10. Squamariæ—Frond lichen-like, rooted by under surface, composed of vertical filaments imbedded in firm gelatine. Spores in beaded threads in wart-like projections.
11. Spongiocarpeæ—Frond cylindrical, branching, cartilaginous, composed of netted filaments imbedded in firm gelatine. Spores large, in radiating clusters in wart-like excrescences.
12. Gelidiaceæ—Frond cartilaginous, inarticulate, composed of hair-like filaments. Spores attached to slender threads in internal conceptacles.
13. Sphærococcoideæ—Frond leaf-like or thread-like, inarticulate, cellular. Spores formed in beaded threads in external conceptacles.
14. Hapalidiaceæ—Frond minute, calcareous, composed of a single layer of cells.
15. Corallinaceæ—Frond calcareous. Spores in tufted threads at the bases of the conceptacles.
16. Laurenciaceæ—Frond rounded or flattened, branching, inarticulate, cellular. Spores in external oval or globular conceptacles. Tetraspores irregularly scattered over the branches.
17. Rhodomelaceæ—Frond leafy, thread-like, or jointed, composed of polygonal cells. Spores in external conceptacles. Tetraspores in distorted branchlets or in receptacles.
C. Melanospermeæ—Olive-spored weeds. Frond tough, leathery. Spores in globular cavities in substance of frond.
18. Ectocarpaceæ—Frond jointed, thread-like. Spores attached to or imbedded in branchlets.