B Annals of the South African Museum. 



afterwards described and illustrated more fully by Yokoyama as 

 Onychiopsis clongata, is spoken of by the latter author as the chief 

 characteristic fossil of the Japanese Flora of Kaga, Hida, and 

 Echizen, which is referred to the Bathonian stage of the Inferior 

 Oolite. Fragments of the same type are figured by Yokoyama, 

 also from the plant-beds of Kozuke, Kii, Awa, and Tosa referred 

 to the Neocomian series.* The Japanese type differs from the 

 European Onychiopsis mantelli in its slightly broader segments, 

 but the difference is hardly enough to warrant a specific separation. 

 The fact that both forms possessed the same type of fertile pinnae 

 demonstrates their close relationship, and such small differences 

 as are exhibited by the sterile fronds are not greater than analogous 

 variations met with in species of existing ferns. 



The specimens figured by Nathorst f from the province of Tosa, in 

 Japan, are undoubtedly specifically identical with Geyler's species,. 

 and I believe also with the XJitenhage plant. 



Eeference is made in the synonomy to the figures of Onychiopsis 

 mantelli, published by Schenk and other authors from European 

 Wealden rocks ; it is unnecessary therefore to do more than draw 

 attention to the abundance of this well-marked type in Wealden 

 floras. The same species is recorded also by Fontaine % and Ward § 

 from the Potomac formation of North America ; some of the ferns 

 referred by the former author to Tliyrsopteris, without a fragment 

 of a fertile pinna to justify the assumed relationship with the recent 

 genus of Cyatheaceee, are in all probability identical with Onychiopsis 

 mantelli. We may quote Thyrsopteris rarinervis, T. insignis, T. 

 microp)hylla as examples of Fontaine's species which bear a close 

 resemblance to Onychiopsis mantelli.\\ A fern described by Heer 

 as Asplenium dichsonianum H from the Kome beds of Greenland, if 

 not identical with the XJitenhage species, is probably a closely allied 

 type. In the late Marquis of Saporta's monograph on the Mesozoic 

 Floras of Portugal,-''-'' Onychiopsis mantelli is recorded from several 

 localities as Sphenoptcris (Davallia) mantelli, but the evidence on 

 which a relationship to Davallia is founded seems to me inadequate ; 

 Saporta speaks of the species as a characteristic Wealden fern, but 

 fragments found in somewhat older beds point to the existence of 



* Yokoyama (94), p. 215, pi. xx., xxi. 



t Nathorst (90), pi. ii., tig. G ; pi. v., fig. 3 ; pi. vi., tig. 5. 



+ Fontaine (89), pi. i. § Ward (9.5), p. 392; (90), p. 483. 



II Fontaine (89), pi. xlii., xliii., xliv., xlv. 



ir Heer (75'), pi. i., tigs. 1-5. 



** Saporta (94), pi. xiii., xxiii., xxviii.-xxxi. 



