154 SPHENOPIERIS. 



S. Sphenopteris Williamsoni, Brongniart. 



[Hist. y6g. foss. p. 177, pi. xlix. figs. 6-8, 1828.] 

 (PL XVII. Figs. 1 and 2.) 



1828. Sphenopteris WiUimnsonis, Brongniart, Hist. veg. foss. p. 177, pi. xlix.. 



figs. 6-8. 

 ? S. denticulata, ibid. pi. Ivi. fig. 1 . 

 S. WilUamsonis, Brongniart, Prodrome, p. 50. 



1829. SpJienopteris digitata, Phillips, Geol. Yorks. p. 147, pi. viii. fig. 6. 

 1834. Sphenopteris WilUamsonis, Lindley & Hutton, Foss. Flor. pi. cxxxi, 

 1836. Hymenophyllites WilUamsonis, Groppert, Foss. Farm. p. 259. 

 1838. Mhodea WilUamsonis, Sternberg, Flor. Vorwelt, faso. vii. p. 110. 



1848. Symenophyllites WilUamsonis, Bronn, Ind. Pal. p. 602. 



1849. Sphenopteris WilUamsonis, Brongniart, Tableau, p. 105. 



1850. Hymenophyllites WiUimnsonis, TJnger, Gen. spec. foss. p. 130. 

 1854. Hymenophyllites WilUamsonis, Morris, Brit. Foss. p. 10. 



1856. Hymenophyllites WilUamsonis, Ziguo, Flor. foss. Oolit. vol. i. p. 89. 

 1864. Hymenophyllites WilUamsonis, Leckenby, Quart. Journ. Geol. Soc. 



vol. XX. p. 76. 

 1869. Sphenopteris [Hymenophyllites) WilUamsonis, Scbimper, Trait. paU 



veg. vol. i. p. 410. 

 1875. Sphenopteris WilUamsonis, Phillips, Geol. Yorks. p. 217, pi. viii. fig. 6. 

 1892. Sphenopteris WilUamsonis, Fox-Strangways, Tab. Foss. p. 135. 



Type-specimen. Brongniart's types in the Paris Museum (?). 

 Type ol Lindley & Hutton in the Scarborough. Museum. 



Frond ? tripinnate ; the rachis slender and winged, bearing short 

 acuminate pinnae attached at an acute angle ; the pinnules are 

 deeply dissected into narrow linear and forked ultimate segments. 



There is not sufficient reason for following the example of some 

 authors and using the generic name Hymenophyllites for this species ; 

 we know nothing as to the character of the sori or sporangia. 



39,281. PI. XVII. Fig. 2. 



The drawing represents a portion of a pinna 7 cm. long, bearing 

 deeply dissected pinnules with narrow ultimate segments. The 

 finer segments are traversed by a single vein, and the general 

 appearance of the specimen suggests a fern with a thin or almost- 

 filmy texture ; this thin brown filmy appearance is misleading and 

 need not necessarily point to an originally thin lamina. There is- 



