Callithamnion.] ALGi5£ RHODOSPERMEiE. 217 



of fructification I have never seen produced in any other species of the 

 genus. 



14. C spongiosum, Harv. Spongy Callithamnion. Stems 

 robust, cartilaginous, branched in every direction ; branches 

 thickly set with dense, quadrifarious, repeatedly dichotomous, 

 round-topped branchlets; axils patent; apices short, bifid; ar- 

 ticulations of the branches swollen at the joints, thrice as long 

 as broad. Harv. in Hook. Br. FL v. ii. p. 346. Wyatt. Alg. 

 Damn. No.'93. 



On perpendicular rocks on our eastern shores ; as at Kingstown, 

 Killiney, Wicklow, &c. where it occupies the place that C. Arbus- 

 cula arid tetricum hold on the western ; W. H. Harvey. 2 — 4 inches 

 high, flaccid. Stems shrubby. Branches spreading in every direction, 

 and densely clothed with short secondary branches. Colour a red- 

 brown. 



15. C. pedicellatum, Ag. Stalk fruited Callithamnion. Stems 

 setaceous, loosely and irregularly branched; branches naked or 

 set with short, alternate, subfasciculate, sparingly dichotomous 

 branchlets; apices obtuse; articulations variable, mostly very 

 long; capsules solitary, elliptical, or pyriform, axillary, pedicel- 

 late. Harv. in Hook. Br. Fl. v. ii. p. 347.— Conf. pedicell. 

 Ditlw. t. 108. E. Hot. t. 1817. 



Rare. Bantry ; Miss Hutchins. Miltown Malbay ; W. H. 

 Harvey. Stems 2 — 6 inches high, as thick as horse hair. Branches 

 sparingly divided, springing near the base, irregularly set with short 

 ramuli, which are crowded round the apices in a penicellate manner ; 

 apices always very blunt. Capsules dark pyriform, seated on hyaline 

 pedicels. Colour full pink, which is almost instantly discharged in 

 fresh water, when the plant assumes a dull brown hue and rapidly 

 decomposes. 



B. Small parasitical species, rising from creeping filaments ; 

 branches erect. Receptacles pedicellate, involucrate. 



16. C. Turneri, Ag. Turners Callithamnion. Stems ris- 

 ing from creeping filaments, erect, simple, or slightly branched, 

 oppositely pinnated ; articulations of the stem 5 — 10 times 

 longer than broad. Harv. in Hook. Br. Fl. v. ii. p. 339 — 

 Conf. Turneri, Dillw. t. 100. E. Bot. t. 2339. (not t. 1637 J 

 Cer. Turneri, Grev. Crypt, t. 355. 



On the larger Algae, not uncommon. Tufts 1 — 2 inches high. 



17. C. Pluma, Ag. Feathery Callithamnion. Stems rising 

 from creeping filaments, erect, subsimple, naked below, the 

 upper half oppositely pinnate ; pinnae erect, appressed ; articu- 

 lations of the stem 2 — 4 times longer than broad. Harv. in 

 Hook. Br. Fl. v. ii. p. 340.— Conf. Pluma, Dillw. Supp. t. F. 



On the stems of Laminaria digitata- Bantry ; Miss Hutchins. 

 Malbay ; W. H. Harvey. Stems half an inch high, resembling beau- 

 tiful minute feathers. 



2 D 



