ONYCHIOPSIS. 47 
become Onychiopsis Mantelli; this change being a necessary con- 
sequence of the discovery by Yokoyama of fertile pinne in 
Onychiopsis elongata (Geyl.), a Japanese plant very closely allied to 
the Western O. Mantelli. Previous to Yokoyama’s important paper 
in the Journal of the Imperial University of Japan, in which the 
generic name Onychiopsis is first proposed, a very similar fern 
with fertile segments had been figured by Velenovsky, from the 
Cenomanian beds of Bohemia, under the name Zhyrsopteris 
capsulifera;’ these species, as Nathorst remarks, must also pass 
into the newer genus. These discoveries of such characteristic 
Onychium-like fructifications enable us to include under Yoko- 
yama’s genus a group of plants previously referred to Sphenopteris, 
Thyrsopteris, Dicksonia, etc., and, at the same time, afford valuable 
evidence as to the existence of an Onychium type of fern in Upper 
Mesozoic times in England, North Germany, Bohemia, Japan, and 
several other districts. 
Finally, the same species has recently been recorded by 
Engelhardt from the Cenomanian of Niederschéna; unfortunately 
no figures accompany the description. 
As Zeiller* has pointed out, this discovery of a Wealden fern 
in rocks referred to a higher horizon in the Cretaceous system is of 
considerable interest. 
In the diagnosis of the species reference has been made to the 
characters of the fertile pinne, which will be more fully dealt with 
in the descriptions of such examples as occur in the collections 
(V. 1069, V. 2151, V. 2159, V. 2159). Having found the fertile 
specimens of this well-known species I endeavoured to determine 
what genus of recent ferns might best be taken as the nearest 
living representative; the two genera Onychium, Kaulf., and 
Cryptogramme, R. Br., appeared to come nearest to the fossil 
forms, but of the two the former showed a more intimate re- 
semblance. 
No distinct traces of sporangia have been detected in the fossil 
species, and the comparison between Onychium and Onychiopsis 
Mantelli is, therefore, based on the general habit of the fertile 
fronds and the form of the sporangiferous pinnules, Whilst still in 
doubt as to how far the evidence at command warranted a change 
1 Velenovsky, Joc. cit. pl. i. figs 6-12. 
? Ann. géol. vol. viii. 1892-93, p. 893. 
