16 100 Proceedings of the Royal Irish Academy. 



Polysiphonia fastigiata Grev. — CI/; CB, AS, ab. See note. 



atro-rubescens Grev. — CI r, CB ab. 



nigrescens Grev. — CB, AS, c. 



Brodiaei Grev. — c. 



subulifera Harv. — CB, AS, I. See note. 



fruticulosa Spreng.—c. 

 Pterosiphonia parasitica Schm. — /. In deep pools and in sub-littoral region. 



thuyoides Schmitz. — CI/, Roonab ab. 

 Brongniartella byssoides Bory. — CB ab. 

 ; Dasya coryinbifera Cru. — CB r. Dredged in 5 fatboms, and washed ashore. 



arbuscula Ag. — CI/, Bellacragber Bay r. See note. 

 Heterosipbonia coccinea Falk. — f. 

 Spondylotbamnion niultifiduni Nag. — CI r, CB/. 

 Spermotbamnion Turneri, Aresch. — CI/, Old Head ab. 



var. subverticillatuin, comb. nov. — CB/ See note. 

 Ptilotharunion pluma Thar. — CI, CB, / On stipes of Laminaria Cloustoni. 

 f lucifugurn sp. nov. — CI r. See note. 

 GrifBtbsia coralbna Ag. — CB, AS, ab. See note. 



setacea Ag. — CI r, CB f. 

 Halurus equisetifolius Ktitz. — /. 



: Bornetia secundiflora Thar. — CI very rare. See note. 



Monospora pedieellata Sol. — CI r, CB/. In rock-pools and in sub-littoral region. 

 Rbodocborton membranaceuni ILagn. — CB >-. 



Rothii^Vaj. — CI/, Roonab/ In sbady situations only. 



parasiticum Batt. — f. On stipes of Laminaria Cloustoni. 



floridulum Niig. — ab. 

 Callitbamnion byssoides Am. — CB, AS, /•. See note. 



polyspermuni Ag. — ■/. 



scopulorurn Ag. — CI / See note. 



roseum Han: — AS, BB, f. 



[tripinnaturu Agardh.] — Roundstone/ (coll. McCalla). 



Hookeri Ag. — CI c. On Cladostephus spoiigiosus. 



arbuscula Lyngb. — CI c. On steep exposed rocks. See note. 



tetragonum Ag. — CI r. On blades of Laminaria digitata. 



corymbosuni Lyngb. — CB, AS, c. See note. 



granulatum Ag. — CI r. See note. 

 Seirospora Griffithsiana Harv. — AS r. 

 * bormocapa Batt. — AS very rare. 

 [Compsotharunion thuyoides ScJmi.} — Roundstone (coll. McCallai. 

 Plumaria elegans Schm. — c. 



Ptilota plumosa Ag. — c. On stipes of Laminaria Cloustoni. See note. 

 Antithamnion cruciatum Nag. — CI very rare. On vertical rocks near low-water. 



