CALLITHAMNION. 173 



(not t. 1637/ Cer. Turner i, Grev. Crypt, t. 355. Cal re- 

 peits, Lyngb.; Harv. Man. Ed. 1, p. 115. Con/, repens, 

 Dillw. t. 18; E. Bot. t. 1608. 



Parasitical on several marine Alga5, common. — Stems risinjjf from creep- 

 ing fibres, erect, forming a dense globular or elongated tuft, from an inch 

 to an inch and a half high, very slender, once or twice pinnated with op- 

 posite branches similar to the stem, which are occasionally, by abortion, 

 alternate. Articulations variable in length, but generally many times 

 longer than broad. Tetraspores globose, with wide borders, seated along 

 the upper sides of the pinns at the joints, either stalked or sessile, clustered 

 or solitary. Favellm stalked, furnished with an involucre, and resembling 

 those of Griffithsia. Colour a line rose-red. I do not hesitate to unite 

 under this species the C. repens, of authors, which chiefly differs from C. 

 Turneri, in having the ramuli often alternate. 



6. C. harhalum, Ag. ; stems (rising from creeping fila- 

 ments) tufted, much and irregularly branched ; branches 

 opposite or alternate, either simple or pinnulated for half 

 their length with minute, opposite, spine-like, erecto-patent 

 ramuli ; articulations 2 or 3 times longer than broad ; cap- 

 sules elliptic-oblong, sessile on the sides of the pinnulae. 

 Harv. Phyc. Brit. t. c\xv. 



On mud-covered rocks within tide-marks. Very rare. Ilfracombe, and 

 on the quay at Penzance, Mr. Ralfs. Dredged at Weymouth, Rev. M. J. 

 Berkeley. — Filaments densely tufted, 1 or 2 Indies high, rising from creep- 

 ing fibres, much and irregularly branched ; branches opposite or alternate, 

 of various lengths, and either simple or bearing others, patent, the upper 

 and lesser branches pinnulated for half their length with minute, opposite, 

 spine-like, erecto-patent ramuli, not a quarter of an inch in length, which 

 are deciduous in winter. Articulations 2 or 3 times longer than broad, 

 deeply coloured. Substance membranaceous and somewhat rijjid, imper- 

 fectly adhering to paper. Colour a brownish or full red. Tetraspores 

 elliptic-oblong, with wide borders, sessile on the sides of the pinnulae. 

 Under the microscope this presents many of the characters of the larger 

 and more branched specimens of C. Pluma, but it is a very much larger, 

 coarser, and more rigid plant, to the naked eye resembling C. Turneri ; 

 {he pinnula are proportionally much shorter and more regular, and the 

 tetraspores are of a different shape. Mr. Ralfs says, " If I am right, it is a 

 perennial plant, but in winter it loses the small, opposite ramuli. The 

 plant, both at Penzance and Ilfracombe, grows in tufts, and is generally 

 covered with mud." The habitat, it may be observed, is very different 

 from that of C. Pluma. 



7. C. Pluma, Dillw. ; stems rising from creeping filaments, 

 erect, sub-simple or alternately branched ; branches naked 

 below, the upper half pinnated with short, erect, close-set, 

 opposite ramuli ; articulations 2 — 4 times longer than broad ; 

 capsules globose, stalked. Harv. in Hook. Br. Fl. ii. p. 340. 

 Conf. Pluma, Dilkv. Suppl. t. F. 



