Sek. GONGYLOSPERMEvE. (147) Fam. CERAMIACEiE. 



CALLITHAMNION CRUCIATUM.— ^i/. 



Gen. Char. — Fronds filiform and articulated, sometimes at lengtli in the older parts 

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

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

 lateral on tlie In-auclies, and filled with minute spores ; 2. Tetraspores, external, 

 tripartite or cruciate. Name from icaAos, "beautiful," and Qdfivos, "a shrub." 



Callithamnion cruciatum. — Fronds ii-regularly branched, between 

 alternate and dicliotomous, each articulation furnished at its summit 

 with two to four slender pinnate branches ; tetraspores elliptical, formed 

 by the metamorphosis of the lower pinnae. 



CALLiTnAMNiON cruciatum. — Ag. Syst. Alg. vol. ii. p. 160 ; Wyatt, Alg. Damn. 

 No. 182 ; J. Ag. Alg. Medit. p. 70; Endl. 8rd. Suppl. p. 34; Hoolc. 

 fil. et Harv. in Lond. Joiirn. Bot. vol. vi. p. 412 ; Ilarv. in Hook. 

 Br. Fl. vol. ii. p. 339 ; Ha^-v. P. B. plate 164 ; Harv. Man. p. 171 ; 

 Harv. Syn. p. 143; Atlas, plate 55, fig. 255; Harv. N. B. A. part 2, 

 p. 240 ; /. G. Agardh, Sp. Oen. Alg. vol. ii. p. 27. 



Var. /3 pumilum. — Smaller, joints shorter, and the ramuli more dense. 



P pumilum.— Harv. P. B. descrip. plate 164 ; Harv. Man. p. 172 ; /. G. Agardh, 

 Sp. Gen. Alg. vol. ii. p. 28. 



Callithamnion 23Mni?7Mni. — Harv. in Hooh. Br. Fl. vol. ii, p. 339 ; Endl. 3rd Suppl. 

 p. 34 ; Harv. in Mach. Fl. Hih. part 3, p. 213. 



IlAB.^On mud-covered rocks, near low- water mark. Annual. Summer. Rather 

 rare. Torquay {Mrs. Griffiths) ; Salcombe {Mrs. Wyatt) ; Milford Haven {Mr. Ralfs) ; 

 Plymouth {Rev. W. S. Hore) ; Cork Harbour {Dr. J. R. Harvey) ; Coast of Down 

 {Mr. W. Thompson) ; Ferriters Cove, Kerry {Mr. W. Andreics) ; /3, Miltown Malbay 

 {Dr. Harvey). 



Geogr. Dist. — Atlantic shores of France and Spain ; Mediterranean and Adriatic 

 Seas ; Tasmania {Mr. Gunn). 



Description. — Fronds much tufted, one to two inches long, slightly 

 branched, the divisions mostly alternate, sometimes dichotomous, all 

 joints furnished with two to four long, slender, cylindrical, erecto-patent, 

 l)innated ramuli, the pinnae about thirteen, erect or erecto-patent, long, 

 cylindrical, and ojiposite, the two or three apical joints only tapering to 

 an obtuse point ; apices of the branchlets ocellated from the density of 

 the nascent ramuli, somewhat in the manner of Dasya ocellata and 

 arlmscula. Articulations of the stem three to three and a-half times 

 longer than broad, those of the ramuli slightly shorter, those of the 

 pinufc about once and a-half as long as broad, with the dissepiments 



