xxi] 



CYATHEACEAE 



369 



mens of fronds which afford no evidence as to the nature of the 

 sori or sporangia. Some of the fronds referred by this author 

 to Thyrsopteris rarinervis'^, which I examined in the Washington 

 Museum, are in all probability examples of Onychiopsis, a, genus 

 included in the Polypodiaceae. The fragments described by 

 Lester Ward^ as species of Thyrsopteris from the Lower 

 Cretaceous of the Black Hills of North America afford no 



Fig. 272. Coniopteris hijmeiiophylloides. Specimen from the Inferior Oolite, 

 Scarborough; in the York Museum. [M.S.] 



satisfactory evidence of relationship to the recent type. Similarly 

 Velenovsky has described a Lower Cretaceous Onychiopsis from 

 Bohemia^ as a .species of Thyrsopteris, although the fertile 

 segments bear little or no resemblance to those of the Cyathe- 

 aceous genus. Some fertile portions of fronds described by 

 Heer* as Asplenium Johnstrupi and afterwards as Dicksonia 



• Fontaine (89) p. 123, Pis. xxvi. xliii. etc. - Ward (99) P!. clxi. 

 3 Velenovsky (88). -* Heer (75) A. PI. i. figs. 6, 7. 



