Order 6. =Gigartinaceæ.= _Gigartina_, _Phyllophora_,
_Ahnfeltia_; _Chondrus crispus_, with dark red, dichotomously
branched thallus, is common on the coasts of Scandinavia and
Great Britain.
Order 7. =Rhodophyllidaceæ.= _Rhodophyllis_, _Euthora_;
_Cystoclonium purpurascens_ is common, and sometimes the ends of
its branches may be modified into tendril-like haptera.
Sub-Family 3. =Rhodymeniales.= The fertilised auxiliary cell
forms the gonimoblast on the side away from the thallus.
Procarpia are abundantly produced.