MESOZOIC PLANTS FROM KOREA. 31 



carpa, Tympanopora racemosa and T. simplex from Yorkshire, 

 DicJcsonia clavipes, T/iyrosopieris 3Iiirrayana, T. Maahiana from 

 Siberia and Dlcksonia {Eudichsonia) Heerii, D. Zarecznyi from 

 Cracow. What are known under these different names have 

 subsequently been proved to be simple modifications of the fertile 

 segments of Coniopteris hymenophylloides, and the presence of a 

 gradual transition in these fertile pinnae from forms with a few 

 broad and round lobes to those with narrow, deeply dissected 

 segments, has been traced by Seward in materials found at 

 Scarborough. 



Nathorst united Dlcksonia clavipes Heer, from Kaja in 

 Siberia, with Sphenopteris nephrocarpa Bunbury ; then, Prof. 

 YoKOYAMA described a fertile pinna from Japan of precisely 

 similar nature as Dichsonia nephrocarpa. Sphenopteris {Hymeno- 

 phyllites) Bunbiirianus^^ from India is also no doubt a close ally, 

 if not identical. 



One of the fructified examples from Korea, being quite 

 similar to Sphenopteris nephrocarpa figured by Bunbury from the 

 Yorkshire Jurassic, is a bipinnatified fragment with an almost 

 straight and slender rachis about 2.5 cm., and alternate pinnae 

 (4 on one side) attached to the rachis at a wide angle. The 

 pinnae are but slightly flexuous and are furnished with alternate 

 pinnules. A round sorus is on the dilated margin of each pinnule 

 or lobe, which is contracted below and at the end of the vein. 



In an other example, the lamina of the segments is much 

 more reduced ; each pinnule has usually a single cup-shaj^ed (?) 

 sorus ; some of the lower portion however have the lamina less 

 reduced and bear 2 or more sori. 



1) Oldham and Mokris : Pal. Indica, pi. XXXII., p. 54. Heer took it to be Thyrso- 

 •pteris Maahiana; and Seward referred it with some doubt to Coniopteris hymenophylloides. 



