See. GONGYLOSPEEMEiE. { 197 ) Fam. CERAMIACE/E. 



CALLITH AMNION MESOCARPUM.— Cann. 



Gen. Chak. — Fronds filiform and articulated, sometimes at length in tlie older parts 

 cellular and partially opaque, single-tubed ; divisions mostly pinnate, dissepiments 

 hyaline. Fructification of two kinds, on distinct plants : 1. Favellaj, mostly 

 lateral on the branches, and filled with minute spores ; 2. Tetraspores, external, 

 tripartite or cruciate. Name from /caA.bs, " beautiful," and Oa^wy, " a shrub." 



Callithamnion viesocarpum. — " Stems rising from creeping filaments, 

 erect, simple or sparingly branched ; branches alternate, very erect, 

 naked or having a few, scattered, erect ramuli ; articulations four or 

 five times as long as broad ; tetraspores elliptical, on long, simple, or 

 forked lateral pedicels." 



Callithamnion mesocarpum. — Carm. Al<j. Ai'tpin, MSS. ; Haw. in Hook. Br. Fl. 

 vol. ii. p. 348 ; Harv. P. B. plate 325 ; Harv. Man. p. 184 ; Harv. 

 Syn. p. 157; Atlas, plate 60, fig. 279; Kiitz. Sp. Alg. p. 642; 

 /. G. Agardh, Sp. Gen. Alg. vol. ii. p. 16. 



Hab. — On rocks at the extremity of low- water mark. Very rare. Appin {Captain 

 Carmichael). 



Geogr. Dist. ? 



Description. — " Tufts continuous, forming a broad, shaggy, purple 

 crust" {Carm.). Stems from an eighth to a quarter of an inch or rather 

 more in height, springing from decumbent filaments, which are attached 

 to the svirface of the rock by little rootlets, erect, simple or having two 

 or three alternate or secund branches ; branches issuing at very acute 

 angles, erect, virgate, either quite naked or furnished with a few distant, 

 erect, scattered, few-jointed ramuli. Articulations four or five times as 

 long as broad, with wide borders ; tetraspores elliptical, borne on the 

 tips of the lateral ramuli, which are generally one-jointed, and either 

 simple or forked, in which case one arm of the fork is converted into 

 a tetraspore. Favellse unknown. Colour, a full deep lake. Substance 

 membranaceous, adhering to paper in drying." — Phyc. Brit. pi. 325. 



The only authority for the present species, so far as we are aware, 

 depends on some solitary fragments preserved in the herbarium of Sir 

 W. Jackson Hooker, and collected at Appin by the late Captain Car- 

 michael, and the only knowledge of the species is derived from the 

 figures and descriptions in Phycologia Britannica, where it is carefully 

 described from Captain Camiichael's original specimens. 



