DBDEBfl AND OBXBRA. 



cartilaginous; of very dense structure. '/' 



in definite, immersed sort. 

 LX III. I'm i ii ophob \. Frond stipitate, rigid-membrana- 



ceous, proliferous; of very dense structure. 1 



spores in superficial sori, or in proper Leaflets. 

 i.\l\ . Peyssonnelia. Frond depressed, expanded, ro< 



by the under Burface, coDcentrically zoned. r J'(tr<t- 



spores contained in superficial warl 

 LXV. Gymn( NGBU8. Frond filiform, dichotomous, 



horny, of very dense structure. Tetraspores in si 



ficial wart-. 

 LXVl. Polyides. Root scutate. Frond cylindrics 



chotomous, cartilaginous. Favellce contained in e: 



nal, Bpongy warts, Tetraspores cruciate, immersed 



in the branch* s. 

 LXVII. Furcellaria. Root branching. Frond cyli 



cal, dichotomous, cartilaginous. Favella immersed in 



the pod-like swollen extremities of the branches. Te~ 



traspores similarly immersed, transversely zoned. 



Sub-order 3. Gastrooabpejb. Frond gelatinoso-membrana- 

 r or fleshy, hollow, or of lax texture within, I 

 lidia immersed in the central substance of the frond 

 numerous. 

 LXVIII. DuiCONTIA. Frond cylindrical, tubular. 



lidia immersed in the wall of the frond. Tetras% 

 also immersed, cruciate. 

 LXIX. Halymenia. Frond compressed or flat, gelatinos •- 

 membranaceous, the membranous Burfacefl conne< 

 by a few slender, anastomosing filaments. Favellidia 

 attached to the inner lace of the wall. 

 L.W. (ii.NA.NNiA. Frond cylindrical, distended, tiw 

 by a fibrous axis; the walls membranaceous, 

 nected with the axis by horizontal filaments. Favel- 

 lidia attached to the \\ alls. 

 L XXI. Kjlllymenia. Ft f - expanded, leaf-like, carnoso- 



membran0U8, solid, of dense structure. Fart Hi, ii, i 

 pimply, half-immersed in the frond, and scattered 

 its surface. 



LXXI1. [ridjea. Frond expanded, leaf-like, thick, 



so-coriaceous, solid, of dense structure. /' i 



wholly immersed. 



LXXI11. Catenella. Frond tubular, branched, con- 

 stricted at intervals into oblong pseudo-arti 

 the tube traversed by a lew filaments. 



