CALLITHAMNION. 175 



mostly solitary. Hook. Br. Fl. ii. p. 340; Wyatt, Alg. 

 Danm. No. 184 ; Harv. Phyc. Gen. t. cxxix. 



In the sea, on other Algae, rare. Forres, Mr. Brodie. Coast of Northum- 

 berland, Mr. Robertson. Torquay, Mrs. Griffiths and Miss Cutler. Corn- 

 wall, Mr. Ralfs. Miltown Malbay, W. H. H. Annual. Spring. Stems 

 1 3 inches high, generally undivided, as thick or thicker than hogs' bristles 

 at base, attenuated upwards, inarticulate or with imperfect joints (which are 

 about twice as long as broad, and full of veins), closely beset throughout 

 its whole length with long, simple, quadrifarious branches, of which the 

 lowest are longest, becoming gradually shorter upwards, often again fur- 

 nished with a second or even third series, and all furnished at the (more or 

 less perfect) joints with short, pinnated ramuli or plumules ; the pinnules 

 erecto-patent, either simple, or having a few secund or alternate pinnulas 

 tapering upwards, but not to an acute point. Joints of the ramuli about 

 twice as long as broad. Tetraspores globose, on the inner face of the ra- 

 muli near the tip, generally solitary, occasionally 2 or 3 together, or on 

 short secund processes of the ramuli. Favella roundish, large, solitary, or 

 in pairs, borne by the lesser branches. Colour a brownish red. Substance 

 cartilagineo-membranaceous, flaccid. The general outline of the frond is 

 ovate. Specimens bearing favellte are more delicate and transparent in 

 the stem than the others. 



10. C. letragonum, With. ; outline of the frond ovate ; 

 stem cartilaginous, sub-simple, setaceous, somewhat opake, 

 veiny, set with sub-qtiadrifarious, lateral branches, furnished 

 sometimes with a second or third series; penultimate branches 

 pellucidly jointed, slender, elongate, set with short, alternate, 

 patent, level-topped plumules, the lowest of which are simply 

 pinnate, the upper sub-bipinnate ; ramuli incurved, narrowed 

 at base, suddenly acuminate, their articulations once and a 

 half as long as broad, constricted at the joints ; tetraspores 

 exceedingly minute, oval, near the tips of the ramuli. Harv. 

 Phyc. Brit. t. cxxxvi. ; Harv. in Hook. Br. Fl. ii. p. 334 ; 

 Wt/att, Alg. Danm. No. 90. Conf. tetragona, E. Bot. t. 

 1690. 



Near low-water mark, on the larger Algae, frequent. Annual. Summer. 

 Fronds 3 6 inches long, stem thicker than a hog's bristle at base, gra- 

 dually attenuated upwards, repeatedly branched alternately, the branches 

 irregularly quadrifarious, the lowest longest, and set with one or more 

 series of lesser branches, the upper gradually shorter and more simple ; 

 the general outline of the frond being ovate, with its principal divisions 

 tapering to the apex. Stem more or less obscurely jointed, naked or 

 clothed with squavrose ramuli ; branches set with quadrifarious or sub-dis- 

 tichous, alternate, pinnato-multifid, minute ramuli, about half a line in 

 length, contracted at base and suddenly acuminate at apex. Substance 

 firm, cartilagineo-membranaceous. Tetraspores excessively minute, sessile, 

 elliptic or roundish, secund, on the upper ramuli. Favellce solitary or in 

 pairs, large. Colour full or brownish red, becoming darker in drying. 



11. C. brachiatutn, Bonnem. ; outline of the frond lanceo- 



