174 CALLITHAMNION. 



On other Algae, generally on the stems of Lammar'm uigitata, rare. 

 Bantry Bay, Miss Hutchins. Appin, Capt. Cannichael. IMalbay, JV. H. H. 

 — Stems rising from creeping fibres, a quarter to half an inch in height, either 

 simple or divided into a greater or less number of alternate, or sometimes 

 opposite branches, which are naked below, their upper half pectinato-pinnate. 

 Pinna opposite, short or long, simple, very erect. Tetraspores globose, 

 with wide borders, stalked or sessile, sometimes clustered, often terminating 

 the pinnulsB. Joints of the stem and branches 2 — 4 times longer than 

 broad. Colour a full rose-red. Nearly allied to C. Turneri, but much 

 smaller and with shorter joints. 



Section 2. Fruticosa. Main stems robust, opake, or nearly 

 opake, sub-simple, filled with longitudinal (rootlike) fila- 

 ments. R-amuli alternate (sp. 8 — 13). 



8. C. Arhitscula, R. Br. ; stems naked below, robust, car- 

 tilaginous, main branches set with shorter branches, which 

 are densely clothed on all sides with minute, imbricated, pin- 

 nated ramuli (or plumules) ; ultimate pinnules simple or 

 forked, recurved, acute, their joints twice as long as broad ; 

 tetraspores lining the inner faces of the pinnules. Harv. in 

 Hook. Br. Fl. ii. p. 340 ; Harv. PJiyc. Brit. t. cclxxiv. Con- 

 ferva Arbnscula, R. Brown ! Dillw. t. 85 ; E. Bot. t. 1916. 



Daftya sponyiosa, Ag. 



On rocks and stones between tide-marks. Perennial. Common on the 

 northern and western shores of Scotland and Ireland. Very rare on the 

 eastern shores of Scotland. Frith of Forth, Drs. GreviUe and Arnott. 

 Ahei'deen, Dr. Dickie. — Stem cartilaginous, inarticulate, as thick as a crow- 

 quill at base, 3 — 8 inches long, shaggy with fibres, but destitute of branches 

 below, divided above, the branches set with a second and third series similar 

 to themselves, but shorter, the smallest about two lines long ; all quadrifari- 

 ous, and densely clothed on all sides with minute, pinnated ramuli or plu- 

 mules. These latter are not a quarter of a line long, simply pinnate, the 

 pinnae long, subulate, very patent or falcato-refiexed. Articulations of the 

 ramuli once and a half or twice as long as broad. Tetraspores spherical, 

 with wide borders, lining the inner face of the ramuli. Favelhe roundish 

 or lobed, mostly in pairs Colour a very dark vinous red. Substaiice of 

 the stem cartilaginous, of the ramidi flaccid. This is the original Conferva 

 Arbuscula of Brown, whose specimens 1 have examined. The figure in 

 Eng. Bot. is not very characteristic: that of Dillwyn is better, except the 

 colour, which is far too bright. 



9. C. Brodicei, Harv. ; stem sub-opake, veiny, obscurely 

 jointed, slender, simple, furnished throughout with patent, 

 alternate branches, which bear at each joint short, quadrifa- 

 rious, secondary branches, with a narrow, hastate outline ; 

 secondary branches laxly set with short, quadrifarious plu- 

 nudes ; ultimate pinntdes erecto-patent, obtuse, sub-simple ; 

 tetraspores roundish, sessile near the tips of the pinnules, 



