Conferva.] ALG/E CHLOROSPERMEiE. 229 



Rocks near low-water mark, not uncommon. Miltown Malbay and 

 Wicklow. Stems subsolitary, simple below, above repeatedly tricho- 

 tomous, thick, rigid, full-green. The filaments are rarely articulated, 

 except in the axils. 



30. C. HutchinsicB, Dillw. 31iss Hutching' Conferva. Fila- 

 ments cartilaginous, rigid, glaucous-green, flexuose, tufted, 

 bristly ; ramuli curved, simple or furnished on the interior face 

 with processes of one articulation ; articulations twice as long 

 as broad. Dillw. t. 109. Harv. in Hook. Br. FL v. ii. p. 357. 



Rare. Bantry bay ; Miss Hutchins. Filaments thicker than 

 horse hair, flexuose, 5 — 8 inches long, much branched. 



31. C. ri/pestris, Linn. Green Bock Conferva. Filaments 

 slender, rigid, dark-green, straight, tufted, bushy; branches 

 erect, crowded ; ramuli fascicled, appressed ; articulations 3 — 4 

 times longer than broad. Dillw. t. 23. E. Bot. 1. 1699. Harv. 

 in Hook. Br. Fl. v. ii. p. 357. 



Rocks in the sea, very common. 



32. C. nuda, Harv. MSS. Brownish bare-branched Con- 

 ferva. Filaments subrigid, slender, very straight, dull-green or 



olivaceous (when dry), sparingly dichotomous; ramuli few and 

 scattered, appressed, the uppermost often opposite; articula- 

 tions many times longer than broad. 



On basalt rocks, Portstewart ; Mr. D. Moore. Filaments loosely 

 tufted, 2 — 3 inches high, sparingly branched, very straight, set with a 

 few, scattered, very erect and appressed ramuli, the uppermost ones 

 often opposite, which makes the apices of the branches appear three- 

 forked. Articulations very long. This differs from any species with 

 which I am acquainted, but may, perhaps, be the C. aspera of Agardh, 

 which, in the British Flora,! have doubtfully referred to C. nigricans. 

 To avoid confusion I think it better to give a new name to our present 

 plant. In the straight filaments and appressed ramuli it resembles C. 

 rupestris, but differs in colour and in the great length of the joints. 



33. C. diffusa, Roth. Diffuse green Conferva. Filaments 

 slender, rigid, dark-green, flexuose, subdichotomous ; branches 

 distant, elongated, furnished towards the top with a few short 

 patent, secund ramuli ; articulations 8 — 4 times longer than 

 broad. Dillw. t. 21. E. Bot. t. 2289. Harv. in Hook. Br. 

 Fl. v. ii. p. 358. 



Marine rocks, rare. Rantry ; Miss Hutchins. Miltown Malbay ; 

 W. H. Harvey. Black rocks, Portrush ; Mr. D. Moore. This re- 

 sembles C. rupestris in microscopic structure, but has a very different 

 habit, being loosely tufted, bristly, with distant and almost naked 

 branches. 



34. C. albida, Huds. Whitish cottony Conferva. Filaments 

 very slender, capillary, flaccid, pale yellow-green, forming 

 dense silky tufts; branches crowded, irregular, the uppermost 

 patent and mostly opposite; ramuli opposite or secund ; articu- 



