Chapter XV: Sea Weeds (3)

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.

19. _Chordariaceæ_--Frond gelatinous or cartilaginous, composed of
interlacing vertical and horizontal filaments. Spores
internal, attached to the filaments.

20. _Dictyotaceæ_--Frond inarticulate. Spores superficial, arranged
in definite spots or lines.

21. _Laminariaceæ_--Frond inarticulate. Spores covering the whole
frond or in cloud-like patches.

22. _Sporochnaceæ_--Frond inarticulate. Spores attached to jointed
filaments which are either free or compacted.

23. _Fucaceæ_--Frond inarticulate, large and tough. Spores in
globular cavities.