ALQJE. 159 



Tribe V. Dictyote^:. Plants membranaceous, flat, or cylin- 

 drical, of a highly reticulated structure. Fructification opaque, 

 seeds with pellucid cases, ranged in lines, sori, or covering the 

 whole frond. 



* Root minute, scutate, naked. 



11. Chorda. Frond simple, filiform, cylindrical, furnished 

 at intervals with distinct septa. 



12. Asperococcus. Frond simple, tubular, (rarety com- 

 pressed.) 



13. Punctaria. Frond simple, flat, foliaceous. 



14. Striaria. Frond tubular, branched ; seeds in trans- 

 verse lines. 



15. Dictyosiphon. Frofid tubular, branched ; seeds scat- 

 tered. 



* * Foot, a mass of woolly filaments. 



16. Dictyota. Frond ribless, dichotomous or irregularly 

 cleft. Seeds scattered over the frond. 



17. Cutleria. Frond ribless, irregularly cleft. Fructifi- 

 cation : clusters of pedicellate capsules. 



18. Padina. Frond flabelliform, cleft. Seeds ranged in 

 concentric lines. 



19. Haliseris. Frond midribbed, subdichotomous. Seeds 

 disposed in sori or groups, mostly arranged in longitudinal 

 lines. 



Tribe VI. EcrocARPEiE. Plants filamentous, often capillary 

 and confervoid, articidated, much branched. Fructification 

 double : capsules and imbedded granules. 



20. Cladostephus. Stem inarticulate, branched, whorled 

 with short articulated ramuli. 



21. Sphacelaria. Stem articulate, branched, distichous, 

 pinnated, rigid. 



22. Ectocarpus. Excessively branched, capillary, flaccid, 

 articulated. 



23. Myriotriciiia. Stem simple, articulate, flaccid, set 

 with short quadrifarious ramuli. 



Tribe VII. Chordarie.e. Plants gelatinoso-cartilaginous, 

 filiform or globose, composed of articulated filaments united 

 together by a firm gelatine. 



24. Chordaria. Frond filiform; axis firmly gelatinous, 



