenfam. p. 112, 1902. 



520. Christ. Bull, de THerb. Boissier. 2me Sdrie, iv, p. 393, 1904. 



521. Slosson. Bull. Toney Club. Vol. xxxix, p. 285, PI. xxiii, 1904. 



522. Von Goebel. Archegoniatenstudien. xiv, Flora. Bd. 105, p. ■>)},, 191 2. 



523. Bower. Ann. of Bot. Vol. xxvii, p. 463, PI. xxxiv, 1913. 



524. Thompson, J. M'^L. Trans. Roy. Soc. Edin. Vol. Hi, p. 715, 1920. 



525. Bower. Ann. of Bot. Vol. xxxvii, p. 349, 1923. 



APPENDIX TO THE LOXSOMACEAE 



StacJiypteris 

 An important Jurassic fossil, probably of this affinity, has recently been 

 brought again into notice by Halle, and by H. H. Thomas. The 

 StacJiypteris was founded by Pomel in 1847, and figured 

 by Saporta {Pal. Franc. II, Vol. i, p. 49, 1873). Pomel 

 compared the spikes that are borne on the margins of 

 its Sphenopterid type of leaf with those of Lygodiuvi. 

 Additional material was found by Halle in 19 10 at 

 Whitby, and again by H. H. Thomas in 191 2 near 

 Saltburn. The leaf is 2 to 4 pinnate, and the pinnae of 

 the second order bear pinnules sometimes terminated 

 by a fertile spike. There are indications that the spike 

 was of the type of Lygodiuui, but the existence of an 

 indusium for each sporangium is uncertain. The 

 sporangia were arranged in 2 or 3 rows, each with a 

 slightly oblique or vertical annulus, which is certainly 

 not of a Schizaeaceous type. The spores were rounded 

 or tetrahedral (Fig. 526). The result of these observa- 

 tions, though not decisive, opens interesting suggestions. ^ 'S: 526. A somewhat 

 ° . o 00 diagrammatic drawing 



Thomas concludes that StacJiypteris does not possess of the marginal sorus 



close affinities with any modern group of Ferns, but fJ^^^'^-i(^'{i%\^omL 



suggests a position intermediate between the Schizaea- Enlarged.) 



ceae and the "Cyatheaceae" — doubtless using the latter, in the sense of the 



