XViii. GKNEBA OH SEBITS : 



Fronds dimorplious, simple or pinnate. Kliizome creeping.— 

 This genus differs from Maphoglossum in having •the parallel 

 Teins united by a vein which traverses the margin. In the secti- 

 onal groups here indicated, the differences presented by the course 

 of these marginal veins are not of generic value. The typical 

 species, 0. cervina, is a larger plant than the others, and more 

 compound, 



§ Siwifersto.— Marginal vein straight. 

 Ex. : O. eervina, Kze. 



% JfeSrojJoMd,— Marginal vein arcuate. 

 Ex. : 0. longifoMa, Presl. \ O. glabrescens, Fred. 



§ ^ctmioptem.— Marginal vein zigzag, with an excurrent veinlet from 

 the exterior angles. 

 Ex. : 0. sabdiaphana (Acrostichnm, Sooh. and Greji.) 



* * * Veins reticulated. 



7. SOB.OMANES, Me, Slst. Acrost. 16. 



POLTBOTBT^ sp., Atlci.; BoTEYOTHALLI sp., Klotsach. 



Son superficial, non-indusiate, the receptacles occupying the 

 under surface of the contracted fertile fronds. Veins pinnate 

 from a central costa ; venules connivent, all anastomosing at an 

 acute angle, and without free included veinlets. 



Fronds large pinnate dimorphous, the fertile pinnato-pinnatifid 

 or bi-pinnate. Bhizome robust, scandent or creeping. — The 

 venation of this genus is analagous to that of G/clodium. 



Ex. : S. Berratifolinm, FSe, 



8. JfETJEOCALLIS, Fee, Bisi. Acrost. 19. 



Chbiloleptom', Fie ; ? Chorizopteeis, Moore ; Aceostichi sp., Ati^. ; 

 liBPTOCHiLi sp., JBlvmtei Polteotet^ sp,, Metienius; Chkxsodii sp., 

 MeUeniug ; Pcecilgpteeidis sp., Pregi; Lomaeiopsldis sp., Metteniue ; 

 Cyetogonii sp., J, Smiths Heteeokeubi sp., JVe; Lomageammatis 

 sp., Brackenridge. 



Sori non-indusiate, the receptacles occupying the under surface 

 of the contracted fertile fronds, superficial or forming a shallow 

 longitudinal furrow each side the costa. Veins all reticulated in 

 hexagonal meshes, without free veinlets, the costal areoles larger. 



