ONYCHIOPSIS. 41 



recent genera OnycTiium and Gymnogramme, especially of the 

 former. The original diagnosis of the genus Onychiopsis, with 

 reference to a single species, 0. elongata, is as follows 1 : 



" Fertile segments different from the sterile. Sori terminal, 

 linear, on each side of the midrib, parallel, with the margin, 

 involucrate; the involucrum of each side confluent over the 

 midrib." 



So far as I have been able to discover, this is the first record 

 of Onychium among fossil ferns. According to the " Synopsis 

 Filicum," 2 the genus occurs at the present time in Northern 

 India, China, Japan, Java, Persia, Abyssinia, and Malayan Pen- 

 insula and Islands, etc. 



The more detailed examination of the points of agreement 

 between the fossil species and the living genus will be attempted 

 in the description of the two species Onychiopsis elongata (Geyl.) 

 and 0. Mantelli (Brong.). 



1. Onychiopsis Mantelli (Brongniart). 



1824. Hymenopteris psilotoides, Stokes and "Webb, Trans. Geol. Soc. ser. ii. 



vol. i. p. 423, pi. xlvi. fig. 7. 



1825. Hymenopteris psilotoides, Sternberg, Flor. Vorwelt. iv. p. xxii. 



1827. Hymenopteris psilotoides, Mantell, Illust. Geol. Sussex, p. 55, pi. i. 



30 and 3b ; pi. iii. fig. 6 ? and 7 ; pi. iii.* fig. 2. 



1828. Sphenopteris Mantelli, Brongniart, Prodrome, p. 50. 

 Sphenopteris Mantelli, Brongniart, Hist. veg. foss. p. 170, pi. xlv. 



figs. 3-7. 



1833. Sphenopteris Mantelli, Mantell, Geol. S.E. England, p. 241. 

 1833. ? Sphenopteris Sillimani, Mantell, Geol. S.E. England, p. 239. 

 1836. Cheilanthites Mantelli, Goppert, Foss. Farnkrt. p. 231, Nova Acta 



Ac. Caes. Leop.-Car. vol. xvii. Supp. 



1838. Sphenopteris Mantelli, Sternberg, Flor. Vorwelt. vii. p. 56. 



1839. Cheilanthites denticulatus, Roemer, Yerstein. Ool.-Geb. p. 9, pi. xvii. 



fig. 1. 

 1843. Cheilanthes (Sphenopteris) Mantelli, Bunker, Progr. p. 5. 



1845. Sphenopteris Mantelli, linger, Syn. plant, foss. p. 59. 



1846. Sphenopteris Mantelli, Dunker, Wealdenbildung, p. 2, pi. i. fig. 4a. 

 1846. Sphenopteris Romeri, Dunker, loc. cit. p. 3, pi. i. figs. 3, 4 and 5. 

 1846. Sphenopteris tenera, Dunker, loc. cit. pi. viii. fig. 5. 



1846. Confervitesjissus, Dunker, loc. cit. pi. i. fig. 1. 



1848. Sphenopteris Mantelli, Bronn, Index Pal. Nomencl, p. 1169. 



1 Yokoyama, loc. cit. p. 26. 



2 Hooker and Baker, p. 143. 



