the Colony of Western Australia. 535 



14. Sporochnus .?/). Fremantle (157). Being uncertain whether this or the preceding be Agardh's 



plant, I defer the description of either. 



15. Spoeochsds radiciformis, Ag. Fremantle and Cape Eiche (156). 



16. Sporochnus scoparius, n. sp.; fronde tereti rigida crassa dendroidea (2-3 pedali); caule strato 



velutino vestito; ramis creberrimis undique egredientibus decomposito-pinnatis angulatis 

 glabris, minoribus erectis strictis sparse spiuosis subalternis ; receptaculis ovalibus v. ob- 

 longis pedicellum ipsis multiple longius coronantibus. At Cape Eiche, and Garden and 

 Eottnest Islands (248). I collected this at first as Fucus inermis, E. Br., or F. caudatus, 

 Lab.; but my plant is a true Sporochnus, and not always unarmed. 



Order III LAMINAEIACE^. 



17. EcKLONiA radiata, Turn. E. radiata and E. exasperata, J. Ag. Lining most of the rocky 



shores at extreme low- water mark. Examination on the sea shore disposes me to unite these 

 two supposed species. They vary extremely in roughness and smoothness, and in the com- 

 parative length of the rachis, all the forms imperceptibly running together (75). 



18. Chorda fomenten'a, Lyngb. Clothing tidal rocks, in winter, at King George's Sound. My spe- 



cimens are not fully grown, being in the state called Asp. castaneus, Carm. (323). 



Order IV DICTYOTACE^. 



19. Haliseris Mulleri, Sond. ; stipite elongato ramoso; fronde dichotoma v. suppressione ramorum 



alterne raraosa, sinubus obtusiusculis, segmentis erectis latis linearibus integerrimis ssepe 

 alterne divitis; lamina crassiusculii enervi; antheridiis sparsis. King George's Sound, Cape 

 Eiche, and Fremantle (102). Much larger and thicker in substance than H. po!i/podioides 

 with rounded sinuses. 



20. IIaliseris 2>ardaUs, n. sp. ; stipite brevi; fronde dichotoma, sinubus rotundatis, segmentis 



patentibus linearibus integerrimis repetite furcatis subuiidulatis obtusis; lamina tenui-mem- 

 branacea enervi ; soris dispositis in lineas recurvas e costa ad marginem proficiscentibus. Fre- 

 mantle, rare (155). A beautiful and distinct species, elegantly marked in dotted lines like 

 a leopard's skin. 



21. Padina Frazeri, Grev. Fremantle and Eottnest, common (158). 



22. ZoNARfA nii/rescens, Sond. Bocky shores, common (49). Very near Z. variegata, if distinct. 



23. ZoNAKiA interrupta, Ag. var. spiralis; segmentis spiraliter tortis. Cape Eiche and Eottnest (295). 

 Metachroma, nov. gen. Caulis basi radicans, cartilagineus, tereti-compressus, alterne ramosus. 



Eavii inferne costati, lineares, pinnatifidi, lacinulis bicuspidatis. Sporce (?) per superficiem 

 laciniarum sparsa;, prominentes, intra perisporum hyalinum singula nidulantes. Alga Aus- 

 tralasica radice ramoso-fibrillosa, caule ramosissimo, ramis spiraliter tortis, laciniis tortione 

 spurie trifariis. 



24. Metachroma thui/oides, n. sp. ; Middleton Bay, King George's Sound; and Cape Eiche at low- 



water mark (21). Frond 12-18 inches long, much branched. The generic name alludes to 

 a remarkable change of colour, from olive to verdigris green, when thrown into fresh water. 



