EOCENE FERNS. 31 



pronounces a decided opinion that they belong to the division of Polypodium with 

 reticulate venation, and does not think that they should be generically separated unless 

 as Poli/podites. Hooker, Carruthers, and others see no reason to create a new genus for 

 their reception. The correctness of our determination of these as Ferns may, we think, 

 be considered as beyond reasonable doubt. 



No fossil Poll/podia with reticulate venation resembling these had hitherto been 

 described. 



Glossochlamys, Eit. 



Filices herhaceee^fronde simpKci, Integra. Nervatio Drynaria irregularis. 



Glossochlamys transmutans. EU. and Gard. Plate III, fig. 3. 



G. fronde suhmembranacea, petiolata, lanceolata, utrincpie angustata, apice longe- 

 acuminata, margine integerrima ; nervatione Drgnaria irregularis, nervo primario rhachi- 

 dromo, recto , prominente, apicem versics sensim attcnuato ; nervis secundariis promine?itibus 

 can^ptodromis adscendentibus, med'iis sub angulis 40 — 50°, reliquis sub angulis aeutioribus 

 orientibus ; nervis tertiariis catadromis ; latere externo angulo subrecto, latere interno 

 vlerumque angulis variis egredientibus ; segmentis tertiariis vix distinctis, inaqualibus, 

 irregularibus, polygonatis ; maculis appendices plerumque liberos includentibus. 



Middle Bagshot, Boiu-nemouth. 



The texture of this frond was membranous. The apex is very elongated and narrow. 

 The venation is somewhat like that met with in certain species of Polypodium, as, for 

 example, Pliymatodes heniionitideum and P. transparens, and in some species of Aspidium, 

 as J. trifoliatum, A. macropJiyllum, A. paclLyphyllum. It deviates, however, in some 

 essential particulars. The secondary veins are not sinuous, but run towards the apex 

 of the frond in long curves, close to and sub-parallel with the margin. Their angles of 

 departure are more acute at apex and base than in the middle of the frond, and in this 

 respect the resemblance to dicotyledonous venation is great. The remaining characters 

 of the venation are of the Drynaria irregularis type. In the catadromous loops of 

 the ternary veins it approaches the above species of Aspidium. The species is founded 

 upon peculiarities of venation, which consist in the ternary diverging from the outer 

 side of the secondary veins at right angles, and from their inner side at varying acute 

 and obtuse angles, and also in their relatively inconspicuous ternaiy segments, in 

 proportion to the meshes and venules that are enclosed in them. 



